WorldWideScience

Sample records for models provide important

  1. The mitochondrial import gene tomm22 is specifically required for hepatocyte survival and provides a liver regeneration model

    Science.gov (United States)

    Curado, Silvia; Ober, Elke A.; Walsh, Susan; Cortes-Hernandez, Paulina; Verkade, Heather; Koehler, Carla M.; Stainier, Didier Y. R.

    2010-01-01

    SUMMARY Understanding liver development should lead to greater insights into liver diseases and improve therapeutic strategies. In a forward genetic screen for genes regulating liver development in zebrafish, we identified a mutant – oliver – that exhibits liver-specific defects. In oliver mutants, the liver is specified, bile ducts form and hepatocytes differentiate. However, the hepatocytes die shortly after their differentiation, and thus the resulting mutant liver consists mainly of biliary tissue. We identified a mutation in the gene encoding translocase of the outer mitochondrial membrane 22 (Tomm22) as responsible for this phenotype. Mutations in tomm genes have been associated with mitochondrial dysfunction, but most studies on the effect of defective mitochondrial protein translocation have been carried out in cultured cells or unicellular organisms. Therefore, the tomm22 mutant represents an important vertebrate genetic model to study mitochondrial biology and hepatic mitochondrial diseases. We further found that the temporary knockdown of Tomm22 levels by morpholino antisense oligonucleotides causes a specific hepatocyte degeneration phenotype that is reversible: new hepatocytes repopulate the liver as Tomm22 recovers to wild-type levels. The specificity and reversibility of hepatocyte ablation after temporary knockdown of Tomm22 provides an additional model to study liver regeneration, under conditions where most hepatocytes have died. We used this regeneration model to analyze the signaling commonalities between hepatocyte development and regeneration. PMID:20483998

  2. Providing medical marijuana: the importance of cannabis clubs.

    Science.gov (United States)

    Feldman, H W; Mandel, J

    1998-01-01

    In 1996, shortly after the San Francisco Cannabis Club was raided and (temporarily) closed by state authorities, the authors conducted an ethnographic study by interviewing selected former members to ascertain how they had benefited from the use of medical marijuana and how they had utilized the clubs. Interviews were augmented by participant observation techniques. Respondents reported highly positive health benefits from marijuana itself, and underscored even greater benefits from the social aspects of the clubs, which they described as providing important emotional supports. As such, cannabis clubs serve as crucial support mechanisms/groups for people with a wide variety of serious illnesses and conditions. The authors concluded that of the various methods so far proposed, the cannabis clubs afford the best therapeutic setting for providing medical cannabis and for offering a healing environment composed of like-minded, sympathetic friends.

  3. How important are peatlands globally in providing drinking water resources?

    Science.gov (United States)

    Xu, Jiren; Morris, Paul; Holden, Joseph

    2017-04-01

    The potential role of peatlands as water stores and sources of downstream water resources for human use is often cited in publications setting the context for the importance of peatlands, but is rarely backed up with substantive evidence. We sought to determine the global role of peatlands in water resource provision. We developed the Peat Population Index (PPI) that combines the coverage of peat and the local population density to show focused (hotspot) areas where there is a combination of both large areas of peat and large populations who would potentially use water sourced from those peatlands. We also developed a method for estimating the proportion of river water that interacted with contributing peatlands before draining into rivers and reservoirs used as a drinking water resource. The Peat Reservoir Index (PRI) estimates the contribution of peatlands to domestic water use to be 1.64 km3 per year which is 0.35 % of the global total. The results suggest that although peatlands are widespread, the spatial distribution of the high PPI and PRI river basins is concentrated in European middle latitudes particularly around major conurbations in The Netherlands, northern England, Scotland (Glasgow) and Ireland (Dublin), although there were also some important systems in Florida, the Niger Delta and Malaysia. More detailed research into water resource provision in high PPI areas showed that they were not always also high PRI areas as often water resources were delivered to urban centres from non-peat areas, despite a large area of peat within the catchment. However, particularly in the UK and Ireland, there are some high PRI systems where peatlands directly supply water to nearby urban centres. Thus both indices are useful and can be used at a global level while more local refinement enables enhanced use which supports global and local peatland protection measures. We now intend to study the impacts of peatland degradation and climate change on water resource

  4. Development of Model for Providing Feasible Scholarship

    Directory of Open Access Journals (Sweden)

    Harry Dhika

    2016-05-01

    Full Text Available The current work focuses on the development of a model to determine a feasible scholarship recipient on the basis of the naiv¨e Bayes’ method using very simple and limited attributes. Those attributes are the applicants academic year, represented by their semester, academic performance, represented by their GPa, socioeconomic ability, which represented the economic capability to attend a higher education institution, and their level of social involvement. To establish and evaluate the model performance, empirical data are collected, and the data of 100 students are divided into 80 student data for the model training and the remaining of 20 student data are for the model testing. The results suggest that the model is capable to provide recommendations for the potential scholarship recipient at the level of accuracy of 95%.

  5. Importance of animal models in schizophrenia research.

    Science.gov (United States)

    van den Buuse, M; Garner, B; Gogos, A; Kusljic, S

    2005-07-01

    This review aims to summarize the importance of animal models for research on psychiatric illnesses, particularly schizophrenia. Several aspects of animal models are addressed, including animal experimentation ethics and theoretical considerations of different aspects of validity of animal models. A more specific discussion is included on two of the most widely used behavioural models, psychotropic drug-induced locomotor hyperactivity and prepulse inhibition, followed by comments on the difficulty of modelling negative symptoms of schizophrenia. Furthermore, we emphasize the impact of new developments in molecular biology and the generation of genetically modified mice, which have generated the concept of behavioural phenotyping. Complex psychiatric illnesses, such as schizophrenia, cannot be exactly reproduced in species such as rats and mice. Nevertheless, by providing new information on the role of neurotransmitter systems and genes in behavioural function, animal 'models' can be an important tool in unravelling mechanisms involved in the symptoms and development of such illnesses, alongside approaches such as post-mortem studies, cognitive and psychophysiological studies, imaging and epidemiology.

  6. Cost Calculation Model for Logistics Service Providers

    Directory of Open Access Journals (Sweden)

    Zoltán Bokor

    2012-11-01

    Full Text Available The exact calculation of logistics costs has become a real challenge in logistics and supply chain management. It is essential to gain reliable and accurate costing information to attain efficient resource allocation within the logistics service provider companies. Traditional costing approaches, however, may not be sufficient to reach this aim in case of complex and heterogeneous logistics service structures. So this paper intends to explore the ways of improving the cost calculation regimes of logistics service providers and show how to adopt the multi-level full cost allocation technique in logistics practice. After determining the methodological framework, a sample cost calculation scheme is developed and tested by using estimated input data. Based on the theoretical findings and the experiences of the pilot project it can be concluded that the improved costing model contributes to making logistics costing more accurate and transparent. Moreover, the relations between costs and performances also become more visible, which enhances the effectiveness of logistics planning and controlling significantly

  7. Stable Isotope Analysis Reveals That Agricultural Habitat Provides an Important Dietary Component for Nonbreeding Dunlin

    Directory of Open Access Journals (Sweden)

    Lesley Joan Evans Ogden

    2005-12-01

    Full Text Available Although shorebirds spending the winter in temperate areas frequently use estuarine and supratidal (upland feeding habitats, the relative contribution of each habitat to individual diets has not been directly quantified. We quantified the proportional use that Calidris alpina pacifica (Dunlin made of estuarine vs. terrestrial farmland resources on the Fraser River Delta, British Columbia, using stable isotope analysis (δ13C, δ15N of blood from 268 Dunlin over four winters, 1997 through 2000. We tested for individual, age, sex, morphological, seasonal, and weather-related differences in dietary sources. Based on single- (δ13C and dual-isotope mixing models, the agricultural habitat contributed approximately 38% of Dunlin diet averaged over four winters, with the balance from intertidal flats. However, there was a wide variation among individuals in the extent of agricultural feeding, ranging from about 1% to 95% of diet. Younger birds had a significantly higher terrestrial contribution to diet (43% than did adults (35%. We estimated that 6% of adults and 13% of juveniles were obtaining at least 75% of their diet from terrestrial sources. The isotope data provided no evidence for sex or overall body size effects on the proportion of diet that is terrestrial in origin. The use of agricultural habitat by Dunlin peaked in early January. Adult Dunlin obtained a greater proportion of their diet terrestrially during periods of lower temperatures and high precipitation, whereas no such relationship existed for juveniles. Seasonal variation in the use of agricultural habitat suggests that it is used more during energetically stressful periods. The terrestrial farmland zone appears to be consistently important as a habitat for juveniles, but for adults it may provide an alternative feeding site used as a buffer against starvation during periods of extreme weather. Loss or reduction of agricultural habitat adjacent to estuaries may negatively impact

  8. Importance Sampling for the Infinite Sites Model*

    OpenAIRE

    Hobolth, Asger; Uyenoyama, Marcy K; Wiuf, Carsten

    2008-01-01

    Importance sampling or Markov Chain Monte Carlo sampling is required for state-of-the-art statistical analysis of population genetics data. The applicability of these sampling-based inference techniques depends crucially on the proposal distribution. In this paper, we discuss importance sampling for the infinite sites model. The infinite sites assumption is attractive because it constraints the number of possible genealogies, thereby allowing for the analysis of larger data sets. We recall th...

  9. Cliff top habitats provide important alternative feeding resources for wading birds of conservation importance wintering on non-estuarine coasts

    Science.gov (United States)

    Furnell, Julie; Hull, Susan L.

    2014-02-01

    Rocky shores and beaches are important over-wintering areas for non-estuarine waders but have rarely been studied. We examined cliff top habitat use by 6 species of wader over 75 km of coast to assess their potential value as alternative feeding sites to rocky and sandy shores. Both the regional and local survey showed that waders occurred on golf courses and recreational grasslands in higher frequencies than expected but arable and pasture use was lower than expected. We also compared local wader densities on rocky and sandy shores, pastures, golf courses, caravan parks and recreational grasslands over two winters. Sanderling predominantly fed on the beach whereas Oystercatcher, Dunlin, Turnstone and Redshank numbers significantly increased on golf courses and recreational grasslands over the winter period, with pasture being rarely used. General linear models were used to relate environmental factors to the presence and absence of each species on the cliff top habitats. Redshank was the only species that showed a higher probability of occurrence on cliff top habitats at high tide whereas the probability of Turnstone, Oystercatcher and Redshank occurring increased as temperatures declined. Using core sampling, we determined that invertebrate richness and abundance was significantly higher on the recreational grasslands and golf courses than on the pasture or the beach. Our data demonstrated that cliff top habitats are important alternative feeding areas for over-wintering waders in areas where the intertidal is bounded by cliffs. Current management creates short sward, open field habitats with a diverse and abundant invertebrate food supply exploited by waders. Any alterations to the land use of these areas should be carefully considered by planning authorities in light of the fact that they support species that are of conservation concern.

  10. Tiering and Scaffolding: Two Strategies for Providing Access to Important Mathematics

    Science.gov (United States)

    Williams, Lori

    2008-01-01

    Tiering and scaffolding are two differentiation strategies that teachers use to support access to a high-quality mathematics curriculum for all students. This article provides examples demonstrating a thinking process for planning tiered activities that focus on important mathematical understandings. Also described are possible scaffolds that can…

  11. Animal models: an important tool in mycology.

    Science.gov (United States)

    Capilla, Javier; Clemons, Karl V; Stevens, David A

    2007-12-01

    Animal models of fungal infections are, and will remain, a key tool in the advancement of the medical mycology. Many different types of animal models of fungal infection have been developed, with murine models the most frequently used, for studies of pathogenesis, virulence, immunology, diagnosis, and therapy. The ability to control numerous variables in performing the model allows us to mimic human disease states and quantitatively monitor the course of the disease. However, no single model can answer all questions and different animal species or different routes of infection can show somewhat different results. Thus, the choice of which animal model to use must be made carefully, addressing issues of the type of human disease to mimic, the parameters to follow and collection of the appropriate data to answer those questions being asked. This review addresses a variety of uses for animal models in medical mycology. It focuses on the most clinically important diseases affecting humans and cites various examples of the different types of studies that have been performed. Overall, animal models of fungal infection will continue to be valuable tools in addressing questions concerning fungal infections and contribute to our deeper understanding of how these infections occur, progress and can be controlled and eliminated.

  12. PURCHASING MANAGEMENT AND ITS IMPORTANT ROLE IN PROVIDING VALUE ADDED TO ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Pop Sitar Corina

    2012-07-01

    Full Text Available Nowadays, in the knowledge based society, purchasing management has become one of the most important tool for improving the profitability of organizations. Because of its important role, purchasing is the function that has a tremendous impact on these efforts to create value in the organizations. This article summarizes the main value that can be provided by the purchasing function to the organizations. The paper starts with the presentation of the evolution stages of purchasing management Furthermore, we present the strategic role of the purchasing management in the knowledge based society. Based on the results of a questionnaire we summarized the main value added by purchasing in the companies from Maramures county. Finally, we draw conclusions and we elaborate some guidelines for managers.

  13. Trust Your Cloud Service Provider: User Based Crypto Model. Sitanaboina

    Directory of Open Access Journals (Sweden)

    Sri Lakshmi Parvathi

    2014-10-01

    Full Text Available In Data Storage as a Service (STaaS cloud computing environment, the equipment used for business operations can be leased from a single service provider along with the application, and the related business data can be stored on equipment provided by the same service provider. This type of arrangement can help a company save on hardware and software infrastructure costs, but storing the company’s data on the service provider’s equipment raises the possibility that important business information may be improperly disclosed to others [1]. Some researchers have suggested that user data stored on a service-provider’s equipment must be encrypted [2]. Encrypting data prior to storage is a common method of data protection, and service providers may be able to build firewalls to ensure that the decryption keys associated with encrypted user data are not disclosed to outsiders. However, if the decryption key and the encrypted data are held by the same service provider, it raises the possibility that high-level administrators within the service provider would have access to both the decryption key and the encrypted data, thus presenting a risk for the unauthorized disclosure of the user data. we in this paper provides an unique business model of cryptography where crypto keys are distributed across the user and the trusted third party(TTP with adoption of such a model mainly the CSP insider attack an form of misuse of valuable user data can be treated secured.

  14. The importance of sensory-motor control in providing core stability: implications for measurement and training.

    Science.gov (United States)

    Borghuis, Jan; Hof, At L; Lemmink, Koen A P M

    2008-01-01

    Although the hip musculature is found to be very important in connecting the core to the lower extremities and in transferring forces from and to the core, it is proposed to leave the hip musculature out of consideration when talking about the concept of core stability. A low level of co-contraction of the trunk muscles is important for core stability. It provides a level of stiffness, which gives sufficient stability against minor perturbations. Next to this stiffness, direction-specific muscle reflex responses are also important in providing core stability, particularly when encountering sudden perturbations. It appears that most trunk muscles, both the local and global stabilization system, must work coherently to achieve core stability. The contributions of the various trunk muscles depend on the task being performed. In the search for a precise balance between the amount of stability and mobility, the role of sensory-motor control is much more important than the role of strength or endurance of the trunk muscles. The CNS creates a stable foundation for movement of the extremities through co-contraction of particular muscles. Appropriate muscle recruitment and timing is extremely important in providing core stability. No clear evidence has been found for a positive relationship between core stability and physical performance and more research in this area is needed. On the other hand, with respect to the relationship between core stability and injury, several studies have found an association between a decreased stability and a higher risk of sustaining a low back or knee injury. Subjects with such injuries have been shown to demonstrate impaired postural control, delayed muscle reflex responses following sudden trunk unloading and abnormal trunk muscle recruitment patterns. In addition, various relationships have been demonstrated between core stability, balance performance and activation characteristics of the trunk muscles. Most importantly, a significant

  15. The human factor: the critical importance of effective teamwork and communication in providing safe care.

    Science.gov (United States)

    Leonard, M; Graham, S; Bonacum, D

    2004-10-01

    Effective communication and teamwork is essential for the delivery of high quality, safe patient care. Communication failures are an extremely common cause of inadvertent patient harm. The complexity of medical care, coupled with the inherent limitations of human performance, make it critically important that clinicians have standardised communication tools, create an environment in which individuals can speak up and express concerns, and share common "critical language" to alert team members to unsafe situations. All too frequently, effective communication is situation or personality dependent. Other high reliability domains, such as commercial aviation, have shown that the adoption of standardised tools and behaviours is a very effective strategy in enhancing teamwork and reducing risk. We describe our ongoing patient safety implementation using this approach within Kaiser Permanente, a non-profit American healthcare system providing care for 8.3 million patients. We describe specific clinical experience in the application of surgical briefings, properties of high reliability perinatal care, the value of critical event training and simulation, and benefits of a standardised communication process in the care of patients transferred from hospitals to skilled nursing facilities. Additionally, lessons learned as to effective techniques in achieving cultural change, evidence of improving the quality of the work environment, practice transfer strategies, critical success factors, and the evolving methods of demonstrating the benefit of such work are described.

  16. Importance of healthcare utilization and multimorbidity level in choosing a primary care provider in Sweden

    DEFF Research Database (Denmark)

    Ranstad, Karin; Midlöv, Patrik; Halling, Anders

    2014-01-01

    OBJECTIVE: To study the associations between active choice of primary care provider and healthcare utilization, multimorbidity, age, and sex, comparing data from primary care and all healthcare in a Swedish population. DESIGN: Descriptive cross-sectional study using descriptive analyses including t.......30-1.32), multimorbidity level (OR 1.69, 95% CI 1.67-1.70), age (OR 1.03, 95% CI 1.03-1.03), and sex (OR for men 0.67, 95% CI 0.65-0.68) were all associated with registered active listing in primary care. Active listing was more strongly associated with number of consultations and multimorbidity level using primary care...... data (OR 2.11, 95% CI 2.08-2.15 and OR 2.14, 95% CI 2.11-2.17, respectively) than using data from all healthcare. Number of consultations and multimorbidity level were correlated and had similar associations with active listing in primary care. Modelling number of consultations, multimorbidity level...

  17. Employee important-satisfaction model for automotive industry

    Science.gov (United States)

    Aziz, Nazrina; Mahat, Nor Idayu; Omar, Zurni

    2014-12-01

    There are many available strategies to measure employee satisfaction. Among the common strategies are employee responses to supervisors during routine meetings or periodic assessments of performance, number of complaints and feedback from employees. Although the management of the company may expect what its employees are most satisfied with, they may not know what is important to their employees' satisfaction. The "satisfaction attributes" and the "importance attributes" are related components that worth to be taken into account. Besides, the management needs to identify what their employees' priorities are, otherwise the management could be wasting their limited energy and resources tackling wrong attributes. In this study the Important-Satisfaction model is proposed. The model is based on the importance and satisfaction score of the attributes where the score for each attribute is placed in the model. It assists the management in identifying attributes that require improvement and provide an excellent measuring instrument for assessing priorities for attribute improvement.

  18. Comprehensive Care For Joint Replacement Model - Provider Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Comprehensive Care for Joint Replacement Model - provider data. This data set includes provider data for two quality measures tracked during an episode of care:...

  19. Importance of plan curvature in watershed modeling

    Science.gov (United States)

    Boll, J.; Ribail, J.; Zhao, M.

    2016-12-01

    A hillslope's hydrologic response to precipitation events is largely controlled by the topographic features of a given hillslope, specifically the profile and plan curvature. Many models simplify hillslope topography and ignore the curvature properties, and some use alternate measures such as a topographic index or the hillslope width function. Models that ignore curvature properties may be calibrated to produce the statistically acceptable integrated response of runoff at a watershed outlet, but incorporating these properties is necessary to model accurately hydrologic processes such as surface flow, erosion, subsurface lateral flow, location of runoff generation and drainage response. In this study, we evaluated the sensitivity of rainfall-runoff modelling to profile and plan curvature in two models. In the first model, the Water Erosion Prediction Project (WEPP) model, hillslope uses a representative width to the hillslope by dividing the drainage area by the average surface channel length. Profile curvature is preserved with a limited spatial resolution due to the number of overland flow elements. In the second model, the distributed Soil Moisture Routing (SMR) model, the geographic information system uses the D8 algorithm to capture profile and plan curvature. Sensitivity to topographic features was tested for three profile curvatures (convex, concave, straight) combined with three plan curvatures (diverging, converging, uniform) resulting in a total of nine hillslopes. Each hillslope was subjected to different rainfall events to detect threshold behavior for when topographic features cannot be ignored. Our findings indicate that concave and convex plan curvature need to be included when subsurface flow processes are the dominant flow process for surface flow runoff generation. We present thresholds for acceptable cases when profile and plan curvature can be simplified in larger spatial hydrologic units.

  20. The Importance of Sensory-Motor Control in Providing Core Stability Implications for Measurement and Training

    NARCIS (Netherlands)

    Borghuis, Jan; Hof, At L.; Lemmink, Koen A. P. M.

    2008-01-01

    Although the hip musculature is found to be very important in connecting the core to the lower extremities and in transferring forces from and to the core, it is proposed to leave the hip musculature out of consideration when talking about the concept of core stability. A low level of co-contraction

  1. The Importance of Sensory-Motor Control in Providing Core Stability Implications for Measurement and Training

    NARCIS (Netherlands)

    Borghuis, Jan; Hof, At L.; Lemmink, Koen A. P. M.

    2008-01-01

    Although the hip musculature is found to be very important in connecting the core to the lower extremities and in transferring forces from and to the core, it is proposed to leave the hip musculature out of consideration when talking about the concept of core stability. A low level of co-contraction

  2. Contracts in the Classroom--Providing Undergraduate Business Students with Important "Real Life" Skills

    Science.gov (United States)

    Denbo, Susan M.

    2005-01-01

    Many business law educators have recognized the importance of teaching students not only the rules of contract law, but the process of implementing these rules in the "real world" of business. This article discusses a contract negotiation exercise that enables students to apply the black letter law of contracts while at the same time honing their…

  3. Semantic Importance Sampling for Statistical Model Checking

    Science.gov (United States)

    2015-01-16

    approach called Statistical Model Checking (SMC) [16], which relies on Monte - Carlo -based simulations to solve this verification task more scalably...Conclusion Statistical model checking (SMC) is a prominent approach for rigorous analysis of stochastic systems using Monte - Carlo simulations. In this... Monte - Carlo simulations, for computing the bounded probability that a specific event occurs during a stochastic system’s execution. Estimating the

  4. A study on important factors influencing customer relationship management: A case study of Mobile service provider

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2013-04-01

    Full Text Available Customers are considered as essential assets in any organizations including mobile services. During the past few years, mobile industry is growing rapidly and the competitions among business owners increases steadily. In this paper, we present an empirical investigation to find important factors influencing customer relationship management. The proposed study of this paper designs a questionnaire and distributes it among 253 customers in mobile industry in city of Tehran, Iran. All questions are designed in Likert scale and Cronbach alpha is calculated as 0.816, which is relatively reliable value. There were 28 questions in this survey and the proposed study extracts five important factors including economic factors, communication skills, organizational resources, service capabilities and flexible market.

  5. Customer-Provider Strategic Alignment: A Maturity Model

    Science.gov (United States)

    Luftman, Jerry; Brown, Carol V.; Balaji, S.

    This chapter presents a new model for assessing the maturity of a ­customer-provider relationship from a collaborative service delivery perspective: the Customer-Provider Strategic Alignment Maturity (CPSAM) Model. This model builds on recent research for effectively managing the customer-provider relationship in IT service outsourcing contexts and a validated model for assessing alignment across internal IT service units and their business customers within the same organization. After reviewing relevant literature by service science and information systems researchers, the six overarching components of the maturity model are presented: value measurements, governance, partnership, communications, human resources and skills, and scope and architecture. A key assumption of the model is that all of the components need be addressed to assess and improve customer-provider alignment. Examples of specific metrics for measuring the maturity level of each component over the five levels of maturity are also presented.

  6. Computerized analysis of isometric tension studies provides important additional information about vasomotor activity

    Directory of Open Access Journals (Sweden)

    Vincent M.B.

    1997-01-01

    Full Text Available Concentration-response curves of isometric tension studies on isolated blood vessels are obtained traditionally. Although parameters such as Imax, EC50 and pA2 may be readily calculated, this method does not provide information on the temporal profile of the responses or the actual nature of the reaction curves. Computerized data acquisition systems can be used to obtain average data that represent a new source of otherwise inaccessible information, since early and late responses may be observed separately in detail

  7. Allergic contact dermatitis from exotic woods: importance of patch-testing with patient-provided samples.

    Science.gov (United States)

    Podjasek, Joshua O; Cook-Norris, Robert H; Richardson, Donna M; Drage, Lisa A; Davis, Mark D P

    2011-01-01

    Exotic woods from tropical and subtropical regions (eg, from South America, south Asia, and Africa) frequently are used occupationally and recreationally by woodworkers and hobbyists. These exotic woods more commonly provoke irritant contact dermatitis reactions, but they also can provoke allergic contact dermatitis reactions. We report three patients seen at Mayo Clinic (Rochester, MN) with allergic contact dermatitis reactions to exotic woods. Patch testing was performed and included patient-provided wood samples. Avoidance of identified allergens was recommended. For all patients, the dermatitis cleared or improved after avoidance of the identified allergens. Clinicians must be aware of the potential for allergic contact dermatitis reactions to compounds in exotic woods. Patch testing should be performed with suspected woods for diagnostic confirmation and allowance of subsequent avoidance of the allergens.

  8. The importance of message framing for providing information about sustainability and environmental aspects of energy

    Energy Technology Data Exchange (ETDEWEB)

    Van de Velde, Liesbeth; Verbeke, Wim; Van Huylenbroeck, Guido [Department of Agricultural Economics, Ghent University, Coupure Links 653, 9000 Gent (Belgium); Popp, Michael [Department of Agricultural Economics and Agribusiness, University of Arkansas, 217 Agriculture Building, Fayetteville, AR 72701 (United States)

    2010-10-15

    With a looming energy crisis, energy conservation and attention to environmental problems are warranted. The transport sector experiences great challenges to introduce more environmental friendly renewable energy like biofuels. The majority of the Belgian people are asking for more information about this issue. Because individuals are sensitive to how information is presented, the choice of the message frame can significantly influence attitudes and behavioural intention. Because of the strengthening effect on both concern and PCE, our findings suggest that for the prevention of energy and environmental problems and the promotion of a more sustainable and environmental friendly energy consumption not the gravity of these problems and the possible disadvantages but the possibilities to overcome these problems (e.g. reduction of energy use, environmental friendly energy sources) have to be stressed. Men, higher educated people, people between 35 and 54 years old and people with the most pro-environmental attitude are less affected by the message frame, while the choice of the frame is more important when addressing women, people younger than 35 and older than 55 years, lower educated and less pro-environmental people. (author)

  9. Low-canopy seagrass beds still provide important coastal protection services.

    Science.gov (United States)

    Christianen, Marjolijn J A; van Belzen, Jim; Herman, Peter M J; van Katwijk, Marieke M; Lamers, Leon P M; van Leent, Peter J M; Bouma, Tjeerd J

    2013-01-01

    One of the most frequently quoted ecosystem services of seagrass meadows is their value for coastal protection. Many studies emphasize the role of above-ground shoots in attenuating waves, enhancing sedimentation and preventing erosion. This raises the question if short-leaved, low density (grazed) seagrass meadows with most of their biomass in belowground tissues can also stabilize sediments. We examined this by combining manipulative field experiments and wave measurements along a typical tropical reef flat where green turtles intensively graze upon the seagrass canopy. We experimentally manipulated wave energy and grazing intensity along a transect perpendicular to the beach, and compared sediment bed level change between vegetated and experimentally created bare plots at three distances from the beach. Our experiments showed that i) even the short-leaved, low-biomass and heavily-grazed seagrass vegetation reduced wave-induced sediment erosion up to threefold, and ii) that erosion was a function of location along the vegetated reef flat. Where other studies stress the importance of the seagrass canopy for shoreline protection, our study on open, low-biomass and heavily grazed seagrass beds strongly suggests that belowground biomass also has a major effect on the immobilization of sediment. These results imply that, compared to shallow unvegetated nearshore reef flats, the presence of a short, low-biomass seagrass meadow maintains a higher bed level, attenuating waves before reaching the beach and hence lowering beach erosion rates. We propose that the sole use of aboveground biomass as a proxy for valuing coastal protection services should be reconsidered.

  10. Scanning of selection signature provides a glimpse into important economic traits in goats (Capra hircus).

    Science.gov (United States)

    Guan, Dailu; Luo, Nanjian; Tan, Xiaoshan; Zhao, Zhongquan; Huang, Yongfu; Na, Risu; Zhang, Jiahua; Zhao, Yongju

    2016-10-31

    Goats (Capra hircus) are one of the oldest livestock domesticated species, and have been used for their milk, meat, hair and skins over much of the world. Detection of selection footprints in genomic regions can provide potential insights for understanding the genetic mechanism of specific phenotypic traits and better guide in animal breeding. The study presented here has generated 192.747G raw data and identified more than 5.03 million single-nucleotide polymorphisms (SNPs) and 334,151 Indels (insertions and deletions). In addition, we identified 155 and 294 candidate regions harboring 86 and 97 genes based on allele frequency differences in Dazu black goats (DBG) and Inner Mongolia cashmere goats (IMCG), respectively. Populations differentiation reflected by Fst values detected 368 putative selective sweep regions including 164 genes. The top 1% regions of both low heterozygosity and high genetic differentiation contained 239 (135 genes) and 176 (106 genes) candidate regions in DBG and IMCG, respectively. These genes were related to reproductive and productive traits, such as "neurohypophyseal hormone activity" and "adipocytokine signaling pathway". These findings may be conducive to molecular breeding and the long-term preservation of the valuable genetic resources for this species.

  11. A Workforce Design Model: Providing Energy to Organizations in Transition

    Science.gov (United States)

    Halm, Barry J.

    2011-01-01

    The purpose of this qualitative study was to examine the change in performance realized by a professional services organization, which resulted in the Life Giving Workforce Design (LGWD) model through a grounded theory research design. This study produced a workforce design model characterized as an organizational blueprint that provides virtuous…

  12. Bring Your Own Device - Providing Reliable Model of Data Access

    Directory of Open Access Journals (Sweden)

    Stąpór Paweł

    2016-10-01

    Full Text Available The article presents a model of Bring Your Own Device (BYOD as a model network, which provides the user reliable access to network resources. BYOD is a model dynamically developing, which can be applied in many areas. Research network has been launched in order to carry out the test, in which as a service of BYOD model Work Folders service was used. This service allows the user to synchronize files between the device and the server. An access to the network is completed through the wireless communication by the 802.11n standard. Obtained results are shown and analyzed in this article.

  13. Service Model for Multi-Provider IP Service Management

    Institute of Scientific and Technical Information of China (English)

    YU Cheng-zhi; SONG Han-tao; LIU Li

    2005-01-01

    In order to solve the problems associated with Internet IP services management, a generic service model for multi-provider IP service management is proposed, which is based on a generalization of the bandwidth broker idea introduced in the differentiated services (DiffServ) environment. This model consists of a hierarchy of service brokers, which makes it fit into providing end-to-end Internet services with QoS support. A simple and scalable mechanism is used to communicate with other cooperative domains to enable customers to dynamically setup services connections over multiple DiffServ domains. The simulation results show that the proposed model is real-time, which can deal with many flow requests in a short period of time, so that it is fit for the service management in a reasonably large network.

  14. The importance of understanding: Model space moderates goal specificity effects.

    Science.gov (United States)

    Kistner, Saskia; Burns, Bruce D; Vollmeyer, Regina; Kortenkamp, Ulrich

    2016-01-01

    The three-space theory of problem solving predicts that the quality of a learner's model and the goal specificity of a task interact on knowledge acquisition. In Experiment 1 participants used a computer simulation of a lever system to learn about torques. They either had to test hypotheses (nonspecific goal), or to produce given values for variables (specific goal). In the good- but not in the poor-model condition they saw torque depicted as an area. Results revealed the predicted interaction. A nonspecific goal only resulted in better learning when a good model of torques was provided. In Experiment 2 participants learned to manipulate the inputs of a system to control its outputs. A nonspecific goal to explore the system helped performance when compared to a specific goal to reach certain values when participants were given a good model, but not when given a poor model that suggested the wrong hypothesis space. Our findings support the three-space theory. They emphasize the importance of understanding for problem solving and stress the need to study underlying processes.

  15. Model of Providing Assistive Technologies in Special Education Schools.

    Science.gov (United States)

    Lersilp, Suchitporn; Putthinoi, Supawadee; Chakpitak, Nopasit

    2015-05-14

    Most students diagnosed with disabilities in Thai special education schools received assistive technologies, but this did not guarantee the greatest benefits. The purpose of this study was to survey the provision, use and needs of assistive technologies, as well as the perspectives of key informants regarding a model of providing them in special education schools. The participants were selected by the purposive sampling method, and they comprised 120 students with visual, physical, hearing or intellectual disabilities from four special education schools in Chiang Mai, Thailand; and 24 key informants such as parents or caregivers, teachers, school principals and school therapists. The instruments consisted of an assistive technology checklist and a semi-structured interview. Results showed that a category of assistive technologies was provided for students with disabilities, with the highest being "services", followed by "media" and then "facilities". Furthermore, mostly students with physical disabilities were provided with assistive technologies, but those with visual disabilities needed it more. Finally, the model of providing assistive technologies was composed of 5 components: Collaboration; Holistic perspective; Independent management of schools; Learning systems and a production manual for users; and Development of an assistive technology center, driven by 3 major sources such as Government and Private organizations, and Schools.

  16. Modelling catchment areas for secondary care providers: a case study.

    Science.gov (United States)

    Jones, Simon; Wardlaw, Jessica; Crouch, Susan; Carolan, Michelle

    2011-09-01

    Hospitals need to understand patient flows in an increasingly competitive health economy. New initiatives like Patient Choice and the Darzi Review further increase this demand. Essential to understanding patient flows are demographic and geographic profiles of health care service providers, known as 'catchment areas' and 'catchment populations'. This information helps Primary Care Trusts (PCTs) to review how their populations are accessing services, measure inequalities and commission services; likewise it assists Secondary Care Providers (SCPs) to measure and assess potential gains in market share, redesign services, evaluate admission thresholds and plan financial budgets. Unlike PCTs, SCPs do not operate within fixed geographic boundaries. Traditionally, SCPs have used administrative boundaries or arbitrary drive times to model catchment areas. Neither approach satisfactorily represents current patient flows. Furthermore, these techniques are time-consuming and can be challenging for healthcare managers to exploit. This paper presents three different approaches to define catchment areas, each more detailed than the previous method. The first approach 'First Past the Post' defines catchment areas by allocating a dominant SCP to each Census Output Area (OA). The SCP with the highest proportion of activity within each OA is considered the dominant SCP. The second approach 'Proportional Flow' allocates activity proportionally to each OA. This approach allows for cross-boundary flows to be captured in a catchment area. The third and final approach uses a gravity model to define a catchment area, which incorporates drive or travel time into the analysis. Comparing approaches helps healthcare providers to understand whether using more traditional and simplistic approaches to define catchment areas and populations achieves the same or similar results as complex mathematical modelling. This paper has demonstrated, using a case study of Manchester, that when estimating

  17. Could structural similarity of specific domains between animal globins and plant antenna proteins provide hints important for the photoprotection mechanism?

    Science.gov (United States)

    Ioannidis, Nikolaos E; Kotzabasis, Kiriakos

    2015-01-07

    Non photochemical quenching is a fundamental mechanism in photosynthesis, which protects plants against excess excitation energy and is of crucial importance for their survival and fitness. In the last decades hundreds of papers have appeared that describe the role of antenna regulation in protection or the so called qE response. However, the exact quenching site is still obscure. Previously overlooked features of the antenna may provide hints towards the elucidation of its functionality and of the quenching mechanism. Recently it was demonstrated that the catalytic domain of human myoglobin that binds the pigment (i.e. heme) is similar in structure to the domain of the light harvesting complex II of pea that binds Chl a 614 (former known as b3). In addition, it is well accepted that conformational changes of the chlorophyll macrocycle result in reversible changes of fluorescence (the lowest fluorescence corresponds to non planar macrocycle). Here we put forward a hypothesis regarding the molecular mechanism that leads to the formation of a quenching center inside the antenna proteins. Our main suggestion is that a conformational change of helix H5 (known also as helix D) forces conformational changes in the macrocycle of Chl a 614 is implicated in the ΔA535 absorbance change and quenching during photoprotective qE. The specific features (some of them similar to those of heme domain of globins) of the b3 domain account for these traits. The model predicts that antenna proteins having b3 pigments (i.e. LHCII, CP29, CP26) can act as potential quenchers.

  18. Provider practice models in ambulatory oncology practice: analysis of productivity, revenue, and provider and patient satisfaction.

    Science.gov (United States)

    Buswell, Lori A; Ponte, Patricia Reid; Shulman, Lawrence N

    2009-07-01

    Physicians, nurse practitioners, and physician assistants often work in teams to deliver cancer care in ambulatory oncology practices. This is likely to become more prevalent as the demand for oncology services rises, and the number of providers increases only slightly.

  19. Importance of resolution and model configuration when downscaling extreme precipitation

    Directory of Open Access Journals (Sweden)

    Adrian J. Champion

    2014-07-01

    Full Text Available Dynamical downscaling is frequently used to investigate the dynamical variables of extra-tropical cyclones, for example, precipitation, using very high-resolution models nested within coarser resolution models to understand the processes that lead to intense precipitation. It is also used in climate change studies, using long timeseries to investigate trends in precipitation, or to look at the small-scale dynamical processes for specific case studies. This study investigates some of the problems associated with dynamical downscaling and looks at the optimum configuration to obtain the distribution and intensity of a precipitation field to match observations. This study uses the Met Office Unified Model run in limited area mode with grid spacings of 12, 4 and 1.5 km, driven by boundary conditions provided by the ECMWF Operational Analysis to produce high-resolution simulations for the Summer of 2007 UK flooding events. The numerical weather prediction model is initiated at varying times before the peak precipitation is observed to test the importance of the initialisation and boundary conditions, and how long the simulation can be run for. The results are compared to raingauge data as verification and show that the model intensities are most similar to observations when the model is initialised 12 hours before the peak precipitation is observed. It was also shown that using non-gridded datasets makes verification more difficult, with the density of observations also affecting the intensities observed. It is concluded that the simulations are able to produce realistic precipitation intensities when driven by the coarser resolution data.

  20. Can quantum probability provide a new direction for cognitive modeling?

    Science.gov (United States)

    Pothos, Emmanuel M; Busemeyer, Jerome R

    2013-06-01

    Classical (Bayesian) probability (CP) theory has led to an influential research tradition for modeling cognitive processes. Cognitive scientists have been trained to work with CP principles for so long that it is hard even to imagine alternative ways to formalize probabilities. However, in physics, quantum probability (QP) theory has been the dominant probabilistic approach for nearly 100 years. Could QP theory provide us with any advantages in cognitive modeling as well? Note first that both CP and QP theory share the fundamental assumption that it is possible to model cognition on the basis of formal, probabilistic principles. But why consider a QP approach? The answers are that (1) there are many well-established empirical findings (e.g., from the influential Tversky, Kahneman research tradition) that are hard to reconcile with CP principles; and (2) these same findings have natural and straightforward explanations with quantum principles. In QP theory, probabilistic assessment is often strongly context- and order-dependent, individual states can be superposition states (that are impossible to associate with specific values), and composite systems can be entangled (they cannot be decomposed into their subsystems). All these characteristics appear perplexing from a classical perspective. However, our thesis is that they provide a more accurate and powerful account of certain cognitive processes. We first introduce QP theory and illustrate its application with psychological examples. We then review empirical findings that motivate the use of quantum theory in cognitive theory, but also discuss ways in which QP and CP theories converge. Finally, we consider the implications of a QP theory approach to cognition for human rationality.

  1. Do Cochrane reviews provide a good model for social science?

    DEFF Research Database (Denmark)

    Konnerup, Merete; Kongsted, Hans Christian

    2012-01-01

    Formalised research synthesis to underpin evidence-based policy and practice has become increasingly important in areas of public policy. In this paper we discuss whether the Cochrane standard for systematic reviews of healthcare interventions is appropriate for social research. We examine...... the formal criteria of the Cochrane Collaboration for including particular study designs and search the Cochrane Library to provide quantitative evidence on the de facto standard of actual Cochrane reviews. By identifying the sample of Cochrane reviews that consider observational designs, we are able...... to conclude that the majority of reviews appears limited to considering randomised controlled trials only. Because recent studies have delineated conditions for observational studies in social research to produce valid evidence, we argue that an inclusive approach is essential for truly evidence-based policy...

  2. Governance, Government, and the Search for New Provider Models.

    Science.gov (United States)

    Saltman, Richard B; Duran, Antonio

    2015-11-03

    A central problem in designing effective models of provider governance in health systems has been to ensure an appropriate balance between the concerns of public sector and/or government decision-makers, on the one hand, and of non-governmental health services actors in civil society and private life, on the other. In tax-funded European health systems up to the 1980s, the state and other public sector decision-makers played a dominant role over health service provision, typically operating hospitals through national or regional governments on a command-and-control basis. In a number of countries, however, this state role has started to change, with governments first stepping out of direct service provision and now de facto pushed to focus more on steering provider organizations rather than on direct public management. In this new approach to provider governance, the state has pulled back into a regulatory role that introduces market-like incentives and management structures, which then apply to both public and private sector providers alike. This article examines some of the main operational complexities in implementing this new governance reality/strategy, specifically from a service provision (as opposed to mostly a financing or even regulatory) perspective. After briefly reviewing some of the key theoretical dilemmas, the paper presents two case studies where this new approach was put into practice: primary care in Sweden and hospitals in Spain. The article concludes that good governance today needs to reflect practical operational realities if it is to have the desired effect on health sector reform outcome.

  3. Governance, Government, and the Search for New Provider Models

    Directory of Open Access Journals (Sweden)

    Richard B. Saltman

    2016-01-01

    Full Text Available A central problem in designing effective models of provider governance in health systems has been to ensure an appropriate balance between the concerns of public sector and/or government decision-makers, on the one hand, and of non-governmental health services actors in civil society and private life, on the other. In tax-funded European health systems up to the 1980s, the state and other public sector decision-makers played a dominant role over health service provision, typically operating hospitals through national or regional governments on a command-and-control basis. In a number of countries, however, this state role has started to change, with governments first stepping out of direct service provision and now de facto pushed to focus more on steering provider organizations rather than on direct public management. In this new approach to provider governance, the state has pulled back into a regulatory role that introduces market-like incentives and management structures, which then apply to both public and private sector providers alike. This article examines some of the main operational complexities in implementing this new governance reality/strategy, specifically from a service provision (as opposed to mostly a financing or even regulatory perspective. After briefly reviewing some of the key theoretical dilemmas, the paper presents two case studies where this new approach was put into practice: primary care in Sweden and hospitals in Spain. The article concludes that good governance today needs to reflect practical operational realities if it is to have the desired effect on health sector reform outcome.

  4. Do proteomics analyses provide insights into reduced oxidative stress in the brain of an Alzheimer disease transgenic mouse model with an M631L amyloid precursor protein substitution and thereby the importance of amyloid-beta-resident methionine 35 in Alzheimer disease pathogenesis?

    Science.gov (United States)

    Sultana, Rukhsana; Robinson, Renã A S; Lange, Miranda Bader; Fiorini, Ada; Galvan, Veronica; Fombonne, Joanna; Baker, Austin; Gorostiza, Olivia; Zhang, Junli; Cai, Jian; Pierce, William M; Bredesen, Dale E; Butterfield, D Allan

    2012-12-01

    The single methionine (Met/M) residue of amyloid-beta (Aβ) peptide, at position 35 of the 42-mer, has important relevance for Aβ-induced oxidative stress and neurotoxicity. Recent in vivo brain studies in a transgenic (Tg) Alzheimer disease (AD) mouse model with Swedish and Indiana familial AD mutations in human amyloid precursor protein (APP) (referred to as the J20 Tg mouse) demonstrated increased levels of oxidative stress. However, the substitution of the Met631 residue of APP to leucine (Leu/L) (M631L in human APP numbering, referred to as M631L Tg and corresponding to residue 35 of Aβ1-42) resulted in no significant in vivo oxidative stress levels, thereby supporting the hypothesis that Met-35 of Aβ contributes to oxidative insult in the AD brain. It is conceivable that oxidative stress mediated by Met-35 of Aβ is important in regulating numerous downstream effects, leading to differential levels of relevant biochemical pathways in AD. Therefore, in the current study using proteomics, we tested the hypothesis that several brain proteins involved in pathways such as energy and metabolism, antioxidant activity, proteasome degradation, and pH regulation are altered in J20Tg versus M631L Tg AD mice.

  5. Providing surgical care in Somalia: A model of task shifting

    Directory of Open Access Journals (Sweden)

    Ford Nathan P

    2011-07-01

    Full Text Available Abstract Background Somalia is one of the most political unstable countries in the world. Ongoing insecurity has forced an inconsistent medical response by the international community, with little data collection. This paper describes the "remote" model of surgical care by Medecins Sans Frontieres, in Guri-El, Somalia. The challenges of providing the necessary prerequisites for safe surgery are discussed as well as the successes and limitations of task shifting in this resource-limited context. Methods In January 2006, MSF opened a project in Guri-El located between Mogadishu and Galcayo. The objectives were to reduce mortality due to complications of pregnancy and childbirth and from violent and non-violent trauma. At the start of the program, expatriate surgeons and anesthesiologists established safe surgical practices and performed surgical procedures. After January 2008, expatriates were evacuated due to insecurity and surgical care has been provided by local Somalian doctors and nurses with periodic supervisory visits from expatriate staff. Results Between October 2006 and December 2009, 2086 operations were performed on 1602 patients. The majority (1049, 65% were male and the median age was 22 (interquartile range, 17-30. 1460 (70% of interventions were emergent. Trauma accounted for 76% (1585 of all surgical pathology; gunshot wounds accounted for 89% (584 of violent injuries. Operative mortality (0.5% of all surgical interventions was not higher when Somalian staff provided care compared to when expatriate surgeons and anesthesiologists. Conclusions The delivery of surgical care in any conflict-settings is difficult, but in situations where international support is limited, the challenges are more extreme. In this model, task shifting, or the provision of services by less trained cadres, was utilized and peri-operative mortality remained low demonstrating that safe surgical practices can be accomplished even without the presence of fully

  6. Importance of predictor variables for models of chemical function

    Data.gov (United States)

    U.S. Environmental Protection Agency — Importance of random forest predictors for all classification models of chemical function. This dataset is associated with the following publication: Isaacs , K., M....

  7. Solitary mammals provide an animal model for autism spectrum disorders.

    Science.gov (United States)

    Reser, Jared Edward

    2014-02-01

    Species of solitary mammals are known to exhibit specialized, neurological adaptations that prepare them to focus working memory on food procurement and survival rather than on social interaction. Solitary and nonmonogamous mammals, which do not form strong social bonds, have been documented to exhibit behaviors and biomarkers that are similar to endophenotypes in autism. Both individuals on the autism spectrum and certain solitary mammals have been reported to be low on measures of affiliative need, bodily expressiveness, bonding and attachment, direct and shared gazing, emotional engagement, conspecific recognition, partner preference, separation distress, and social approach behavior. Solitary mammals also exhibit certain biomarkers that are characteristic of autism, including diminished oxytocin and vasopressin signaling, dysregulation of the endogenous opioid system, increased Hypothalamic-pituitary-adrenal axis (HPA) activity to social encounters, and reduced HPA activity to separation and isolation. The extent of these similarities suggests that solitary mammals may offer a useful model of autism spectrum disorders and an opportunity for investigating genetic and epigenetic etiological factors. If the brain in autism can be shown to exhibit distinct homologous or homoplastic similarities to the brains of solitary animals, it will reveal that they may be central to the phenotype and should be targeted for further investigation. Research of the neurological, cellular, and molecular basis of these specializations in other mammals may provide insight for behavioral analysis, communication intervention, and psychopharmacology for autism.

  8. Private Sector An Important But Not Dominant Provider Of Key Health Services In Low- And Middle-Income Countries.

    Science.gov (United States)

    Grépin, Karen A

    2016-07-01

    There is debate about the role of the private sector in providing services in the health systems of low- and middle-income countries and about how the private sector could help achieve the goal of universal health coverage. Yet the role that the private sector plays in the delivery of health services is poorly understood. Using data for the period 1990-2013 from 205 Demographic and Health Surveys in seventy low- and middle-income countries, I analyzed the use of the private sector for the treatment of diarrhea and of fever or cough in children, for antenatal care, for institutional deliveries, and as a source of modern contraception for women. I found that private providers were the dominant source of treatment for childhood illnesses but not for the other services. I also found no evidence of increased use of the private sector over time. There is tremendous variation in use of the private sector across countries and health services. Urban and wealthier women disproportionately use the private sector, compared to rural and poorer women. The private sector plays an important role in providing coverage, but strategies to further engage the sector, if they are to be effective, will need to take into consideration the variation in its use.

  9. Model-Free importance indicators for dependent input

    Energy Technology Data Exchange (ETDEWEB)

    Saltelli, A.; Ratto, M.; Tarantola, S

    2001-07-01

    A number of methods are available to asses uncertainty importance in the predictions of a simulation model for orthogonal sets of uncertain input factors. However, in many practical cases input factors are correlated. Even for these cases it is still possible to compute the correlation ratio and the partial (or incremental) importance measure, two popular sensitivity measures proposed in the recent literature on the subject. Unfortunately, the existing indicators of importance have limitations in terms of their use in sensitivity analysis of model output. Correlation ratios are indeed effective for priority setting (i.e. to find out what input factor needs better determination) but not, for instance, for the identification of the subset of the most important input factors, or for model simplification. In such cases other types of indicators are required that can cope with the simultaneous occurrence of correlation and interaction (a property of the model) among the input factors. In (1) the limitations of current measures of importance were discussed and a general approach was identified to quantify uncertainty importance for correlated inputs in terms of different betting contexts. This work was later submitted to the Journal of the American Statistical Association. However, the computational cost of such approach is still high, as it happens when dealing with correlated input factors. In this paper we explore how suitable designs could reduce the numerical load of the analysis. (Author) 11 refs.

  10. Do Lumped-Parameter Models Provide the Correct Geometrical Damping?

    DEFF Research Database (Denmark)

    Andersen, Lars

    This paper concerns the formulation of lumped-parameter models for rigid footings on homogenous or stratified soil. Such models only contain a few degrees of freedom, which makes them ideal for inclusion in aero-elastic codes for wind turbines and other models applied to fast evaluation of struct......This paper concerns the formulation of lumped-parameter models for rigid footings on homogenous or stratified soil. Such models only contain a few degrees of freedom, which makes them ideal for inclusion in aero-elastic codes for wind turbines and other models applied to fast evaluation...... response during excitation and the geometrical damping related to free vibrations of a hexagonal footing. The optimal order of a lumped-parameter model is determined for each degree of freedom, i.e. horizontal and vertical translation as well as torsion and rocking. In particular, the necessity of coupling...... between horizontal sliding and rocking is discussed....

  11. Modeling the Visual and Linguistic Importance of Objects

    Directory of Open Access Journals (Sweden)

    Moreno Ignazio Coco

    2012-05-01

    Full Text Available Previous work measuring the visual importance of objects has shown that only spatial information, such as object position and size, is predictive of importance, whilst low-level visual information, such as saliency, is not (Spain and Perona 2010, IJCV 91, 59–76. Objects are not important solely on the basis of their appearance. Rather, they are important because of their contextual information (eg, a pen in an office versus in a bathroom, which is needed in tasks requiring cognitive control (eg, visual search; Henderson 2007, PsySci 16 219–222. Given that most visual objects have a linguistic counterpart, their importance depends also on linguistic information, especially in tasks where language is actively involved—eg, naming. In an eye-tracking naming study, where participants are asked to name 5 objects in a scene, we investigated how visual saliency, contextual features, and linguistic information of the mentioned objects predicted their importance. We measured object importance based on the urn model of Spain and Perona (2010 and estimated the predictive role of visual and linguistic features using different regression frameworks: LARS (Efron et al 2004, Annals of Statistics 32 407–499 and LME (Baayen et al 2008, JML 59, 390–412. Our results confirmed the role of spatial information in predicting object importance, and in addition, we found effects of saliency. Crucially to our hypothesis, we demonstrated that the lexical frequency of objects and their contextual fit in the scene significantly contributed to object importance.

  12. Do Lumped-Parameter Models Provide the Correct Geometrical Damping?

    DEFF Research Database (Denmark)

    Andersen, Lars

    2007-01-01

    This paper concerns the formulation of lumped-parameter models for rigid footings on homogenous or stratified soil with focus on the horizontal sliding and rocking. Such models only contain a few degrees of freedom, which makes them ideal for inclusion in aero-elastic codes for wind turbines...

  13. Do Lumped-Parameter Models Provide the Correct Geometrical Damping?

    DEFF Research Database (Denmark)

    Andersen, Lars

    2007-01-01

    This paper concerns the formulation of lumped-parameter models for rigid footings on homogenous or stratified soil with focus on the horizontal sliding and rocking. Such models only contain a few degrees of freedom, which makes them ideal for inclusion in aero-elastic codes for wind turbines...

  14. Plant Growth Modelling and Applications: The Increasing Importance of Plant Architecture in Growth Models

    Science.gov (United States)

    Fourcaud, Thierry; Zhang, Xiaopeng; Stokes, Alexia; Lambers, Hans; Körner, Christian

    2008-01-01

    Background Modelling plant growth allows us to test hypotheses and carry out virtual experiments concerning plant growth processes that could otherwise take years in field conditions. The visualization of growth simulations allows us to see directly and vividly the outcome of a given model and provides us with an instructive tool useful for agronomists and foresters, as well as for teaching. Functional–structural (FS) plant growth models are nowadays particularly important for integrating biological processes with environmental conditions in 3-D virtual plants, and provide the basis for more advanced research in plant sciences. Scope In this viewpoint paper, we ask the following questions. Are we modelling the correct processes that drive plant growth, and is growth driven mostly by sink or source activity? In current models, is the importance of soil resources (nutrients, water, temperature and their interaction with meristematic activity) considered adequately? Do classic models account for architectural adjustment as well as integrating the fundamental principles of development? Whilst answering these questions with the available data in the literature, we put forward the opinion that plant architecture and sink activity must be pushed to the centre of plant growth models. In natural conditions, sinks will more often drive growth than source activity, because sink activity is often controlled by finite soil resources or developmental constraints. PMA06 This viewpoint paper also serves as an introduction to this Special Issue devoted to plant growth modelling, which includes new research covering areas stretching from cell growth to biomechanics. All papers were presented at the Second International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA06), held in Beijing, China, from 13–17 November, 2006. Although a large number of papers are devoted to FS models of agricultural and forest crop species, physiological and genetic

  15. Provide a Model for Handover Technology in Wireless Networks

    CERN Document Server

    Asosheh, Abbas; Khodkari, Hourieh

    2011-01-01

    Fast Handovers for the MIPv6 (FMIPv6) has been proposed to reduce the Handover latency, in the IETF. It could not find the acceptable reduction, so led to more efforts to improve it and however the creation of multiple Handover methods in the literature. A stable connection is very important in mobile services so the mobility of device would not cause any interruption in network services and thus mobility management plays a very important role. Mobile IPv6 has become a general solution for supporting mobility between different networks on the internet which a flawless connection needs to be managed properly. In order to select the appropriate method, in this paper, all the proposed methods have been classified according to the identified performance metrics. Call blocking probability, Handover blocking probability, Probability of an unnecessary handover, Duration of interruption and delay, as the most important Handover algorithm performance metrics are introduced. The AHP method will be deployed to weight th...

  16. The Importance of Statistical Modeling in Data Analysis and Inference

    Science.gov (United States)

    Rollins, Derrick, Sr.

    2017-01-01

    Statistical inference simply means to draw a conclusion based on information that comes from data. Error bars are the most commonly used tool for data analysis and inference in chemical engineering data studies. This work demonstrates, using common types of data collection studies, the importance of specifying the statistical model for sound…

  17. Homology modeling: an important tool for the drug discovery.

    Science.gov (United States)

    França, Tanos Celmar Costa

    2015-01-01

    In the last decades, homology modeling has become a popular tool to access theoretical three-dimensional (3D) structures of molecular targets. So far several 3D models of proteins have been built by this technique and used in a great diversity of structural biology studies. But are those models consistent enough with experimental structures to make this technique an effective and reliable tool for drug discovery? Here we present, briefly, the fundamentals and current state-of-the-art of the homology modeling techniques used to build 3D structures of molecular targets, which experimental structures are not available in databases, and list some of the more important works, using this technique, available in literature today. In many cases those studies have afforded successful models for the drug design of more selective agonists/antagonists to the molecular targets in focus and guided promising experimental works, proving that, when the appropriate templates are available, useful models can be built using some of the several software available today for this purpose. Limitations of the experimental techniques used to solve 3D structures allied to constant improvements in the homology modeling software will maintain the need for theoretical models, establishing the homology modeling as a fundamental tool for the drug discovery.

  18. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2017-05-01

    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  19. Landscape as a model: the importance of geometry.

    Science.gov (United States)

    Holland, E Penelope; Aegerter, James N; Dytham, Calvin; Smith, Graham C

    2007-10-01

    In all models, but especially in those used to predict uncertain processes (e.g., climate change and nonnative species establishment), it is important to identify and remove any sources of bias that may confound results. This is critical in models designed to help support decisionmaking. The geometry used to represent virtual landscapes in spatially explicit models is a potential source of bias. The majority of spatial models use regular square geometry, although regular hexagonal landscapes have also been used. However, there are other ways in which space can be represented in spatially explicit models. For the first time, we explicitly compare the range of alternative geometries available to the modeller, and present a mechanism by which uncertainty in the representation of landscapes can be incorporated. We test how geometry can affect cell-to-cell movement across homogeneous virtual landscapes and compare regular geometries with a suite of irregular mosaics. We show that regular geometries have the potential to systematically bias the direction and distance of movement, whereas even individual instances of landscapes with irregular geometry do not. We also examine how geometry can affect the gross representation of real-world landscapes, and again show that individual instances of regular geometries will always create qualitative and quantitative errors. These can be reduced by the use of multiple randomized instances, though this still creates scale-dependent biases. In contrast, virtual landscapes formed using irregular geometries can represent complex real-world landscapes without error. We found that the potential for bias caused by regular geometries can be effectively eliminated by subdividing virtual landscapes using irregular geometry. The use of irregular geometry appears to offer spatial modellers other potential advantages, which are as yet underdeveloped. We recommend their use in all spatially explicit models, but especially for predictive models

  20. Drosophila provides rapid modeling of renal development, function, and disease.

    Science.gov (United States)

    Dow, Julian A T; Romero, Michael F

    2010-12-01

    The evolution of specialized excretory cells is a cornerstone of the metazoan radiation, and the basic tasks performed by Drosophila and human renal systems are similar. The development of the Drosophila renal (Malpighian) tubule is a classic example of branched tubular morphogenesis, allowing study of mesenchymal-to-epithelial transitions, stem cell-mediated regeneration, and the evolution of a glomerular kidney. Tubule function employs conserved transport proteins, such as the Na(+), K(+)-ATPase and V-ATPase, aquaporins, inward rectifier K(+) channels, and organic solute transporters, regulated by cAMP, cGMP, nitric oxide, and calcium. In addition to generation and selective reabsorption of primary urine, the tubule plays roles in metabolism and excretion of xenobiotics, and in innate immunity. The gene expression resource FlyAtlas.org shows that the tubule is an ideal tissue for the modeling of renal diseases, such as nephrolithiasis and Bartter syndrome, or for inborn errors of metabolism. Studies are assisted by uniquely powerful genetic and transgenic resources, the widespread availability of mutant stocks, and low-cost, rapid deployment of new transgenics to allow manipulation of renal function in an organotypic context.

  1. Spatial correlations in bed load transport: evidence, importance, and modelling

    CERN Document Server

    Heyman, J; Mettra, F; Ancey, C

    2016-01-01

    This article examines the spatial {dynamics of bed load particles} in water. We focus particularly on the fluctuations of particle activity, which is defined as the number of moving particles per unit bed {length}. Based on a stochastic model recently proposed by \\citet{Ancey2013}, we derive the second moment of particle activity analytically; that is the spatial correlation functions of particle activity. From these expressions, we show that large moving particle clusters can develop spatially. Also, we provide evidence that fluctuations of particle activity are scale-dependent. Two characteristic lengths emerge from the model: a saturation length $\\ell_{sat}$ describing the length needed for a perturbation in particle activity to relax to the homogeneous solution, and a correlation length $\\ell_c$ describing the typical size of moving particle clusters. A dimensionless P\\'eclet number can also be defined according to the transport model. Three different experimental data sets are used to test the theoretica...

  2. Developing Research Agendas on Whole School Improvement Models: The Model Providers' Perspective

    Science.gov (United States)

    Shambaugh, Larisa; Graczewski, Cheryl; Therriault, Susan Bowles; Darwin, Marlene J.

    2007-01-01

    The current education policy environment places a heavy emphasis on scientifically based research. This article examines how whole school improvement models approach the development of a research agenda, including what influences and challenges model providers face in implementing their agenda. Responses also detail the advantages and…

  3. The importance of volume exclusion in modelling cellular migration.

    Science.gov (United States)

    Dyson, Louise; Baker, Ruth E

    2015-09-01

    The modelling of collective migration has traditionally been undertaken in a continuous framework, with little reference to the individual-level mechanisms that give rise to such a concerted movement. One factor whose importance is now coming to light is that the individuals themselves occupy space in the domain, thus obstructing others from moving past them (volume exclusion). In this work, we systematically derive continuous descriptions of cellular migration with volume exclusion for a wide range of individual-based mechanisms and in one, two and three dimensions. We also consider subpopulations of migrating individuals, which may have different characteristics, such as differing sizes and speeds of migration. We demonstrate that volume exclusion is of particular importance when biased movement is included, and thus conclude that volume exclusion may have its greatest effect when considering directed migratory mechanisms such as chemotaxis.

  4. Modeling The Economics Of PACS: What Is Important?

    Science.gov (United States)

    Saarinen, Allan O.; Haynor, David R.; Loop, John W.; Johnson, Linda; Russell, John; Mitchell, Kate; Nemerever, Marilyn

    1989-05-01

    Picture Archive and Communications Systems (PACS) represent a significant long term capital investment for radiology departments and hospitals. Many radiology departments want to acquire this new imaging technology, but they are still concerned about the cost of these systems. While a few studies have tried to quantify the costs and benefits of PACS, these studies have been limited in scope. The University of Washington is evaluating a Digital Imaging Network System (DINS) and PACS for the U.S. Army Medical Research and Development Command. Part of this evaluation includes developing a comprehensive cost model of PACS for one of the military's large health care facilities (a 400 bed hospital). The paper summarizes the methodology and multi-layered spreadsheet model developed at the University to forecast the costs and potential cost savings this health care facility might accrue if a hospital wide PACS is installed and film is eliminated. It also discusses the many important assumptions made in the model. A sensitivity analysis of the model is also presented. The model indicates that keeping PACS maintenance costs down is particularly critical to the cost effectiveness of PACS. That is, the film cost savings attributed to PACS can be largely offset by PACS equipment maintenance cost. The cost effectiveness of PACS will also hinge upon whether a number of intangible benefits, such as referring physician and support staff productivity gains can be attributed to PACS. This model also suggests that the pay back period for a hospital wide PACS will vary significantly dependent upon the mix of tangible versus intangible cost savings incorporated into the modeling process.

  5. Modeling Potential Surface and Shallow Groundwater Storage Provided by Beaver Ponds Across Watersheds

    Science.gov (United States)

    Hafen, K.; Wheaton, J. M.; Macfarlane, W.

    2016-12-01

    Damming of streams by North American Beaver (Castor canadensis) has been shown to provide a host of potentially desirable hydraulic and hydrologic impacts. Notably, increases in surface water storage and groundwater storage may alter the timing and delivery of water around individual dams and dam complexes. Anecdotal evidence suggests these changes may be important for increasing and maintaining baseflow and even helping some intermittent streams flow perennially. In the arid west, these impacts could be particularly salient in the face of climate change. However, few studies have examined the hydrologic impacts of beaver dams at scales large enough to provide insight for water management, in part because understanding or modeling these impacts at large spatial scales has been precluded by uncertainty concerning the number of beaver dams a drainage network can support. Using the recently developed Beaver Restoration Assessment Tool (BRAT) to identify possible densities and spatial configurations of beaver dams, we developed a model that predicts the area and volume of surface water storage associated with dams of various sizes, and applied this model at different dam densities across multiple watersheds (HUC12) in northern Utah. We then used model results as inputs to the MODFLOW groundwater model to identify the subsequent changes to shallow groundwater storage. The spatially explicit water storage estimates produced by our approach will be useful in evaluating potential beaver restoration and conservation, and will also provide necessary information for developing hydrologic models to specifically identify the effects beaver dams may have on water delivery and timing.

  6. Anti-Smoking Communication to Preadolescents with and without a Cancer Diagnosis: Parents and Healthcare Providers as Important Communicators.

    Science.gov (United States)

    Throckmorton-Belzer, Leslee; Tyc, Vida L; Robinson, Leslie A; Klosky, James L; Lensing, Shelly; Booth, Andrea K

    2009-10-01

    A cancer diagnosis does not prevent smoking among pediatric oncology patients, and anti-smoking communications among parents and health care providers have been proposed as influencing smoking outcomes in this group. Anti-smoking communications were compared among 93 preadolescents with cancer and 402 controls. After adjusting for demographics and covariates, preadolescents with cancer were less likely than control participants to report receipt of anti-smoking messages from physicians and parents, and recalled more messages >/= 4 months post-diagnosis as compared to 1-3 months. Should anti-tobacco communications prove to influence smoking outcomes, parents and physicians may be uniquely positioned to provide smoking prevention interventions to these patients.

  7. Medical students' perceptions regarding the importance of nutritional knowledge and their confidence in providing competent nutrition practice.

    Science.gov (United States)

    Perlstein, R; McCoombe, S; Shaw, C; Nowson, C

    2016-11-01

    The objective of this study was to examine the perceived importance, knowledge and confidence in nutritional management in a sample of Australian medical students undertaking a 4-year postgraduate medical degree. In 2015, students in years 1-4 were anonymously surveyed to assess students' perceived importance of nutrition, and knowledge and confidence in nutritional management. A total of 131 first and second year (preclinical/yr 1-2) medical students (46% response rate) and 66 third and fourth year (clinical/yr 3-4) students (24% response rate) completed the questionnaire. Most preclinical students agreed that medical graduates should understand nutritional issues in managing cardiovascular disease (99%), type 2 diabetes (93%), coeliac disease (95%), and renal impairment (97%). However, students were limited in their confidence to demonstrate this knowledge (range of confidence: 26%-41%) for individual medical conditions. This improved for students in the clinical context of years 3 and 4, although it was still not optimal (range 26%-81%). Few year 3 and 4 students reported confidence in knowledge related to medicolegal issues, respiratory disease, nutritional guidelines and nutrition assessment (all 80%) reported confidence in the dietary management of type 2 diabetes, cardiovascular disease and coeliac disease and >60% indicated they would refer onto nutrition professionals. This cohort of postgraduate medical students recognize the importance of nutrition in disease. The number of students reporting increased confidence in nutritional management of a few select diseases where dietary management is one of the cornerstones of treatment (e.g. type 2 diabetes) rises throughout the course. However, students reported lower levels of knowledge in diseases where diet is secondary to other treatments and preventative strategies (e.g. respiratory disease). Filling the gap by integrating the nutritional management into the range of common chronic diseases during training

  8. Parameter sensitivity analysis of stochastic models provides insights into cardiac calcium sparks.

    Science.gov (United States)

    Lee, Young-Seon; Liu, Ona Z; Hwang, Hyun Seok; Knollmann, Bjorn C; Sobie, Eric A

    2013-03-05

    We present a parameter sensitivity analysis method that is appropriate for stochastic models, and we demonstrate how this analysis generates experimentally testable predictions about the factors that influence local Ca(2+) release in heart cells. The method involves randomly varying all parameters, running a single simulation with each set of parameters, running simulations with hundreds of model variants, then statistically relating the parameters to the simulation results using regression methods. We tested this method on a stochastic model, containing 18 parameters, of the cardiac Ca(2+) spark. Results show that multivariable linear regression can successfully relate parameters to continuous model outputs such as Ca(2+) spark amplitude and duration, and multivariable logistic regression can provide insight into how parameters affect Ca(2+) spark triggering (a probabilistic process that is all-or-none in a single simulation). Benchmark studies demonstrate that this method is less computationally intensive than standard methods by a factor of 16. Importantly, predictions were tested experimentally by measuring Ca(2+) sparks in mice with knockout of the sarcoplasmic reticulum protein triadin. These mice exhibit multiple changes in Ca(2+) release unit structures, and the regression model both accurately predicts changes in Ca(2+) spark amplitude (30% decrease in model, 29% decrease in experiments) and provides an intuitive and quantitative understanding of how much each alteration contributes to the result. This approach is therefore an effective, efficient, and predictive method for analyzing stochastic mathematical models to gain biological insight.

  9. The Importance of Computational Modeling of Large Pumping Stations

    Directory of Open Access Journals (Sweden)

    S. M. Bozh'eva

    2015-01-01

    Full Text Available The article presents main design and structure principles of pumping stations. It specifies basic requirements for the favorable hydraulic operation conditions of the pumping units. The article also describes the designing cases, when computational modeling is necessary to analyse activity of pumping station and provide its reliable operation. A specific example of the large pumping station with submersible pumps describes the process of computational modeling of its operation. As the object of simulation was selected the underground pumping station with a diameter of 26 m and a depth of 13 m, divided into two independent branches, equipped with 8 submersible pumps. The objective of this work was to evaluate the effectiveness of the design solution by CFD methods, to analyze the design of the inlet chamber, to identify possible difficulties with the operation of the facility. In details are described the structure of the considered pumping station and applied computational models of physical processes. The article gives the detailed formulation of the task of simulation and the methods of its solving and presents the initial and boundary conditions. It describes the basic operation modes of the pumping station. The obtained results were presented as the flow patterns for each operation mode with detailed explanations. Data obtained as a result of CFD, prove the correctness of the general design solutions of the project. The submersible pump operation at the minimum water level was verified, was confirmed a lack of vortex formation as well as were proposed measures to improve the operating conditions of the facility. In the inlet chamber there are shown the stagnant zones, requiring separate schedule of cleaning. The measure against floating debris and foam was proposed. It justifies the use of computational modeling (CFD for the verifying and adjusting of the projects of large pumping stations as a much more precise tool that takes into account

  10. Providing health messages to Hispanics/Latinos: understanding the importance of language, trust in health information sources, and media use.

    Science.gov (United States)

    Clayman, Marla L; Manganello, Jennifer A; Viswanath, K; Hesse, Bradford W; Arora, Neeraj K

    2010-01-01

    Health communication is critical to promoting healthy lifestyles and preventing unhealthy behaviors. However, populations may differ in terms of their trust in and use of health information sources, including mass media, the Internet, and interpersonal channels. We used the 2005 Health Information National Trends Survey (HINTS) to test the hypothesis that Hispanics who are less comfortable speaking English would differ from Hispanics who are comfortable speaking English with respect to trust in health information sources and media use. Hispanics/Latinos comprised 9% of the 2005 HINTS sample (n = 496). Respondents not born in the United States regardless of race/ethnicity and all Hispanics were asked, "How comfortable do you feel speaking English?" Responses of "completely," "very," or "native speaker" were combined into "comfortable speaking English": all other responses were categorized as "less comfortable speaking English." Those comfortable speaking English reported higher trust for health information from newspapers (p media exposure: daily hours listening to the radio and watching television (both p media, but also because they report relatively little use of various media channels. These findings have important implications for health communications toward non-native speakers of English in general and Hispanics in particular.

  11. Structural Characterization of Mucin O-Glycosylation May Provide Important Information to Help Prevent Colorectal Tumor Recurrence.

    Science.gov (United States)

    Mihalache, Adriana; Delplanque, Jean-François; Ringot-Destrez, Bélinda; Wavelet, Cindy; Gosset, Pierre; Nunes, Bertrand; Groux-Degroote, Sophie; Léonard, Renaud; Robbe-Masselot, Catherine

    2015-01-01

    Although colorectal cancer is a preventable and curable disease if early stage tumors are removed, it still represents the second cause of cancer-related death worldwide. Surgical resection is the only curative treatment but once operated the patient is either subjected to adjuvant chemotherapy or not, depending on the invasiveness of the cancer and risks of recurrence. In this context, we investigated, by mass spectrometry (MS), alterations in the repertoire of glycosylation of mucins from colorectal tumors of various stages, grades, and recurrence status. Tumors were also compared with their counterparts in resection margins from the same patients and with healthy controls. The obtained data showed an important decrease in the level of expression of sialylated core 3-based O-glycans in tumors correlated with an increase in sialylated core 1 structures. No correlation was established between stages of the tumor samples and mucin O-glycosylation. However, with the notable exception of sialyl Tn antigens, tumors with recurrence presented a milder alteration of glycosylation profile than tumors without recurrence. These results suggest that mucin O-glycans from tumors with recurrence might mimic a healthier physiological situation, hence deceiving the immune defense system.

  12. Provide a model to improve the performance of intrusion detection systems in the cloud

    Directory of Open Access Journals (Sweden)

    Foroogh Sedighi

    2016-12-01

    Full Text Available High availability of tools and service providers in cloud computing and the fact that cloud computing services are provided by internet and deal with public, have caused important challenges for new computing model. Cloud computing faces problems and challenges such as user privacy, data security, data ownership, availability of services, and recovery after breaking down, performance, scalability, programmability. So far, many different methods are presented for detection of intrusion in cloud computing. There are two important factors that differentarticlesand researches are presented based on them. These factors are location of establishing intrusion detection systems in cloud computing systems and also algorithms that are used in intrusion detection. Their final goal is maximum coverage of intrusions, increasing the speed and accuracy of intrusion detection, and decreasing of wrong alarms. Our goal in this article is to increase intrusion detection in cloud computing and decrease the rate of generatingfalsealarmsby presenting a combined method.

  13. Winning an important customer. CRM: A recipe for success for energy providers?; Gefragter Kunde. CRM: Ein Erfolgsrezept fuer Energieanbieter?

    Energy Technology Data Exchange (ETDEWEB)

    Grunenberg, J. [BBDO InterOne GmbH, Muenchen (Germany)

    2002-07-01

    Changes in the energy market have forced providers to respond to increased levels of competition and the higher standards expected by today's customers. As a result, a growing number of energy suppliers are now availing of CRM to adapt their business increasingly to suit the needs of their customers. However, success in the field of CRM means more than just introducing new software or restructuring your service centre. It is a holistic strategy, one which has as its goal the gradual but complete overhaul and improvement of customer relationship management practices in all customer-oriented divisions of your company. [German] Der Wandel auf dem Energiemarkt zwingt die Anbieter, sich mehr denn je mit dem verschaerften Wettbewerb und den gestiegenen Anspruechen der Verbraucher auseinander zu setzen. Immer mehr Energieversorger richten deswegen mit gezielten CRM-Massnahmen ihre Geschaeftsprozesse verstaerkt an ihren Kunden aus. Doch erfolgreiches CRM ist mehr als nur eine Software oder die Restrukturierung eines Service-Centers: Es ist eine ganzheitliche Strategie, die eine schrittweise und konsequente Optimierung des Kundenbeziehungsmanagements in allen kundenorientierten Unternehmensbereiche anstrebt.

  14. Examining an important urban transportation management tool: subarea modeling

    Directory of Open Access Journals (Sweden)

    Xueming CHEN

    2009-12-01

    Full Text Available At present, customized subarea models have been widely used in local transportation planning throughout the United States. The biggest strengths of a subarea model lie in its more detailed and accurate modeling outputs which better meet local planning requirements. In addition, a subarea model can substantially reduce database size and model running time. In spite of these advantages, subarea models remain quite weak in maintaining consistency with a regional model, modeling transit projects, smart growth measures, air quality conformity, and other areas. Both opportunities and threats exist for subarea modeling. In addition to examining subarea models, this paper introduces the decision-making process in choosing a proper subarea modeling approach (windowing versus focusing and software package. This study concludes that subarea modeling will become more popular in the future. More GIS applications, travel surveys, transit modeling, microsimulation software utilization, and other modeling improvements are expected to be incorporated into the subarea modeling process.

  15. Importance of Sea Ice for Validating Global Climate Models

    Science.gov (United States)

    Geiger, Cathleen A.

    1997-01-01

    Reproduction of current day large-scale physical features and processes is a critical test of global climate model performance. Without this benchmark, prognoses of future climate conditions are at best speculation. A fundamental question relevant to this issue is, which processes and observations are both robust and sensitive enough to be used for model validation and furthermore are they also indicators of the problem at hand? In the case of global climate, one of the problems at hand is to distinguish between anthropogenic and naturally occuring climate responses. The polar regions provide an excellent testing ground to examine this problem because few humans make their livelihood there, such that anthropogenic influences in the polar regions usually spawn from global redistribution of a source originating elsewhere. Concomitantly, polar regions are one of the few places where responses to climate are non-anthropogenic. Thus, if an anthropogenic effect has reached the polar regions (e.g. the case of upper atmospheric ozone sensitivity to CFCs), it has most likely had an impact globally but is more difficult to sort out from local effects in areas where anthropogenic activity is high. Within this context, sea ice has served as both a monitoring platform and sensitivity parameter of polar climate response since the time of Fridtjof Nansen. Sea ice resides in the polar regions at the air-sea interface such that changes in either the global atmospheric or oceanic circulation set up complex non-linear responses in sea ice which are uniquely determined. Sea ice currently covers a maximum of about 7% of the earth's surface but was completely absent during the Jurassic Period and far more extensive during the various ice ages. It is also geophysically very thin (typically global climate.

  16. Simulation modeling to derive the value-of-information for risky animal disease-import decisions.

    Science.gov (United States)

    Disney, W Terry; Peters, Mark A

    2003-11-12

    Simulation modeling can be used in aiding decision-makers in deciding when to invest in additional research and when the risky animal disease-import decision should go forward. Simulation modeling to evaluate value-of-information (VOI) techniques provides a robust, objective and transparent framework for assisting decision-makers in making risky animal and animal product decisions. In this analysis, the hypothetical risk from poultry disease in chicken-meat imports was modeled. Economic criteria were used to quantify alternative confidence-increasing decisions regarding potential import testing and additional research requirements. In our hypothetical example, additional information about poultry disease in the exporting country (either by requiring additional export-flock surveillance that results in no sign of disease, or by conducting additional research into lack of disease transmittal through chicken-meat ingestion) captured >75% of the value-of-information attainable regarding the chicken-meat-import decision.

  17. Combining models of behaviour with operational data to provide enhanced condition monitoring of AGR cores

    Energy Technology Data Exchange (ETDEWEB)

    West, Graeme M., E-mail: graeme.west@strath.ac.uk; Wallace, Christopher J.; McArthur, Stephen D.J.

    2014-06-01

    Highlights: • Combining laboratory model outputs with operational data. • Isolation of single component from noisy data. • Better understanding of the health of graphite cores. • Extended plant operation through leveraging existing data sources. - Abstract: Installation of new monitoring equipment in Nuclear Power Plants (NPPs) is often difficult and expensive and therefore maximizing the information that can be extracted from existing monitoring equipment is highly desirable. This paper describes the process of combining models derived from laboratory experimentation with current operational plant data to infer an underlying measure of health. A demonstration of this process is provided where the fuel channel bore profile, a measure of core health, is inferred from data gathered during the refuelling process of an Advanced Gas-cooled Reactor (AGR) nuclear power plant core. Laboratory simulation was used to generate a model of an interaction between the fuel assembly and the core. This model is used to isolate a single frictional component from a noisy input signal and use this friction component as a measure of health to assess the current condition of the graphite bricks that comprise the core. In addition, the model is used to generate an expected refuelling response (the noisy input signal) for a given set of channel bore diameter measurements for either insertion of new fuel or removal of spent fuel, providing validation of the model. This benefit of this work is that it provides a greater understanding of the health of the graphite core, which is important for continued and extended operation of the AGR plants in the UK.

  18. Family child care home providers as role models for children: Cause for concern?

    Directory of Open Access Journals (Sweden)

    Alison Tovar

    2017-03-01

    Full Text Available Health behaviors associated with chronic disease, particularly healthy eating and regular physical activity, are important role modeling opportunities for individuals working in child care programs. Prior studies have not explored these risk factors in family child care home (FCCH providers which care for vulnerable and at-risk populations. To address this gap, we describe the socio-demographic and health risk behavior profiles in a sample of providers (n = 166 FCCH taken from baseline data of an ongoing cluster-randomized controlled intervention (2011–2016 in North Carolina. Data were collected during on-site visits where providers completed self-administered questionnaires (socio-demographics, physical activity, fruit and vegetable consumption, number of hours of sleep per night and perceived stress and had their height and weight measured. A risk score (range: 0–6; 0 no risk to 6 high risk was calculated based on how many of the following were present: not having health insurance, being overweight/obese, not meeting physical activity, fruit and vegetable, and sleep recommendations, and having high stress. Mean and frequency distributions of participant and FCCH characteristics were calculated. Close to one third (29.3% of providers reported not having health insurance. Almost all providers (89.8% were overweight or obese with approximately half not meeting guidelines for physical activity, fruit and vegetable consumption, and sleep. Over half reported a “high” stress score. The mean risk score was 3.39 (±1.2, with close to half of the providers having a risk score of 4, 5 or 6 (45.7%. These results stress the need to promote the health of these important care providers.

  19. Relative importance of secondary settling tank models in WWTP simulations

    DEFF Research Database (Denmark)

    Ramin, Elham; Flores-Alsina, Xavier; Sin, Gürkan

    2012-01-01

    Results obtained in a study using the Benchmark Simulation Model No. 1 (BSM1) show that a one-dimensional secondary settling tank (1-D SST) model structure and its parameters are among the most significant sources of uncertainty in wastewater treatment plant (WWTP) simulations [Ramin et al., 2011......]. The sensitivity results consistently indicate that the prediction of sludge production is most sensitive to the variation of the settling parameters. In the present study, we use the Benchmark Simulation Model No. 2 (BSM2), a plant-wide benchmark, that combines the Activated Sludge Model No. 1 (ASM1......) with the Anaerobic Digestion Model No. 1 (ADM1). We use BSM2 as a vehicle to compare two different 1-D SST models, and to assess the relative significance of their performance on WWTP simulation model outputs. The two 1-D SST models assessed include the firstorder model by Takács et al. [1991] and the second...

  20. Wind farms providing secondary frequency regulation: Evaluating the performance of model-based receding horizon control

    Science.gov (United States)

    Shapiro, Carl R.; Meyers, Johan; Meneveau, Charles; Gayme, Dennice F.

    2016-09-01

    We investigate the use of wind farms to provide secondary frequency regulation for a power grid. Our approach uses model-based receding horizon control of a wind farm that is tested using a large eddy simulation (LES) framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and interactions, both of which play an important role in wind farm power production. This controller is implemented in an LES model of an 84-turbine wind farm represented by actuator disk turbine models. Differences between the velocities at each turbine predicted by the wake model and measured in LES are used for closed-loop feedback. The controller is tested on two types of regulation signals, “RegA” and “RegD”, obtained from PJM, an independent system operator in the eastern United States. Composite performance scores, which are used by PJM to qualify plants for regulation, are used to evaluate the performance of the controlled wind farm. Our results demonstrate that the controlled wind farm consistently performs well, passing the qualification threshold for all fastacting RegD signals. For the RegA signal, which changes over slower time scales, the controlled wind farm's average performance surpasses the threshold, but further work is needed to enable the controlled system to achieve qualifying performance all of the time.

  1. On the importance of having accurate data for astrophysical modelling

    Science.gov (United States)

    Lique, Francois

    2016-06-01

    The Herschel telescope and the ALMA and NOEMA interferometers have opened new windows of observation for wavelengths ranging from far infrared to sub-millimeter with spatial and spectral resolutions previously unmatched. To make the most of these observations, an accurate knowledge of the physical and chemical processes occurring in the interstellar and circumstellar media is essential.In this presentation, I will discuss what are the current needs of astrophysics in terms of molecular data and I will show that accurate molecular data are crucial for the proper determination of the physical conditions in molecular clouds.First, I will focus on collisional excitation studies that are needed for molecular lines modelling beyond the Local Thermodynamic Equilibrium (LTE) approach. In particular, I will show how new collisional data for the HCN and HNC isomers, two tracers of star forming conditions, have allowed solving the problem of their respective abundance in cold molecular clouds. I will also present the last collisional data that have been computed in order to analyse new highly resolved observations provided by the ALMA interferometer.Then, I will present the calculation of accurate rate constants for the F+H2 → HF+H and Cl+H2 ↔ HCl+H reactions, which have allowed a more accurate determination of the physical conditions in diffuse molecular clouds. I will also present the recent work on the ortho-para-H2 conversion due to hydrogen exchange that allow more accurate determination of the ortho-to-para-H2 ratio in the universe and that imply a significant revision of the cooling mechanism in astrophysical media.

  2. A general pairwise interaction model provides an accurate description of in vivo transcription factor binding sites.

    Directory of Open Access Journals (Sweden)

    Marc Santolini

    Full Text Available The identification of transcription factor binding sites (TFBSs on genomic DNA is of crucial importance for understanding and predicting regulatory elements in gene networks. TFBS motifs are commonly described by Position Weight Matrices (PWMs, in which each DNA base pair contributes independently to the transcription factor (TF binding. However, this description ignores correlations between nucleotides at different positions, and is generally inaccurate: analysing fly and mouse in vivo ChIPseq data, we show that in most cases the PWM model fails to reproduce the observed statistics of TFBSs. To overcome this issue, we introduce the pairwise interaction model (PIM, a generalization of the PWM model. The model is based on the principle of maximum entropy and explicitly describes pairwise correlations between nucleotides at different positions, while being otherwise as unconstrained as possible. It is mathematically equivalent to considering a TF-DNA binding energy that depends additively on each nucleotide identity at all positions in the TFBS, like the PWM model, but also additively on pairs of nucleotides. We find that the PIM significantly improves over the PWM model, and even provides an optimal description of TFBS statistics within statistical noise. The PIM generalizes previous approaches to interdependent positions: it accounts for co-variation of two or more base pairs, and predicts secondary motifs, while outperforming multiple-motif models consisting of mixtures of PWMs. We analyse the structure of pairwise interactions between nucleotides, and find that they are sparse and dominantly located between consecutive base pairs in the flanking region of TFBS. Nonetheless, interactions between pairs of non-consecutive nucleotides are found to play a significant role in the obtained accurate description of TFBS statistics. The PIM is computationally tractable, and provides a general framework that should be useful for describing and predicting

  3. Antibody VH and VL recombination using phage and ribosome display technologies reveals distinct structural routes to affinity improvements with VH-VL interface residues providing important structural diversity.

    Science.gov (United States)

    Groves, Maria A T; Amanuel, Lily; Campbell, Jamie I; Rees, D Gareth; Sridharan, Sudharsan; Finch, Donna K; Lowe, David C; Vaughan, Tristan J

    2014-01-01

    In vitro selection technologies are an important means of affinity maturing antibodies to generate the optimal therapeutic profile for a particular disease target. Here, we describe the isolation of a parent antibody, KENB061 using phage display and solution phase selections with soluble biotinylated human IL-1R1. KENB061 was affinity matured using phage display and targeted mutagenesis of VH and VL CDR3 using NNS randomization. Affinity matured VHCDR3 and VLCDR3 library blocks were recombined and selected using phage and ribosome display protocol. A direct comparison of the phage and ribosome display antibodies generated was made to determine their functional characteristics.In our analyses, we observed distinct differences in the pattern of beneficial mutations in antibodies derived from phage and ribosome display selections, and discovered the lead antibody Jedi067 had a ~3700-fold improvement in KD over the parent KENB061. We constructed a homology model of the Fv region of Jedi067 to map the specific positions where mutations occurred in the CDR3 loops. For VL CDR3, positions 94 to 97 carry greater diversity in the ribosome display variants compared with the phage display. The positions 95a, 95b and 96 of VLCDR3 form part of the interface with VH in this model. The model shows that positions 96, 98, 100e, 100f, 100 g, 100h, 100i and 101 of the VHCDR3 include residues at the VH and VL interface. Importantly, Leu96 and Tyr98 are conserved at the interface positions in both phage and ribosome display indicating their importance in maintaining the VH-VL interface. For antibodies derived from ribosome display, there is significant diversity at residues 100a to 100f of the VH CDR3 compared with phage display. A unique deletion of isoleucine at position 102 of the lead candidate, Jedi067, also occurs in the VHCDR3.As anticipated, recombining the mutations via ribosome display led to a greater structural diversity, particularly in the heavy chain CDR3, which in turn

  4. Importance of Computer Model Validation in Pyroprocessing Technology Development

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y. E.; Li, Hui; Yim, M. S. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    In this research, we developed a plan for experimental validation of one of the computer models developed for ER process modeling, i. e., the ERAD code. Several candidate surrogate materials are selected for the experiment considering the chemical and physical properties. Molten salt-based pyroprocessing technology is being examined internationally as an alternative to treat spent nuclear fuel over aqueous technology. The central process in pyroprocessing is electrorefining(ER) which separates uranium from transuranic elements and fission products present in spent nuclear fuel. ER is a widely used process in the minerals industry to purify impure metals. Studies of ER by using actual spent nuclear fuel materials are problematic for both technical and political reasons. Therefore, the initial effort for ER process optimization is made by using computer models. A number of models have been developed for this purpose. But as validation of these models is incomplete and often times problematic, the simulation results from these models are inherently uncertain.

  5. Important limitations in the modeling of activated sludge : biased calibration of the hydrolysis process

    DEFF Research Database (Denmark)

    Insel, G.; Gul, Ö.K.; Orhon, D.

    2002-01-01

    ), provides the majority of the required experimental database. However, currently used procedures still involve a number of basic and practical problems. Model evaluation of the OUR data may generate a distorted image of the processes involved. Hydrolysis is the most important, yet the most vulnerable...... process as far as the experimental assessment of accurate kinetic parameters is concerned. This study intends to provide an overview of major experimental limitations in the modeling of activated sludge, with emphasis on the appropriate experimental design for the assessment of the hydrolysis rate....

  6. On the importance of hysteresis in hydrological modeling

    Science.gov (United States)

    Gharari, S.; Razavi, S.

    2016-12-01

    Hysteresis is a widely observed phenomenon in hydrology and beyond at a range of spatio-temporal scales. Despite significant research efforts, hysteretic behaviors and their implications for hydrologic modelling and prediction have remained poorly defined and understood. The current state of the art is that almost all practical models in use do not include any hysteretic component or relationship that directly represents such behaviors. In this study, we review different types of hysteretic behaviors in hydrology and formulate a general definition for hysteresis that might be useful in the context of hydrological modeling. We show how hysteresis can be the result of missing (or ignoring) dimensions/physics that govern a real system. Further, using existing strategies for hysteresis modeling from other disciples, we evaluate to what extent the addition of hysteretic components to a hydrological model (such as soil moisture and soil suction head - soil hydraulic conductivity) change the model performance and associated uncertainties. Our analyses also show that properly designed model structures can largely compensate for the lack of hysteretic components in models and allow mimicking the observed hysteretic behaviors.

  7. On the importance of conserving mass in sea ice models

    CERN Document Server

    Moon, Woosok

    2013-01-01

    We describe how a long standing approach used in the thermodynamic modeling of sea ice fails to conserve mass. The missing mass is traced to a term that is equivalent to neglecting a leading order latent heat flux and we demonstrate its influence using energy balance models with a fractional ice cover. It is shown that this neglect is particularly acute in a decaying ice cover approaching the transitions to seasonal and ice-free conditions. Accordingly, it is suggested that it may be of considerable relevance to re-examine the relevant climate model schemes.

  8. Clinic expert information extraction based on domain model and block importance model.

    Science.gov (United States)

    Zhang, Yuanpeng; Wang, Li; Qian, Danmin; Geng, Xingyun; Yao, Dengfu; Dong, Jiancheng

    2015-11-01

    To extract expert clinic information from the Deep Web, there are two challenges to face. The first one is to make a judgment on forms. A novel method based on a domain model, which is a tree structure constructed by the attributes of query interfaces is proposed. With this model, query interfaces can be classified to a domain and filled in with domain keywords. Another challenge is to extract information from response Web pages indexed by query interfaces. To filter the noisy information on a Web page, a block importance model is proposed, both content and spatial features are taken into account in this model. The experimental results indicate that the domain model yields a precision 4.89% higher than that of the rule-based method, whereas the block importance model yields an F1 measure 10.5% higher than that of the XPath method.

  9. The climate4impact platform: Providing, tailoring and facilitating climate model data access

    Science.gov (United States)

    Pagé, Christian; Pagani, Andrea; Plieger, Maarten; Som de Cerff, Wim; Mihajlovski, Andrej; de Vreede, Ernst; Spinuso, Alessandro; Hutjes, Ronald; de Jong, Fokke; Bärring, Lars; Vega, Manuel; Cofiño, Antonio; d'Anca, Alessandro; Fiore, Sandro; Kolax, Michael

    2017-04-01

    One of the main objectives of climate4impact is to provide standardized web services and tools that are reusable in other portals. These services include web processing services, web coverage services and web mapping services (WPS, WCS and WMS). Tailored portals can be targeted to specific communities and/or countries/regions while making use of those services. Easier access to climate data is very important for the climate change impact communities. To fulfill this objective, the climate4impact (http://climate4impact.eu/) web portal and services has been developed, targeting climate change impact modellers, impact and adaptation consultants, as well as other experts using climate change data. It provides to users harmonized access to climate model data through tailored services. It features static and dynamic documentation, Use Cases and best practice examples, an advanced search interface, an integrated authentication and authorization system with the Earth System Grid Federation (ESGF), a visualization interface with ADAGUC web mapping tools. In the latest version, statistical downscaling services, provided by the Santander Meteorology Group Downscaling Portal, were integrated. An innovative interface to integrate statistical downscaling services will be released in the upcoming version. The latter will be a big step in bridging the gap between climate scientists and the climate change impact communities. The climate4impact portal builds on the infrastructure of an international distributed database that has been set to disseminate the results from the global climate model results of the Coupled Model Intercomparison project Phase 5 (CMIP5). This database, the ESGF, is an international collaboration that develops, deploys and maintains software infrastructure for the management, dissemination, and analysis of climate model data. The European FP7 project IS-ENES, Infrastructure for the European Network for Earth System modelling, supports the European

  10. Exploratory regression analysis: a tool for selecting models and determining predictor importance.

    Science.gov (United States)

    Braun, Michael T; Oswald, Frederick L

    2011-06-01

    Linear regression analysis is one of the most important tools in a researcher's toolbox for creating and testing predictive models. Although linear regression analysis indicates how strongly a set of predictor variables, taken together, will predict a relevant criterion (i.e., the multiple R), the analysis cannot indicate which predictors are the most important. Although there is no definitive or unambiguous method for establishing predictor variable importance, there are several accepted methods. This article reviews those methods for establishing predictor importance and provides a program (in Excel) for implementing them (available for direct download at http://dl.dropbox.com/u/2480715/ERA.xlsm?dl=1) . The program investigates all 2(p) - 1 submodels and produces several indices of predictor importance. This exploratory approach to linear regression, similar to other exploratory data analysis techniques, has the potential to yield both theoretical and practical benefits.

  11. The importance of structural model availability on seismic interpretation

    Science.gov (United States)

    Alcalde, Juan; Bond, Clare E.; Johnson, Gareth; Butler, Robert W. H.; Cooper, Mark A.; Ellis, Jennifer F.

    2017-04-01

    Interpretation of faults in seismic images is central to the creation of geological models of the subsurface. The use of prior knowledge acquired through learning allows interpreters to move from singular observations to reasoned interpretations based on the conceptual models available to them. The amount and variety of fault examples available in textbooks, articles and training exercises is therefore likely to be a determinant factor in the interpreters' ability to interpret realistic fault geometries in seismic data. We analysed the differences in fault type and geometry interpreted in seismic data by students before and after completing a masters module in structural geology, and compared them to the characteristics of faults represented in the module and textbooks. We propose that the observed over-representation of normal-planar faults in early teaching materials influences the interpretation of data, making this fault type and geometry dominant in the pre-module interpretations. However, when the students were exposed to a greater range in fault models in the module, the range of fault type and geometry increased. This work explores the role of model availability in interpretation and advocates for the use of realistic fault models in training materials.

  12. Exact travelling wave solutions for some important nonlinear physical models

    Indian Academy of Sciences (India)

    Jonu Lee; Rathinasamy Sakthivel

    2013-05-01

    The two-dimensional nonlinear physical models and coupled nonlinear systems such as Maccari equations, Higgs equations and Schrödinger–KdV equations have been widely applied in many branches of physics. So, finding exact travelling wave solutions of such equations are very helpful in the theories and numerical studies. In this paper, the Kudryashov method is used to seek exact travelling wave solutions of such physical models. Further, three-dimensional plots of some of the solutions are also given to visualize the dynamics of the equations. The results reveal that the method is a very effective and powerful tool for solving nonlinear partial differential equations arising in mathematical physics.

  13. Importance of Dynamic Inflow Model Predictive Control of Wind Turbines

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Knudsen, Torben; Overgaard, Anders;

    2015-01-01

    The efficiency of including dynamic inflow in the model based design of wind turbine controller has been discussed for many years in the wind energy community with out getting to a safe conclusion. This paper delivers a good argument in favor of including dynamic inflow. The main contributions...

  14. Social Importance Dynamics: A Model for Culturally-Adaptive Agents

    NARCIS (Netherlands)

    Mascarenhas, S.; Prada, R.; Paiva, A.; Hofstede, G.J.

    2013-01-01

    The unwritten rules of human cultures greatly affect social behaviour and as such should be considered in the development of socially intelligent agents. So far, there has been a large focus on modeling cultural aspects related to non-verbal behaviour such as gaze or body posture. However, culture a

  15. The Importance of Formalizing Computational Models of Face Adaptation Aftereffects

    Science.gov (United States)

    Ross, David A.; Palmeri, Thomas J.

    2016-01-01

    Face adaptation is widely used as a means to probe the neural representations that support face recognition. While the theories that relate face adaptation to behavioral aftereffects may seem conceptually simple, our work has shown that testing computational instantiations of these theories can lead to unexpected results. Instantiating a model of face adaptation not only requires specifying how faces are represented and how adaptation shapes those representations but also specifying how decisions are made, translating hidden representational states into observed responses. Considering the high-dimensionality of face representations, the parallel activation of multiple representations, and the non-linearity of activation functions and decision mechanisms, intuitions alone are unlikely to succeed. If the goal is to understand mechanism, not simply to examine the boundaries of a behavioral phenomenon or correlate behavior with brain activity, then formal computational modeling must be a component of theory testing. To illustrate, we highlight our recent computational modeling of face adaptation aftereffects and discuss how models can be used to understand the mechanisms by which faces are recognized. PMID:27378960

  16. On the importance of local connectivity for internet topology models

    NARCIS (Netherlands)

    Haddadi, H.; Fay, D.; Jamakovic, A.; Maennel, O.; Moore, A.W.; Mortier, R.; Uhlig, S.

    2009-01-01

    Existing models for Internet Autonomous System (AS) topology generation make structural assumptions about the AS graph. Those assumptions typically stem from beliefs about the true properties of the Internet, e.g. hierarchy and powerlaws, which arise from incorrect interpretations of incomplete obse

  17. Risks, Benefits, and Importance of Collecting Sexual Orientation and Gender Identity Data in Healthcare Settings: A Multi-Method Analysis of Patient and Provider Perspectives.

    Science.gov (United States)

    Maragh-Bass, Allysha C; Torain, Maya; Adler, Rachel; Schneider, Eric; Ranjit, Anju; Kodadek, Lisa M; Shields, Ryan; German, Danielle; Snyder, Claire; Peterson, Susan; Schuur, Jeremiah; Lau, Brandyn; Haider, Adil H

    2017-04-01

    Research suggests that LGBT populations experience barriers to healthcare. Organizations such as the Institute of Medicine recommend routine documentation of sexual orientation (SO) and gender identity (GI) in healthcare, to reduce LGBT disparities. We explore patient views regarding the importance of SO/GI collection, and patient and provider views on risks and benefits of routine SO/GI collection in various settings. We surveyed LGBT/non-LGBT patients and providers on their views on SO/GI collection. Weighted data were analyzed with descriptive statistics; content analysis was conducted with open-ended responses. One-half of the 1516 patients and 60% of 429 providers were female; 64% of patients and 71% of providers were White. Eighty percent of providers felt that collecting SO data would offend patients, whereas only 11% of patients reported that they would be offended. Patients rated it as more important for primary care providers to know the SO of all patients compared with emergency department (ED) providers knowing the SO of all patients (41.3% vs. 31.6%; P discrimination risk most frequently (49.7%; N = 781), whereas provider comments cited patient discomfort/offense most frequently (54.5%; N = 433). Patients see the importance of SO/GI more in primary care than ED settings. However, many LGBT patients seek ED care due to factors including uninsurance; therefore, the ED may represent an initial point of contact for SO/GI collection. Therefore, patient-centered approaches to collecting SO/GI are needed. Patients and providers differed in perceived risks and benefits to routine SO/GI collection. Provider training in LGBT health may address patients' bias/discrimination concerns, and ultimately reduce LGBT health disparities.

  18. ASYMMETRIC PRICE TRANSMISSION MODELING: THE IMPORTANCE OF MODEL COMPLEXITY AND THE PERFORMANCE OF THE SELECTION CRITERIA

    Directory of Open Access Journals (Sweden)

    Henry de-Graft Acquah

    2013-01-01

    Full Text Available Information Criteria provides an attractive basis for selecting the best model from a set of competing asymmetric price transmission models or theories. However, little is understood about the sensitivity of the model selection methods to model complexity. This study therefore fits competing asymmetric price transmission models that differ in complexity to simulated data and evaluates the ability of the model selection methods to recover the true model. The results of Monte Carlo experimentation suggest that in general BIC, CAIC and DIC were superior to AIC when the true data generating process was the standard error correction model, whereas AIC was more successful when the true model was the complex error correction model. It is also shown that the model selection methods performed better in large samples for a complex asymmetric data generating process than with a standard asymmetric data generating process. Except for complex models, AIC's performance did not make substantial gains in recovery rates as sample size increased. The research findings demonstrate the influence of model complexity in asymmetric price transmission model comparison and selection.

  19. An Extension of the Rasch Model for Ratings Providing Both Location and Dispersion Parameters.

    Science.gov (United States)

    Andrich, David

    1982-01-01

    An elaboration of a psychometric model for rated data, which belongs to the class of Rasch models, is shown to provide a model with two parameters, one characterizing location and one characterizing dispersion. Characteristics of the dispersion parameter are discussed. (Author/JKS)

  20. Factors Determinants the Choice of Mobile Service Providers: Structural Equation Modeling Approach on Bangladeshi Consumers

    Directory of Open Access Journals (Sweden)

    Ahasanul Haque

    2010-07-01

    Full Text Available The aim of this study is to find out what were the factors that may have played significant role to select the telecommunication service providers. In general this research has an intention to develop a research framework grounded on a strong theoretical and literature review background. The survey instruments employed on Bangladeshi consumers included demographic background, price, service quality, product quality and availability and promotional offers for consumer perception. Thus the structural equation modeling approach was necessary in order to examine the variables. The data analysis was conducted using SPSS and AMOS (Analysis of Moment Structure with the software package for windows. From the result it is revealed that paths are related to the casual processes significantly. Among all the significant variables, from our result, Price is the most important among our respondents followed by Service quality, product quality and promotion. Further research should be considered to gather more information regarding the service quality and customers’ satisfaction dimensions in context of the Bangladeshi mobile phone operators. It is hoped that the findings of this study may assist mobile phone industry in Bangladesh about their services and promotion of their services. However, the findings of this study may provide needed feedback and contribute to the improvement of players’ strategy and their marketing program

  1. Providing a Security Model Based on Service Oriented Architecture in Electronic Banking

    Directory of Open Access Journals (Sweden)

    Sima Emadi

    2013-10-01

    Full Text Available With the increasing advances in IT world and the use of distributed systems, complexity and performance ofapplications have also changed. Banks require proper cooperation and integration among organizational systems toprovide effective and correct services. On the other hand, they contain diverse and heterogeneous infrastructures,applications and systems. Cooperation and integration among these systems require interactions and informationsharing among the users. The service-oriented architecture is the latest generation of information systems'architecture and has become quickly inclusive in recent years. One of the important features of this architecture isthe numerous users of different subsystems and their communication and cooperation in activities. In thisarchitecture, resources and services are often provided in sharing for different users. But, such features in serviceorientedarchitecture have brought about some challenges to the technology, one of which is 'the security'. Theneed for a security model in service-oriented architecture seems essential due to the distributed nature of thearchitecture, its reusability and accessibility. In this model, security requirements and standards for different layersare studied.

  2. Providing Real-time Sea Ice Modeling Support to the U.S. Coast Guard

    Science.gov (United States)

    Allard, Richard; Dykes, James; Hebert, David; Posey, Pamela; Rogers, Erick; Wallcraft, Alan; Phelps, Michael; Smedstad, Ole Martin; Wang, Shouping; Geiszler, Dan

    2016-04-01

    The Naval Research Laboratory (NRL) supported the U.S. Coast Guard Research Development Center (RDC) through a demonstration project during the summer and autumn of 2015. Specifically, a modeling system composed of a mesoscale atmospheric model, regional sea ice model, and regional wave model were loosely coupled to provide real-time 72-hr forecasts of environmental conditions for the Beaufort/Chukchi Seas. The system components included a 2-km regional Community Ice CodE (CICE) sea ice model, 15-km Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS) atmospheric model, and a 5-km regional WAVEWATCH III wave model. The wave model utilized modeled sea ice concentration fields to incorporate the effects of sea ice on waves. The other modeling components assimilated atmosphere, ocean, and ice observations available from satellite and in situ sources. The modeling system generated daily 72-hr forecasts of synoptic weather (including visibility), ice drift, ice thickness, ice concentration and ice strength for missions within the economic exclusion zone off the coast of Alaska and a transit to the North Pole in support of the National Science Foundation GEOTRACES cruise. Model forecasts graphics were shared on a common web page with selected graphical products made available via ftp for bandwidth limited users. Model ice thickness and ice drift show very good agreement compared with Cold Regions Research and Engineering Laboratory (CRREL) Ice Mass Balance buoys. This demonstration served as a precursor to a fully coupled atmosphere-ocean-wave-ice modeling system under development. National Ice Center (NIC) analysts used these model data products (CICE and COAMPS) along with other existing model and satellite data to produce the predicted 48-hr position of the ice edge. The NIC served as a liaison with the RDC and NRL to provide feedback on the model predictions. This evaluation provides a baseline analysis of the current models for future comparison studies

  3. The Role of Logistics Service Providers in the Distribution Channel of Imported Perishable and Processed Food Product to Java Island, Indonesia

    OpenAIRE

    Tanuputri, Megita Ryanjani; Chaveesuk, Ravipim; Guritno, Adi Djoko

    2017-01-01

    Today fierce competition has highly enforced the company to focus more on their core competency and has encouraged them to strengthen competitive advantage. This condition reinforces the role of logistics service providers (LSP) to help company run their supporting activities. This research aims to identify the characteristics of LSP and to analyze their role in the distribution channel of imported perishable and processed food products in Indonesia. Convenience sampling was employed as sampl...

  4. Resampling: An improvement of importance sampling in varying population size models.

    Science.gov (United States)

    Merle, C; Leblois, R; Rousset, F; Pudlo, P

    2017-04-01

    Sequential importance sampling algorithms have been defined to estimate likelihoods in models of ancestral population processes. However, these algorithms are based on features of the models with constant population size, and become inefficient when the population size varies in time, making likelihood-based inferences difficult in many demographic situations. In this work, we modify a previous sequential importance sampling algorithm to improve the efficiency of the likelihood estimation. Our procedure is still based on features of the model with constant size, but uses a resampling technique with a new resampling probability distribution depending on the pairwise composite likelihood. We tested our algorithm, called sequential importance sampling with resampling (SISR) on simulated data sets under different demographic cases. In most cases, we divided the computational cost by two for the same accuracy of inference, in some cases even by one hundred. This study provides the first assessment of the impact of such resampling techniques on parameter inference using sequential importance sampling, and extends the range of situations where likelihood inferences can be easily performed.

  5. Importance of demand modelling in network water quality models: a review

    Directory of Open Access Journals (Sweden)

    J. C. van Dijk

    2008-09-01

    Full Text Available Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological contaminant propagation; for particulate substances it is in sediment leading to discolouration. There is a strong influence of flows and velocities on transport, mixing, production and decay of these substances in the network. This imposes a different approach to demand modelling which is reviewed in this article.

    For the large diameter lines that comprise the transport portion of a typical municipal pipe system, a skeletonised network model with a top-down approach of demand pattern allocation, a hydraulic time step of 1 h, and a pure advection-reaction water quality model will usually suffice. For the smaller diameter lines that comprise the distribution portion of a municipal pipe system, an all-pipes network model with a bottom-up approach of demand pattern allocation, a hydraulic time step of 1 min or less, and a water quality model that considers dispersion and transients may be needed.

    Demand models that provide stochastic residential demands per individual home and on a one-second time scale are available. A stochastic demands based network water quality model needs to be developed and validated with field measurements. Such a model will be probabilistic in nature and will offer a new perspective for assessing water quality in the drinking water distribution system.

  6. The Import of Trust in Regular Providers to Trust in Cancer Physicians among White, African American, and Hispanic Breast Cancer Patients

    Science.gov (United States)

    Rauscher, Garth H.; Jacobs, Elizabeth A.; Strenski, Teri A.; Estwing Ferrans, Carol; Warnecke, Richard B.

    2010-01-01

    BACKGROUND Interpersonal trust is an important component of the patient-doctor relationship. Little is known about patients’ trust in the multiple providers seen when confronting serious illness. OBJECTIVES To characterize breast cancer patients’ trust in their regular providers, diagnosing physicians, and cancer treatment team and examine whether high trust in one’s regular provider confers high trust to cancer physicians. DESIGN In-person interviews. PARTICIPANTS 704 white, black, and Hispanic breast cancer patients, age 30 to 79, with a first primary in situ or invasive breast cancer who reported having a regular provider. MEASURES We measure trust in: (1) regular provider, (2) diagnosing doctors, and (3) cancer treatment team. Other variables include demographic variables, preventive health care, comorbidities, time with regular provider, time since diagnosis, cancer stage, and treatment modality. RESULTS Sixty-five percent of patients reported high trust in their regular provider, 84% indicated high trust in their diagnosing doctors, and 83% reported high trust in their treatment team. Women who reported high trust in their regular provider were significantly more likely to be very trusting of diagnosing doctors (OR: 3.44, 95% CI: 2.27–5.21) and cancer treatment team (OR: 3.09, 95% CI: 2.02–4.72 ). Black women were significantly less likely to be very trusting of their regular doctor (OR: 0.58, 95% CI: 0.38–0.88) and cancer treatment team (OR: 0.45, 95% CI: 0.25–0.80). English-speaking Hispanic women were significantly less trusting of their diagnosing doctors (OR: 0.29, 95% CI: 0.11–0.80). CONCLUSIONS Our results suggest that patients are very trusting of their breast cancer providers. This is an important finding given that research with other populations has shown an association between trust and patient satisfaction and treatment adherence. Our findings also suggest that a trusting relationship with a regular provider facilitates trusting

  7. Model of mechanism of providing of strategic firmness of machine-building enterprise

    Directory of Open Access Journals (Sweden)

    I.V. Movchan

    2011-03-01

    Full Text Available In the article is considered theoretical aspects of strategic firmness and the developed algorithmic model of mechanism providing of strategic firmness of machine-building enterprise.

  8. Cameroon mid-level providers offer a promising public health dentistry model

    Directory of Open Access Journals (Sweden)

    Achembong Leo

    2012-11-01

    Full Text Available Background Oral health services are inadequate and unevenly distributed in many developing countries, particularly those in sub-Saharan Africa. Rural areas in these countries and poorer sections of the population in urban areas often do not have access to oral health services mainly because of a significant shortage of dentists and the high costs of care. We reviewed Cameroon’s experience with deploying a mid-level cadre of oral health professionals and the feasibility of establishing a more formal and predictable role for these health workers. We anticipate that a task-shifting approach in the provision of dental care will significantly improve the uneven distribution of oral health services particularly in the rural areas of Cameroon, which is currently served by only 3% of the total number of dentists. Methods The setting of this study was the Cameroon Baptist Convention Health Board (BCHB, which has four dentists and 42 mid-level providers. De-identified data were collected manually from the registries of 10 Baptist Convention clinics located in six of Cameroon’s 10 regions and then entered into an Excel format before importing into STATA. A retrospective abstraction of all entries for patient visits starting October 2010, and going back in time until 1500 visits were extracted from each clinic. Results This study showed that mid-level providers in BCHB clinics are offering a full scope of dental work across the 10 clinics, with the exception of treatment for major facial injuries. Mid-level providers alone performed 93.5% of all extractions, 87.5% of all fillings, 96.5% of all root canals, 97.5% of all cleanings, and 98.1% of all dentures. The dentists also typically played a teaching role in training the mid-level providers. Conclusions The Ministry of Health in Cameroon has an opportunity to learn from the BCHB model to expand access to oral health care across the country. This study shows the benefits of using a simple, workable, low

  9. Effectiveness of Video Modeling Provided by Mothers in Teaching Play Skills to Children with Autism

    Science.gov (United States)

    Besler, Fatma; Kurt, Onur

    2016-01-01

    Video modeling is an evidence-based practice that can be used to provide instruction to individuals with autism. Studies show that this instructional practice is effective in teaching many types of skills such as self-help skills, social skills, and academic skills. However, in previous studies, videos used in the video modeling process were…

  10. Building the Bridge between Operations and Outcomes : Modelling and Evaluation of Health Service Provider Networks

    NARCIS (Netherlands)

    M. Mahdavi (Mahdi)

    2015-01-01

    markdownabstract__Abstract__ The PhD research has two objectives: - To develop generally applicable operational models which allow developing the evidence base for health service operations in provider networks. - To contribute to the evidence base by validating the model through application to hea

  11. Importance of demand modelling in network water quality models: a review

    Directory of Open Access Journals (Sweden)

    J. C. van Dijk

    2008-01-01

    Full Text Available Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances, with the main interest in residual chlorine and (microbiological contaminant propagation, respectively in sediment leading to discolouration. There is a strong influence of flows and velocities on transport, mixing, production and decay of these substances in the network. This imposes a different approach to demand modelling which is reviewed in this article.

    For transport systems the current hydraulic models suffice; for the more detailed distribution system a network water quality model is needed that is based on short time scale demands that considers the effect of dispersion and transients. Demand models that provide stochastic residential demands per individual home and on a one-second time scale are available. A stochastic demands based network water quality model needs to be developed and validated with field measurements. Such a model will be probabilistic in nature and will offer a new perspective for assessing water quality in the DWDS.

  12. Assessing the importance of demographic parameters for population dynamics using Bayesian integrated population modeling.

    Science.gov (United States)

    Eacker, Daniel R; Lukacs, Paul M; Proffitt, Kelly M; Hebblewhite, Mark

    2017-06-01

    To successfully respond to changing habitat, climate or harvest, managers need to identify the most effective strategies to reverse population trends of declining species and/or manage harvest of game species. A classic approach in conservation biology for the last two decades has been the use of matrix population models to determine the most important vital rates affecting population growth rate (λ), that is, sensitivity. Ecologists quickly realized the critical role of environmental variability in vital rates affecting λ by developing approaches such as life-stage simulation analysis (LSA) that account for both sensitivity and variability of a vital rate. These LSA methods used matrix-population modeling and Monte Carlo simulation methods, but faced challenges in integrating data from different sources, disentangling process and sampling variation, and in their flexibility. Here, we developed a Bayesian integrated population model (IPM) for two populations of a large herbivore, elk (Cervus canadensis) in Montana, USA. We then extended the IPM to evaluate sensitivity in a Bayesian framework. We integrated known-fate survival data from radio-marked adults and juveniles, fecundity data, and population counts in a hierarchical population model that explicitly accounted for process and sampling variance. Next, we tested the prevailing paradigm in large herbivore population ecology that juvenile survival of neonates modeling in a Bayesian framework can provide multiple advantages. Our Bayesian LSA framework will provide a useful approach to addressing conservation challenges across a variety of species and data types. © 2017 by the Ecological Society of America.

  13. How important is a detailed hydrological representation when modelling soil carbon dynamics in Chinese red soils.

    Science.gov (United States)

    Oyesiku-Blakemore, Joseph; Verrot, Lucile; Geris, Josie; Zhang, Ganlin; Peng, Xinhua; Hallett, Paul; Smith, Jo

    2017-04-01

    Soil carbon and nitrogen processing are strongly influenced by the hydrology of soils. When simulating these processes models represent soil hydrology in some way. The hydrological components of soil carbon and nitrogen models vary greatly in their complexity, as does the burden of simulation time and data requirements. Hydrology specific models, such as Hydrus, have more detailed representations of soil hydrology than those used in some soil carbon and nitrogen models, such as ECOSSE, and can provide a more accurate and precise description of the movement and content of water in soil. Moisture content is one of the key variables controlling the processing of carbon and nitrogen in soil models. A higher soil moisture content results in increased methane production through the anaerobic decomposition of soil carbon pools. It also alters the rate at which aerobic decomposition occurs, with low and high soil moisture contents limiting the decomposition of SOC. An inaccurate estimate of soil moisture will introduce errors in the estimated rates of model SOC transformations, which would result in errors in the simulated SOC. In order to shed light on this uncertainty we use the same input data to simulate soil moisture contents in a Red Soil region of China, using both the ECOSSE model and Hydrus 2D. We compare the simulations of both models with measurements of soil moisture at the site and each other. We highlight where the models differ and identify the conditions under which errors are likely to occur. We then simulate SOC dynamics using the ECOSSE model and its original hydrology with the ECOSSE model simulations using the Hydrus 2D simulations. This shows the importance of including a detailed representation of soil moisture when simulating soil organic matter dynamics.

  14. Colicin import into E. coli cells: a model system for insights into the import mechanisms of bacteriocins.

    Science.gov (United States)

    Kim, Young Chan; Tarr, Alexander W; Penfold, Christopher N

    2014-08-01

    Bacteriocins are a diverse group of ribosomally synthesized protein antibiotics produced by most bacteria. They range from small lanthipeptides produced by lactic acid bacteria to much larger multi domain proteins of Gram negative bacteria such as the colicins from Escherichia coli. For activity bacteriocins must be released from the producing cell and then bind to the surface of a sensitive cell to instigate the import process leading to cell death. For over 50years, colicins have provided a working platform for elucidating the structure/function studies of bacteriocin import and modes of action. An understanding of the processes that contribute to the delivery of a colicin molecule across two lipid membranes of the cell envelope has advanced our knowledge of protein-protein interactions (PPI), protein-lipid interactions and the role of order-disorder transitions of protein domains pertinent to protein transport. In this review, we provide an overview of the arrangement of genes that controls the synthesis and release of the mature protein. We examine the uptake processes of colicins from initial binding and sequestration of binding partners to crossing of the outer membrane, and then discuss the translocation of colicins through the cell periplasm and across the inner membrane to their cytotoxic site of action. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.

  15. Evaluation of factors important in modeling plasma concentrations of tetracycline hydrochloride administered in water in swine.

    Science.gov (United States)

    Mason, Sharon E; Almond, Glen W; Riviere, Jim E; Baynes, Ronald E

    2012-10-01

    To model the plasma tetracycline concentrations in swine (Sus scrofa domestica) treated with medication administered in water and determine the factors that contribute to the most accurate predictions of measured plasma drug concentrations. Plasma tetracycline concentrations measured in blood samples from 3 populations of swine. Data from previous studies provided plasma tetracycline concentrations that were measured in blood samples collected from 1 swine population at 0, 4, 8, 12, 24, 32, 48, 56, 72, 80, 96, and 104 hours and from 2 swine populations at 0, 12, 24, 48, and 72 hours hours during administration of tetracycline hydrochloride dissolved in water. A 1-compartment pharmacostatistical model was used to analyze 5 potential covariate schemes and determine factors most important in predicting the plasma concentrations of tetracycline in swine. 2 models most accurately predicted the tetracycline plasma concentrations in the 3 populations of swine. Factors of importance were body weight or age of pig, ambient temperature, concentration of tetracycline in water, and water use per unit of time. The factors found to be of importance, combined with knowledge of the individual pharmacokinetic and chemical properties of medications currently approved for administration in water, may be useful in more prudent administration of approved medications administered to swine. Factors found to be important in pharmacostatistical models may allow prediction of plasma concentrations of tetracycline or other commonly used medications administered in water. The ability to predict in vivo concentrations of medication in a population of food animals can be combined with bacterial minimum inhibitory concentrations to decrease the risk of developing antimicrobial resistance.

  16. Structural equation modelling of determinants of customer satisfaction of mobile network providers: Case of Kolkata, India

    Directory of Open Access Journals (Sweden)

    Shibashish Chakraborty

    2014-12-01

    Full Text Available The Indian market of mobile network providers is growing rapidly. India is the second largest market of mobile network providers in the world and there is intense competition among existing players. In such a competitive market, customer satisfaction becomes a key issue. The objective of this paper is to develop a customer satisfaction model of mobile network providers in Kolkata. The results indicate that generic requirements (an aggregation of output quality and perceived value, flexibility, and price are the determinants of customer satisfaction. This study offers insights for mobile network providers to understand the determinants of customer satisfaction.

  17. Providing a Connection between a Bayesian Inverse Modeling Tool and a Coupled Hydrogeological Processes Modeling Software

    Science.gov (United States)

    Frystacky, H.; Osorio-Murillo, C. A.; Over, M. W.; Kalbacher, T.; Gunnell, D.; Kolditz, O.; Ames, D.; Rubin, Y.

    2013-12-01

    The Method of Anchored Distributions (MAD) is a Bayesian technique for characterizing the uncertainty in geostatistical model parameters. Open-source software has been developed in a modular framework such that this technique can be applied to any forward model software via a driver. This presentation is about the driver that has been developed for OpenGeoSys (OGS), open-source software that can simulate many hydrogeological processes, including couple processes. MAD allows the use of multiple data types for conditioning the spatially random fields and assessing model parameter likelihood. For example, if simulating flow and mass transport, the inversion target variable could be hydraulic conductivity and the inversion data types could be head, concentration, or both. The driver detects from the OGS files which processes and variables are being used in a given project and allows MAD to prompt the user to choose those that are to be modeled or to be treated deterministically. In this way, any combination of processes allowed by OGS can have MAD applied. As for the software, there are two versions, each with its own OGS driver. A Windows desktop version is available as a graphical user interface and is ideal for the learning and teaching environment. High-throughput computing can even be achieved with this version via HTCondor if large projects want to be pursued in a computer lab. In addition to this desktop application, a Linux version is available equipped with MPI such that it can be run in parallel on a computer cluster. All releases can be downloaded from the MAD Codeplex site given below.

  18. The Importance of Precise Digital Elevation Models (DEM) in Modelling Floods

    Science.gov (United States)

    Demir, Gokben; Akyurek, Zuhal

    2016-04-01

    Digital elevation Models (DEM) are important inputs for topography for the accurate modelling of floodplain hydrodynamics. Floodplains have a key role as natural retarding pools which attenuate flood waves and suppress flood peaks. GPS, LIDAR and bathymetric surveys are well known surveying methods to acquire topographic data. It is not only time consuming and expensive to obtain topographic data through surveying but also sometimes impossible for remote areas. In this study it is aimed to present the importance of accurate modelling of topography for flood modelling. The flood modelling for Samsun-Terme in Blacksea region of Turkey is done. One of the DEM is obtained from the point observations retrieved from 1/5000 scaled orthophotos and 1/1000 scaled point elevation data from field surveys at x-sections. The river banks are corrected by using the orthophotos and elevation values. This DEM is named as scaled DEM. The other DEM is obtained from bathymetric surveys. 296 538 number of points and the left/right bank slopes were used to construct the DEM having 1 m spatial resolution and this DEM is named as base DEM. Two DEMs were compared by using 27 x-sections. The maximum difference at thalweg of the river bed is 2m and the minimum difference is 20 cm between two DEMs. The channel conveyance capacity in base DEM is larger than the one in scaled DEM and floodplain is modelled in detail in base DEM. MIKE21 with flexible grid is used in 2- dimensional shallow water flow modelling. The model by using two DEMs were calibrated for a flood event (July 9, 2012). The roughness is considered as the calibration parameter. From comparison of input hydrograph at the upstream of the river and output hydrograph at the downstream of the river, the attenuation is obtained as 91% and 84% for the base DEM and scaled DEM, respectively. The time lag in hydrographs does not show any difference for two DEMs and it is obtained as 3 hours. Maximum flood extents differ for the two DEMs

  19. Social models provide a norm of appropriate food intake for young women.

    Directory of Open Access Journals (Sweden)

    Lenny R Vartanian

    Full Text Available It is often assumed that social models influence people's eating behavior by providing a norm of appropriate food intake, but this hypothesis has not been directly tested. In three experiments, female participants were exposed to a low-intake model, a high-intake model, or no model (control condition. Experiments 1 and 2 used a remote-confederate manipulation and were conducted in the context of a cookie taste test. Experiment 3 used a live confederate and was conducted in the context of a task during which participants were given incidental access to food. Participants also rated the extent to which their food intake was influenced by a variety of factors (e.g., hunger, taste, how much others ate. In all three experiments, participants in the low-intake conditions ate less than did participants in the high-intake conditions, and also reported a lower perceived norm of appropriate intake. Furthermore, perceived norms of appropriate intake mediated the effects of the social model on participants' food intake. Despite the observed effects of the social models, participants were much more likely to indicate that their food intake was influenced by taste and hunger than by the behavior of the social models. Thus, social models appear to influence food intake by providing a norm of appropriate eating behavior, but people may be unaware of the influence of a social model on their behavior.

  20. Value-added strategy models to provide quality services in senior health business.

    Science.gov (United States)

    Yang, Ya-Ting; Lin, Neng-Pai; Su, Shyi; Chen, Ya-Mei; Chang, Yao-Mao; Handa, Yujiro; Khan, Hafsah Arshed Ali; Elsa Hsu, Yi-Hsin

    2017-06-20

    The rapid population aging is now a global issue. The increase in the elderly population will impact the health care industry and health enterprises; various senior needs will promote the growth of the senior health industry. Most senior health studies are focused on the demand side and scarcely on supply. Our study selected quality enterprises focused on aging health and analyzed different strategies to provide excellent quality services to senior health enterprises. We selected 33 quality senior health enterprises in Taiwan and investigated their excellent quality services strategies by face-to-face semi-structured in-depth interviews with CEO and managers of each enterprise in 2013. A total of 33 senior health enterprises in Taiwan. Overall, 65 CEOs and managers of 33 enterprises were interviewed individually. None. Core values and vision, organization structure, quality services provided, strategies for quality services. This study's results indicated four type of value-added strategy models adopted by senior enterprises to offer quality services: (i) residential care and co-residence model, (ii) home care and living in place model, (iii) community e-business experience model and (iv) virtual and physical portable device model. The common part in these four strategy models is that the services provided are elderly centered. These models offer virtual and physical integrations, and also offer total solutions for the elderly and their caregivers. Through investigation of successful strategy models for providing quality services to seniors, we identified opportunities to develop innovative service models and successful characteristics, also policy implications were summarized. The observations from this study will serve as a primary evidenced base for enterprises developing their senior market and, also for promoting the value co-creation possibility through dialogue between customers and those that deliver service.

  1. Slab2 - Providing updated subduction zone geometries and modeling tools to the community

    Science.gov (United States)

    Hayes, G. P.; Hearne, M. G.; Portner, D. E.; Borjas, C.; Moore, G.; Flamme, H.

    2015-12-01

    The U.S. Geological Survey database of global subduction zone geometries (Slab1.0) combines a variety of geophysical data sets (earthquake hypocenters, moment tensors, active source seismic survey images of the shallow subduction zone, bathymetry, trench locations, and sediment thickness information) to image the shape of subducting slabs in three dimensions, at approximately 85% of the world's convergent margins. The database is used extensively for a variety of purposes, from earthquake source imaging, to magnetotelluric modeling. Gaps in Slab1.0 exist where input data are sparse and/or where slabs are geometrically complex (and difficult to image with an automated approach). Slab1.0 also does not include information on the uncertainty in the modeled geometrical parameters, or the input data used to image them, and provides no means to reproduce the models it described. Currently underway, Slab2 will update and replace Slab1.0 by: (1) extending modeled slab geometries to all global subduction zones; (2) incorporating regional data sets that may describe slab geometry in finer detail than do previously used teleseismic data; (3) providing information on the uncertainties in each modeled slab surface; (4) modifying our modeling approach to a fully-three dimensional data interpolation, rather than following the 2-D to 3-D steps of Slab1.0; (5) migrating the slab modeling code base to a more universally distributable language, Python; and (6) providing the code base and input data we use to create our models, such that the community can both reproduce the slab geometries, and add their own data sets to ours to further improve upon those models in the future. In this presentation we describe our vision for Slab2, and the first results of this modeling process.

  2. Provider dismissal policies and clustering of vaccine-hesitant families: an agent-based modeling approach.

    Science.gov (United States)

    Buttenheim, Alison M; Cherng, Sarah T; Asch, David A

    2013-08-01

    Many pediatric practices have adopted vaccine policies that require parents who refuse to vaccinate according to the ACIP schedule to find another health care provider. Such policies may inadvertently cluster unvaccinated patients into practices that tolerate non vaccination or alternative schedules, turning them into risky pockets of low herd immunity. The objective of this study was to assess the effect of provider zero-tolerance vaccination policies on the clustering of intentionally unvaccinated children. We developed an agent-based model of parental vaccine hesitancy, provider non-vaccination tolerance, and selection of patients into pediatric practices. We ran 84 experiments across a range of parental hesitancy and provider tolerance scenarios. When the model is initialized, all providers accommodate refusals and intentionally unvaccinated children are evenly distributed across providers. As provider tolerance decreases, hesitant children become more clustered in a smaller number of practices and eventually are not able to find a practice that will accept them. Each of these effects becomes more pronounced as the level of hesitancy in the population rises. Heterogeneity in practice tolerance to vaccine-hesitant parents has the unintended result of concentrating susceptible individuals within a small number of tolerant practices, while providing little if any compensatory protection to adherent individuals. These externalities suggest an agenda for stricter policy regulation of individual practice decisions.

  3. De novo pyrimidine nucleotide synthesis mainly occurs outside of plastids, but a previously undiscovered nucleobase importer provides substrates for the essential salvage pathway in Arabidopsis.

    Science.gov (United States)

    Witz, Sandra; Jung, Benjamin; Fürst, Sarah; Möhlmann, Torsten

    2012-04-01

    Nucleotide de novo synthesis is highly conserved among organisms and represents an essential biochemical pathway. In plants, the two initial enzymatic reactions of de novo pyrimidine synthesis occur in the plastids. By use of green fluorescent protein fusions, clear support is provided for a localization of the remaining reactions in the cytosol and mitochondria. This implies that carbamoyl aspartate, an intermediate of this pathway, must be exported and precursors of pyrimidine salvage (i.e., nucleobases or nucleosides) are imported into plastids. A corresponding uracil transport activity could be measured in intact plastids isolated from cauliflower (Brassica oleracea) buds. PLUTO (for plastidic nucleobase transporter) was identified as a member of the Nucleobase:Cation-Symporter1 protein family from Arabidopsis thaliana, capable of transporting purine and pyrimidine nucleobases. A PLUTO green fluorescent protein fusion was shown to reside in the plastid envelope after expression in Arabidopsis protoplasts. Heterologous expression of PLUTO in an Escherichia coli mutant lacking the bacterial uracil permease uraA allowed a detailed biochemical characterization. PLUTO transports uracil, adenine, and guanine with apparent affinities of 16.4, 0.4, and 6.3 μM, respectively. Transport was markedly inhibited by low concentrations of a proton uncoupler, indicating that PLUTO functions as a proton-substrate symporter. Thus, a protein for the absolutely required import of pyrimidine nucleobases into plastids was identified.

  4. Tools and Algorithms to Link Horizontal Hydrologic and Vertical Hydrodynamic Models and Provide a Stochastic Modeling Framework

    Science.gov (United States)

    Salah, Ahmad M.; Nelson, E. James; Williams, Gustavious P.

    2010-04-01

    We present algorithms and tools we developed to automatically link an overland flow model to a hydrodynamic water quality model with different spatial and temporal discretizations. These tools run the linked models which provide a stochastic simulation frame. We also briefly present the tools and algorithms we developed to facilitate and analyze stochastic simulations of the linked models. We demonstrate the algorithms by linking the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model for overland flow with the CE-QUAL-W2 model for water quality and reservoir hydrodynamics. GSSHA uses a two-dimensional horizontal grid while CE-QUAL-W2 uses a two-dimensional vertical grid. We implemented the algorithms and tools in the Watershed Modeling System (WMS) which allows modelers to easily create and use models. The algorithms are general and could be used for other models. Our tools create and analyze stochastic simulations to help understand uncertainty in the model application. While a number of examples of linked models exist, the ability to perform automatic, unassisted linking is a step forward and provides the framework to easily implement stochastic modeling studies.

  5. Tools and Algorithms to Link Horizontal Hydrologic and Vertical Hydrodynamic Models and Provide a Stochastic Modeling Framework

    Directory of Open Access Journals (Sweden)

    Ahmad M Salah

    2010-12-01

    Full Text Available We present algorithms and tools we developed to automatically link an overland flow model to a hydrodynamic water quality model with different spatial and temporal discretizations. These tools run the linked models which provide a stochastic simulation frame. We also briefly present the tools and algorithms we developed to facilitate and analyze stochastic simulations of the linked models. We demonstrate the algorithms by linking the Gridded Surface Subsurface Hydrologic Analysis (GSSHA model for overland flow with the CE-QUAL-W2 model for water quality and reservoir hydrodynamics. GSSHA uses a two-dimensional horizontal grid while CE-QUAL-W2 uses a two-dimensional vertical grid. We implemented the algorithms and tools in the Watershed Modeling System (WMS which allows modelers to easily create and use models. The algorithms are general and could be used for other models. Our tools create and analyze stochastic simulations to help understand uncertainty in the model application. While a number of examples of linked models exist, the ability to perform automatic, unassisted linking is a step forward and provides the framework to easily implement stochastic modeling studies.

  6. Providing the meta-model of development of competency using the meta-ethnography approach: Part 2. Synthesis of the available competency development models

    Directory of Open Access Journals (Sweden)

    Somayeh Akbari Farmad

    2016-06-01

    Full Text Available Background and Purpose: Considering the importance and necessity of competency-based education at a global level and with respect to globalization and the requirement of minimum competencies in medical fields, medical education communities and organizations worldwide have tried to determine the competencies, present frameworks and education models to respond to be sure of the ability of all graduates. In the literature, we observed numerous competency development models that refer to the same issues with different terminologies. It seems that evaluation and synthesis of all these models can finally result in designing a comprehensive meta-model for competency development. Methods: Meta-ethnography is a useful method for synthesis of qualitative research that is used to develop models that interpret the results in several studies. Considering that the aim of this study is to ultimately provide a competency development meta-model, in the previous section of the study, the literature review was conducted to achieve competency development models. Models obtained through the search were studied in details, and the key concepts of the models and overarching concepts were extracted in this section, models’ concepts were reciprocally translated and the available competency development models were synthesized. Results: A presentation of the competency development meta-model and providing a redefinition of the Dreyfus brothers model. Conclusions: Given the importance of competency-based education at a global level and the need to review curricula and competency-based curriculum design, it is required to provide competency development as well as meta-model to be the basis for curriculum development. As there are a variety of competency development models available, in this study, it was tried to develop the curriculum using them. Keywords: Meta-ethnography, Competency development, Meta-model, Qualitative synthesis

  7. Providing evidence of likely being on time – Counterexample generation for CTMC model checking

    NARCIS (Netherlands)

    Han, T.; Katoen, J.P.; Namjoshi, K.; Yoneda, T.; Higashino, T.; Okamura, Y.

    2007-01-01

    Probabilistic model checkers typically provide a list of individual state probabilities on the refutation of a temporal logic formula. For large state spaces, this information is far too detailed to act as useful diagnostic feedback. For quantitative (constrained) reachability problems, sets of path

  8. Physical Models that Provide Guidance in Visualization Deconstruction in an Inorganic Context

    Science.gov (United States)

    Schiltz, Holly K.; Oliver-Hoyo, Maria T.

    2012-01-01

    Three physical model systems have been developed to help students deconstruct the visualization needed when learning symmetry and group theory. The systems provide students with physical and visual frames of reference to facilitate the complex visualization involved in symmetry concepts. The permanent reflection plane demonstration presents an…

  9. Using a Behavior Modeling Approach to Teach Students the Art of Providing and Receiving Verbal Feedback

    Science.gov (United States)

    Maritz, Carol A.

    2008-01-01

    Using a behavior modeling approach, this study examined how students' perceived self-efficacy improved as they developed, delivered, and evaluated professional presentations. Using journal entries and a self-efficacy assessment, students' perceived self-efficacy increased as they learned to provide and receive verbal peer feedback, and to stage…

  10. Using a Behavior Modeling Approach to Teach Students the Art of Providing and Receiving Verbal Feedback

    Science.gov (United States)

    Maritz, Carol A.

    2008-01-01

    Using a behavior modeling approach, this study examined how students' perceived self-efficacy improved as they developed, delivered, and evaluated professional presentations. Using journal entries and a self-efficacy assessment, students' perceived self-efficacy increased as they learned to provide and receive verbal peer feedback, and to stage…

  11. Using Models to Provide Predicted Ranges for Building-Human Interfaces: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Long, N.; Scheib, J.; Pless, S.; Schott, M.

    2013-09-01

    Most building energy consumption dashboards provide only a snapshot of building performance; whereas some provide more detailed historic data with which to compare current usage. This paper will discuss the Building Agent(tm) platform, which has been developed and deployed in a campus setting at the National Renewable Energy Laboratory as part of an effort to maintain the aggressive energyperformance achieved in newly constructed office buildings and laboratories. The Building Agent(tm) provides aggregated and coherent access to building data, including electric energy, thermal energy, temperatures, humidity, and lighting levels, and occupant feedback, which are displayed in various manners for visitors, building occupants, facility managers, and researchers. This paper focuseson the development of visualizations for facility managers, or an energy performance assurance role, where metered data are used to generate models that provide live predicted ranges of building performance by end use. These predicted ranges provide simple, visual context for displayed performance data without requiring users to also assess historical information or trends. Several energymodelling techniques were explored including static lookup-based performance targets, reduced-order models derived from historical data using main effect variables such as solar radiance for lighting performance, and integrated energy models using a whole-building energy simulation program.

  12. Modeling Customer Loyalty by System Dynamics Methodology (Case Study: Internet Service Provider Company

    Directory of Open Access Journals (Sweden)

    Alireza Bafandeh Zendeh

    2016-03-01

    Full Text Available Due to the complexity of the customer loyalty, we tried to provide a conceptual model to explain it in an Internet service provider company with system dynamics approach. To do so, the customer’s loyalty for statistical population was analyzed according to Sterman’s modeling methodology. First of all the reference modes (historical behavior of customer loyalty was evaluated. Then dynamic hypotheses was developed by utilizing causal - loop diagrams and stock-flow maps, based on theoretical literature. In third stage, initial conditions of variables, parameters, and mathematical functions between them were estimated. The model was tested, finally advertising, quality of services improvement and continuing the current situation scenarios were evaluated. Results showed improving the quality of service scenario is more effectiveness in compare to others

  13. Importance of the type of provider seen to begin health care for a new episode low back pain: associations with future utilization and costs.

    Science.gov (United States)

    Fritz, Julie M; Kim, Jaewhan; Dorius, Josette

    2016-04-01

    Low back pain (LBP) care can involve many providers. The provider chosen for entry into care may predict future health care utilization and costs. The objective of this study was to explore associations between entry settings and future LBP-related utilization and costs. A retrospective review of claims data identified new entries into health care for LBP. We examined the year after entry to identify utilization outcomes (imaging, surgeon or emergency visits, injections, surgery) and total LBP-related costs. Multivariate models with inverse probability weighting on propensity scores were used to evaluate relationships between utilization and cost outcomes with entry setting. 747 patients were identified (mean age = 38.2 (± 10.7) years, 61.2% female). Entry setting was primary care (n = 409, 54.8%), chiropractic (n = 207, 27.7%), physiatry (n = 83, 11.1%) and physical therapy (n = 48, 6.4%). Relative to primary care, entry in physiatry increased risk for radiographs (OR = 3.46, P = 0.001), advanced imaging (OR = 3.38, P costs (standardized Β = 0.67, P costs. Consideration of where patients chose to enter care may be a strategy to improve outcomes and reduce costs. © 2015 John Wiley & Sons, Ltd.

  14. Rhizosphere Processes Are Quantitatively Important Components of Terrestrial Biogeochemical Cycles: Data & Models

    Science.gov (United States)

    Finzi, A.

    2016-12-01

    The rhizosphere is a hot spot and hot moment for biogeochemical cycles. Microbial activity, extracellular enzyme activity and element cycles are greatly enhanced by root derived carbon inputs. As such the rhizosphere may be an important driver of ecosystem responses to global changes such as rising temperatures and atmospheric CO2 concentrations. Empirical research on the rhizosphere is extensive but extrapolation of rhizosphere processes to large spatial and temporal scales is largely uninterrogated. Using a combination of field studies, meta-analysis and numerical models we have found good reason to think that scaling is possible. In this talk I discuss the results of this research and focus on the results of a new modeling effort that explicitly links root distribution and architecture with a model of microbial physiology to assess the extent to which rhizosphere processes may affect ecosystem responses to global change. Results to date suggest that root inputs of C and possibly nutrients (ie, nitrogen) impact the fate of new C inputs to the soil (ie, accumulation or loss) in response to warming and enhanced productivity at elevated CO2. The model also provides qualitative guidance on incorporating the known effects of ectomycorrhizal fungi on decomposition and rates of soil C and N cycling.

  15. Models for measuring and predicting shareholder value: A study of third party software service providers

    Indian Academy of Sciences (India)

    N Viswanadham; Poornima Luthra

    2005-04-01

    In this study, we use the strategic profit model (SPM) and the economic value-added (EVA to measure shareholder value). SPM measures the return on net worth (RONW) which is defined as the return on assets (ROA) multiplied by the financial leverage. EVA is defined as the firm’s net operating profit after taxes (NOPAT) minus the capital charge. Both, RONW and EVA provide an indication of how much shareholder value a firm creates for its shareholders, year on year. With the increasing focus on creation of shareholder value and core competencies, many companies are outsourcing their information technology (IT) related activities to third party software companies. Indian software companies have become leaders in providing these services. Companies from several other countries are also competing for the top slot. We use the SPM and EVA models to analyse the four listed players of the software industry using the publicly available published data. We compare the financial data obtained from the models, and use peer average data to provide customized recommendations for each company to improve their shareholder value. Assuming that the companies follow these rules, we also predict future RONW and EVA for the companies for the financial year 2005. Finally, we make several recommendations to software providers for effectively competing in the global arena.

  16. Conceptual Model of Providing Traffic Navigation Services to Visually Impaired Persons

    Directory of Open Access Journals (Sweden)

    Marko Periša

    2014-05-01

    Full Text Available In order to include people of reduced mobility in the traffic system it is necessary to provide accessibility and information of the users to all the facilities surrounding them. By analysing the currently available information and communication technologies a new conceptual model of providing navigation services to the visually impaired persons has been proposed. This model is based on Cloud Computing platform, and this research describes the method of navigating the users based on accurate and updated data. The users’ requirements have been analysed according to the needs of the movement of visually impaired persons along the traffic network. The information and communication solutions with the function of informing these groups of users have to provide accurate and updated data, which is made possible by the proposed model. This research was conducted on the most frequent routes in the city of Zagreb. With the review of model efficiency user’s sense of security is increased in the amount of 87%.

  17. Towards a realistic interpretation of quantum physics providing a physical model of the natural world

    CERN Document Server

    Santos, Emilio

    2012-01-01

    It is stressed the advantage of a realistic interpretation of quantum mechanics providing a physical model of the quantum world. After some critical comments on the most popular interpretations, the difficulties for a model are pointed out and possible solutions proposed. In particular the existence of discrete states, the quantum jumps, the alleged lack of objective properties, measurement theory, the probabilistic character of quantum physics, the wave-particle duality and the Bell inequalities are commented. It is conjectured that an intuitive picture of the quantum world could be obtained compatible with the quantum predictions for actual experiments, although maybe incompatible with alleged predictions for ideal, unrealizable, experiments.

  18. Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae.

    Science.gov (United States)

    Aguilar, María; Lado, Carlos

    2012-08-01

    Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds-protosteloid amoebae-in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species. Although protosteloid amoebae share similar morphologies and life history strategies, canonical correspondence analyses showed that they have varied ecological optima, and that climate conditions have an important effect in niche differentiation. Maxent environmental niche models provided consistent predictions of the probability of presence of the species based on climate data, and they were used to generate maps of potential distribution in an 'everything is everywhere' scenario. The most important climatic factors were, in both analyses, variables that measure changes in conditions throughout the year, confirming that the alternation of fruiting bodies, cysts and amoeboid stages in the life cycles of protosteloid amoebae constitutes an advantage for surviving in a changing environment. Microhabitat affinity seems to be influenced by climatic conditions, which suggests that the micro-environment may vary at a local scale and change together with the external climate at a larger scale.

  19. Hitting the moving target: modelling ontogenetic shifts with stable isotopes reveals the importance of isotopic turnover.

    Science.gov (United States)

    Hertz, Eric; Trudel, Marc; El-Sabaawi, Rana; Tucker, Strahan; Dower, John F; Beacham, Terry D; Edwards, Andrew M; Mazumder, Asit

    2016-05-01

    Ontogenetic niche shifts are widely prevalent in nature and are important in shaping the structure and dynamics of ecosystems. Stable isotope analysis is a powerful tool to assess these shifts, with δ(15) N providing a measure of trophic level and δ(13) C a measure of energy source. Previous applications of stable isotopes to study ontogenetic niche shifts have not considered the appreciable time lag between diet and consumer tissue associated with isotopic turnover. These time lags introduce significant complexity into field studies of ontogenetic niche shifts. Juvenile Chinook salmon (Oncorhynchus tshawytscha) migrate from freshwater to marine ecosystems and shift their diet from feeding primarily on invertebrates to feeding primarily on fish. This dual ontogenetic habitat and diet shift, in addition to the long time lag associated with isotopic turnover, suggests that there is potential for a disconnect between the prey sources that juvenile salmon are consuming, and the inferred prey sources from stable isotopes. We developed a model that considered ontogenetic niche shifts and time lags associated with isotopic turnover, and compared this 'ontogeny' model to one that considered only isotopic turnover. We used a Bayesian framework to explicitly account for parameter uncertainty. Data showed overwhelming support for the ontogeny model relative to the isotopic turnover model. Estimated variables from best model fits indicate that the ontogeny model predicts a much greater reliance on fish prey than does the stomach content data. Overall, we found that this method of quantifying ontogenetic niche shifts effectively accounted for both isotopic turnover and ontogenetic diet shifts; a finding that could be widely applicable to a variety of systems.

  20. The importance of the Non Obese Diabetic (NOD) mouse model in autoimmune diabetes.

    Science.gov (United States)

    Pearson, James A; Wong, F Susan; Wen, Li

    2016-01-01

    Type 1 Diabetes (T1D) is an autoimmune disease characterized by the pancreatic infiltration of immune cells resulting in T cell-mediated destruction of the insulin-producing beta cells. The successes of the Non-Obese Diabetic (NOD) mouse model have come in multiple forms including identifying key genetic and environmental risk factors e.g. Idd loci and effects of microorganisms including the gut microbiota, respectively, and how they may contribute to disease susceptibility and pathogenesis. Furthermore, the NOD model also provides insights into the roles of the innate immune cells as well as the B cells in contributing to the T cell-mediated disease. Unlike many autoimmune disease models, the NOD mouse develops spontaneous disease and has many similarities to human T1D. Through exploiting these similarities many targets have been identified for immune-intervention strategies. Although many of these immunotherapies did not have a significant impact on human T1D, they have been shown to be effective in the NOD mouse in early stage disease, which is not equivalent to trials in newly-diagnosed patients with diabetes. However, the continued development of humanized NOD mice would enable further clinical developments, bringing T1D research to a new translational level. Therefore, it is the aim of this review to discuss the importance of the NOD model in identifying the roles of the innate immune system and the interaction with the gut microbiota in modifying diabetes susceptibility. In addition, the role of the B cells will also be discussed with new insights gained through B cell depletion experiments and the impact on translational developments. Finally, this review will also discuss the future of the NOD mouse and the development of humanized NOD mice, providing novel insights into human T1D.

  1. Partnerships to provide care and medicine for chronic diseases: a model for emerging markets.

    Science.gov (United States)

    Goroff, Michael; Reich, Michael R

    2010-12-01

    The challenge of expanding access to treatment and medicine for chronic diseases in emerging markets is both a public health imperative and a commercial opportunity. Cross-sector partnerships-involving a pharmaceutical manufacturer; a local health care provider; and other private, public, and nonprofit entities-could address this challenge. Such partnerships would provide integrated, comprehensive care and medicines for a specific chronic disease, with medicines directly supplied to the partnership at preferential prices by the manufacturer. The model discussed here requires additional specification, using real numbers and specific contexts, to assess its feasibility. Still, we believe that this model has the potential for public health and private business to cooperate in addressing the rising problem of chronic diseases in emerging markets.

  2. Ecological niche modeling in Maxent: the importance of model complexity and the performance of model selection criteria.

    Science.gov (United States)

    Warren, Dan L; Seifert, Stephanie N

    2011-03-01

    Maxent, one of the most commonly used methods for inferring species distributions and environmental tolerances from occurrence data, allows users to fit models of arbitrary complexity. Model complexity is typically constrained via a process known as L1 regularization, but at present little guidance is available for setting the appropriate level of regularization, and the effects of inappropriately complex or simple models are largely unknown. In this study, we demonstrate the use of information criterion approaches to setting regularization in Maxent, and we compare models selected using information criteria to models selected using other criteria that are common in the literature. We evaluate model performance using occurrence data generated from a known "true" initial Maxent model, using several different metrics for model quality and transferability. We demonstrate that models that are inappropriately complex or inappropriately simple show reduced ability to infer habitat quality, reduced ability to infer the relative importance of variables in constraining species' distributions, and reduced transferability to other time periods. We also demonstrate that information criteria may offer significant advantages over the methods commonly used in the literature.

  3. Providing comprehensive and consistent access to astronomical observatory archive data: the NASA archive model

    Science.gov (United States)

    McGlynn, Thomas; Fabbiano, Giuseppina; Accomazzi, Alberto; Smale, Alan; White, Richard L.; Donaldson, Thomas; Aloisi, Alessandra; Dower, Theresa; Mazzerella, Joseph M.; Ebert, Rick; Pevunova, Olga; Imel, David; Berriman, Graham B.; Teplitz, Harry I.; Groom, Steve L.; Desai, Vandana R.; Landry, Walter

    2016-07-01

    Since the turn of the millennium a constant concern of astronomical archives have begun providing data to the public through standardized protocols unifying data from disparate physical sources and wavebands across the electromagnetic spectrum into an astronomical virtual observatory (VO). In October 2014, NASA began support for the NASA Astronomical Virtual Observatories (NAVO) program to coordinate the efforts of NASA astronomy archives in providing data to users through implementation of protocols agreed within the International Virtual Observatory Alliance (IVOA). A major goal of the NAVO collaboration has been to step back from a piecemeal implementation of IVOA standards and define what the appropriate presence for the US and NASA astronomy archives in the VO should be. This includes evaluating what optional capabilities in the standards need to be supported, the specific versions of standards that should be used, and returning feedback to the IVOA, to support modifications as needed. We discuss a standard archive model developed by the NAVO for data archive presence in the virtual observatory built upon a consistent framework of standards defined by the IVOA. Our standard model provides for discovery of resources through the VO registries, access to observation and object data, downloads of image and spectral data and general access to archival datasets. It defines specific protocol versions, minimum capabilities, and all dependencies. The model will evolve as the capabilities of the virtual observatory and needs of the community change.

  4. A Global Remote Laboratory Experimentation Network and the Experiment Service Provider Business Model and Plans

    Directory of Open Access Journals (Sweden)

    Tor Ivar Eikaas

    2003-07-01

    Full Text Available This paper presents results from the IST KAII Trial project ReLAX - Remote LAboratory eXperimentation trial (IST 1999-20827, and contributes with a framework for a global remote laboratory experimentation network supported by a new business model. The paper presents this new Experiment Service Provider business model that aims at bringing physical experimentation back into the learning arena, where remotely operable laboratory experiments used in advanced education and training schemes are made available to a global education and training market in industry and academia. The business model is based on an approach where individual experiment owners offer remote access to their high-quality laboratory facilities to users around the world. The usage can be for research, education, on-the-job training etc. The access to these facilities is offered via an independent operating company - the Experiment Service Provider. The Experiment Service Provider offers eCommerce services like booking, access control, invoicing, dispute resolution, quality control, customer evaluation services and a unified Lab Portal.

  5. The importance of information goods abstraction levels for information commerce process models

    NARCIS (Netherlands)

    Wijnhoven, Fons

    2002-01-01

    A process model, in the context of e-commerce, is an organized set of activities for the creation, (re-)production, trade and delivery of goods. Electronic commerce studies have created important process models for the trade of physical goods via Internet. These models are not easily suitable for th

  6. A new process sensitivity index to identify important system processes under process model and parametric uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Heng [Pacific Northwest National Laboratory, Richland Washington USA; Ye, Ming [Department of Scientific Computing, Florida State University, Tallahassee Florida USA; Walker, Anthony P. [Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Chen, Xingyuan [Pacific Northwest National Laboratory, Richland Washington USA

    2017-04-01

    Hydrological models are always composed of multiple components that represent processes key to intended model applications. When a process can be simulated by multiple conceptual-mathematical models (process models), model uncertainty in representing the process arises. While global sensitivity analysis methods have been widely used for identifying important processes in hydrologic modeling, the existing methods consider only parametric uncertainty but ignore the model uncertainty for process representation. To address this problem, this study develops a new method to probe multimodel process sensitivity by integrating the model averaging methods into the framework of variance-based global sensitivity analysis, given that the model averaging methods quantify both parametric and model uncertainty. A new process sensitivity index is derived as a metric of relative process importance, and the index includes variance in model outputs caused by uncertainty in both process models and model parameters. For demonstration, the new index is used to evaluate the processes of recharge and geology in a synthetic study of groundwater reactive transport modeling. The recharge process is simulated by two models that converting precipitation to recharge, and the geology process is also simulated by two models of different parameterizations of hydraulic conductivity; each process model has its own random parameters. The new process sensitivity index is mathematically general, and can be applied to a wide range of problems in hydrology and beyond.

  7. ERK activation by the polyphenols fisetin and resveratrol provides neuroprotection in multiple models of Huntington's disease

    Science.gov (United States)

    Maher, Pamela; Dargusch, Richard; Bodai, Laszlo; Gerard, Paul E.; Purcell, Judith M.; Marsh, J. Lawrence

    2011-01-01

    Huntington's disease (HD) is an inherited, progressive and ultimately fatal neurodegenerative disorder that is characterized by psychiatric, cognitive and motor symptoms. Among the pathways implicated in HD are those involving mitogen-activated protein kinase signaling and particularly the Ras-extracellular signal-regulated kinase (ERK) cascade. Studies in both cells and animal models suggest that ERK activation might provide a novel therapeutic target for the treatment of HD but compounds that specifically activate ERK are few. To test the hypothesis that pharmaceutical activation of ERK might be protective for HD, a polyphenol, fisetin, which was previously shown to activate the Ras-ERK cascade, was tested in three different models of HD: PC12 cells expressing mutant Httex1 under the control of an inducible promoter, Drosophila expressing mutant Httex1 and the R6/2 mouse model of HD. The results indicate that fisetin can reduce the impact of mutant huntingtin in each of these disease models. Prompted by this observation, we determined that the related polyphenol, resveratrol, also activates ERK and is protective in HD models. Notably, although more than a dozen small molecule inhibitors of ERK activation are in clinical trials, very few small molecule activators of ERK signaling are reported. Thus, fisetin, resveratrol and related compounds might be useful for the treatment of HD by virtue of their unique ability to activate ERK. PMID:20952447

  8. Capabilities of stochastic rainfall models as data providers for urban hydrology

    Science.gov (United States)

    Haberlandt, Uwe

    2017-04-01

    For planning of urban drainage systems using hydrological models, long, continuous precipitation series with high temporal resolution are needed. Since observed time series are often too short or not available everywhere, the use of synthetic precipitation is a common alternative. This contribution compares three precipitation models regarding their suitability to provide 5 minute continuous rainfall time series for a) sizing of drainage networks for urban flood protection and b) dimensioning of combined sewage systems for pollution reduction. The rainfall models are a parametric stochastic model (Haberlandt et al., 2008), a non-parametric probabilistic approach (Bárdossy, 1998) and a stochastic downscaling of dynamically simulated rainfall (Berg et al., 2013); all models are operated both as single site and multi-site generators. The models are applied with regionalised parameters assuming that there is no station at the target location. Rainfall and discharge characteristics are utilised for evaluation of the model performance. The simulation results are compared against results obtained from reference rainfall stations not used for parameter estimation. The rainfall simulations are carried out for the federal states of Baden-Württemberg and Lower Saxony in Germany and the discharge simulations for the drainage networks of the cities of Hamburg, Brunswick and Freiburg. Altogether, the results show comparable simulation performance for the three models, good capabilities for single site simulations but low skills for multi-site simulations. Remarkably, there is no significant difference in simulation performance comparing the tasks flood protection with pollution reduction, so the models are finally able to simulate both the extremes and the long term characteristics of rainfall equally well. Bárdossy, A., 1998. Generating precipitation time series using simulated annealing. Wat. Resour. Res., 34(7): 1737-1744. Berg, P., Wagner, S., Kunstmann, H., Schädler, G

  9. Daily Suction Provided by External Volume Expansion Inducing Regeneration of Grafted Fat in a Murine Model.

    Science.gov (United States)

    Ye, Yuan; Liao, Yunjun; Lu, Feng; Gao, Jianhua

    2017-02-01

    Fat grafting has variable and sometimes poor outcomes, and therefore new methods are needed. Multiple studies have demonstrated the excellent performance of external volume expansion and focused only on preexpansion with emphasis on the recipient. Two mouse models (a suction model and a fat-exchange transplantation model) were established to investigate changes in the origins and biological behaviors of regeneration-related cells in grafted fat under daily suction provided by external volume expansion. Blood supply increased from new host-derived capillaries or macrophage infiltration under suction. CD34-positive cells showed increased migration from the host into the grafts under suction. At week 12, nearly half of the mature adipocytes regenerated in the grafts in the suction group were derived from the host. Peroxisome proliferator-activated receptor γ expression of the suction group was significantly higher than that of controls at weeks 2 and 4 during adipogenesis. The normalized sample weight of the grafted fat was significantly greater than that of controls at 1 (0.081 ± 0.001 versus 0.072 ± 0.005; p suction provided by external volume expansion favors the regeneration of grafted fat and improves retention by promoting the migration of regeneration-related cells and the differentiation of adipocytes. Thus, more mature fat tissue with a well-organized structure was formed under suction.

  10. Reserved or On-Demand Instances? A Revenue Maximization Model for Cloud Providers

    CERN Document Server

    Mazzucco, Michele

    2011-01-01

    We examine the problem of managing a server farm in a way that attempts to maximize the net revenue earned by a cloud provider by renting servers to customers according to a typical Platform-as-a-Service model. The Cloud provider offers its resources to two classes of customers: `premium' and `basic'. Premium customers pay upfront fees to reserve servers for a specified period of time (e.g. a year). Premium customers can submit jobs for their reserved servers at any time and pay a fee for the server-hours they use. The provider is liable to pay a penalty every time a `premium' job can not be executed due to lack of resources. On the other hand, `basic' customers are served on a best-effort basis, and pay a server-hour fee that may be higher than the one paid by premium customers. The provider incurs energy costs when running servers. Hence, it has an incentive to turn off idle servers. The question of how to choose the number of servers to allocate to each pool (basic and premium) is answered by analyzing a s...

  11. How Modelling of Crystal Defects at the Atomic Scale can Provide Information on Seismic Anisotropy

    Science.gov (United States)

    Cordier, P.; Carrez, P.; Goryaeva, A.; Gouriet, K.; Hirel, P.; Kraych, A.; Ritterbex, S.

    2014-12-01

    Seismic anisotropy represents one of the few sources of information about flow in the mantle that takes place at timescales that are barely accessible at human timescales. Seismic waves travelling through rocks at the speed of sound can reveal flow lines frozen in rocks over hundreds of million years. The interpretation of seismic anisotropy also needs to bridge length-scales since crystal defects are responsible for the plastic anisotropy that align crystals in a deforming rock thus revealing elastic anisotropy at the macroscopic scale. Knowing the easiest slip systems for a given crystal structure is thus the fundamental information needed. To obtain it we propose the following approach based on multiscale numerical modeling. As a first approach, we calculate generalized stacking faults which inform us about the easiest shear paths imposed by the crystal chemistry. This leads to a short list of potential slip systems for which lattice friction will be calculated. A further selection will be done by modeling the core structures of screw dislocations. The tendency for core spreading of screw dislocations impose a selection on potential glide planes which is further validated by modeling corresponding edge dislocations and their respective mobilities. Finally, we model the mobility of these dislocations under the conjugate influence of stress and temperature using the kink-pair model which is based on the activation enthalpy of the critical configuration which allows a dislocation to glide from one stable position to the next. The output of this model is the so-called critical resolved shear stress which is the onset of plastic glide at a given temperature and strain rate. Comparison between slip systems provides constraints on the plastic anisotropy. Examples are presented among the major phases of the Earth's mantle.

  12. State and Alternative Fuel Provider Fleets - Fleet Compliance Annual Report: Model Year 2015, Fiscal Year 2016

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    The U.S. Department of Energy (DOE) regulates covered state government and alternative fuel provider fleets, pursuant to the Energy Policy Act of 1992 (EPAct), as amended. Covered fleets may meet their EPAct requirements through one of two compliance methods: Standard Compliance or Alternative Compliance. For model year (MY) 2015, the compliance rate with this program for the more than 3011 reporting fleets was 100%. More than 294 fleets used Standard Compliance and exceeded their aggregate MY 2015 acquisition requirements by 8% through acquisitions alone. The seven covered fleets that used Alternative Compliance exceeded their aggregate MY 2015 petroleum use reduction requirements by 46%.

  13. Do NHS walk-in centres in England provide a model of integrated care?

    Directory of Open Access Journals (Sweden)

    C. Salisbury

    2003-08-01

    Full Text Available Purpose: To undertake a comprehensive evaluation of NHS walk-in centres against criteria of improved access, quality, user satisfaction and efficiency. Context: Forty NHS walk-in centres have been opened in England, as part of the UK governments agenda to modernise the NHS. They are intended to improve access to primary care, provide high quality treatment at convenient times, and reduce inappropriate demand on other NHS providers. Care is provided by nurses rather than doctors, using computerised algorithms, and nurses use protocols to supply treatments previously only available from doctors. Data sources: Several linked studies were conducted using different sources of data and methodologies. These included routinely collected data, site visits, patient interviews, a survey of users of walk-in centres, a study using simulated patients to assess quality of care, analysis of consultation rates in NHS services near to walk-in centres, and audit of compliance with protocols. Conclusion & discussion: The findings illustrate many of the issues described in a recent WHO reflective paper on Integrated Care, including tensions between professional judgement and use of protocols, problems with incompatible IT systems, balancing users' demands and needs, the importance of understanding health professionals' roles and issues of technical versus allocative efficiency.

  14. Demand Estimation for US Apple Juice Imports: A Restricted Source Differentiated AIDS Model

    OpenAIRE

    Mekonnen, Dawit Kelemework; Fonsah, Esendugue Greg

    2011-01-01

    Although this paper focuses on apple juice, a restricted version of source differentiated Almost Ideal Demand System (RSDAIDS) was used to examine U.S. import demand for fresh apple, apple juice and other processed apple. Apple imports were differentiated by type and source of origin and the RSDAIDS model was estimated after imposing the general demand restrictions of adding-up, homogeneity and slutsky symmetry. Seasonality and trend variables were also included on the model. The estimation r...

  15. Quantitative Hydraulic Models Of Early Land Plants Provide Insight Into Middle Paleozoic Terrestrial Paleoenvironmental Conditions

    Science.gov (United States)

    Wilson, J. P.; Fischer, W. W.

    2010-12-01

    Fossil plants provide useful proxies of Earth’s climate because plants are closely connected, through physiology and morphology, to the environments in which they lived. Recent advances in quantitative hydraulic models of plant water transport provide new insight into the history of climate by allowing fossils to speak directly to environmental conditions based on preserved internal anatomy. We report results of a quantitative hydraulic model applied to one of the earliest terrestrial plants preserved in three dimensions, the ~396 million-year-old vascular plant Asteroxylon mackei. This model combines equations describing the rate of fluid flow through plant tissues with detailed observations of plant anatomy; this allows quantitative estimates of two critical aspects of plant function. First and foremost, results from these models quantify the supply of water to evaporative surfaces; second, results describe the ability of plant vascular systems to resist tensile damage from extreme environmental events, such as drought or frost. This approach permits quantitative comparisons of functional aspects of Asteroxylon with other extinct and extant plants, informs the quality of plant-based environmental proxies, and provides concrete data that can be input into climate models. Results indicate that despite their small size, water transport cells in Asteroxylon could supply a large volume of water to the plant's leaves--even greater than cells from some later-evolved seed plants. The smallest Asteroxylon tracheids have conductivities exceeding 0.015 m^2 / MPa * s, whereas Paleozoic conifer tracheids do not reach this threshold until they are three times wider. However, this increase in conductivity came at the cost of little to no adaptations for transport safety, placing the plant’s vegetative organs in jeopardy during drought events. Analysis of the thickness-to-span ratio of Asteroxylon’s tracheids suggests that environmental conditions of reduced relative

  16. Modeling the interaction of electric current and tissue: importance of accounting for time varying electric properties.

    Science.gov (United States)

    Evans, Daniel J; Manwaring, Mark L

    2007-01-01

    Time varying computer models of the interaction of electric current and tissue are very valuable in helping to understand the complexity of the human body and biological tissue. The electrical properties of tissue, permittivity and conductivity, are vital to accurately modeling the interaction of the human tissue with electric current. Past models have represented the electric properties of the tissue as constant or temperature dependent. This paper presents time dependent electric properties that change as a result of tissue damage, temperature, blood flow, blood vessels, and tissue property. Six models are compared to emphasize the importance of accounting for these different tissue properties in the computer model. In particular, incorporating the time varying nature of the electric properties of human tissue into the model leads to a significant increase in tissue damage. An important feature of the model is the feedback loop created between the electric properties, tissue damage, and temperature.

  17. Using spatially explicit surveillance models to provide confidence in the eradication of an invasive ant.

    Science.gov (United States)

    Ward, Darren F; Anderson, Dean P; Barron, Mandy C

    2016-10-10

    Effective detection plays an important role in the surveillance and management of invasive species. Invasive ants are very difficult to eradicate and are prone to imperfect detection because of their small size and cryptic nature. Here we demonstrate the use of spatially explicit surveillance models to estimate the probability that Argentine ants (Linepithema humile) have been eradicated from an offshore island site, given their absence across four surveys and three surveillance methods, conducted since ant control was applied. The probability of eradication increased sharply as each survey was conducted. Using all surveys and surveillance methods combined, the overall median probability of eradication of Argentine ants was 0.96. There was a high level of confidence in this result, with a high Credible Interval Value of 0.87. Our results demonstrate the value of spatially explicit surveillance models for the likelihood of eradication of Argentine ants. We argue that such models are vital to give confidence in eradication programs, especially from highly valued conservation areas such as offshore islands.

  18. Learned graphical models for probabilistic planning provide a new class of movement primitives.

    Science.gov (United States)

    Rückert, Elmar A; Neumann, Gerhard; Toussaint, Marc; Maass, Wolfgang

    2012-01-01

    BIOLOGICAL MOVEMENT GENERATION COMBINES THREE INTERESTING ASPECTS: its modular organization in movement primitives (MPs), its characteristics of stochastic optimality under perturbations, and its efficiency in terms of learning. A common approach to motor skill learning is to endow the primitives with dynamical systems. Here, the parameters of the primitive indirectly define the shape of a reference trajectory. We propose an alternative MP representation based on probabilistic inference in learned graphical models with new and interesting properties that complies with salient features of biological movement control. Instead of endowing the primitives with dynamical systems, we propose to endow MPs with an intrinsic probabilistic planning system, integrating the power of stochastic optimal control (SOC) methods within a MP. The parameterization of the primitive is a graphical model that represents the dynamics and intrinsic cost function such that inference in this graphical model yields the control policy. We parameterize the intrinsic cost function using task-relevant features, such as the importance of passing through certain via-points. The system dynamics as well as intrinsic cost function parameters are learned in a reinforcement learning (RL) setting. We evaluate our approach on a complex 4-link balancing task. Our experiments show that our movement representation facilitates learning significantly and leads to better generalization to new task settings without re-learning.

  19. Using time-varying global sensitivity analysis to understand the importance of different uncertainty sources in hydrological modelling

    Science.gov (United States)

    Pianosi, Francesca; Wagener, Thorsten

    2016-04-01

    Simulations from environmental models are affected by potentially large uncertainties stemming from various sources, including model parameters and observational uncertainty in the input/output data. Understanding the relative importance of such sources of uncertainty is essential to support model calibration, validation and diagnostic evaluation, and to prioritize efforts for uncertainty reduction. Global Sensitivity Analysis (GSA) provides the theoretical framework and the numerical tools to gain this understanding. However, in traditional applications of GSA, model outputs are an aggregation of the full set of simulated variables. This aggregation of propagated uncertainties prior to GSA may lead to a significant loss of information and may cover up local behaviour that could be of great interest. In this work, we propose a time-varying version of a recently developed density-based GSA method, called PAWN, as a viable option to reduce this loss of information. We apply our approach to a medium-complexity hydrological model in order to address two questions: [1] Can we distinguish between the relative importance of parameter uncertainty versus data uncertainty in time? [2] Do these influences change in catchments with different characteristics? The results present the first quantitative investigation on the relative importance of parameter and data uncertainty across time. They also provide a demonstration of the value of time-varying GSA to investigate the propagation of uncertainty through numerical models and therefore guide additional data collection needs and model calibration/assessment.

  20. Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs?

    Science.gov (United States)

    Hansen, Suzanne L; Sterjev, Zoran; Werngreen, Marie; Simonsen, Bodil J; Knudsen, Katrine E; Nielsen, Ane H; Pedersen, Mikael E; Badolo, Lassiana; Kristiansen, Uffe; Vestergaard, Henrik T

    2012-05-05

    The cortical wedge is a commonly applied model for in vitro screening of new antiepileptic drugs (AEDs) and has been extensively used in characterization of well-known AEDs. However, the predictive validity of this model as a screening model has been questioned as, e.g., carbamazepine has been reported to lack effect in this model. The neuroplastic changes induced in acute and chronic animal models of epilepsy are known to affect the pharmacological profile of AEDs in vivo. Hence, we investigated whether brain slices from pentylenetetrazole (PTZ)-kindled animals could provide a more predictive screening model for AEDs. To this end, we compared the in vitro and in vivo pharmacological profile of several selected AEDs (phenobarbital, phenytoin, tiagabine, fosphenytoin, valproate, and carbamazepine) along with citalopram using the PTZ-kindled model and brain slices from naïve, saline-injected and PTZ-kindled mice. Our data suggest that the use of slices from PTZ-kindled mice in the cortical wedge does not increase the predictive validity of the model as an in vitro screening model for AEDs. Traditionally, the incidence of certain seizure types is widely used as a measure to characterize drug action in animal models of epilepsy. In our study, the anticonvulsant effect of the AEDs was investigated in vivo using several observational parameters (i.e., incidence and duration of convulsions, latency to clonic convulsions, and severity of convulsions). We found that including the observational parameter "severity" offered important additional information about the drug profile that would otherwise be lost if only a single parameter as "incidence" was used.

  1. The importance of spatial ability and mental models in learning anatomy

    Science.gov (United States)

    Chatterjee, Allison K.

    As a foundational course in medical education, gross anatomy serves to orient medical and veterinary students to the complex three-dimensional nature of the structures within the body. Understanding such spatial relationships is both fundamental and crucial for achievement in gross anatomy courses, and is essential for success as a practicing professional. Many things contribute to learning spatial relationships; this project focuses on a few key elements: (1) the type of multimedia resources, particularly computer-aided instructional (CAI) resources, medical students used to study and learn; (2) the influence of spatial ability on medical and veterinary students' gross anatomy grades and their mental models; and (3) how medical and veterinary students think about anatomy and describe the features of their mental models to represent what they know about anatomical structures. The use of computer-aided instruction (CAI) by gross anatomy students at Indiana University School of Medicine (IUSM) was assessed through a questionnaire distributed to the regional centers of the IUSM. Students reported using internet browsing, PowerPoint presentation software, and email on a daily bases to study gross anatomy. This study reveals that first-year medical students at the IUSM make limited use of CAI to study gross anatomy. Such studies emphasize the importance of examining students' use of CAI to study gross anatomy prior to development and integration of electronic media into the curriculum and they may be important in future decisions regarding the development of alternative learning resources. In order to determine how students think about anatomical relationships and describe the features of their mental models, personal interviews were conducted with select students based on students' ROT scores. Five typologies of the characteristics of students' mental models were identified and described: spatial thinking, kinesthetic approach, identification of anatomical structures

  2. The fornix provides multiple biomarkers to characterize circuit disruption in a mouse model of Alzheimer's disease.

    Science.gov (United States)

    Badea, Alexandra; Kane, Lauren; Anderson, Robert J; Qi, Yi; Foster, Mark; Cofer, Gary P; Medvitz, Neil; Buckley, Anne F; Badea, Andreas K; Wetsel, William C; Colton, Carol A

    2016-11-15

    Multivariate biomarkers are needed for detecting Alzheimer's disease (AD), understanding its etiology, and quantifying the effect of therapies. Mouse models provide opportunities to study characteristics of AD in well-controlled environments that can help facilitate development of early interventions. The CVN-AD mouse model replicates multiple AD hallmark pathologies, and we identified multivariate biomarkers characterizing a brain circuit disruption predictive of cognitive decline. In vivo and ex vivo magnetic resonance imaging (MRI) revealed that CVN-AD mice replicate the hippocampal atrophy (6%), characteristic of humans with AD, and also present changes in subcortical areas. The largest effect was in the fornix (23% smaller), which connects the septum, hippocampus, and hypothalamus. In characterizing the fornix with diffusion tensor imaging, fractional anisotropy was most sensitive (20% reduction), followed by radial (15%) and axial diffusivity (2%), in detecting pathological changes. These findings were strengthened by optical microscopy and ultrastructural analyses. Ultrastructual analysis provided estimates of axonal density, diameters, and myelination-through the g-ratio, defined as the ratio between the axonal diameter, and the diameter of the axon plus the myelin sheath. The fornix had reduced axonal density (47% fewer), axonal degeneration (13% larger axons), and abnormal myelination (1.5% smaller g-ratios). CD68 staining showed that white matter pathology could be secondary to neuronal degeneration, or due to direct microglial attack. In conclusion, these findings strengthen the hypothesis that the fornix plays a role in AD, and can be used as a disease biomarker and as a target for therapy.

  3. Guarana Provides Additional Stimulation over Caffeine Alone in the Planarian Model

    Science.gov (United States)

    Moustakas, Dimitrios; Mezzio, Michael; Rodriguez, Branden R.; Constable, Mic Andre; Mulligan, Margaret E.; Voura, Evelyn B.

    2015-01-01

    The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose. PMID:25880065

  4. Guarana provides additional stimulation over caffeine alone in the planarian model.

    Directory of Open Access Journals (Sweden)

    Dimitrios Moustakas

    Full Text Available The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose.

  5. Creating a market: an economic analysis of the purchaser-provider model.

    Science.gov (United States)

    Shackley, P; Healey, A

    1993-09-01

    The focus of this paper is the extent to which the purchaser-provider split and the creation of a market in the provision of health care can be expected to bring about greater efficiency within the new NHS. The starting point is a theoretical discussion of markets and competition. In particular, emphasis is placed upon the economic model of perfect competition. It is argued that because of the existence of externalities, uncertainty and a lack of perfect information, an unregulated market in health care will almost certainly fail. In view of this, the imperfect provider markets of monopoly and contestable markets, which are of particular relevance to health care, are discussed. A description of the new health care market and the principal actors within it is followed by an evaluation of the new health care market. It is argued that in view of the restrictions to competition that exist between providers, some form of price regulation will be necessary to prevent monopolistic behaviour in the hospital sector. Regulation of purchasers is also suggested as a means of improving efficiency. It is concluded that competition may be a necessary condition for increased efficiency in health care provision, but is not sufficient in itself. Other incentives in the hospital sector are necessary to assist the market process and to enhance its impact on efficiency.

  6. MODEL REQUEST FOR PROPOSALS TO PROVIDE ENERGY AND OTHER ATTRIBUTES FROM AN OFFSHORE WIND POWER PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Firestone; Dawn Kurtz Crompton

    2011-10-22

    This document provides a model RFP for new generation. The 'base' RFP is for a single-source offshore wind RFP. Required modifications are noted should a state or utility seek multi-source bids (e.g., all renewables or all sources). The model is premised on proposals meeting threshold requirements (e.g., a MW range of generating capacity and a range in terms of years), RFP issuer preferences (e.g., likelihood of commercial operation by a date certain, price certainty, and reduction in congestion), and evaluation criteria, along with a series of plans (e.g., site, environmental effects, construction, community outreach, interconnection, etc.). The Model RFP places the most weight on project risk (45%), followed by project economics (35%), and environmental and social considerations (20%). However, if a multi-source RFP is put forward, the sponsor would need to either add per-MWh technology-specific, life-cycle climate (CO2), environmental and health impact costs to bid prices under the 'Project Economics' category or it should increase the weight given to the 'Environmental and Social Considerations' category.

  7. Mathematical modeling provides kinetic details of the human immune response to vaccination

    Directory of Open Access Journals (Sweden)

    Dustin eLe

    2015-01-01

    Full Text Available With major advances in experimental techniques to track antigen-specific immune responses many basic questions on the kinetics of virus-specific immunity in humans remain unanswered. To gain insights into kinetics of T and B cell responses in human volunteers we combine mathematical models and experimental data from recent studies employing vaccines against yellow fever and smallpox. Yellow fever virus-specific CD8 T cell population expanded slowly with the average doubling time of 2 days peaking 2.5 weeks post immunization. Interestingly, we found that the peak of the yellow fever-specific CD8 T cell response is determined by the rate of T cell proliferation and not by the precursor frequency of antigen-specific cells as has been suggested in several studies in mice. We also found that while the frequency of virus-specific T cells increases slowly, the slow increase can still accurately explain clearance of yellow fever virus in the blood. Our additional mathematical model describes well the kinetics of virus-specific antibody-secreting cell and antibody response to vaccinia virus in vaccinated individuals suggesting that most of antibodies in 3 months post immunization are derived from the population of circulating antibody-secreting cells. Taken together, our analysis provides novel insights into mechanisms by which live vaccines induce immunity to viral infections and highlight challenges of applying methods of mathematical modeling to the current, state-of-the-art yet limited immunological data.

  8. MODEL REQUEST FOR PROPOSALS TO PROVIDE ENERGY AND OTHER ATTRIBUTES FROM AN OFFSHORE WIND POWER PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Firestone; Dawn Kurtz Crompton

    2011-10-22

    This document provides a model RFP for new generation. The 'base' RFP is for a single-source offshore wind RFP. Required modifications are noted should a state or utility seek multi-source bids (e.g., all renewables or all sources). The model is premised on proposals meeting threshold requirements (e.g., a MW range of generating capacity and a range in terms of years), RFP issuer preferences (e.g., likelihood of commercial operation by a date certain, price certainty, and reduction in congestion), and evaluation criteria, along with a series of plans (e.g., site, environmental effects, construction, community outreach, interconnection, etc.). The Model RFP places the most weight on project risk (45%), followed by project economics (35%), and environmental and social considerations (20%). However, if a multi-source RFP is put forward, the sponsor would need to either add per-MWh technology-specific, life-cycle climate (CO2), environmental and health impact costs to bid prices under the 'Project Economics' category or it should increase the weight given to the 'Environmental and Social Considerations' category.

  9. Explaining German imports of olive oil: evidence from a gravity model

    OpenAIRE

    2008-01-01

    In this study the case of olive oil imports of Germany is examined since olive oil is a traditional Mediterranean commodity and Germany is the biggest importer in the EU. A gravity model has been employed so as to analyse those factors that explain the German imports of olive oil that were identified in a preceding analysis of the German olive oil supply chain. The results of two random-effects models corrected for serial correlation and heteroskedasticity suggest that being a Mediterranean P...

  10. The Importance and Weaknesses of the Productivist Industrial Model of Knowledge Production

    Science.gov (United States)

    Persson, Roland S.

    2010-01-01

    To view contemporary Science as an industry is a very apt and timely stance. Ghassib's (2010) historical analysis of knowledge production, which he terms "A Productivist Industrial Model of Knowledge Production," is an interesting one. It is important, however, to observe that the outline of this model is based entirely on the production of…

  11. Scientist Role Models in the Classroom: How Important Is Gender Matching?

    Science.gov (United States)

    Conner, Laura D. Carsten; Danielson, Jennifer

    2016-01-01

    Gender-matched role models are often proposed as a mechanism to increase identification with science among girls, with the ultimate aim of broadening participation in science. While there is a great deal of evidence suggesting that role models can be effective, there is mixed support in the literature for the importance of gender matching. We used…

  12. The common fate model for dyadic data: variations of a theoretically important but underutilized model.

    Science.gov (United States)

    Ledermann, Thomas; Kenny, David A

    2012-02-01

    Studying dyads, very often there is a theoretical construct that has an effect on both members, such as relationship harmony or shared environment. To model such influences, the common fate model (CFM) is often the most appropriate approach. In this article, we address conceptual and statistical issues in the use of the standard CFM and present a series of variations, all of which are estimated by structural equation modeling (SEM). For indistinguishable dyad members (e.g., gay couples), we describe the use of a multilevel SEM method. Throughout the paper, we draw connections to the actor-partner interdependence model (APIM). We also discuss the analysis of hybrid models that combines both the CFM and the APIM. The models are illustrated using data from heterosexual couples.

  13. Cross-entropy optimisation of importance sampling parameters for statistical model checking

    CERN Document Server

    Jégourel, Cyrille; Sedwards, Sean

    2012-01-01

    Statistical model checking avoids the exponential growth of states associated with probabilistic model checking by estimating properties from multiple executions of a system and by giving results within confidence bounds. Rare properties are often very important but pose a particular challenge for simulation-based approaches, hence a key objective under these circumstances is to reduce the number and length of simulations necessary to produce a given level of confidence. Importance sampling is a well-established technique that achieves this, however to maintain the advantages of statistical model checking it is necessary to find good importance sampling distributions without considering the entire state space. Motivated by the above, we present a simple algorithm that uses the notion of cross-entropy to find the optimal parameters for an importance sampling distribution. In contrast to previous work, our algorithm uses a low dimensional vector of parameters to define this distribution and thus avoids the ofte...

  14. The importance of the reference populations for coherent mortality forecasting models

    DEFF Research Database (Denmark)

    Kjærgaard, Søren; Canudas-Romo, Vladimir; Vaupel, James W.

    -population mortality models aiming to find the optimal of the set of countries to use as reference population and analyse the importance of the selection of countries. The two multi-population mortality models used are the Li-Lee model and the Double-Gap life expectancy forecasting model. The reference populations...... is calculated taking into account all the possible combinations of a set of 20 industrialized countries. The different reference populations possibilities are compared by their forecast performance. The results show that the selection of countries for multi-population mortality models has a significant effect...

  15. Modelling of Limestone Dissolution in Wet FGD Systems: The Importance of an Accurate Particle Size Distribution

    DEFF Research Database (Denmark)

    Kiil, Søren; Johnsson, Jan Erik; Dam-Johansen, Kim

    1999-01-01

    In wet flue gas desulphurisation (FGD) plants, the most common sorbent is limestone. Over the past 25 years, many attempts to model the transient dissolution of limestone particles in aqueous solutions have been performed, due to the importance for the development of reliable FGD simu-lation tools....... In this work, a critical examination of the models was conducted. The survey revealed that the models rely on the use of adjustable parameters in order to match experimental data. To investigate this, a simple particle model was set up. Model predictions were compared to experi-mental data for three different...

  16. A model of cell biological signaling predicts a phase transition of signaling and provides mathematical formulae.

    Science.gov (United States)

    Tsuruyama, Tatsuaki

    2014-01-01

    A biological signal is transmitted by interactions between signaling molecules in the cell. To date, there have been extensive studies regarding signaling pathways using numerical simulation of kinetic equations that are based on equations of continuity and Fick's law. To obtain a mathematical formulation of cell signaling, we propose a stability kinetic model of cell biological signaling of a simple two-parameter model based on the kinetics of the diffusion-limiting step. In the present model, the signaling is regulated by the binding of a cofactor, such as ATP. Non-linearity of the kinetics is given by the diffusion fluctuation in the interaction between signaling molecules, which is different from previous works that hypothesized autocatalytic reactions. Numerical simulations showed the presence of a critical concentration of the cofactor beyond which the cell signaling molecule concentration is altered in a chaos-like oscillation with frequency, which is similar to a discontinuous phase transition in physics. Notably, we found that the frequency is given by the logarithm function of the difference of the outside cofactor concentration from the critical concentration. This implies that the outside alteration of the cofactor concentration is transformed into the oscillatory alteration of cell inner signaling. Further, mathematical stability kinetic analysis predicted a discontinuous dynamic phase transition in the critical state at which the cofactor concentration is equivalent to the critical concentration. In conclusion, the present model illustrates a unique feature of cell signaling, and the stability analysis may provide an analytical framework of the cell signaling system and a novel formulation of biological signaling.

  17. ARIMA MODEL BUILDING AND FORECASTING ON IMPORTS AND EXPORTS OF PAKISTAN

    Directory of Open Access Journals (Sweden)

    Ahmad Farooqi

    2014-08-01

    Full Text Available From the day one, mankind has always been interested in to the future. As the civilization advanced with growing sophistication in all phases of life, the need to look in to the future also grew with it. Today every government, public private organizations, as well as an individual would like to predict and plan for the future. In order to attain a better growth in the economy of a country, modeling and forecasting is the most important tool now a day, this can be done by one of the statistical technique called a Time series analysis. In this paper we tried to build a time series model called ARIMA (Auto Regressive Integrated Moving Average model with particular reference of Box and Jenkins approach on annually total Imports and Exports of Pakistan from the year 1947 to the year 2013 with useful statistical software R. Validity of the fitted model is tested using standard statistical techniques. The fitted model is then use to forecast some future values of Imports and export of Pakistan. It is found that an ARIMA (2, 2, 2 and ARIMA (1, 2, 2 model looks suitable to forecast the annual Imports and Exports of Pakistan respectively. We also found an increasing trend both in case of Imports and Exports during this study.

  18. Growth and division of active droplets provides a model for protocells

    Science.gov (United States)

    Zwicker, David; Seyboldt, Rabea; Weber, Christoph A.; Hyman, Anthony A.; Jülicher, Frank

    2017-04-01

    It has been proposed that during the early steps in the origin of life, small droplets could have formed via the segregation of molecules from complex mixtures by phase separation. These droplets could have provided chemical reaction centres. However, whether these droplets could divide and propagate is unclear. Here we examine the behaviour of droplets in systems that are maintained away from thermodynamic equilibrium by an external supply of energy. In these systems, droplets grow by the addition of droplet material generated by chemical reactions. Surprisingly, we find that chemically driven droplet growth can lead to shape instabilities that trigger the division of droplets into two smaller daughters. Therefore, chemically active droplets can exhibit cycles of growth and division that resemble the proliferation of living cells. Dividing active droplets could serve as a model for prebiotic protocells, where chemical reactions in the droplet play the role of a prebiotic metabolism.

  19. Integration of remotely sensed and model data to provide the spatial information basis for sustainable landuse

    Science.gov (United States)

    Backhaus, R.; Braun, G.

    Sustainable development is by now generally accepted as the paramount objective of environmental policy. Environmental applications of Earth observation, on the other hand, have been successfully demonstrated over a wide range of monitoring activities, mostly with the aim of describing the spatial distribution and time course of geophysical parameters and land surface structures. With landuse structures being of major influence on the sustainability of terrestrial ecosystems, and being also a highly suitable object of Earth observation, it is still an open question, however, in which way Earth observation data can be processed and integrated to provide an approximate indicator of sustainability. Based on an ecological sustainability model developed by Ripl and his co-workers at Berlin Technical University, this question was investigated in the framework of the joint project "Development of a Land-Water-Management Concept to Decrease Matter Losses to Open Waters" (Stör project), which was funded by the German Federal Ministry of Research and Technology. Present results may be summarized as follows: 1. Apart from hydrological point measurements, there are several spatial parameters which are of indicative value as to sustainability, especially the spatio-temporal distribution of biomass, surface temperature, and precipitation. 2. To provide the spatial information basis for enhanced efficiency of immediate measures such as reforestation, agricultural extension etc., a global information system (GIS) concept was developed and demonstrated which is based on a landuse/vegetation classification derived from Landsat TM data, a digital evaluation mode (DEM) and a relief dependent water distribution model (WDM). Further implications such as the organisation of information systems which are to serve sustainability strategies are discussed.

  20. The Importance of Older Family Members in Providing Social Resources and Promoting Cancer Screening in Families with a Hereditary Cancer Syndrome

    Science.gov (United States)

    Ashida, Sato; Hadley, Donald W.; Goergen, Andrea F.; Skapinsky, Kaley F.; Devlin, Hillary C.; Koehly, Laura M.

    2011-01-01

    Purpose: This study evaluates the role of older family members as providers of social resources within familial network systems affected by an inherited cancer susceptibility syndrome. Design and Methods: Respondents who previously participated in a study that involved genetic counseling and testing for Lynch syndrome and their family network…

  1. Immunization of stromal cell targeting fibroblast activation protein providing immunotherapy to breast cancer mouse model.

    Science.gov (United States)

    Meng, Mingyao; Wang, Wenju; Yan, Jun; Tan, Jing; Liao, Liwei; Shi, Jianlin; Wei, Chuanyu; Xie, Yanhua; Jin, Xingfang; Yang, Li; Jin, Qing; Zhu, Huirong; Tan, Weiwei; Yang, Fang; Hou, Zongliu

    2016-08-01

    Unlike heterogeneous tumor cells, cancer-associated fibroblasts (CAF) are genetically more stable which serve as a reliable target for tumor immunotherapy. Fibroblast activation protein (FAP) which is restrictively expressed in tumor cells and CAF in vivo and plays a prominent role in tumor initiation, progression, and metastasis can function as a tumor rejection antigen. In the current study, we have constructed artificial FAP(+) stromal cells which mimicked the FAP(+) CAF in vivo. We immunized a breast cancer mouse model with FAP(+) stromal cells to perform immunotherapy against FAP(+) cells in the tumor microenvironment. By forced expression of FAP, we have obtained FAP(+) stromal cells whose phenotype was CD11b(+)/CD34(+)/Sca-1(+)/FSP-1(+)/MHC class I(+). Interestingly, proliferation capacity of the fibroblasts was significantly enhanced by FAP. In the breast cancer-bearing mouse model, vaccination with FAP(+) stromal cells has significantly inhibited the growth of allograft tumor and reduced lung metastasis indeed. Depletion of T cell assays has suggested that both CD4(+) and CD8(+) T cells were involved in the tumor cytotoxic immune response. Furthermore, tumor tissue from FAP-immunized mice revealed that targeting FAP(+) CAF has induced apoptosis and decreased collagen type I and CD31 expression in the tumor microenvironment. These results implicated that immunization with FAP(+) stromal cells led to the disruption of the tumor microenvironment. Our study may provide a novel strategy for immunotherapy of a broad range of cancer.

  2. Mouse xenograft modeling of human adult acute lymphoblastic leukemia provides mechanistic insights into adult LIC biology

    Science.gov (United States)

    Dey, Aditi; Castleton, Anna Z.; Schwab, Claire; Samuel, Edward; Sivakumaran, Janani; Beaton, Brendan; Zareian, Nahid; Zhang, Christie Yu; Rai, Lena; Enver, Tariq; Moorman, Anthony V.; Fielding, Adele K.

    2014-01-01

    The distinct nature of acute lymphoblastic leukemia (ALL) in adults, evidenced by inferior treatment outcome and different genetic landscape, mandates specific studies of disease-initiating mechanisms. In this study, we used NOD/LtSz-scid IL2Rγ nullc (NSG) mouse xenotransplantation approaches to elucidate leukemia-initiating cell (LIC) biology in primary adult precursor B (pre-B) ALL to optimize disease modeling. In contrast with xenografting studies of pediatric ALL, we found that modification of the NSG host environment using preconditioning total body irradiation (TBI) was indispensable for efficient engraftment of adult non-t(4;11) pre-B ALL, whereas t(4;11) pre-B ALL was successfully reconstituted without this adaptation. Furthermore, TBI-based xenotransplantation of non-t(4;11) pre-B ALL enabled detection of a high frequency of LICs (<1:6900) and permitted frank leukemic engraftment from a remission sample containing drug-resistant minimal residual disease. Investigation of TBI-sensitive stromal-derived factor-1/chemokine receptor type 4 signaling revealed greater functional dependence of non-t(4;11) pre-B ALL on this niche-based interaction, providing a possible basis for the differential engraftment behavior. Thus, our studies establish the optimal conditions for experimental modeling of human adult pre-B ALL and demonstrate the critical protumorogenic role of microenvironment-derived SDF-1 in regulating adult pre-B LIC activity that may present a therapeutic opportunity. PMID:24825861

  3. A multi-objective location-inventory model for 3PL providers with sustainable considerations under uncertainty

    Directory of Open Access Journals (Sweden)

    R. Daghigh

    2016-09-01

    Full Text Available In recent years, logistics development is considered as an important aspect of any country’s development. Outsourcing logistics activities to third party logistics (3PL providers is a common way to achieve logistics development. On the other hand, globalization and increasing customers’ concern about the environmental impact of activities as well as the appearance of the issue of social responsibility have led companies employ sustainable supply chain management, which considers economic, environmental and social benefits, simultaneously. This paper proposes a multi-objective model to design logistics network for 3PL providers by considering sustainable objectives under uncertainty. Objective functions include minimizing the total cost, minimizing greenhouse gas emission and maximizing social responsibility subject to fair access to products, number of created job opportunities and local community development. It is worth mentioning that in the present paper the perishability of products is also considered. A numerical example is provided to solve and validate model using augmented Epsilon-Constraint method. The results show that three sustainable objectives were in conflict and as the one receives more desirable values, the others fall into more undesirable values. In addition, by increasing maximum perishable time periods and by considering lateral transshipment among facilities of a level one can improve sustainability indices of the problem, which indicates the necessity of such policy in improving network sustainability.

  4. The importance of accounting for the uncertainty of published prognostic model estimates.

    Science.gov (United States)

    Young, Tracey A; Thompson, Simon

    2004-01-01

    Reported is the importance of properly reflecting uncertainty associated with prognostic model estimates when calculating the survival benefit of a treatment or technology, using liver transplantation as an example. Monte Carlo simulation techniques were used to account for the uncertainty of prognostic model estimates using the standard errors of the regression coefficients and their correlations. These methods were applied to patients with primary biliary cirrhosis undergoing liver transplantation using a prognostic model from a historic cohort who did not undergo transplantation. The survival gain over 4 years from transplantation was estimated. Ignoring the uncertainty in the prognostic model, the estimated survival benefit of liver transplantation was 16.7 months (95 percent confidence interval [CI], 13.5 to 20.1), and was statistically significant (p important that the precision of regression coefficients is available for users of published prognostic models. Ignoring this additional information substantially underestimates uncertainty, which can then impact misleadingly on policy decisions.

  5. Modeling self on others: An import theory of subjectivity and selfhood.

    Science.gov (United States)

    Prinz, Wolfgang

    2017-03-01

    This paper outlines an Import Theory of subjectivity and selfhood. Import theory claims that subjectivity is initially perceived as a key feature of other minds before it then becomes imported from other minds to own minds whereby it lays the ground for mental selfhood. Import theory builds on perception-production matching, which in turn draws on both representational mechanisms and social practices. Representational mechanisms rely on common coding of perception and production. Social practices rely on action mirroring in dyadic interactions. The interplay between mechanisms and practices gives rise to model self on others. Individuals become intentional agents in virtue of perceiving others mirroring themselves. The outline of the theory is preceded by an introductory section that locates import theory in the broader context of competing approaches, and it is followed by a concluding section that assesses import theory in terms of empirical evidence and explanatory power.

  6. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence.

    Science.gov (United States)

    Mazzacavallo, Michael G; Kulmatiski, Andrew

    2015-01-01

    Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D). The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0-20 cm) and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20-90 cm), the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone.

  7. The Evidence in Support of Physicians and Health Care Providers as Physical Activity Role Models

    Science.gov (United States)

    Lobelo, Felipe; de Quevedo, Isabel Garcia

    2015-01-01

    Physical inactivity constitutes the fourth leading cause of death worldwide. Health care providers (HCPs) should play a key role in counseling and appropriately referring their patients to adopt physical activity (PA). Previous reports suggest that active HCPs are more likely to provide better, more credible, and motivating preventive counseling to their patients. This review summarizes the available evidence on the association between HCPs’ personal PA habits and their related PA counseling practices. Based on relevant studies, a snowball search strategy identified, out of 196 studies screened, a total of 47 pertinent articles published between 1979 and 2012. Of those, 23 described HCPs’ PA habits and/or their counseling practices and 24 analytic studies evaluated the association between HCPs’ personal PA habits and their PA counseling practices. The majority of studies came from the United States (n = 33), and 9 studies included nonphysicians (nurses, pharmacists, and other HCPs). PA levels were mostly self-reported, and counseling was typically assessed as self-reported frequency or perceived self-efficacy in clinical practice. Most (19 out of 24) analytic studies reported a significant positive association between HCPs’ PA habits and counseling frequency, with odds ratios ranging between 1.4 and 5.7 (P < .05), in 6 studies allowing direct comparison. This review found consistent evidence supporting the notion that physically active physicians and other HCPs are more likely to provide PA counseling to their patients and can indeed become powerful PA role models. This evidence appears sufficient to justify randomized trials to determine if adding interventions to promote PA among HCPs, also results in improvements in the frequency and quality of PA preventive counseling and referrals, delivered by HCPs, to patients in primary care settings. Future studies should also aim at objectively quantifying the effect of HCPs’ PA role-modeling and how it

  8. Hoxb8 conditionally immortalised macrophage lines model inflammatory monocytic cells with important similarity to dendritic cells.

    Science.gov (United States)

    Rosas, Marcela; Osorio, Fabiola; Robinson, Matthew J; Davies, Luke C; Dierkes, Nicola; Jones, Simon A; Reis e Sousa, Caetano; Taylor, Philip R

    2011-02-01

    We have examined the potential to generate bona fide macrophages (MØ) from conditionally immortalised murine bone marrow precursors. MØ can be derived from Hoxb8 conditionally immortalised macrophage precursor cell lines (MØP) using either M-CSF or GM-CSF. When differentiated in GM-CSF (GM-MØP) the resultant cells resemble GM-CSF bone marrow-derived dendritic cells (BMDC) in morphological phenotype, antigen phenotype and functional responses to microbial stimuli. In spite of this high similarity between the two cell types and the ability of GM-MØP to effectively present antigen to a T-cell hybridoma, these cells are comparatively poor at priming the expansion of IFN-γ responses from naïve CD4(+) T cells. The generation of MØP from transgenic or genetically aberrant mice provides an excellent opportunity to study the inflammatory role of GM-MØP, and reduces the need for mouse colonies in many studies. Hence differentiation of conditionally immortalised MØPs in GM-CSF represents a unique in vitro model of inflammatory monocyte-like cells, with important differences from bone marrow-derived dendritic cells, which will facilitate functional studies relating to the many 'sub-phenotypes' of inflammatory monocytes.

  9. Comparative Cytogenetics between Two Important Songbird, Models: The Zebra Finch and the Canary.

    Science.gov (United States)

    Dos Santos, Michelly da Silva; Kretschmer, Rafael; Frankl-Vilches, Carolina; Bakker, Antje; Gahr, Manfred; O Brien, Patricia C M; Ferguson-Smith, Malcolm A; de Oliveira, Edivaldo H C

    2017-01-01

    Songbird species (order Passeriformes, suborder Oscines) are important models in various experimental fields spanning behavioural genomics to neurobiology. Although the genomes of some songbird species were sequenced recently, the chromosomal organization of these species is mostly unknown. Here we focused on the two most studied songbird species in neuroscience, the zebra finch (Taeniopygia guttata) and the canary (Serinus canaria). In order to clarify these issues and also to integrate chromosome data with their assembled genomes, we used classical and molecular cytogenetics in both zebra finch and canary to define their chromosomal homology, localization of heterochromatic blocks and distribution of rDNA clusters. We confirmed the same diploid number (2n = 80) in both species, as previously reported. FISH experiments confirmed the occurrence of multiple paracentric and pericentric inversions previously found in other species of Passeriformes, providing a cytogenetic signature for this order, and corroborating data from in silico analyses. Additionally, compared to other Passeriformes, we detected differences in the zebra finch karyotype concerning the morphology of some chromosomes, in the distribution of 5S rDNA clusters, and an inversion in chromosome 1.

  10. Comparative Cytogenetics between Two Important Songbird, Models: The Zebra Finch and the Canary

    Science.gov (United States)

    dos Santos, Michelly da Silva; Kretschmer, Rafael; Frankl-Vilches, Carolina; Bakker, Antje; Gahr, Manfred; O´Brien, Patricia C. M.; Ferguson-Smith, Malcolm A.

    2017-01-01

    Songbird species (order Passeriformes, suborder Oscines) are important models in various experimental fields spanning behavioural genomics to neurobiology. Although the genomes of some songbird species were sequenced recently, the chromosomal organization of these species is mostly unknown. Here we focused on the two most studied songbird species in neuroscience, the zebra finch (Taeniopygia guttata) and the canary (Serinus canaria). In order to clarify these issues and also to integrate chromosome data with their assembled genomes, we used classical and molecular cytogenetics in both zebra finch and canary to define their chromosomal homology, localization of heterochromatic blocks and distribution of rDNA clusters. We confirmed the same diploid number (2n = 80) in both species, as previously reported. FISH experiments confirmed the occurrence of multiple paracentric and pericentric inversions previously found in other species of Passeriformes, providing a cytogenetic signature for this order, and corroborating data from in silico analyses. Additionally, compared to other Passeriformes, we detected differences in the zebra finch karyotype concerning the morphology of some chromosomes, in the distribution of 5S rDNA clusters, and an inversion in chromosome 1. PMID:28129381

  11. Characteristics of primary care providers who adopted the hospitalist model from 2001 to 2009.

    Science.gov (United States)

    Boonyasai, Romsai T; Lin, Yu-Li; Brotman, Daniel J; Kuo, Yong-Fang; Goodwin, James S

    2015-02-01

    The characteristics of primary care providers (PCPs) who use hospitalists are unknown. Retrospective study using 100% Texas Medicare claims from 2001 through 2009. Descriptive statistics characterized proportion of PCPs using hospitalists over time. Trajectory analysis and multilevel models of 1172 PCPs with ≥20 inpatients in every study year characterized how PCPs adopted the hospitalist model and PCP factors associated with this transition. Hospitalist use increased between 2001 and 2009. PCPs who adopted the hospitalist model transitioned rapidly. In multilevel models, hospitalist use was associated with US training (odds ratio [OR] 1.46, 95% confidence interval [CI]: 1.23-1.73 in 2007-2009), family medicine specialty (OR: 1.46, 95% CI: 1.25-1.70 in 2007-2009), and having high outpatient volumes (OR: 1.32, 95% CI: 1.20-1.44 in 2007-2009). Over time, relative hospitalist use decreased among female PCPs (OR: 1.91, 95% CI: 1.46-2.50 in 2001-2003; OR: 1.50, 95% CI: 1.15-1.95 in 2007-2009), those in urban locations (OR: 3.34, 95% CI: 2.72-4.09 in 2001-2003; OR: 2.22, 95% CI: 1.82-2.71 in 2007-2009), and those with higher inpatient volumes (OR: 1.05, 95% CI: 0.95-1.18 in 2001-2003; OR: 0.55, 95% CI: 0.51-0.60 in 2007-2009). Longest-practicing PCPs were more likely to transition in the early 2000s, but this effect disappeared by the end of the study period (OR: 1.35, 95% CI: 1.06-1.72 in 2001-2003; OR: 0.92, 95% CI: 0.73-1.17 in 2007-2009). PCPs with practice panels dominated by patients who were white, male, or had comorbidities are more likely to use hospitalists. PCP characteristics are associated with hospitalist use. The association between PCP characteristics and hospitalist use has evolved over time. © 2015 Society of Hospital Medicine.

  12. Trichodiene Production in a Trichoderma harzianum erg1-Silenced Strain Provides Evidence of the Importance of the Sterol Biosynthetic Pathway in Inducing Plant Defense-Related Gene Expression.

    Science.gov (United States)

    Malmierca, M G; McCormick, S P; Cardoza, R E; Monte, E; Alexander, N J; Gutiérrez, S

    2015-11-01

    Trichoderma species are often used as biocontrol agents against plant-pathogenic fungi. A complex molecular interaction occurs among the biocontrol agent, the antagonistic fungus, and the plant. Terpenes and sterols produced by the biocontrol fungus have been found to affect gene expression in both the antagonistic fungus and the plant. The terpene trichodiene (TD) elicits the expression of genes related to tomato defense and to Botrytis virulence. We show here that TD itself is able to induce the expression of Botrytis genes involved in the synthesis of botrydial (BOT) and also induces terpene gene expression in Trichoderma spp. The terpene ergosterol, in addition to its role as a structural component of the fungal cell membranes, acts as an elicitor of defense response in plants. In the present work, using a transformant of T. harzianum, which is silenced in the erg1 gene and accumulates high levels of squalene, we show that this ergosterol precursor also acts as an important elicitor molecule of tomato defense-related genes and induces Botrytis genes involved in BOT biosynthesis, in both cases, in a concentration-dependent manner. Our data emphasize the importance of a balance of squalene and ergosterol in fungal interactions as well as in the biocontrol activity of Trichoderma spp.

  13. Importance of fossil fuel emission uncertainties over Europe for CO2 modeling: model intercomparison

    Directory of Open Access Journals (Sweden)

    F. Delage

    2011-07-01

    Full Text Available Inverse modeling techniques used to quantify surface carbon fluxes commonly assume that the uncertainty of fossil fuel CO2 (FFCO2 emissions is negligible and that intra-annual variations can be neglected. To investigate these assumptions, we analyzed the differences between four fossil fuel emission inventories with spatial and temporal differences over Europe and their impact on the model simulated CO2 concentration. Large temporal flux variations characterize the hourly fields (~40 % and ~80 % for the seasonal and diurnal cycles, peak-to-peak and annual country totals differ by 10 % on average and up to 40 % for some countries (i.e., the Netherlands. These emissions have been prescribed to seven different transport models, resulting in 28 different FFCO2 concentrations fields. The modeled FFCO2 concentration time series at surface sites using time-varying emissions show larger seasonal cycles (+2 ppm at the Hungarian tall tower (HUN and smaller diurnal cycles in summer (−1 ppm at HUN than when using constant emissions. The concentration range spanned by all simulations varies between stations, and is generally larger in winter (up to ~10 ppm peak-to-peak at HUN than in summer (~5 ppm. The contribution of transport model differences to the simulated concentration std-dev is 2–3 times larger than the contribution of emission differences only, at typical European sites used in global inversions. These contributions to the hourly (monthly std-dev's amount to ~1.2 (0.8 ppm and ~0.4 (0.3 ppm for transport and emissions, respectively. First comparisons of the modeled concentrations with 14C-based fossil fuel CO2 observations show that the large transport differences still hamper a quantitative evaluation/validation of the emission inventories. Changes in the estimated monthly biosphere flux (Fbio over Europe, using two inverse modeling approaches, are relatively small (less that 5 % while changes in annual Fbio (up to ~0.15 % GtC yr−1 are only

  14. The importance of behavior theory in control system modeling of physical activity sensor data.

    Science.gov (United States)

    Riley, William T; Martin, Cesar A; Rivera, Daniel E

    2014-01-01

    Among health behaviors, physical activity has the most extensive record of research using passive sensors. Control systems and other system dynamic approaches have long been considered applicable for understanding human behavior, but only recently has the technology provided the precise and intensive longitudinal data required for these analytic approaches. Although sensors provide intensive data on the patterns and variations of physical activity over time, the influences of these variations are often unmeasured. Health behavior theories provide an explanatory framework of the putative mediators of physical activity changes. Incorporating the intensive longitudinal measurement of these theoretical constructs is critical to improving the fit of control system model of physical activity and for advancing behavioral theory. Theory-based control models also provide guidance on the nature of the controllers which serve as the basis for just-in-time adaptive interventions based on these control system models.

  15. Logoplaste : how business models can play an important role in the achievement of sustained competitive advantage

    OpenAIRE

    Pita, Miguel Vieira

    2011-01-01

    Dissertation title: Logoplaste: How Business Models can play an important role in the achievement of Sustained Competitive Advantage Author: Miguel Vieira Pita The following dissertation gives focus to the case study of Logoplaste, a successful Portuguese company where strategy plays an important role in the short and long term success of the company. Focusing on writing a dissertation that gives highlight to the creation and development of the firm’s valuable resources and ...

  16. Importance of demand modelling in network water quality models: a review

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Buchberger, S.G.; Van Dijk, J.C.

    2008-01-01

    Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological) contaminant propagation; for particulate substance

  17. Importance of demand modelling in network water quality models: a review

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Buchberger, S.G.; Van Dijk, J.C.

    2008-01-01

    Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological) contaminant propagation; for particulate substance

  18. Importance of fossil fuel emission uncertainties over Europe for CO2 modeling: model intercomparison

    NARCIS (Netherlands)

    Peylin, P.; Houweling, S.; Krol, M.C.|info:eu-repo/dai/nl/078760410; Karstens, U.; Pieterse, G.|info:eu-repo/dai/nl/304840858; Ciais, P.; Heimann, M.

    2011-01-01

    Inverse modeling techniques used to quantify surface carbon fluxes commonly assume that the uncertainty of fossil fuel CO2 (FFCO2) emissions is negligible and that intra-annual variations can be neglected. To investigate these assumptions, we analyzed the differences between four fossil fuel

  19. Moving From Digitalization to Digitization in Cardiovascular Care: Why Is it Important, and What Could it Mean for Patients and Providers?

    Science.gov (United States)

    Steinhubl, Steven R; Topol, Eric J

    2015-09-29

    So far, the digitization of health care is best exemplified by electronic medical records, which have been far from favorably or uniformly accepted. However, properly implemented digitization can enable better patient outcomes, improve convenience, potentially lower healthcare costs, and possibly lead to much greater physician satisfaction. Precision (also known as personalized or individualized) medicine is frequently discussed today, but, in reality, it is what physicians have attempted to do as best they could for millennia. But now we have new tools that can begin to give us a much more high-definition view of our patients; from affordable and rapid genetic testing to wearable sensors that track a wide range of important physiologic parameters continuously. Although seemingly counterintuitive, the digitization of health care can also markedly improve the physician-patient relationship, allowing more time for human interaction when care is bolstered by digital technologies that better individualize diagnostics and treatments.

  20. Editorial to: Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes by Sucha et al

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, F.E.C.M. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Kietselaer, B.L.J.H. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands)

    2016-04-15

    Over the last years a growing number of prosthetic heart valve (PHV) implantation procedures have been performed in sequence with the aging of the population and improving surgical techniques. Currently, echocardiography is the most important tool in the follow-up and evaluation of complications associated with the PHV (pannus, thrombus, endocarditis). However, echocardiographic examination of PHV associated disease may be hampered by poor acoustic window or scatter artefacts caused by the PHV. PHV related disease such as endocarditis is related with a poor prognosis, especially when complications such as periannular abscess formation occurs. Early treatment of PHV associated disease improves prognosis. Therefore, an unmet clinical need for early detection of complications exists. In the evaluation of PHV (dys)function, multidetector-row computed tomography (MDCT) has shown to be of additive value. A necessity for MDCT to be implemented in daily practice is to be able to distinguish between normal and pathological features. (orig.)

  1. Estimated Nutritive Value of Low-Price Model Lunch Sets Provided to Garment Workers in Cambodia

    Directory of Open Access Journals (Sweden)

    Jan Makurat

    2017-07-01

    Full Text Available Background: The establishment of staff canteens is expected to improve the nutritional situation of Cambodian garment workers. The objective of this study is to assess the nutritive value of low-price model lunch sets provided at a garment factory in Phnom Penh, Cambodia. Methods: Exemplary lunch sets were served to female workers through a temporary canteen at a garment factory in Phnom Penh. Dish samples were collected repeatedly to examine mean serving sizes of individual ingredients. Food composition tables and NutriSurvey software were used to assess mean amounts and contributions to recommended dietary allowances (RDAs or adequate intake of energy, macronutrients, dietary fiber, vitamin C (VitC, iron, vitamin A (VitA, folate and vitamin B12 (VitB12. Results: On average, lunch sets provided roughly one third of RDA or adequate intake of energy, carbohydrates, fat and dietary fiber. Contribution to RDA of protein was high (46% RDA. The sets contained a high mean share of VitC (159% RDA, VitA (66% RDA, and folate (44% RDA, but were low in VitB12 (29% RDA and iron (20% RDA. Conclusions: Overall, lunches satisfied recommendations of caloric content and macronutrient composition. Sets on average contained a beneficial amount of VitC, VitA and folate. Adjustments are needed for a higher iron content. Alternative iron-rich foods are expected to be better suited, compared to increasing portions of costly meat/fish components. Lunch provision at Cambodian garment factories holds the potential to improve food security of workers, approximately at costs of <1 USD/person/day at large scale. Data on quantitative total dietary intake as well as physical activity among workers are needed to further optimize the concept of staff canteens.

  2. Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model

    Energy Technology Data Exchange (ETDEWEB)

    Roth, R; Navratil, P

    2007-05-22

    We propose an importance truncation scheme for the no-core shell model, which enables converged calculations for nuclei well beyond the p-shell. It is based on an a priori measure for the importance of individual basis states constructed by means of many-body perturbation theory. Only the physically relevant states of the no-core model space are considered, which leads to a dramatic reduction of the basis dimension. We analyze the validity and efficiency of this truncation scheme using different realistic nucleon-nucleon interactions and compare to conventional no-core shell model calculations for {sup 4}He and {sup 16}O. Then, we present the first converged calculations for the ground state of {sup 40}Ca within no-core model spaces including up to 16{h_bar}{Omega}-excitations using realistic low-momentum interactions. The scheme is universal and can be easily applied to other quantum many-body problems.

  3. AN ECONOMIC MODEL OF U.S. IMPORTS OF BUTTER AND MILK FAT PRODUCTS

    OpenAIRE

    Bailey, Kenneth W.; Wu, Zhen

    2005-01-01

    This study developed a model to explain monthly imports of butter and butter substitutes. The U.S. imports butter and other high milk fat products that can substitute for a strict definition of butter. These products include dairy spreads, butter substitutes, anhydrous milk fat, and food preparations. The U.S. imports these high milk fat products under a tariff-rate quota system (TRQ) implemented by the World Trade Organization (WTO). This study quantified all the milk fat contained in U.S. b...

  4. Determining relative importance of variables in developing and validating predictive models

    Directory of Open Access Journals (Sweden)

    Atenafu Eshetu G

    2009-09-01

    Full Text Available Abstract Background Multiple regression models are used in a wide range of scientific disciplines and automated model selection procedures are frequently used to identify independent predictors. However, determination of relative importance of potential predictors and validating the fitted models for their stability, predictive accuracy and generalizability are often overlooked or not done thoroughly. Methods Using a case study aimed at predicting children with acute lymphoblastic leukemia (ALL who are at low risk of Tumor Lysis Syndrome (TLS, we propose and compare two strategies, bootstrapping and random split of data, for ordering potential predictors according to their relative importance with respect to model stability and generalizability. We also propose an approach based on relative increase in percentage of explained variation and area under the Receiver Operating Characteristic (ROC curve for developing models where variables from our ordered list enter the model according to their importance. An additional data set aimed at identifying predictors of prostate cancer penetration is also used for illustrative purposes. Results Age is chosen to be the most important predictor of TLS. It is selected 100% of the time using the bootstrapping approach. Using the random split method, it is selected 99% of the time in the training data and is significant (at 5% level 98% of the time in the validation data set. This indicates that age is a stable predictor of TLS with good generalizability. The second most important variable is white blood cell count (WBC. Our methods also identified an important predictor of TLS that was otherwise omitted if relying on any of the automated model selection procedures alone. A group at low risk of TLS consists of children younger than 10 years of age, without T-cell immunophenotype, whose baseline WBC is 9/L and palpable spleen is Conclusion Our model selection procedures based on bootstrap re-sampling and

  5. An integrated Biophysical CGE model to provide Sustainable Development Goal insights

    Science.gov (United States)

    Sanchez, Marko; Cicowiez, Martin; Howells, Mark; Zepeda, Eduardo

    2016-04-01

    Future projected changes in the energy system will inevitably result in changes to the level of appropriation of environmental resources, particularly land and water, and this will have wider implications for environmental sustainability, and may affect other sectors of the economy. An integrated climate, land, energy and water (CLEW) system will provide useful insights, particularly with regard to the environmental sustainability. However, it will require adequate integration with other tools to detect economic impacts and broaden the scope for policy analysis. A computable general equilibrium (CGE) model is a well suited tool to channel impacts, as detected in a CLEW analysis, onto all sectors of the economy, and evaluate trade-offs and synergies, including those of possible policy responses. This paper will show an application of such integration in a single-country CGE model with the following key characteristics. Climate is partly exogenous (as proxied by temperature and rainfall) and partly endogenous (as proxied by emissions generated by different sectors) and has an impact on endogenous variables such as land productivity and labor productivity. Land is a factor of production used in agricultural and forestry activities which can be of various types if land use alternatives (e.g., deforestation) are to be considered. Energy is an input to the production process of all economic sectors and a consumption good for households. Because it is possible to allow for substitution among different energy sources (e.g. renewable vs non-renewable) in the generation of electricity, the production process of energy products can consider the use of natural resources such as oil and water. Water, data permitting, can be considered as an input into the production process of agricultural sectors, which is particularly relevant in case of irrigation. It can also be considered as a determinant of total factor productivity in hydro-power generation. The integration of a CLEW

  6. IMPORTANCE OF DIFFERENT MODELS IN DECISION MAKING, EXPLAINING THE STRATEGIC BEHAVIOR IN ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Cristiano de Oliveira Maciel

    2006-11-01

    Full Text Available This study is about the different models of decision process analyzing the organizational strategy. The article presents the strategy according to a cognitive approach. The discussion about that approach has three models of decision process: rational actor model, organizational behavior, and political model. These models, respectively, present some improvement in the decision making results, search for a good decision facing the cognitive restrictions of the administrator, and lots of talks for making a decision. According to the emphasis of each model, the possibilities for analyzing the strategy are presented. The article also shows that it is necessary to take into account the three different ways of analysis. That statement is justified once the analysis as well as the decision making become more complex, mainly those which are more important for the organizations.

  7. Aromatase inhibitor associated arthralgia: the importance of oncology provider-patient communication about side effects and potential management through physical activity.

    Science.gov (United States)

    Nyrop, Kirsten A; Callahan, Leigh F; Rini, Christine; Altpeter, Mary; Hackney, Betsy; DePue, Amy; Wilson, Anne; Schechter, Arielle; Muss, Hyman B

    2016-06-01

    Breast cancer survivors on aromatase inhibitors (AI) often experience side effects of joint pain, stiffness, or achiness (arthralgia). This study presents findings from a qualitative study of survivors on an AI regarding their knowledge of potential joint pain side effects and how both AI side effects and their management through moderate physical activity could be discussed during routine visits with their oncology provider. Qualitative data from semi-structured interviews were content analyzed for emergent themes. Descriptive statistics summarize sample characteristics. Our sample included 36 survivors, mean age of 67 (range 46-87); 86 % Caucasian and 70 % had education beyond high school. AI experience are as follows: 64 % anastrozole/Arimidex, 48 % letrozole/Femara, and 31 % exemestane/Aromasin. Participants expressed interest in having more information about potential joint pain side effects when the AI was prescribed so they could understand their joint symptoms when they appeared or intensified. They were relieved to learn that their joint symptoms were not unusual or "in their head." Participants would have been especially motivated to try walking as a way to manage their joint pain if physical activity had been recommended by their oncologist. Breast cancer survivors who are prescribed an AI as part of their adjuvant treatment want ongoing communication with their oncology provider about the potential for joint pain side effects and how these symptoms may be managed through regular physical activity. The prescription of an AI presents a "teachable moment" for oncologists to recommend and encourage their patients to engage in regular physical activity.

  8. Modeling the Variability and Importance of Snow Sublimation in the North-Central Colorado Rocky Mountains

    Science.gov (United States)

    Sexstone, G. A.; Clow, D. W.; Fassnacht, S. R.; Liston, G. E.; Hiemstra, C. A.; Knowles, J. F.

    2016-12-01

    In the western United States, where seasonal snowmelt is a critical water resource for ecological and anthropological needs, snow sublimation (sublimation) has been suggested by many studies to be an important component of the snow cover mass balance. However, few studies have evaluated the spatial and temporal variability of sublimation in complex mountainous environments. In this study, we use a process-based snow model (SnowModel) and eddy covariance (EC) measurements to evaluate the variability and importance of sublimation across the north-central Colorado Rocky Mountains for 5 water years (WY 2011 - WY 2015). In-situ EC observations of sublimation compare well with modeled sublimation at sites dominated by surface and canopy components of sublimation, but model verification of blowing sublimation in alpine areas was not feasible because these fluxes often occur when snow is in turbulent suspension, which cannot always be resolved by EC instrumentation. Model simulations showed substantial spatial and temporal variability of sublimation across the study domain. Sublimation rates were found to exhibit differences across landscape characteristics such as elevation and land cover. Land cover type was an important driver of snow sublimation variability, with substantial sublimation occurring in alpine and forested areas, and relatively lower sublimation occurring in open areas below treeline. Sublimation from forested areas accounted for the majority of modeled sublimation losses across the study domain and highlights the importance of sublimation from snow stored in the forest canopy in this region. Additionally, the interannual differences in total sublimation were strongly linked with seasonal snowfall amounts. Results from this study suggest that snow sublimation is a significant component of the winter water balance and have important implications for future water management and decision making.

  9. Capturing optically important constituents and properties in a marine biogeochemical and ecosystem model

    Science.gov (United States)

    Dutkiewicz, S.; Hickman, A. E.; Jahn, O.; Gregg, W. W.; Mouw, C. B.; Follows, M. J.

    2015-02-01

    We present a numerical model of the ocean that couples a three-stream radiative transfer component with a marine biogeochemical-ecosystem in a dynamic three-dimensional physical framework. The radiative transfer component resolves spectral irradiance as it is absorbed and scattered within the water column. We explicitly include the effect of several optically important water constituents (the phytoplankton community, detrital particles, and coloured dissolved organic matter, CDOM). The model is evaluated against in situ observed and satellite derived products. In particular we compare to concurrently measured biogeochemical, ecosystem and optical data along a north-south transect of the Atlantic Ocean. The simulation captures the patterns and magnitudes of these data, and estimates surface upwelling irradiance analogous to that observed by ocean colour satellite instruments. We conduct a series of sensitivity experiments to demonstrate, globally, the relative importance of each of the water constituents, and the crucial feedbacks between the light field and the relative fitness of phytoplankton types, and the biogeochemistry of the ocean. CDOM has proportionally more importance at short wavelengths and in more productive waters, phytoplankton absorption is especially important at the deep chlorophyll a (Chl a) maximum, and absorption by water molecules is relatively most important in the highly oligotrophic gyres. Sensitivity experiments in which absorption by any of the optical constituents was increased led to a decrease in the size of the oligotrophic regions of the subtropical gyres: lateral nutrient supplies were enhanced as a result of decreasing high latitude productivity. Scattering does not as strongly affect the ecosystem and biogeochemistry fields within the water column but is important for setting the surface upwelling irradiance, and hence sea surface reflectance. Having a model capable of capturing bio-optical feedbacks will be important for

  10. Explanatory models of diabetes in the U.S. and Mexico: the patient-provider gap and cultural competence.

    Science.gov (United States)

    Weller, Susan C; Baer, Roberta D; Garcia de Alba Garcia, Javier; Salcedo Rocha, Ana L

    2012-09-01

    Successful management of type 2 diabetes requires support and collaboration between diabetic patients, their health care providers, family and community. Using data collected in 1994-2001, we describe illness beliefs of physicians, patients, and representative samples of community members in the US and Mexico. We test whether differences in conceptualizations of diabetes are greater across national and linguistic boundaries or between physicians and lay groups. Interviews were conducted in southern Texas on the Mexican border and in Guadalajara, Mexico. Culturally appropriate interview materials were developed with a mixed-methods approach. Qualitative interviews elicited beliefs about causes, risks, symptoms, and treatments for diabetes and salient themes were incorporated into structured interviews. A cultural consensus analysis was used to verify salient themes within each of the six samples. The consistency in responses in each of the six samples indicated a shared core of beliefs that transcended individual variations. The greatest differences occurred between physician and lay samples; patient and community models were more similar to one another than to the physician models. Differences between physicians and patients may affect optimal management of diabetes, but these differences do not appear to be simply a function of differences in national culture and language, as the largest differences occurred in Mexico. This suggests that rather than cultural competence per se, formal educational levels and class differences may also play an important role in patient understanding and the gap in patient-provider understanding.

  11. Water quality modeling based on landscape analysis: Importance of riparian hydrology

    Science.gov (United States)

    Thomas Grabs

    2010-01-01

    Several studies in high-latitude catchments have demonstrated the importance of near-stream riparian zones as hydrogeochemical hotspots with a substantial influence on stream chemistry. An adequate representation of the spatial variability of riparian-zone processes and characteristics is the key for modeling spatiotemporal variations of stream-water quality. This...

  12. The importance of weather data in crop growth simulation models and assessment of climatic change effects

    NARCIS (Netherlands)

    Nonhebel, S.

    1993-01-01

    Yields of agricultural crops are largely determined by the weather conditions during the growing season. Weather data are therefore important input variables for crop growth simulation models. In practice, these data are accepted at their face value. This is not realistic. Like all measured

  13. Improving Adaptive Importance Sampling Simulation of Markovian Queueing Models using Non-parametric Smoothing

    NARCIS (Netherlands)

    Woudt, Edwin; de Boer, Pieter-Tjerk; van Ommeren, Jan C.W.

    2007-01-01

    Previous work on state-dependent adaptive importance sampling techniques for the simulation of rare events in Markovian queueing models used either no smoothing or a parametric smoothing technique, which was known to be non-optimal. In this paper, we introduce the use of kernel smoothing in this con

  14. Capturing optically important constituents and properties in a marine biogeochemical and ecosystem model

    Directory of Open Access Journals (Sweden)

    S. Dutkiewicz

    2015-07-01

    This new model that captures bio-optical feedbacks will be important for improving our understanding of the role of light and optical constituents on ocean biogeochemistry, especially in a changing environment. Further, resolving surface upwelling irradiance will make it easier to connect to satellite-derived products in the future.

  15. The Importance of Positive Self-Concept for Islamic Education Teachers as a Role Model

    Science.gov (United States)

    Muhamad, Nurul Asiah Fasehah; Hamzah, Mohd Isa; Tamuri, Ab. Halim; Ja'afar, Noornajihan; Ghazali, Norzulaili Mohd; Amat, Robiatul Adawiyah Mohd; Raus, Norakyairee Mohd; Hassan, Syed Najihuddin Syed

    2013-01-01

    This study embarks from the great and huge responsibility of teachers nowadays especially the IRT (Islamic religious teachers). As the role model of students, they play an important task especially in producing the good Muslim character. Therefore, their job not only focuses on the content of subject but becomes wider in scope, more than other…

  16. Conceptual Resources in Self-developed Explanatory Models: The importance of integrating conscious and intuitive knowledge

    Science.gov (United States)

    Cheng, Meng-Fei; Brown, David E.

    2010-11-01

    This study explores the spontaneous explanatory models children construct, critique, and revise in the context of tasks in which children need to predict, observe, and explain phenomena involving magnetism. It further investigates what conceptual resources students use, and in what ways they use them, to construct explanatory models, and the obstacles preventing them from constructing a useful explanatory model. Our findings indicate that several of the children were able to construct explanatory models. However, of the six children interviewed multiple times (three third-graders and three sixth-graders), only one was consistently able to critique and revise her models to arrive at a consistent, coherent, and sophisticated explanatory model. Connecting intuitive knowledge and abstract knowledge was important in her construction of a coherent and sophisticated explanatory model. Students who relied only on intuitive knowledge constructed tentative and non-sophisticated explanatory models. Students who relied only on verbal-symbolic knowledge at an abstract level without connection with their intuition also did not construct coherent and sophisticated models. These results indicate that instruction should help students to become meta-conceptually aware and connect their verbal-symbolic knowledge and intuition in order to construct explanatory models to make sense of abstract scientific knowledge.

  17. Importance of coherence in models of mid-infrared quantum cascade laser gain spectra

    Science.gov (United States)

    Cui, Yuzhang I.; Harter, Michael P.; Dikmelik, Yamac; Hoffman, Anthony J.

    2017-09-01

    We present a three-level model based on a density matrix to examine the influence of coherence and dephasing on the gain spectrum of mid-infrared quantum cascade lasers. The model is used to examine a quantum cascade active region with multiple optical transitions. We show how coherence can explain the origin of additional peaks in the gain spectrum. We also analyze the spectra calculated using the three-level model with a rate equation formalism to demonstrate the importance of considering interface roughness and limitations of the rate equation formalism. Specifically, we present how interface roughness influences the broadening and oscillator strength that are recovered using a rate equation analysis. The results of this work are important when considering the design of active regions with multiple optical transitions and could lead to devices with improved performance.

  18. Implementing integrated models of care: the importance of the macro-level context.

    Science.gov (United States)

    Ashton, Toni

    2015-01-01

    Reports of how different countries are responding to the need to develop more integrated health and social care services for older adults can provide useful lessons for other health systems. However an understanding of how the wider structural, political, economic and cultural context affects implementation of these models of care is essential when considering the potential for models to be scaled up or transferred to other jurisdictions.

  19. Primary Care Providers' Perceptions of and Experiences with an Integrated Healthcare Model

    Science.gov (United States)

    Westheimer, Joshua M.; Steinley-Bumgarner, Michelle; Brownson, Chris

    2008-01-01

    Objective and Participants: The authors examined the experiences of primary care providers participating in an integrated healthcare service between mental health and primary care in a university health center. In this program, behavioral health providers work collaboratively with primary care providers in the treatment of students. Participants…

  20. Critical analysis of the current approaches to modelling educational effectiveness : The importance of establishing a dynamic model

    NARCIS (Netherlands)

    Creemers, B. P. M.; Kyriakides, L.

    2006-01-01

    Researchers in the area of educational effectiveness should attempt to develop a new theoretical framework. A critical analysis of the current models of educational effectiveness research is provided and reveals that a dynamic model of effectiveness must: (a) be multilevel in nature, (b) be based on

  1. Salt effects on functional traits in model and in economically important Lotus species.

    Science.gov (United States)

    Uchiya, P; Escaray, F J; Bilenca, D; Pieckenstain, F; Ruiz, O A; Menéndez, A B

    2016-07-01

    A common stress on plants is NaCl-derived soil salinity. Genus Lotus comprises model and economically important species, which have been studied regarding physiological responses to salinity. Leaf area ratio (LAR), root length ratio (RLR) and their components, specific leaf area (SLA) and leaf mass fraction (LMF) and specific root length (SRL) and root mass fraction (RMF) might be affected by high soil salinity. We characterised L. tenuis, L. corniculatus, L. filicaulis, L. creticus, L. burtii and L. japonicus grown under different salt concentrations (0, 50, 100 and 150 mm NaCl) on the basis of SLA, LMF, SRL and RMF using PCA. We also assessed effects of different salt concentrations on LAR and RLR in each species, and explored whether changes in these traits provide fitness benefit. Salinity (150 mm NaCl) increased LAR in L. burtii and L. corniculatus, but not in the remaining species. The highest salt concentration caused a decrease of RLR in L. japonicus Gifu, but not in the remaining species. Changes in LAR and RLR would not be adaptive, according to adaptiveness analysis, with the exception of SLA changes in L. corniculatus. PCA revealed that under favourable conditions plants optimise surfaces for light and nutrient acquisition (SLA and SRL), whereas at higher salt concentrations they favour carbon allocation to leaves and roots (LMF and RMF) in detriment to their surfaces. PCA also showed that L. creticus subjected to saline treatment was distinguished from the remaining Lotus species. We suggest that augmented carbon partitioning to leaves and roots could constitute a salt-alleviating mechanism through toxic ion dilution.

  2. 75 FR 2562 - Publication of Model Notices for Health Care Continuation Coverage Provided Pursuant to the...

    Science.gov (United States)

    2010-01-15

    ... Benefits Security Administration Publication of Model Notices for Health Care Continuation Coverage... Administration, Department of Labor. ACTION: Notice of the Availability of the Model Health Care Continuation... document announces the availability of the model health care continuation coverage notices required by...

  3. 75 FR 26276 - Publication of Model Notices for Health Care Continuation Coverage Provided Pursuant to the...

    Science.gov (United States)

    2010-05-11

    ... Benefits Security Administration Publication of Model Notices for Health Care Continuation Coverage... Administration, Department of Labor. ACTION: Notice of the Availability of the Model Health Care Continuation... announces the availability of the model health care continuation coverage notices required by ARRA,...

  4. 75 FR 13595 - Publication of Model Notices for Health Care Continuation Coverage Provided Pursuant to the...

    Science.gov (United States)

    2010-03-22

    ... Benefits Security Administration Publication of Model Notices for Health Care Continuation Coverage... Administration, Department of Labor. ACTION: Notice of the availability of the Model Health Care Continuation... document announces the availability of the model health care continuation coverage notices required by...

  5. The EZ diffusion model provides a powerful test of simple empirical effects

    NARCIS (Netherlands)

    van Ravenzwaaij, Don; Donkin, Chris; Vandekerckhove, Joachim

    Over the last four decades, sequential accumulation models for choice response times have spread through cognitive psychology like wildfire. The most popular style of accumulator model is the diffusion model (Ratcliff Psychological Review, 85, 59–108, 1978), which has been shown to account for data

  6. How important is diversity for capturing environmental-change responses in ecosystem models?

    DEFF Research Database (Denmark)

    Prowe, Friederike; Pahlow, M.; Dutkiewicz, S.

    2014-01-01

    Marine ecosystem models used to investigate how global change affects ocean ecosystems and their functioning typically omit pelagic plankton diversity. Diversity, however, may affect functions such as primary production and their sensitivity to environmental changes. Here we use a global ocean...... mixing causes diversity and primary-production changes that turn out to be largely independent of the number of coexisting phytoplankton subtypes. The way diversity is represented in the model provides a small number of niches with respect to nutrient use in accordance with the PFTs defined in the model...

  7. The importance of temporal collocation for the evaluation of aerosol models with observations

    Science.gov (United States)

    Schutgens, N. A. J.; Partridge, D. G.; Stier, P.

    2016-01-01

    It is often implicitly assumed that over suitably long periods the mean of observations and models should be comparable, even if they have different temporal sampling. We assess the errors incurred due to ignoring temporal sampling and show that they are of similar magnitude as (but smaller than) actual model errors (20-60 %).Using temporal sampling from remote-sensing data sets, the satellite imager MODIS (MODerate resolution Imaging Spectroradiometer) and the ground-based sun photometer network AERONET (AErosol Robotic NETwork), and three different global aerosol models, we compare annual and monthly averages of full model data to sampled model data. Our results show that sampling errors as large as 100 % in AOT (aerosol optical thickness), 0.4 in AE (Ångström Exponent) and 0.05 in SSA (single scattering albedo) are possible. Even in daily averages, sampling errors can be significant. Moreover these sampling errors are often correlated over long distances giving rise to artificial contrasts between pristine and polluted events and regions. Additionally, we provide evidence that suggests that models will underestimate these errors. To prevent sampling errors, model data should be temporally collocated to the observations before any analysis is made.We also discuss how this work has consequences for in situ measurements (e.g. aircraft campaigns or surface measurements) in model evaluation.Although this study is framed in the context of model evaluation, it has a clear and direct relevance to climatologies derived from observational data sets.

  8. Consistently modeling the same movement strategy is more important than model skill level in observational learning contexts.

    Science.gov (United States)

    Buchanan, John J; Dean, Noah

    2014-02-01

    The experiment undertaken was designed to elucidate the impact of model skill level on observational learning processes. The task was bimanual circle tracing with a 90° relative phase lead of one hand over the other hand. Observer groups watched videos of either an instruction model, a discovery model, or a skilled model. The instruction and skilled model always performed the task with the same movement strategy, the right-arm traced clockwise and the left-arm counterclockwise around circle templates with the right-arm leading. The discovery model used several movement strategies (tracing-direction/hand-lead) during practice. Observation of the instruction and skilled model provided a significant benefit compared to the discovery model when performing the 90° relative phase pattern in a post-observation test. The observers of the discovery model had significant room for improvement and benefited from post-observation practice of the 90° pattern. The benefit of a model is found in the consistency with which that model uses the same movement strategy, and not within the skill level of the model. It is the consistency in strategy modeled that allows observers to develop an abstract perceptual representation of the task that can be implemented into a coordinated action. Theoretically, the results show that movement strategy information (relative motion direction, hand lead) and relative phase information can be detected through visual perception processes and be successfully mapped to outgoing motor commands within an observational learning context.

  9. An accurate simulation model for single-photon avalanche diodes including important statistical effects

    Science.gov (United States)

    Qiuyang, He; Yue, Xu; Feifei, Zhao

    2013-10-01

    An accurate and complete circuit simulation model for single-photon avalanche diodes (SPADs) is presented. The derived model is not only able to simulate the static DC and dynamic AC behaviors of an SPAD operating in Geiger-mode, but also can emulate the second breakdown and the forward bias behaviors. In particular, it considers important statistical effects, such as dark-counting and after-pulsing phenomena. The developed model is implemented using the Verilog-A description language and can be directly performed in commercial simulators such as Cadence Spectre. The Spectre simulation results give a very good agreement with the experimental results reported in the open literature. This model shows a high simulation accuracy and very fast simulation rate.

  10. Modelling importance of sediment effects on fate and transport of enterococci in the Severn Estuary, UK.

    Science.gov (United States)

    Gao, Guanghai; Falconer, Roger A; Lin, Binliang

    2013-02-15

    The paper detailed a water quality modelling study of a hyper-tidal estuary, undertaken to assess the impact of various bacteria input loads on the receiving waters in a coastal basin in the UK, by using the model developed in previous study of the same authors enterococci, used as the indicators for bathing water quality under the new European Union (EU) Bathing Water Directive, were numerically modelled using a hydro-environmental model. In particular, the numerical model used in this study includes the effects of sediment on bacteria transport processes in surface water. Finally, the importance of sediment bacteria inputs on the bathing water quality was also investigated under different weather and tidal condition. During spring tide, the bacteria input from the bed sediments are dominant for both wet and dry weather conditions. During neap tides and during dry weather conditions the inputs of bacteria from the bed sediment were still dominant, but during wet weather conditions the inputs from river were dominant. Under different tidal flow conditions some parameters had a more significant role than others. During high flow conditions the sediment re-suspensions processes were dominant, therefore the bed bacteria concentrations played a dominant role on the overall bacteria concentration levels in the water column. In contrast, during low flow conditions sediment deposition prevails and bacteria are removed from the water column. The partition coefficient was found to be more important than the bed bacteria concentrations, during low flow conditions.

  11. Importance of three-dimensional grids and time-dependent factors for applications of earthquake forecasting models to subduction environments

    Science.gov (United States)

    Chan, Chung-Han

    2016-09-01

    This study provides some new insights into earthquake forecasting models that are applied to regions with subduction systems, including the depth component for forecasting grids and time-dependent factors. To demonstrate the importance of depth component, a forecasting approach, which incorporates three-dimensional grids, is compared with an approach with two-dimensional cells. Through application to the two subduction regions, Ryukyu and Kanto, it is shown that the approaches with three-dimensional grids always demonstrate a better forecasting ability. I thus confirm the importance of depth dependency for forecasting, especially for applications to a subduction environment or a region with non-vertical seismogenic structures. In addition, this study discusses the role of time-dependent factors for forecasting models and concludes that time dependency only becomes crucial during the period with significant seismicity rate change that follows a large earthquake.

  12. The importance of temporal collocation for the evaluation of aerosol models with observations

    Directory of Open Access Journals (Sweden)

    N. A. J. Schutgens

    2015-09-01

    Full Text Available It is often implicitly assumed that over suitably long periods the mean of observations and models should be comparable, even if they have different temporal sampling. We assess the errors incurred due to ignoring temporal sampling and show they are of similar magnitude as (but smaller than actual model errors (20–60 %. Using temporal sampling from remote sensing datasets (the satellite imager MODIS and the ground-based sun photometer network AERONET and three different global aerosol models, we compare annual and monthly averages of full model data to sampled model data. Our results show that sampling errors as large as 100 % in AOT (Aerosol Optical Thickness, 0.4 in AE (Ångström Exponent and 0.05 in SSA (Single Scattering Albedo are possible. Even in daily averages, sampling errors can be significant. More-over these sampling errors are often correlated over long distances giving rise to artificial contrasts between pristine and polluted events and regions. Additionally, we provide evidence that suggests that models will underestimate these errors. To prevent sampling errors, model data should be temporally collocated to the observations before any analysis is made. We also discuss how this work has consequences for in-situ measurements (e.g. aircraft campaigns or surface measurements in model evaluation.

  13. The Importance of Cognitive Phenotypes in Experimental Modeling of Animal Anxiety and Depression

    OpenAIRE

    Kalueff, Allan V.; Murphy, Dennis L.

    2007-01-01

    Cognitive dysfunctions are commonly seen in many stress-related disorders, including anxiety and depression—the world's most common neuropsychiatric illnesses. Various genetic, pharmacological, and behavioral animal models have long been used to establish animal anxiety-like and depression-like phenotypes, as well as to assess their memory, learning, and other cognitive functions. Mounting clinical and animal evidences strongly supports the notion that disturbed cognitions represent an import...

  14. Phylogenetic Gaussian process model for the inference of functionally important regions in protein tertiary structures.

    Science.gov (United States)

    Huang, Yi-Fei; Golding, G Brian

    2014-01-01

    A critical question in biology is the identification of functionally important amino acid sites in proteins. Because functionally important sites are under stronger purifying selection, site-specific substitution rates tend to be lower than usual at these sites. A large number of phylogenetic models have been developed to estimate site-specific substitution rates in proteins and the extraordinarily low substitution rates have been used as evidence of function. Most of the existing tools, e.g. Rate4Site, assume that site-specific substitution rates are independent across sites. However, site-specific substitution rates may be strongly correlated in the protein tertiary structure, since functionally important sites tend to be clustered together to form functional patches. We have developed a new model, GP4Rate, which incorporates the Gaussian process model with the standard phylogenetic model to identify slowly evolved regions in protein tertiary structures. GP4Rate uses the Gaussian process to define a nonparametric prior distribution of site-specific substitution rates, which naturally captures the spatial correlation of substitution rates. Simulations suggest that GP4Rate can potentially estimate site-specific substitution rates with a much higher accuracy than Rate4Site and tends to report slowly evolved regions rather than individual sites. In addition, GP4Rate can estimate the strength of the spatial correlation of substitution rates from the data. By applying GP4Rate to a set of mammalian B7-1 genes, we found a highly conserved region which coincides with experimental evidence. GP4Rate may be a useful tool for the in silico prediction of functionally important regions in the proteins with known structures.

  15. Transtheoretical model for behavior changes: an important tool when adopting active life

    OpenAIRE

    Álvarez, Carlos

    2008-01-01

    Despite the worship of beauty that has ruled this globalized society and the importance of physical activity for the prevention of cardio-degenerative diseases (US.DHHS, 1996), sedentary behavior continues to increase in the population.  What strategies can be used by professionals of human movement to make the population physically active? It is at this point where the Transtheoretical Model appears as an innovative option that greatly surpasses the classic short-term biological intervention...

  16. Numerical Study of φ4 Model by Potential Importance Sampling Method

    Institute of Scientific and Technical Information of China (English)

    YUAN Qing-Xin; DING Guo-Hui

    2006-01-01

    We investigate the phenomena of spontaneous symmetry breaking for φ4 modelon a square lattice in the parameter space by using the potential importance samplingmethod, which was proposed by Milchev, Heermann, and Binder [J. Stat. Phys. 44 (1986) 749]. The critical values of the parameters allow us to determine the phase diagram of the model. At the same time, some relevant quantities such as susceptibility and specific heat are also obtained.

  17. Simplified three-dimensional model provides anatomical insights in lizards' caudal autotomy as printed illustration

    Directory of Open Access Journals (Sweden)

    JOANA D.C.G. DE AMORIM

    2015-03-01

    Full Text Available Lizards' caudal autotomy is a complex and vastly employed antipredator mechanism, with thorough anatomic adaptations involved. Due to its diminished size and intricate structures, vertebral anatomy is hard to be clearly conveyed to students and researchers of other areas. Three-dimensional models are prodigious tools in unveiling anatomical nuances. Some of the techniques used to create them can produce irregular and complicated forms, which despite being very accurate, lack didactical uniformity and simplicity. Since both are considered fundamental characteristics for comprehension, a simplified model could be the key to improve learning. The model here presented depicts the caudal osteology of Tropidurus itambere, and was designed to be concise, in order to be easily assimilated, yet complete, not to compromise the informative aspect. The creation process requires only basic skills in manipulating polygons in 3D modeling softwares, in addition to the appropriate knowledge of the structure to be modeled. As reference for the modeling, we used microscopic observation and a photograph database of the caudal structures. This way, no advanced laboratory equipment was needed and all biological materials were preserved for future research. Therefore, we propose a wider usage of simplified 3D models both in the classroom and as illustrations for scientific publications.

  18. The importance of tumor volume in the prognosis of patients with glioblastoma. Comparison of computerized volumetry and geometric models

    Energy Technology Data Exchange (ETDEWEB)

    Iliadis, Georgios; Misailidou, Despina [Dept. of Radiation Oncology, ' ' Papageorgiou' ' General Hospital, Thessaloniki (Greece); Selviaridis, Panagiotis; Chatzisotiriou, Athanasios [Dept. of Neurosurgery, ' ' AHEPA' ' Hospital, Aristotle Univ. of Thessaloniki, School of Medicine (Greece); Kalogera-Fountzila, Anna [Dept. of Radiology, ' ' AHEPA' ' Hospital, Aristotle Univ. of Thessaloniki, School of Medicine (Greece); Fragkoulidi, Anna; Fountzilas, George [Dept. of Medical Oncology, ' ' Papageorgiou' ' General Hospital, Aristotle Univ. of Thessaloniki, School of Medicine (Greece); Baltas, Dimos; Tselis, Nikolaos; Zamboglou, Nikolaos [Dept. of Radiation Oncology, Klinikum Offenbach (Germany)

    2009-11-15

    Background and purpose: the importance of tumor volume as a prognostic factor in high-grade gliomas is highly controversial and there are numerous methods estimating this parameter. In this study, a computer-based application was used in order to assess tumor volume from hard copies and a survival analysis was conducted in order to evaluate the prognostic significance of preoperative volumetric data in patients harboring glioblastomas. Patients and methods: 50 patients suffering from glioblastoma were analyzed retrospectively. Tumor volume was determined by the various geometric models as well as by an own specialized software (Volumio). Age, performance status, type of excision, and tumor location were also included in the multivariate analysis. Results: the spheroid and rectangular models overestimated tumor volume, while the ellipsoid model offered the best approximation. Volume failed to attain any statistical significance in prognosis, while age and performance status confirmed their importance in progression-free and overall survival of patients. Conclusion: geometric models provide a rough approximation of tumor volume and should not be used, as accurate determination of size is of paramount importance in order to draw safe conclusions in oncology. Although the significance of volumetry was not disclosed, further studies are definitely required. (orig.)

  19. Clinical Scholar Model: providing excellence in clinical supervision of nursing students.

    Science.gov (United States)

    Preheim, Gayle; Casey, Kathy; Krugman, Mary

    2006-01-01

    The Clinical Scholar Model (CSM) is a practice-education partnership focused on improving the outcomes of clinical nursing education by bridging the academic and service settings. An expert clinical nurse serves as a clinical scholar (CS) to coordinate, supervise, and evaluate the clinical education of nursing students in collaboration with school of nursing faculty. This article describes the model's evolution, how the model is differentiated from traditional clinical instruction roles and responsibilities, and the benefits to the collaborating clinical agency and school of nursing.

  20. Assessing the importance of conduit geometry and physical parameters in karst systems using the storm water management model (SWMM)

    Science.gov (United States)

    Peterson, Eric W.; Wicks, Carol M.

    2006-09-01

    SummaryQuestions about the importance of conduit geometry and about the values of hydraulic parameters in controlling ground-water flow and solute transport through karstic aquifers have remained largely speculative. One goal of this project was to assess the role that the conduit geometry and the hydraulic parameters have on controlling transport dynamics within karstic aquifers. The storm water management model (SWMM) was applied to the Devil's Icebox-Connor's Cave System in central Missouri, USA. Simulations with incremental changes to conduit geometry or hydraulic parameters were performed with the output compared to a calibrated baseline model. Ten percent changes in the length or width of a conduit produced statistically significant different fluid flow responses. The model exhibited minimal sensitivity to slope and infiltration rates; however, slight changes in Manning's roughness coefficient can highly alter the simulated output. Traditionally, the difference in flow dynamics between karstified aquifers and porous media aquifers has led to the idea that modeling of karst aquifers is more difficult and less precise than modeling of porous media aquifers. When evaluated against models for porous media aquifers, SWMM produced results that were as accurate (10% error compared to basecase). In addition, SWMM has the advantage of providing data about local flow. While SWMM may be an appropriate modeling technique for some karstic aquifers, SWMM should not be viewed as a universal solution to modeling karst systems.

  1. ERK activation by the polyphenols fisetin and resveratrol provides neuroprotection in multiple models of Huntington's disease

    National Research Council Canada - National Science Library

    Maher, Pamela; Dargusch, Richard; Bodai, Laszlo; Gerard, Paul E; Purcell, Judith M; Marsh, J Lawrence

    2011-01-01

    .... To test the hypothesis that pharmaceutical activation of ERK might be protective for HD, a polyphenol, fisetin, which was previously shown to activate the Ras-ERK cascade, was tested in three different models of HD...

  2. Sea-ice extent provides a limited metric of model performance

    Directory of Open Access Journals (Sweden)

    D. Notz

    2013-06-01

    Full Text Available We examine the common practice of using sea-ice extent as the primary metric to evaluate modeled sea-ice coverage. Based on this analysis, we recommend a possible best practice for model evaluation. We find that for Arctic summer sea ice, model biases in sea-ice extent can be qualitatively different compared to biases in the geophysically more meaningful sea-ice area. These differences come about by a different frequency distribution of high-concentration sea-ice: while in summer about half of the CMIP5 models and satellite retrievals based on the Bootstrap and the ASI algorithm show a compact ice cover with large areas of high concentration sea ice, the other half of the CMIP5 models and satellite retrievals based on the NASA Team algorithm show a loose ice cover. The different behaviour of the CMIP5 models can be explained by their different distribution of excess heat between lateral melt and sea-ice thinning. Differences in grid geometry and round-off errors during interpolation only have a minor impact on the different biases in sea-ice extent and sea-ice area. Because of regional cancellation of biases in the integrative measures sea-ice extent and sea-ice area, these measures show little correlation with the more meaningful mean absolute bias in sea-ice concentration. Comparing the uncertainty arising directly from the satellite retrievals with those that arise from internal variability, we find that the latter by far dominates the uncertainty estimate for trends in sea-ice extent and area: much of the differences between modeled and observed trends can simply be explained by internal variability. Only for the absolute value of sea-ice area, differences between observations and models are so large that they cannot be explained by either observational uncertainty nor internal variability.

  3. Plasmaspheric electron densities: the importance in modelling radiation belts and in SSA operation

    Science.gov (United States)

    Lichtenberger, János; Jorgensen, Anders; Koronczay, Dávid; Ferencz, Csaba; Hamar, Dániel; Steinbach, Péter; Clilverd, Mark; Rodger, Craig; Juhász, Lilla; Sannikov, Dmitry; Cherneva, Nina

    2016-04-01

    The Automatic Whistler Detector and Analyzer Network (AWDANet, Lichtenberger et al., J. Geophys. Res., 113, 2008, A12201, doi:10.1029/2008JA013467) is able to detect and analyze whistlers in quasi-realtime and can provide equatorial electron density data. The plasmaspheric electron densities are key parameters for plasmasphere models in Space Weather related investigations, particularly in modeling charged particle accelerations and losses in Radiation Belts. The global AWDANet detects millions of whistlers in a year. The network operates since early 2002 with automatic whistler detector capability and it has been recently completed with automatic analyzer capability in PLASMON (http://plasmon.elte.hu, Lichtenberger et al., Space Weather Space Clim. 3 2013, A23 DOI: 10.1051/swsc/2013045.) Eu FP7-Space project. It is based on a recently developed whistler inversion model (Lichtenberger, J. J. Geophys. Res., 114, 2009, A07222, doi:10.1029/2008JA013799), that opened the way for an automated process of whistler analysis, not only for single whistler events but for complex analysis of multiple-path propagation whistler groups. The network operates in quasi real-time mode since mid-2014, fifteen stations provide equatorial electron densities that are used as inputs for a data assimilative plasmasphere model but they can also be used directly in space weather research and models. We have started to process the archive data collected by AWDANet stations since 2002 and in this paper we present the results of quasi-real-time and off-line runs processing whistlers from quiet and disturb periods. The equatorial electron densities obtained by whistler inversion are fed into the assimilative model of the plasmasphere providing a global view of the region for processed the periods

  4. Numerical Considerations for Lagrangian Stochastic Dispersion Models: Eliminating Rogue Trajectories, and the Importance of Numerical Accuracy

    Science.gov (United States)

    Bailey, Brian N.

    2017-01-01

    When Lagrangian stochastic models for turbulent dispersion are applied to complex atmospheric flows, some type of ad hoc intervention is almost always necessary to eliminate unphysical behaviour in the numerical solution. Here we discuss numerical strategies for solving the non-linear Langevin-based particle velocity evolution equation that eliminate such unphysical behaviour in both Reynolds-averaged and large-eddy simulation applications. Extremely large or `rogue' particle velocities are caused when the numerical integration scheme becomes unstable. Such instabilities can be eliminated by using a sufficiently small integration timestep, or in cases where the required timestep is unrealistically small, an unconditionally stable implicit integration scheme can be used. When the generalized anisotropic turbulence model is used, it is critical that the input velocity covariance tensor be realizable, otherwise unphysical behaviour can become problematic regardless of the integration scheme or size of the timestep. A method is presented to ensure realizability, and thus eliminate such behaviour. It was also found that the numerical accuracy of the integration scheme determined the degree to which the second law of thermodynamics or `well-mixed condition' was satisfied. Perhaps more importantly, it also determined the degree to which modelled Eulerian particle velocity statistics matched the specified Eulerian distributions (which is the ultimate goal of the numerical solution). It is recommended that future models be verified by not only checking the well-mixed condition, but perhaps more importantly by checking that computed Eulerian statistics match the Eulerian statistics specified as inputs.

  5. Capturing optically important constituents and properties in a marine biogeochemical and ecosystem model

    Science.gov (United States)

    Dutkiewicz, S.; Hickman, A. E.; Jahn, O.; Gregg, W. W.; Mouw, C. B.; Follows, M. J.

    2015-07-01

    We present a numerical model of the ocean that couples a three-stream radiative transfer component with a marine biogeochemical-ecosystem component in a dynamic three-dimensional physical framework. The radiative transfer component resolves the penetration of spectral irradiance as it is absorbed and scattered within the water column. We explicitly include the effect of several optically important water constituents (different phytoplankton functional types; detrital particles; and coloured dissolved organic matter, CDOM). The model is evaluated against in situ-observed and satellite-derived products. In particular we compare to concurrently measured biogeochemical, ecosystem, and optical data along a meridional transect of the Atlantic Ocean. The simulation captures the patterns and magnitudes of these data, and estimates surface upwelling irradiance analogous to that observed by ocean colour satellite instruments. We find that incorporating the different optically important constituents explicitly and including spectral irradiance was crucial to capture the variability in the depth of the subsurface chlorophyll a (Chl a) maximum. We conduct a series of sensitivity experiments to demonstrate, globally, the relative importance of each of the water constituents, as well as the crucial feedbacks between the light field, the relative fitness of phytoplankton types, and the biogeochemistry of the ocean. CDOM has proportionally more importance at attenuating light at short wavelengths and in more productive waters, phytoplankton absorption is relatively more important at the subsurface Chl a maximum, and water molecules have the greatest contribution when concentrations of other constituents are low, such as in the oligotrophic gyres. Scattering had less effect on attenuation, but since it is important for the amount and type of upwelling irradiance, it is crucial for setting sea surface reflectance. Strikingly, sensitivity experiments in which absorption by any of the

  6. Importance of facial physical attractiveness of audiovisual models in descriptions and preferences of children and adolescents.

    Science.gov (United States)

    Ruiz, Cristina; Conde, Elena; Torres, Esteban

    2005-08-01

    We performed a cross-sectional study with three age groups (8, 14, and 17 years) to evaluate developmental differences in stereotyped beliefs about physical attractiveness and the value of this as perceived by the participants. Given the current importance of television in the development of social knowledge, television models were used. The children and adolescents were asked to evaluate, using bipolar open scales, the physical attractiveness, likeableness, generosity, intelligence, fun, and altruism of 12 television models of both sexes, previously selected by judges, as well as the desire to resemble or feel close to the models. Analysis showed developmental differences across age groups both in the concept of physical attractiveness and in stereotyped beliefs about this. As in other areas of social knowledge, the younger children's responses were bipolar, global, and much more stereotyped, while the adolescents introduced subtle distinctions and elaborated their responses. Nevertheless, physical attractiveness appeared a desirable characteristic for all age groups.

  7. Oxygen distribution in tumors: A qualitative analysis and modeling study providing a novel Monte Carlo approach

    Energy Technology Data Exchange (ETDEWEB)

    Lagerlöf, Jakob H., E-mail: Jakob@radfys.gu.se [Department of Radiation Physics, Göteborg University, Göteborg 41345 (Sweden); Kindblom, Jon [Department of Oncology, Sahlgrenska University Hospital, Göteborg 41345 (Sweden); Bernhardt, Peter [Department of Radiation Physics, Göteborg University, Göteborg 41345, Sweden and Department of Nuclear Medicine, Sahlgrenska University Hospital, Göteborg 41345 (Sweden)

    2014-09-15

    Purpose: To construct a Monte Carlo (MC)-based simulation model for analyzing the dependence of tumor oxygen distribution on different variables related to tumor vasculature [blood velocity, vessel-to-vessel proximity (vessel proximity), and inflowing oxygen partial pressure (pO{sub 2})]. Methods: A voxel-based tissue model containing parallel capillaries with square cross-sections (sides of 10 μm) was constructed. Green's function was used for diffusion calculations and Michaelis-Menten's kinetics to manage oxygen consumption. The model was tuned to approximately reproduce the oxygenational status of a renal carcinoma; the depth oxygenation curves (DOC) were fitted with an analytical expression to facilitate rapid MC simulations of tumor oxygen distribution. DOCs were simulated with three variables at three settings each (blood velocity, vessel proximity, and inflowing pO{sub 2}), which resulted in 27 combinations of conditions. To create a model that simulated variable oxygen distributions, the oxygen tension at a specific point was randomly sampled with trilinear interpolation in the dataset from the first simulation. Six correlations between blood velocity, vessel proximity, and inflowing pO{sub 2} were hypothesized. Variable models with correlated parameters were compared to each other and to a nonvariable, DOC-based model to evaluate the differences in simulated oxygen distributions and tumor radiosensitivities for different tumor sizes. Results: For tumors with radii ranging from 5 to 30 mm, the nonvariable DOC model tended to generate normal or log-normal oxygen distributions, with a cut-off at zero. The pO{sub 2} distributions simulated with the six-variable DOC models were quite different from the distributions generated with the nonvariable DOC model; in the former case the variable models simulated oxygen distributions that were more similar to in vivo results found in the literature. For larger tumors, the oxygen distributions became

  8. Learning to Measure Biodiversity: Two Agent-Based Models that Simulate Sampling Methods & Provide Data for Calculating Diversity Indices

    Science.gov (United States)

    Jones, Thomas; Laughlin, Thomas

    2009-01-01

    Nothing could be more effective than a wilderness experience to demonstrate the importance of conserving biodiversity. When that is not possible, though, there are computer models with several features that are helpful in understanding how biodiversity is measured. These models are easily used when natural resources, transportation, and time…

  9. Learning to Measure Biodiversity: Two Agent-Based Models that Simulate Sampling Methods & Provide Data for Calculating Diversity Indices

    Science.gov (United States)

    Jones, Thomas; Laughlin, Thomas

    2009-01-01

    Nothing could be more effective than a wilderness experience to demonstrate the importance of conserving biodiversity. When that is not possible, though, there are computer models with several features that are helpful in understanding how biodiversity is measured. These models are easily used when natural resources, transportation, and time…

  10. The Roy Adaptation Model: A Theoretical Framework for Nurses Providing Care to Individuals With Anorexia Nervosa.

    Science.gov (United States)

    Jennings, Karen M

    2017-08-18

    Using a nursing theoretical framework to understand, elucidate, and propose nursing research is fundamental to knowledge development. This article presents the Roy Adaptation Model as a theoretical framework to better understand individuals with anorexia nervosa during acute treatment, and the role of nursing assessments and interventions in the promotion of weight restoration. Nursing assessments and interventions situated within the Roy Adaptation Model take into consideration how weight restoration does not occur in isolation but rather reflects an adaptive process within external and internal environments, and has the potential for more holistic care.

  11. The importance of data quality for generating reliable distribution models for rare, elusive, and cryptic species.

    Science.gov (United States)

    Aubry, Keith B; Raley, Catherine M; McKelvey, Kevin S

    2017-01-01

    The availability of spatially referenced environmental data and species occurrence records in online databases enable practitioners to easily generate species distribution models (SDMs) for a broad array of taxa. Such databases often include occurrence records of unknown reliability, yet little information is available on the influence of data quality on SDMs generated for rare, elusive, and cryptic species that are prone to misidentification in the field. We investigated this question for the fisher (Pekania pennanti), a forest carnivore of conservation concern in the Pacific States that is often confused with the more common Pacific marten (Martes caurina). Fisher occurrence records supported by physical evidence (verifiable records) were available from a limited area, whereas occurrence records of unknown quality (unscreened records) were available from throughout the fisher's historical range. We reserved 20% of the verifiable records to use as a test sample for both models and generated SDMs with each dataset using Maxent. The verifiable model performed substantially better than the unscreened model based on multiple metrics including AUCtest values (0.78 and 0.62, respectively), evaluation of training and test gains, and statistical tests of how well each model predicted test localities. In addition, the verifiable model was consistent with our knowledge of the fisher's habitat relations and potential distribution, whereas the unscreened model indicated a much broader area of high-quality habitat (indices > 0.5) that included large expanses of high-elevation habitat that fishers do not occupy. Because Pacific martens remain relatively common in upper elevation habitats in the Cascade Range and Sierra Nevada, the SDM based on unscreened records likely reflects primarily a conflation of marten and fisher habitat. Consequently, accurate identifications are far more important than the spatial extent of occurrence records for generating reliable SDMs for the

  12. ALP: Alternate Learning Project; Overview of a Model High School in Providence, Rhode Island.

    Science.gov (United States)

    Kenyon, Charles B.

    The Alternate Learning Project (ALP) is a community based public high school in Providence, Rhode Island. The ALP student population participates in a program offering individualized basic skills instruction, college preparatory courses, career exploration activities, and a broad arts curriculum. Throughout, the emphasis is on continuous…

  13. Models Provide Specificity: Testing a Proposed Mechanism of Visual Working Memory Capacity Development

    Science.gov (United States)

    Simmering, Vanessa R.; Patterson, Rebecca

    2012-01-01

    Numerous studies have established that visual working memory has a limited capacity that increases during childhood. However, debate continues over the source of capacity limits and its developmental increase. Simmering (2008) adapted a computational model of spatial cognitive development, the Dynamic Field Theory, to explain not only the source…

  14. JSBML 1.0: providing a smorgasbord of options to encode systems biology models

    DEFF Research Database (Denmark)

    Rodriguez, Nicolas; Thomas, Alex; Watanabe, Leandro

    2015-01-01

    JSBML, the official pure Java programming library for the Systems Biology Markup Language (SBML) format, has evolved with the advent of different modeling formalisms in systems biology and their ability to be exchanged and represented via extensions of SBML. JSBML has matured into a major, active...

  15. MODELING QUEUING SYSTEM OF INTERACTION BETWEEN TERMINAL DEVICES AND SERVICES PROVIDERS IN THE BANK

    Directory of Open Access Journals (Sweden)

    Ivan A. Mnatsakanyan

    2014-01-01

    Full Text Available The article focuses on the development of mathematical models and tools to optimize the system of queuing at the bank. The article discusses the mathematical aspects that will achieve redistribution of transaction flow, reduce the time of the request in the queue, increase the bank’s profit and gain competitive advantage.

  16. The importance of object geometric properties for trajectory modeling of functional reach-to-grasp robotic therapy tasks - biomed 2009.

    Science.gov (United States)

    Nathan, Dominic; Jeutter, Dean C

    2009-01-01

    Reaching-to-grasp is essential for the performance of activities of daily living. Pathologies such as stroke, spinal cord injury, cerebral palsy, etc. limit individuals from being able to perform meaningful upper extremity movements, leading to a reduced quality of life. Robotic aided therapy is gaining prevalence as a rehabilitation tool because it can provide consistent and quantitative therapy. Such systems are dependent upon models to generate trajectories that dictate their movements. Time scaled polynomial techniques have been extensively used for robotic model development and trajectory generation. However, this approach is limited because it cannot support functional therapy tasks. This is largely due to the influence of cognitive complexity not completely considered with regards to the activity performed. We examine the influence of task cognitive complexity as manifested through the geometric properties of each object on the movement trajectories and kinematic dependent variables tasks through a motion analysis study using healthy subjects (N=8). We then compare the predicted results from several robotic trajectory models with the actual motion analysis data. Our results show that there are differences present, between the trajectory data and kinematic properties for each task, that are specific to the geometric properties of each object. In addition, the predicted results from the robotic trajectory models do not fully correlate with the actual movement information. This study is important as it will help provide some insight with regards to factors that need to be considered during the development of future robotic trajectory models and controllers for upper extremity functional rehabilitation tasks.

  17. An agent-based simulation model of patient choice of health care providers in accountable care organizations.

    Science.gov (United States)

    Alibrahim, Abdullah; Wu, Shinyi

    2016-10-04

    Accountable care organizations (ACO) in the United States show promise in controlling health care costs while preserving patients' choice of providers. Understanding the effects of patient choice is critical in novel payment and delivery models like ACO that depend on continuity of care and accountability. The financial, utilization, and behavioral implications associated with a patient's decision to forego local health care providers for more distant ones to access higher quality care remain unknown. To study this question, we used an agent-based simulation model of a health care market composed of providers able to form ACO serving patients and embedded it in a conditional logit decision model to examine patients capable of choosing their care providers. This simulation focuses on Medicare beneficiaries and their congestive heart failure (CHF) outcomes. We place the patient agents in an ACO delivery system model in which provider agents decide if they remain in an ACO and perform a quality improving CHF disease management intervention. Illustrative results show that allowing patients to choose their providers reduces the yearly payment per CHF patient by $320, reduces mortality rates by 0.12 percentage points and hospitalization rates by 0.44 percentage points, and marginally increases provider participation in ACO. This study demonstrates a model capable of quantifying the effects of patient choice in a theoretical ACO system and provides a potential tool for policymakers to understand implications of patient choice and assess potential policy controls.

  18. Self-potentials in partially saturated media: the importance of explicit modeling of electrode effects

    CERN Document Server

    Jougnot, D

    2013-01-01

    Self-potential (SP) data are of interest to vadose zone hydrology because of their direct sensitivity to water flow and ionic transport. There is unfortunately little consensus in the literature about how to best model SP data under partially saturated conditions and different approaches (often supported by one laboratory data set alone) have been proposed. We argue herein that this lack of agreement can largely be traced to electrode effects that have not been properly taken into account. A series of drainage and imbibition experiments are considered, in which we find that previously proposed approaches to remove electrode effects are unlikely to provide adequate corrections. Instead, we explicitly model the electrode effects together with classical SP contributions using a flow and transport model. The simulated data agree overall with the observed SP signals and allow decomposing the different signal contributions to analyze them separately. By reviewing other published experimental data, we suggest that m...

  19. The importance of Resilience to Primary Care Practitioners: an Interactive Psycho-Social Model

    Directory of Open Access Journals (Sweden)

    Dr Robert Muller

    2009-01-01

    Full Text Available In this paper, it is argued that an understanding of the factors that make up resilience canenhance communication and concordance between practitioner and patient. A model ispresented demonstrating that resilience is an interaction between factors in the internaldomain, comprising psychological characteristics and resources, and the external domain,comprising the social environment surrounding the individual. As resilience manifests itselfin different ways across the life-cycle, and according to individual circumstances, time is alsoan important part of the model presented in this paper. Understanding this model of resiliencecan lead to an insight that there are factors that can be influenced whereby the primary carepractitioner can treat the patient, or refer them after a process of concordance through adeeper understanding of the factors that surround a patient’s current health status. Underlyingthe model is the view that resilience is linked to the assets model of health, seeking topromote and maintain health and prevent illness. Therefore, primary care practitioners,through a deeper understanding of the circumstances of the patient, and throughunderstanding the factors that promote resilience, may be better able to take action in healthpromotion and maintenance.

  20. Forty years of 90Sr in situ migration: importance of soil characterization in modeling transport phenomena.

    Science.gov (United States)

    Fernandez, J M; Piault, E; Macouillard, D; Juncos, C

    2006-01-01

    In 1960 experiments were carried out on the transfer of (90)Sr between soil, grapes and wine. The experiments were conducted in situ on a piece of land limited by two control strips. The (90)Sr migration over the last 40 years was studied by performing radiological and physico-chemical characterizations of the soil on eight 70 cm deep cores. The vertical migration modeling of (90)Sr required the definition of a triple layer conceptual model integrating the rainwater infiltration at constant flux as the only external factor of influence. Afterwards the importance of a detailed soil characterization for modeling was discussed and satisfactory simulation of the (90)Sr vertical transport was obtained and showed a calculated migration rate of about 1.0 cm year(-1) in full agreement with the in situ measured values. The discussion was regarding some of the key parameters such as granulometry, organic matter content (in the Van Genuchten parameter determination), Kd and the efficient rainwater infiltration. Besides the experimental data, simplifying assumptions in modeling such as water-soil redistribution calculation and factual discontinuities in conceptual model were examined.

  1. A structural and stochastic optimal model for projections of LNG imports and exports in Asia-Pacific.

    Science.gov (United States)

    Kompas, Tom; Che, Tuong Nhu

    2016-06-01

    The Asia-Pacific region, the largest and fastest growing liquefied natural gas (LNG) market in the world, has been undergoing radical changes over the past few years. These changes include considerable additional supplies from North America and Australia, and a recent LNG price slump resulting from an oil-linked pricing mechanism and demand uncertainties. This paper develops an Asia-Pacific Gas Model (APGM), based on a structural, stochastic and optimising framework, providing a valuable tool for the projection of LNG trade in the Asia-Pacific region. With existing social-economic conditions, the model projects that Asia-Pacific LNG imports are expected to increase by 49.1 percent in 2020 and 95.7 percent in 2030, compared to 2013. Total LNG trade value is estimated to increase to US$127.2 billion in 2020 and US$199.0 billion in 2030. Future LNG trade expansion is mainly driven by emerging and large importers (i.e., China and India), and serviced, most importantly, by new supplies from Australia and the USA. The model's projected results are sensitive to changes in expected oil prices, pricing mechanisms, economic growth and energy policies, as well as unexpected geopolitical-economic events.

  2. A structural and stochastic optimal model for projections of LNG imports and exports in Asia-Pacific

    Directory of Open Access Journals (Sweden)

    Tom Kompas

    2016-06-01

    Full Text Available The Asia-Pacific region, the largest and fastest growing liquefied natural gas (LNG market in the world, has been undergoing radical changes over the past few years. These changes include considerable additional supplies from North America and Australia, and a recent LNG price slump resulting from an oil-linked pricing mechanism and demand uncertainties. This paper develops an Asia-Pacific Gas Model (APGM, based on a structural, stochastic and optimising framework, providing a valuable tool for the projection of LNG trade in the Asia-Pacific region. With existing social-economic conditions, the model projects that Asia-Pacific LNG imports are expected to increase by 49.1 percent in 2020 and 95.7 percent in 2030, compared to 2013. Total LNG trade value is estimated to increase to US$127.2 billion in 2020 and US$199.0 billion in 2030. Future LNG trade expansion is mainly driven by emerging and large importers (i.e., China and India, and serviced, most importantly, by new supplies from Australia and the USA. The model's projected results are sensitive to changes in expected oil prices, pricing mechanisms, economic growth and energy policies, as well as unexpected geopolitical-economic events.

  3. Using an established telehealth model to train urban primary care providers on hypertension management.

    Science.gov (United States)

    Masi, Christopher; Hamlish, Tamara; Davis, Andrew; Bordenave, Kristine; Brown, Stephen; Perea, Brenda; Aduana, Glen; Wolfe, Marcus; Bakris, George; Johnson, Daniel

    2012-01-01

    The objective of this study was to determine whether a videoconference-based telehealth network can increase hypertension management knowledge and self-assessed competency among primary care providers (PCPs) working in urban Federally Qualified Health Centers (FQHCs). We created a telehealth network among 6 urban FQHCs and our institution to support a 12-session educational program designed to teach state-of-the-art hypertension management. Each 1-hour session included a brief lecture by a university-based hypertension specialist, case presentations by PCPs, and interactive discussions among the specialist and PCPs. Twelve PCPs (9 intervention and 3 controls) were surveyed at baseline and immediately following the curriculum. The mean number of correct answers on the 26-item hypertension knowledge questionnaire increased in the intervention group (13.11 [standard deviation (SD)]=3.06) to 17.44 [SD=1.59], Phypertension management self-assessed competency scale increased in the intervention group (4.68 [SD=0.94] to 5.41 [SD=0.89], Phypertension care provided by urban FQHC providers.

  4. Programming with models: modularity and abstraction provide powerful capabilities for systems biology.

    Science.gov (United States)

    Mallavarapu, Aneil; Thomson, Matthew; Ullian, Benjamin; Gunawardena, Jeremy

    2009-03-06

    Mathematical models are increasingly used to understand how phenotypes emerge from systems of molecular interactions. However, their current construction as monolithic sets of equations presents a fundamental barrier to progress. Overcoming this requires modularity, enabling sub-systems to be specified independently and combined incrementally, and abstraction, enabling generic properties of biological processes to be specified independently of specific instances. These, in turn, require models to be represented as programs rather than as datatypes. Programmable modularity and abstraction enables libraries of modules to be created, which can be instantiated and reused repeatedly in different contexts with different components. We have developed a computational infrastructure that accomplishes this. We show here why such capabilities are needed, what is required to implement them and what can be accomplished with them that could not be done previously.

  5. Large-scale modeling provides insights into Arabidopsis's acclimation to changing light and temperature conditions.

    Science.gov (United States)

    Töpfer, Nadine; Niokoloski, Zoran

    2013-09-01

    Classical flux balance analysis predicts steady-state flux distributions that maximize a given objective function. A recent study, Schuetz et al., (1) demonstrated that competing objectives constrain the metabolic fluxes in E. coli. For plants, with multiple cell types, fulfilling different functions, the objectives remain elusive and, therefore, hinder the prediction of actual fluxes, particularly for changing environments. In our study, we presented a novel approach to predict flux capacities for a large collection of metabolic pathways under eight different temperature and light conditions. (2) By integrating time-series transcriptomics data to constrain the flux boundaries of the metabolic model, we captured the time- and condition-specific state of the network. Although based on a single time-series experiment, the comparison of these capacities to a novel null model for transcript distribution allowed us to define a measure for differential behavior that accounts for the underlying network structure and the complex interplay of metabolic pathways.

  6. Model to identify mathematics topics in MXit lingo to provide tutors quick access to supporting documentation

    CSIR Research Space (South Africa)

    Butgereit, L

    2011-11-01

    Full Text Available of ?parabola? could be a subtopic in the major topic of ?algebra?. Subtopics could belong to more than one major topic; for example, the subtopic ?parabola? could also belong to the major topic ?graphs?. As with the compilation of the Create... instantiation of the ? model for integration into the Dr Math tutoring platform, mathematics topics were subdivided into topics and subtopics. The topics were algebra, geometry, trigonometry, calculus, statistics, financial mathematics, number theory...

  7. Importance sampling for Lambda-coalescents in the infinitely many sites model

    CERN Document Server

    Birkner, Matthias; Steinruecken, Matthias; 10.1016/j.tpb.2011.01.005

    2011-01-01

    We present and discuss new importance sampling schemes for the approximate computation of the sample probability of observed genetic types in the infinitely many sites model from population genetics. More specifically, we extend the 'classical framework', where genealogies are assumed to be governed by Kingman's coalescent, to the more general class of Lambda-coalescents and develop further Hobolth et. al.'s (2008) idea of deriving importance sampling schemes based on 'compressed genetrees'. The resulting schemes extend earlier work by Griffiths and Tavar\\'e (1994), Stephens and Donnelly (2000), Birkner and Blath (2008) and Hobolth et. al. (2008). We conclude with a performance comparison of classical and new schemes for Beta- and Kingman coalescents.

  8. The importance of high spatial resolution for the performance of atmospheric chemistry-transport models

    Science.gov (United States)

    Mantzius Hansen, Kaj

    2010-05-01

    We have investigated the importance of spatial resolution for the performance of the Danish Eulerian Hemispheric Model (DEHM), a state-of-the-art atmospheric chemistry-transport model covering the majority of the Northern Hemisphere with a horizontal grid resolution of 150 km X 150 km. DEHM has 29 vertical layers in terrain-following sigma-coordinates extending up to a height of 100 hPa. Two-way nesting options with a nesting factor of three can be applied with higher resolution over a limited area of the model. At present the model can be run without nests or with one, two or three nests, each with resolutions of 50 km X 50 km, 16.7 km X 16.7 km, and 5.6 km X 5.6 km, respectively. The model includes a comprehensive chemistry scheme with more than 100 reactions and 67 atmospheric constituents, of which 4 relate to primary particulates (PM2.5, PM10, TSP and sea salt), other species are SOx, NOx, NHx, VOCs, and secondary inorganic particulates. DEHM is driven by meteorological data from the numerical weather prediction model MM5v3. Three simulations were performed with DEHM: one simulation with only the mother domain, one simulation with one nest over Europe, and one simulation with an additional nest covering Denmark and surrounding countries. All three simulations cover the period from 1989 to 2006. The predicted concentrations were evaluated against measurements from the EMEP monitoring network. Only sites within the innermost nest were included in the evaluation and the evaluations of the three simulations were compared to test the influence of spatial resolution on the performance of the model.

  9. Incorporating risk attitude into Markov-process decision models: importance for individual decision making.

    Science.gov (United States)

    Cher, D J; Miyamoto, J; Lenert, L A

    1997-01-01

    Most decision models published in the medical literature take a risk-neutral perspective. Under risk neutrality, the utility of a gamble is equivalent to its expected value and the marginal utility of living a given unit of time is the same regardless of when it occurs. Most patients, however, are not risk-neutral. Not only does risk aversion affect decision analyses when tradeoffs between short- and long-term survival are involved, it also affects the interpretation of time-tradeoff measures of health-state utility. The proportional time tradeoff under- or overestimates the disutility of an inferior health state, depending on whether the patient is risk-seeking or risk-averse (it is unbiased if the patient is risk-neutral). The authors review how risk attitude with respect to gambles for survival duration can be incorporated into decision models using the framework of risk-adjusted quality-adjusted life years (RA-QALYs). They present a simple extension of this framework that allows RA-QALYs to be calculated for Markov-process decision models. Using a previously published Markov-process model of surgical vs expectant treatment for benign prostatic hypertrophy (BPH), they show how attitude towards risk affects the expected number of QALYs calculated by the model. In this model, under risk neutrality, surgery was the preferred option. Under mild risk aversion, expectant treatment was the preferred option. Risk attitude is an important aspect of preferences that should be incorporated into decision models where one treatment option has upfront risks of morbidity or mortality.

  10. Representing ozone extremes in European megacities: the importance of resolution in a global chemistry climate model

    Directory of Open Access Journals (Sweden)

    Z. S. Stock

    2013-10-01

    Full Text Available The continuing growth of the world's urban population has led to an increasing number of cities with more than 10 million inhabitants. The higher emissions of pollutants, coupled to higher population density, makes predictions of air quality in these megacities of particular importance from both a science and a policy perspective. Global climate models are typically run at coarse resolution to enable both the efficient running of long time integrations, and the ability to run multiple future climate scenarios. However, when considering surface ozone concentrations at the local scale, coarse resolution can lead to inaccuracies arising from the highly non-linear ozone chemistry and the sensitivity of ozone to the distribution of its precursors on smaller scales. In this study, we use UM-UKCA, a global atmospheric chemistry model, coupled to the UK Met Office Unified Model, to investigate the impact of model resolution on tropospheric ozone, ranging from global to local scales. We focus on the model's ability to represent the probability of high ozone concentrations in the summer and low ozone concentrations, associated with polluted megacity environments, in the winter, and how this varies with horizontal resolution. We perform time-slice integrations with two model configurations at typical climate resolution (CR, ~150 km and at a higher resolution (HR, ~40 km. The CR configuration leads to overestimation of ozone concentrations on both regional and local scales, while it gives broadly similar results to the HR configuration on the global scale. The HR configuration is found to produce a more realistic diurnal cycle of ozone concentrations and to give a better representation of the probability density function of ozone values in urban areas such as the megacities of London and Paris. We discuss the possible causes for the observed difference in model behaviour between CR and HR configurations and estimate the relative contribution of chemical and

  11. Model of a multiverse providing the dark energy of our universe

    Science.gov (United States)

    Rebhan, E.

    2017-09-01

    It is shown that the dark energy presently observed in our universe can be regarded as the energy of a scalar field driving an inflation-like expansion of a multiverse with ours being a subuniverse among other parallel universes. A simple model of this multiverse is elaborated: Assuming closed space geometry, the origin of the multiverse can be explained by quantum tunneling from nothing; subuniverses are supposed to emerge from local fluctuations of separate inflation fields. The standard concept of tunneling from nothing is extended to the effect that in addition to an inflationary scalar field, matter is also generated, and that the tunneling leads to an (unstable) equilibrium state. The cosmological principle is assumed to pertain from the origin of the multiverse until the first subuniverses emerge. With increasing age of the multiverse, its spatial curvature decays exponentially so fast that, due to sharing the same space, the flatness problem of our universe resolves by itself. The dark energy density imprinted by the multiverse on our universe is time-dependent, but such that the ratio w = ϱ/(c2p) of its mass density and pressure (times c2) is time-independent and assumes a value ‑ 1 + 𝜖 with arbitrary 𝜖 > 0. 𝜖 can be chosen so small, that the dark energy model of this paper can be fitted to the current observational data as well as the cosmological constant model.

  12. RESEARCH OF PROBLEMS OF DESIGN OF COMPLEX TECHNICAL PROVIDING AND THE GENERALIZED MODEL OF THEIR DECISION

    Directory of Open Access Journals (Sweden)

    A. V. Skrypnikov

    2015-01-01

    Full Text Available Summary. In this work the general ideas of a method of V. I. Skurikhin taking into account the specified features develop and questions of the analysis and synthesis of a complex of technical means, with finishing them to the level suitable for use in engineering practice of design of information management systems are in more detail considered. In work the general system approach to the solution of questions of a choice of technical means of the information management system is created, the general technique of the sys tem analysis and synthesis of a complex of the technical means and its subsystems providing achievement of extreme value of criterion of efficiency of functioning of a technical complex of the information management system is developed. The main attention is paid to the applied party of system researches of complex technical providing, in particular, to definition of criteria of quality of functioning of a technical complex, development of methods of the analysis of information base of the information management system and definition of requirements to technical means, and also methods of structural synthesis of the main subsystems of complex technical providing. Thus, the purpose is research on the basis of system approach of complex technical providing the information management system and development of a number of methods of the analysis and the synthesis of complex technical providing suitable for use in engineering practice of design of systems. The well-known paradox of development of management information consists of that parameters of the system, and consequently, and requirements to the complex hardware, can not be strictly reasonable to development of algorithms and programs, and vice versa. The possible method of overcoming of these difficulties is prognostication of structure and parameters of complex hardware for certain management informations on the early stages of development, with subsequent clarification and

  13. Understanding the relationship between Kano model's customer satisfaction scores and self-stated requirements importance.

    Science.gov (United States)

    Mkpojiogu, Emmanuel O C; Hashim, Nor Laily

    2016-01-01

    Customer satisfaction is the result of product quality and viability. The place of the perceived satisfaction of users/customers for a software product cannot be neglected especially in today competitive market environment as it drives the loyalty of customers and promotes high profitability and return on investment. Therefore understanding the importance of requirements as it is associated with the satisfaction of users/customers when their requirements are met is worth the pain considering. It is necessary to know the relationship between customer satisfactions when their requirements are met (or their dissatisfaction when their requirements are unmet) and the importance of such requirement. So many works have been carried out on customer satisfaction in connection with the importance of requirements but the relationship between customer satisfaction scores (coefficients) of the Kano model and users/customers self-stated requirements importance have not been sufficiently explored. In this study, an attempt is made to unravel the underlying relationship existing between Kano model's customer satisfaction indexes and users/customers self reported requirements importance. The results of the study indicate some interesting associations between these considered variables. These bivariate associations reveal that customer satisfaction index (SI), and average satisfaction coefficient (ASC) and customer dissatisfaction index (DI) and average satisfaction coefficient (ASC) are highly correlated (r = 96 %) and thus ASC can be used in place of either SI or DI in representing customer satisfaction scores. Also, these Kano model's customer satisfaction variables (SI, DI, and ASC) are each associated with self-stated requirements importance (IMP). Further analysis indicates that the value customers or users place on requirements that are met or on features that are incorporated into a product influences the level of satisfaction such customers derive from the product. The

  14. Importance of the Hydrogen Isocyanide Isomer in Modeling Hydrogen Cyanide Oxidation in Combustion

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul

    2017-01-01

    Hydrogen isocyanide (HNC) has been proposed as an important intermediate in oxidation of hydrogen cyanide (HCN) in combustion, but details of its chemistry are still in discussion. At higher temperatures, HCN and HNC equilibrate rapidly, and being more reactive than HCN, HNC offers a fast...... alternative route of oxidation for cyanides. However, in previous modeling, it has been required to omit the HNC subset partly or fully in the reaction mechanisms to obtain satisfactory predictions. In the present work, we re-examine the chemistry of HNC and its role in combustion nitrogen chemistry. The HNC...

  15. Use of a professional practice model to illuminate the importance of relationships.

    Science.gov (United States)

    Johnson, Linda; Ezekielian, Jamie

    2014-01-01

    At the Ohio State University Comprehensive Cancer Center-James Cancer Hospital and Solove Research Institute (OSUCCC-James), implementation of relationship-based care (RBC) and primary nursing (PN) along with enculturation of the James Nursing professional practice model (PPM), have improved patient and nurse satisfaction. This article describes the importance of relationships with self, colleagues, patients and families, and the community. Best practices and outcomes are shared to inspire others who seek to transform professional practice environments and organizational cultures by focusing on patients and families and engaging frontline leaders in the change process.

  16. A Model for Providing Guidance Services in Elementary Schools: A Generalist-Preventive Approach. Implemented Model. Maxi II Practicum.

    Science.gov (United States)

    Horne, Sydney B.

    The purpose of this practicum was to develop, implement, and evaluate a model for elementary school guidance at Northwoods Elementary School, if the need for such a model could be demonstrated. The need was demonstrated, the model was developed and tested. Subsequent investigation demonstrated that guidance services were increased as a result of…

  17. Modeling treatment couches in the Pinnacle treatment planning system: Especially important for arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Duggar, William Neil, E-mail: wduggar@umc.edu [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States); Nguyen, Alex [Ironwood Cancer and Research Center, Chandler, AZ (United States); Stanford, Jason; Morris, Bart; Yang, Claus C. [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States)

    2016-04-01

    This study is to demonstrate the importance and a method of properly modeling the treatment couch for dose calculation in patient treatment using arc therapy. The 2 treatment couch tops—Aktina AK550 and Elekta iBEAM evo—of Elekta LINACs were scanned using Philips Brilliance Big Bore CT Simulator. Various parts of the couch tops were contoured, and their densities were measured and recorded on the Pinnacle treatment planning system (TPS) using the established computed tomography density table. These contours were saved as organ models to be placed beneath the patient during planning. Relative attenuation measurements were performed following procedures outlined by TG-176 as well as absolute dose comparison of static fields of 10 × 10 cm{sup 2} that were delivered through the couch tops with that calculated in the TPS with the couch models. A total of 10 random arc therapy treatment plans (5 volumetric-modulated arc therapy [VMAT] and 5 stereotactic body radiation therapy [SBRT]), using 24 beams, were selected for this study. All selected plans were calculated with and without couch modeling. Each beam was evaluated using the Delta{sup 4} dosimetry system (Delta{sup 4}). The Student t-test was used to determine statistical significance. Independent reviews were exploited as per the Imaging and Radiation Oncology Core head and neck credentialing phantom. The selected plans were calculated on the actual patient anatomies with and without couch modeling to determine potential clinical effects. Large relative beam attenuations were noted dependent on which part of the couch top beams were passing through. Substantial improvements were also noted for static fields both calculated with the TPS and delivered physically when the couch models were included in the calculation. A statistically significant increase in agreement was noted for dose difference, distance to agreement, and γ-analysis with the Delta{sup 4} on VMAT and SBRT plans. A credentialing review showed

  18. Provide a New Model for Query Processing in P2P Integration Systems

    Directory of Open Access Journals (Sweden)

    Hassan Shojaee Mend

    2014-07-01

    Full Text Available Most of organizations and companies meet their needs for software by providing distinguished software system during the time. Each one of these systems utilize own way for saving information which are not necessarily similar to other systems. Therefore, we are facing with a collection of information related to an organization which have been scattered in a series of heterogeneous databases. On the other hand, by the emergence of network and internet the number of existing and interrelated databases is increasing daily. The information must be extracted from this data sources. This task can be done through asking query about the information, but the combination of information from different data sources, due to different data structures, different schemas, different access protocols which they need and the distribution of data sources on the surface of network, is a hard and boring task. The purpose of integration systems is to provide an integrated query interface on a set of database, such a way that the user by using this integrated interface, without the need for knowing the location and the way of access to the data, can ask his query in the system and receive the existing results through the network. In this study, architecture has been provided for querying p2p integration system. In the suggested architecture, the features of a p2p environment and the changeability of the environment of the network have been considered. Also, the utilized mechanism for processing the query is such a way that to decrease the network traffic and the time of responding to the minimum. The practical results indicated that the suggested method has a close manner to the optimized status

  19. Statistical Combination of Several Important Standard Model Higgs Boson Search Channels.

    CERN Document Server

    The ATLAS collaboration

    2009-01-01

    In this note we describe statistical procedures for combination of results from independent searches for the Higgs boson. Here only the Standard Model Higgs is considered, although the methods can easily be extended to non-standard Higgs models as well as to other searches. The methods are applied to Monte Carlo studies of four important search channels: H to tau+ tau-, H to W+ W- to e-nu mu-nu, H to gamma gamma, and H to ZZ)(*) to 4 leptons. The statistical treatment relies on a large sample approximation that is expected to be valid for an integrated luminosity of at least 2 fb-1 . Results are presented for the expected statistical significance of discovery and expected exclusion limits.

  20. Modelling of Limestone Dissolution in Wet FGD Systems: The Importance of an Accurate Particle Size Distribution

    DEFF Research Database (Denmark)

    Kiil, Søren; Johnsson, Jan Erik; Dam-Johansen, Kim

    1999-01-01

    In wet flue gas desulphurisation (FGD) plants, the most common sorbent is limestone. Over the past 25 years, many attempts to model the transient dissolution of limestone particles in aqueous solutions have been performed, due to the importance for the development of reliable FGD simu-lation tools...... suspended in a liquid solution. The measured PSDs were sensitive to the addition of a dispersing agent, the dispersion time, and the presence of ultrasound. It was found that the different PSDs influenced the simulated rate of dis-solution significantly (i.e. from below to above the measured dissolution...... rate). The results of this work show that a representative PSD is essential in order to model the rate of dissolution of lime-stone particles accurately....

  1. Model reduction algorithms for optimal control and importance sampling of diffusions

    Science.gov (United States)

    Hartmann, Carsten; Schütte, Christof; Zhang, Wei

    2016-08-01

    We propose numerical algorithms for solving optimal control and importance sampling problems based on simplified models. The algorithms combine model reduction techniques for multiscale diffusions and stochastic optimization tools, with the aim of reducing the original, possibly high-dimensional problem to a lower dimensional representation of the dynamics, in which only a few relevant degrees of freedom are controlled or biased. Specifically, we study situations in which either a reaction coordinate onto which the dynamics can be projected is known, or situations in which the dynamics shows strongly localized behavior in the small noise regime. No explicit assumptions about small parameters or scale separation have to be made. We illustrate the approach with simple, but paradigmatic numerical examples.

  2. MODELING THE DETERMINANTS OF EXPORTS AND IMPORTS: ASSESSMENT OF THE MACEDONIAN COMPETITIVE PERFORMANCES

    Directory of Open Access Journals (Sweden)

    Goce PETRESKI

    2009-01-01

    Full Text Available So far Macedonia has undergone an unsuccessful attempt to transition,distinguished by low growth rates, high unemployment, extensive poverty,balance of payments unfavorable position, technological lag etc. The externalsector, as a core element to growth perspectives of a small open economy iscritically dependant upon the export competitiveness. Consequently, thispaper will address some critical points of the Macedonian economy,particularly the vulnerability of the external sector alongside with the priceand trade liberalization. The set of analyses is to be carried out to explore theforeign trade structure, current account developments, as well as the majoraspects of qualitative competitiveness. In addition, we have examined theimpact of macroeconomic variables on exports and imports within theselected timeframe. We have therefore applied a comprehensive approach ofdynamic modeling based upon a vector - autoregression model determinedto control for endogeneity and set to estimate the long - run equilibriumrelations, as well as the short-run dynamics of the key variables.

  3. An artificial pancreas provided a novel model of blood glucose level variability in beagles.

    Science.gov (United States)

    Munekage, Masaya; Yatabe, Tomoaki; Kitagawa, Hiroyuki; Takezaki, Yuka; Tamura, Takahiko; Namikawa, Tsutomu; Hanazaki, Kazuhiro

    2015-12-01

    Although the effects on prognosis of blood glucose level variability have gained increasing attention, it is unclear whether blood glucose level variability itself or the manifestation of pathological conditions that worsen prognosis. Then, previous reports have not been published on variability models of perioperative blood glucose levels. The aim of this study is to establish a novel variability model of blood glucose concentration using an artificial pancreas. We maintained six healthy, male beagles. After anesthesia induction, a 20-G venous catheter was inserted in the right femoral vein and an artificial pancreas (STG-22, Nikkiso Co. Ltd., Tokyo, Japan) was connected for continuous blood glucose monitoring and glucose management. After achieving muscle relaxation, total pancreatectomy was performed. After 1 h of stabilization, automatic blood glucose control was initiated using the artificial pancreas. Blood glucose level varied for 8 h, alternating between the target blood glucose values of 170 and 70 mg/dL. Eight hours later, the experiment was concluded. Total pancreatectomy was performed for 62 ± 13 min. Blood glucose swings were achieved 9.8 ± 2.3 times. The average blood glucose level was 128.1 ± 5.1 mg/dL with an SD of 44.6 ± 3.9 mg/dL. The potassium levels after stabilization and at the end of the experiment were 3.5 ± 0.3 and 3.1 ± 0.5 mmol/L, respectively. In conclusion, the results of the present study demonstrated that an artificial pancreas contributed to the establishment of a novel variability model of blood glucose levels in beagles.

  4. A Spirulina-Enhanced Diet Provides Neuroprotection in an α-Synuclein Model of Parkinson's Disease

    Science.gov (United States)

    Pabon, Mibel M.; Jernberg, Jennifer N.; Morganti, Josh; Contreras, Jessika; Hudson, Charles E.; Klein, Ronald L.; Bickford, Paula C.

    2012-01-01

    Inflammation in the brain plays a major role in neurodegenerative diseases. In particular, microglial cell activation is believed to be associated with the pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD). An increase in microglia activation has been shown in the substantia nigra pars compacta (SNpc) of PD models when there has been a decrease in tyrosine hydroxylase (TH) positive cells. This may be a sign of neurotoxicity due to prolonged activation of microglia in both early and late stages of disease progression. Natural products, such as spirulina, derived from blue green algae, are believed to help reverse this effect due to its anti-inflammatory/anti-oxidant properties. An adeno-associated virus vector (AAV9) for α-synuclein was injected in the substantia nigra of rats to model Parkinson's disease and to study the effects of spirulina on the inflammatory response. One month prior to surgeries, rats were fed either a diet enhanced with spirulina or a control diet. Immunohistochemistry was analyzed with unbiased stereological methods to quantify lesion size and microglial activation. As hypothesized, spirulina was neuroprotective in this α-synuclein model of PD as more TH+ and NeuN+ cells were observed; spirulina concomitantly decreased the numbers of activated microglial cells as determined by MHCII expression. This decrease in microglia activation may have been due, in part, to the effect of spirulina to increase expression of the fractalkine receptor (CX3CR1) on microglia. With this study we hypothesize that α-synuclein neurotoxicity is mediated, at least in part, via an interaction with microglia. We observed a decrease in activated microglia in the rats that received a spirulina- enhanced diet concomitant to neuroprotection. The increase in CX3CR1 in the groups that received spirulina, suggests a potential mechanism of action. PMID:23028885

  5. A spirulina-enhanced diet provides neuroprotection in an α-synuclein model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Mibel M Pabon

    Full Text Available Inflammation in the brain plays a major role in neurodegenerative diseases. In particular, microglial cell activation is believed to be associated with the pathogenesis of neurodegenerative diseases, including Parkinson's disease (PD. An increase in microglia activation has been shown in the substantia nigra pars compacta (SNpc of PD models when there has been a decrease in tyrosine hydroxylase (TH positive cells. This may be a sign of neurotoxicity due to prolonged activation of microglia in both early and late stages of disease progression. Natural products, such as spirulina, derived from blue green algae, are believed to help reverse this effect due to its anti-inflammatory/anti-oxidant properties. An adeno-associated virus vector (AAV9 for α-synuclein was injected in the substantia nigra of rats to model Parkinson's disease and to study the effects of spirulina on the inflammatory response. One month prior to surgeries, rats were fed either a diet enhanced with spirulina or a control diet. Immunohistochemistry was analyzed with unbiased stereological methods to quantify lesion size and microglial activation. As hypothesized, spirulina was neuroprotective in this α-synuclein model of PD as more TH+ and NeuN+ cells were observed; spirulina concomitantly decreased the numbers of activated microglial cells as determined by MHCII expression. This decrease in microglia activation may have been due, in part, to the effect of spirulina to increase expression of the fractalkine receptor (CX3CR1 on microglia. With this study we hypothesize that α-synuclein neurotoxicity is mediated, at least in part, via an interaction with microglia. We observed a decrease in activated microglia in the rats that received a spirulina- enhanced diet concomitant to neuroprotection. The increase in CX3CR1 in the groups that received spirulina, suggests a potential mechanism of action.

  6. A spirulina-enhanced diet provides neuroprotection in an α-synuclein model of Parkinson's disease.

    Science.gov (United States)

    Pabon, Mibel M; Jernberg, Jennifer N; Morganti, Josh; Contreras, Jessika; Hudson, Charles E; Klein, Ronald L; Bickford, Paula C

    2012-01-01

    Inflammation in the brain plays a major role in neurodegenerative diseases. In particular, microglial cell activation is believed to be associated with the pathogenesis of neurodegenerative diseases, including Parkinson's disease (PD). An increase in microglia activation has been shown in the substantia nigra pars compacta (SNpc) of PD models when there has been a decrease in tyrosine hydroxylase (TH) positive cells. This may be a sign of neurotoxicity due to prolonged activation of microglia in both early and late stages of disease progression. Natural products, such as spirulina, derived from blue green algae, are believed to help reverse this effect due to its anti-inflammatory/anti-oxidant properties. An adeno-associated virus vector (AAV9) for α-synuclein was injected in the substantia nigra of rats to model Parkinson's disease and to study the effects of spirulina on the inflammatory response. One month prior to surgeries, rats were fed either a diet enhanced with spirulina or a control diet. Immunohistochemistry was analyzed with unbiased stereological methods to quantify lesion size and microglial activation. As hypothesized, spirulina was neuroprotective in this α-synuclein model of PD as more TH+ and NeuN+ cells were observed; spirulina concomitantly decreased the numbers of activated microglial cells as determined by MHCII expression. This decrease in microglia activation may have been due, in part, to the effect of spirulina to increase expression of the fractalkine receptor (CX3CR1) on microglia. With this study we hypothesize that α-synuclein neurotoxicity is mediated, at least in part, via an interaction with microglia. We observed a decrease in activated microglia in the rats that received a spirulina- enhanced diet concomitant to neuroprotection. The increase in CX3CR1 in the groups that received spirulina, suggests a potential mechanism of action.

  7. User modeling and adaptation for daily routines providing assistance to people with special needs

    CERN Document Server

    Martín, Estefanía; Carro, Rosa M

    2013-01-01

    User Modeling and Adaptation for Daily Routines is motivated by the need to bring attention to how people with special needs can benefit from adaptive methods and techniques in their everyday lives. Assistive technologies, adaptive systems and context-aware applications are three well-established research fields. There is, in fact, a vast amount of literature that covers HCI-related issues in each area separately. However, the contributions in the intersection of these areas have been less visible, despite the fact that such synergies may have a great impact on improving daily living.Presentin

  8. Software applications for providing comprehensive computing capabilities to problems related to mixed models in animal breeding

    Institute of Scientific and Technical Information of China (English)

    Monchai; DAUNGJINDA

    2005-01-01

    Recently,several computer packages havebeen developed to accomplish problems relatedto mixed model in animal breeding.Special soft-ware for estimation of variance components andprediction of genetic merits are basically neededfor genetic evaluation and selection program.Al-though there are some packages available on theinternet,however,most of them are commercialor unfriendly to be used.The lists of recent soft-ware available on the internet are shown in Tab.1.Most software is free license(mostly for ac-ade...

  9. Implementation of cancer clinical care pathways: a successful model of collaboration between payers and providers.

    Science.gov (United States)

    Feinberg, Bruce A; Lang, James; Grzegorczyk, James; Stark, Donna; Rybarczyk, Thomas; Leyden, Thomas; Cooper, Joseph; Ruane, Thomas; Milligan, Scott; Stella, Philip; Scott, Jeffrey A

    2012-05-01

    Despite rising medical costs within the US health care system, quality and outcomes are not improving. Without significant policy reform, the cost-quality imbalance will reach unsustainable proportions in the foreseeable future. The rising cost of health care in part results from an expanding aging population with an increasing number of life-threatening diseases. This is further compounded by a growing arsenal of high-cost therapies. In no medical specialty is this more apparent than in the area of oncology. Numerous attempts to reduce costs have been attempted, often with limited benefit and brief duration. Because physicians directly or indirectly control or influence the majority of medical care costs, physician behavioral changes must occur to bend the health care cost curve in a sustainable fashion. Experts within academia, health policy, and business agree that a significant paradigm change in stakeholder collaboration will be necessary to accomplish behavioral change. Such a collaboration has been pioneered by Blue Cross Blue Shield of Michigan and Physician Resource Management, a highly specialized oncology health care consulting firm with developmental and ongoing technical, analytic, and consultative support from Cardinal Health Specialty Solutions, a division of Cardinal Health. We describe a successful statewide collaboration between payers and providers to create a cancer clinical care pathways program. We show that aligned stakeholder incentives can drive high levels of provider participation and compliance in the pathways that lead to physician behavioral changes. In addition, claims-based data can be collected, analyzed, and used to create and maintain such a program.

  10. Implementation of cancer clinical care pathways: s successful model of collaboration between payers and providers.

    Science.gov (United States)

    Feinberg, Bruce A; Lang, James; Grzegorczyk, James; Stark, Donna; Rybarczyk, Thomas; Leyden, Thomas; Cooper, Joseph; Ruane, Thomas; Milligan, Scott; Stella, Phillip; Scott, Jeffrey A

    2012-05-01

    Despite rising medical costs within the US healthcare system, quality and outcomes are not improving. Without significant policy reform, the cost-quality imbalance will reach unsustainable proportions in the foreseeable future. The rising cost of healthcare in part results from an expanding aging population with an increasing number of life-threatening diseases. This is further compounded by a growing arsenal of high-cost therapies. In no medical specialty is this more apparent than in the area of oncology. Numerous attempts to reduce costs have been attempted, often with limited benefit and brief duration. Because physicians directly or indirectly control or influence the majority of medical care costs, physician behavioral changes must occur to bend the healthcare cost curve in a sustainable fashion. Experts within academia, health policy, and business agree that a significant paradigm change in stakeholder collaboration will be necessary to accomplish behavioral change. Such a collaboration has been pioneered by Blue Cross Blue Shield of Michigan and Physician Resource Management, a highly specialized oncology healthcare consulting firm with developmental and ongoing technical, analytic, and consultative support from Cardinal Health Specialty Solutions, a division of Cardinal Health. We describe a successful statewide collaboration between payers and providers to create a cancer clinical care pathways program. We show that aligned stakeholder incentives can drive high levels of provider participation and compliance in the pathways that lead to physician behavioral changes. In addition, claims-based data can be collected, analyzed, and used to create and maintain such a program.

  11. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    Science.gov (United States)

    Wohlfahrt, Georg; Widmoser, Peter

    2013-02-15

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements.

  12. Animal models and their importance to human physiological responses in microgravity

    Science.gov (United States)

    Tipton, C. M.

    1996-01-01

    Two prominent theories to explain the physiological effects of microgravity relate to the cascade of changes associated with the cephalic shifts of fluids and the absence of tissue deformation forces. One-g experiments for humans used bed rest and the head-down tilt (HDT) method, while animal experiments have been conducted using the tail-suspended, head-down, and hindlimbs non-weightbearing model. Because of the success of the HDT approach with rats to simulate the gravitational effects on the musculoskeletal system exhibited by humans, the same model has been used to study the effects of gravity on the cardiopulmonary systems of humans and other vertebrates. Results to date indicate the model is effective in producing comparable changes associated with blood volume, erythropoiesis, cardiac mass, baroreceptor responsiveness, carbohydrate metabolism, post-flight VO2max, and post-flight cardiac output during exercise. Inherent with these results is the potential of the model to be useful in investigating responsible mechanisms. The suspension model has promise in understanding the capillary blood PO2 changes in space as well as the arterial PO2 changes in subjects participating in a HDT experiment. However, whether the model can provide insights on the up-or-down regulation of adrenoreceptors remains to be determined, and many investigators believe the HDT approach should not be followed to study gravitational influences on pulmonary function in either humans or animals. It was concluded that the tail-suspended animal model had sufficient merit to study in-flight and post-flight human physiological responses and mechanisms.

  13. Metabolomic perfusate analysis during kidney machine perfusion: the pig provides an appropriate model for human studies.

    Directory of Open Access Journals (Sweden)

    Jay Nath

    Full Text Available Hypothermic machine perfusion offers great promise in kidney transplantation and experimental studies are needed to establish the optimal conditions for this to occur. Pig kidneys are considered to be a good model for this purpose and share many properties with human organs. However it is not established whether the metabolism of pig kidneys in such hypothermic hypoxic conditions is comparable to human organs.Standard criteria human (n = 12 and porcine (n = 10 kidneys underwent HMP using the LifePort Kidney Transporter 1.0 (Organ Recovery Systems using KPS-1 solution. Perfusate was sampled at 45 minutes and 4 hours of perfusion and metabolomic analysis performed using 1-D 1H-NMR spectroscopy.There was no inter-species difference in the number of metabolites identified. Of the 30 metabolites analysed, 16 (53.3% were present in comparable concentrations in the pig and human kidney perfusates. The rate of change of concentration for 3-Hydroxybutyrate was greater for human kidneys (p<0.001. For the other 29 metabolites (96.7%, there was no difference in the rate of change of concentration between pig and human samples.Whilst there are some differences between pig and human kidneys during HMP they appear to be metabolically similar and the pig seems to be a valid model for human studies.

  14. How important are the descriptions of vegetation in distributed hydrologic models?

    Science.gov (United States)

    Cuntz, Matthias; Thober, Stephan; Zink, Matthias; Rakovec, Oldrich; Samaniego, Luis

    2016-04-01

    The land surface transforms incoming, absorbed radiation into other energy forms and radiation with longer wavelengths. The land surface emits long-wave radiation, stores energy in the soil, the biomass and the air in the boundary layer, and exchanges sensible and latent heat with the atmosphere. The latter, latent heat consists of evaporation from the soil and canopy and transpiration by plants. Plants enhance in this picture the absorption of incoming radiation and decrease the resistance for evaporation of deeper soil water. Transpiration by plants is therefore either energy-limited by low incoming radiation or water-limited by small soil moisture. In the extreme cases, all available energy will be used for evapotranspiration in cold regions and all available water will be used for evapotranspiration in arid regions. Very simple formulations of latent heat, which include plant processes only very indirectly, work well in hydrologic models for these limiting cases. These simple formulations seem to work also surprisingly well in temperate regions. Hydrologic models have, however, considerable problems in semi-arid regions where the vegetation influence on latent heat should be largest. But the models have to deal with much more problems in these regions. For example data scarcity in the Mediterranean leads to very large model uncertainty due to the forcing data. Water supply is also often very regulated in semi-arid regions. Variability in river discharge can hence be largely driven by the anthropogenic influence rather than natural meteorological variations in these regions. Here we will show for Europe the areas and times when the descriptions of plant processes are important for hydrologic models. We will compare differences in model uncertainties that come from 1. different formulations of evapotranspiration, 2. different descriptions of soil-plant interactions, and 3. uncertainty in the model's input data. It can be seen that model uncertainty stemming from

  15. Understanding the Importance of Shape in Thermal Modeling: The Case of 1627 Ivar

    Science.gov (United States)

    Crowell, Jenna L.; Howell, Ellen S.; Magri, Christopher; Fernandez, Yanga R.; Nolan, Michael C.; Vervack, Ronald J., Jr.; Marshall, Sean E.

    2016-10-01

    We seek to investigate the compositional surface variation of near Earth asteroids (NEAs). To do this, we employ detailed shape models and near-IR observations, taken over a range of viewing geometries, in order to create thermophysical models. The thermal spectra are therefore linked to regions on the asteroid, and we can seek out a set of thermal parameters that are capable of reproducing the thermal spectra over the entirety of the asteroid's surface. This method also enables us to characterize portions of the asteroid that may have different thermal properties than other regions, in which case there is no single set of thermal parameters that satisfy all of the thermal observations, indicating a heterogeneous surface.We present our findings on 1627 Ivar, an Amor class NEA with a taxonomic type of Sqw [1], and a rotation period of 4.7951689 hr ± 0.0000026 [2]. During Ivar's apparition in 2013, we obtained CCD lightcurves, radar data, and near-IR spectra. Using the software SHAPE, we have used lightcurve and radar data to generate an improved shape model of Ivar [2][3].For the thermophysical modeling, we have used SHERMAN [3,4] to determine which reflective, thermal, and surface properties for Ivar best reproduce our spectra, taken using the SpeX instrument at the NASA IRTF [5]. Input parameters for SHERMAN include the asteroid's IR emissivity, optical scattering law and thermal inertia in order to complete thermal computations based on the shape model. We also compare these results to those created by using the Kaasalainen lightcurve model [6]. Since models created from lightcurve inversion techniques far outnumber those created using radar data, it is important to understand how these two models differ when studying thermal models.References: [1] DeMeo et al. 2009, Icarus 202, 160-180 [2] Crowell et al. 2016, Icarus, in press [3] Crowell et al. 2014, AAS/DPS 46 [4] Howell et al. 2015, AAS/DPS 47 [5] Rayner et al. 2003, PASP 115, 362 [6] Kaasalainen et al. 2004

  16. Bridging the financial gap through providing contract services: a model for publicly funded clinical biobanks.

    Science.gov (United States)

    Kozlakidis, Zisis; Mant, Christine; Cason, John

    2012-08-01

    Biobanks offer translational researchers a novel method of obtaining clinical research materials, patient data, and relevant ethical and legal permissions. However, such tissue collections are expensive to establish and maintain. Current opinion is that such initiatives can only survive with core funding from Government or major funding bodies. Given the present climate of financial austerity, funding agencies may be tempted to invest in fast-return research projects rather than in maintaining tissue collections, whose benefits will only become apparent in much longer timescales. Thus, securing additional funding for biobanks could provide a valuable boost enabling an extension of core services. Here we suggest that using biobank expertise to offer contract services to clinicians and industry may be an alternative approach to obtaining such extra funding.

  17. SNP Discovery and Chromosome Anchoring Provide the First Physically-Anchored Hexaploid Oat Map and Reveal Synteny with Model Species

    Science.gov (United States)

    Chao, Shiaoman; Jellen, Eric N.; Carson, Martin L.; Rines, Howard W.; Obert, Donald E.; Lutz, Joseph D.; Shackelford, Irene; Korol, Abraham B.; Wight, Charlene P.; Gardner, Kyle M.; Hattori, Jiro; Beattie, Aaron D.; Bjørnstad, Åsmund; Bonman, J. Michael; Jannink, Jean-Luc; Sorrells, Mark E.; Brown-Guedira, Gina L.; Mitchell Fetch, Jennifer W.; Harrison, Stephen A.; Howarth, Catherine J.; Ibrahim, Amir; Kolb, Frederic L.; McMullen, Michael S.; Murphy, J. Paul; Ohm, Herbert W.; Rossnagel, Brian G.; Yan, Weikai; Miclaus, Kelci J.; Hiller, Jordan; Maughan, Peter J.; Redman Hulse, Rachel R.; Anderson, Joseph M.; Islamovic, Emir

    2013-01-01

    A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42) has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources. PMID:23533580

  18. SNP discovery and chromosome anchoring provide the first physically-anchored hexaploid oat map and reveal synteny with model species.

    Directory of Open Access Journals (Sweden)

    Rebekah E Oliver

    Full Text Available A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42 has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources.

  19. Measuring the Quality of Services Provided for Outpatients in Kowsar Clinic in Ardebil City Based on the SERVQUAL Model

    Directory of Open Access Journals (Sweden)

    Hasan Ghobadi

    2014-12-01

    Full Text Available Background & objectives: Today, the concept of q uality of services is particularly important in health care and customer satisfaction can be defined by comparing the expectations of the services with perception of provided services. The aim of this study was to evaluate the quality of services provided for outpatients in clinic of Ardebil city based on the SERVQUAL model.   Methods: This descriptive study was conducted on 650 patients referred to outpatient clinic since July to September 201 3 using a standardized SERVQUAL questionnaire (1988 with confirmed reliability and validity. The paired t-test and Friedman test were used for analysis of data by SPSS software.   Results: 56.1 % of respondents were male and 43.9 % of them were female . The mean age of patients was 33 ± 11.91 , 68.9 % of patients were in Ardabil and 27.3 % of them had bachelor's or higher. The results showed that there is a significant difference between perceptions and expectations of the patients about five dimensions of the service quality (tangibility, reliability, assurance, responsiveness, and empathy in the studied clinic (P< 0.001. The highest mean gap and minimum gap were related to empathy and assurance, respectively.   Conclusion: Regarding to observed differences in quality , the managers and also planners have to evaluate their performance more accurately in order to have better planning for future actions. In fact, any efforts to reduce the gap between expectation and perception of patients result in greater satisfaction, loyalty and further visits to organizations.

  20. Aire-deficient mice provide a model of corneal and lacrimal gland neuropathy in Sjögren's syndrome.

    Science.gov (United States)

    Chen, Feeling Y; Lee, Albert; Ge, Shaokui; Nathan, Sara; Knox, Sarah M; McNamara, Nancy A

    2017-01-01

    Sjögren's syndrome (SS) is a chronic, autoimmune exocrinopathy that leads to severe dryness of the mouth and eyes. Exocrine function is highly regulated by neuronal mechanisms but little is known about the link between chronic inflammation, innervation and altered exocrine function in the diseased eyes and exocrine glands of SS patients. To gain a better understanding of neuronal regulation in the immunopathogenesis of autoimmune exocrinopathy, we profiled a mouse model of spontaneous, autoimmune exocrinopathy that possess key characteristics of peripheral neuropathy experienced by SS patients. Mice deficient in the autoimmune regulator (Aire) gene developed spontaneous, CD4+ T cell-mediated exocrinopathy and aqueous-deficient dry eye that were associated with loss of nerves innervating the cornea and lacrimal gland. Changes in innervation and tear secretion were accompanied by increased proliferation of corneal epithelial basal cells, limbal expansion of KRT19-positive progenitor cells, increased vascularization of the peripheral cornea and reduced nerve function in the lacrimal gland. In addition, we found extensive loss of MIST1+ secretory acinar cells in the Aire -/- lacrimal gland suggesting that acinar cells are a primary target of the disease, Finally, topical application of ophthalmic steroid effectively restored corneal innervation in Aire -/- mice thereby functionally linking nerve loss with local inflammation in the aqueous-deficient dry eye. These data provide important insight regarding the relationship between chronic inflammation and neuropathic changes in autoimmune-mediated dry eye. Peripheral neuropathies characteristic of SS appear to be tightly linked with the underlying immunopathological mechanism and Aire -/- mice provide an excellent tool to explore the interplay between SS-associated immunopathology and peripheral neuropathy.

  1. Residuals of autoregressive model providing additional information for feature extraction of pattern recognition-based myoelectric control.

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

    2015-01-01

    Myoelectric control based on pattern recognition has been studied for several decades. Autoregressive (AR) features are one of the mostly used feature extraction methods among myoelectric control studies. Almost all previous studies only used the AR coefficients without the residuals of AR model for classification. However, the residuals of AR model contain important amplitude information of the electromyography (EMG) signals. In this study, we added the residuals to the AR features (AR+re) and compared its performance with the classical sixth-order AR coefficients. We tested six unilateral transradial amputees and eight able-bodied subjects for eleven hand and wrist motions. The classification accuracy (CA) of the intact side for amputee subjects and the right hand for able-bodied subjects showed that the CA of AR+re features was slightly but significantly higher than that of classical AR features (p = 0.009), which meant that residuals could provide additional information to classical AR features for classification. Interestingly, the CA of the affected side for amputee subjects showed that there was no significant difference between the CA of AR+re features and classical AR features (p > 0.05). We attributed this to the fact that the amputee subjects could not use their affected side to produce consistent EMG patterns as their intact side or the dominant hand of the able-bodied subjects. Since the residuals were already available when the AR coefficients were computed, the results of this study suggested adding the residuals to classical AR features to potentially improve the performance of pattern recognition-based myoelectric control.

  2. Providing a Model for Successful Implementation of Customer Relationship Management (Case Study: Zahedan Industrial City

    Directory of Open Access Journals (Sweden)

    Amin-Reza Kamalian

    2013-05-01

    Full Text Available This study presents a model for Successful Implementation of Customer Relationship Management (CRM for small and medium-sized enterprises (SMEs in Zahedan industrial city. Having extensive theoretical study, the factors influencing the success of customer relationship management were identified. Using a standard questionnaire with reliability of 96.2 percent (Cronbach's alpha coefficient, existing and desired situations of these factors were compared by experts' point of view. Research population consists of industrialists and professionals in Zahedan industrial city. Because of small population size, data obtained by the entire population; i.e. 54 companies. This applied study is in descriptive-analytical type. Data analysis was performed using SPSS software. Results indicated that all factors affecting the success of implementing customer relationship management, except technology, are used in these companies.

  3. Preconditioning Provides Neuroprotection in Models of CNS Disease: Paradigms and Clinical Significance

    Science.gov (United States)

    Stetler, R. Anne; Leak, Rehana K.; Gan, Yu; Li, Peiying; Hu, Xiaoming; Jing, Zheng; Chen, Jun; Zigmond, Michael J.; Gao, Yanqin

    2014-01-01

    Preconditioning is a phenomenon in which brief episodes of a sublethal insult induce robust protection against subsequent lethal injuries. Preconditioning has been observed in multiple organisms and can occur in the brain as well as other tissues. Extensive animal studies suggest that the brain can be preconditioned to resist acute injuries, such as ischemic stroke, neonatal hypoxia/ischemia, trauma, and agents that are used in models of neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. Effective preconditioning stimuli are numerous and diverse, ranging from transient ischemia, hypoxia, hyperbaric oxygen, hypothermia and hyperthermia, to exposure to neurotoxins and pharmacological agents. The phenomenon of “cross-tolerance,” in which a sublethal stress protects against a different type of injury, suggests that different preconditioning stimuli may confer protection against a wide range of injuries. Research conducted over the past few decades indicates that brain preconditioning is complex, involving multiple effectors such as metabolic inhibition, activation of extra- and intracellular defense mechanisms, a shift in the neuronal excitatory/inhibitory balance, and reduction in inflammatory sequelae. An improved understanding of brain preconditioning should help us identify innovative therapeutic strategies that prevent or at least reduce neuronal damage in susceptible patients. In this review, we focus on the experimental evidence of preconditioning in the brain and systematically survey the models used to develop paradigms for neuroprotection, and then discuss the clinical potential of brain preconditioning. In a subsequent components of this two-part series, we will discuss the cellular and molecular events that are likely to underlie these phenomena. PMID:24389580

  4. MODELING OF WORLD'S SYSTEMICALLY IMPORTANT ECONOMIES IMPACT ON THE DYNAMICS OF MACROECONOMIC INDICATORS IN UKRAINE

    Directory of Open Access Journals (Sweden)

    O. Bazhenova

    2015-03-01

    Full Text Available This paper develops the vector autoregression model of the Ukraine’s economy for exploring the dynamics of key indicators of the domestic economy in response to the shocks from systemically important economies. The foreign variables in the model are growth rates of real GDP, consumer price indices in the advanced economies and in countries of emerging and developing Asia and oil price. The results suggest that the shocks from the “large” economies are absorbed by the domestic economy for a long time. A significant part of the variability of real GDP growth index in Ukraine is due to external factors. Inflation in advanced countries has the most significant influence on this variability (among other external shocks that confirms inflation import from these economies. At the same time the price of oil does not significantly contribute to the explanation of the mentioned variability. Given the euro area share increase in foreign trade and China’s impact on metal market conditions this paper also explores the influence of these economies’ indicators (notably production indices and consumer price indices on Ukraine’s economy.

  5. Importance of landscape features and Earth observation derived habitat maps for modelling amphibian distribution in the Alta Murgia National Park

    Science.gov (United States)

    Ficetola, Gentile Francesco; Adamo, Maria; Bonardi, Anna; De Pasquale, Vito; Liuzzi, Cristiano; Lovergine, Francesco; Marcone, Francesco; Mastropasqua, Fabio; Tarantino, Cristina; Blonda, Palma; Padoa-Schioppa, Emilio

    2015-05-01

    Traditionally, analyses of relationships between amphibians and habitat focused on breeding environments (i.e., pond features) more than on the features of the surrounding environment. Nevertheless, for most amphibians the terrestrial phase is longer than the aquatic phase, and consequently landscape features (i.e., habitat mosaics) may have an important role for modelling amphibian distribution. There were different aims in this analysis. Firstly, we compared the effectiveness of the information provided by land cover/use (LC/LU) classes and habitat classes defined according to a new habitat taxonomy named General Habitat Category (GHC), which is based on the concept of biological forms of dominant vegetation and class naturalness. The GHC map used was obtained from a pre-existing validated LC/LU map, by integrating spectral and spatial measurements from very high resolution Earth observation data according to ecological expert rules involving concepts related to spatial and temporal relationships among LC/LU and habitat classes. Then, we investigated the importance for amphibians of the landscape surrounding ponds within the Italian Alta Murgia National Park. The work assessed whether LC/LU classes in pond surrounds are important for the presence/absence of amphibians in this area, and identified which classes are more important for amphibians. The results obtained can provide useful indications to management strategies aiming at the conservation of amphibians within the study area. An information-theoretic approach was adopted to assess whether GHC maps allow to improve the performance of species distribution models. We used the Akaike's Information Criterion (AICc) to compare the effectiveness of GHC categories versus LC/LU categories in explaining the presence/absence of pool frogs. AICc weights suggest that GHC categories can better explain the distribution of frogs, compared to LC/LU classes.

  6. The importance of data quality for generating reliable distribution models for rare, elusive, and cryptic species

    Science.gov (United States)

    Aubry, Keith B.; Raley, Catherine M.; McKelvey, Kevin S.

    2017-01-01

    The availability of spatially referenced environmental data and species occurrence records in online databases enable practitioners to easily generate species distribution models (SDMs) for a broad array of taxa. Such databases often include occurrence records of unknown reliability, yet little information is available on the influence of data quality on SDMs generated for rare, elusive, and cryptic species that are prone to misidentification in the field. We investigated this question for the fisher (Pekania pennanti), a forest carnivore of conservation concern in the Pacific States that is often confused with the more common Pacific marten (Martes caurina). Fisher occurrence records supported by physical evidence (verifiable records) were available from a limited area, whereas occurrence records of unknown quality (unscreened records) were available from throughout the fisher’s historical range. We reserved 20% of the verifiable records to use as a test sample for both models and generated SDMs with each dataset using Maxent. The verifiable model performed substantially better than the unscreened model based on multiple metrics including AUCtest values (0.78 and 0.62, respectively), evaluation of training and test gains, and statistical tests of how well each model predicted test localities. In addition, the verifiable model was consistent with our knowledge of the fisher’s habitat relations and potential distribution, whereas the unscreened model indicated a much broader area of high-quality habitat (indices > 0.5) that included large expanses of high-elevation habitat that fishers do not occupy. Because Pacific martens remain relatively common in upper elevation habitats in the Cascade Range and Sierra Nevada, the SDM based on unscreened records likely reflects primarily a conflation of marten and fisher habitat. Consequently, accurate identifications are far more important than the spatial extent of occurrence records for generating reliable SDMs for the

  7. A provider-based water planning and management model--WaterSim 4.0--for the Phoenix Metropolitan Area.

    Science.gov (United States)

    Sampson, D A; Escobar, V; Tschudi, M K; Lant, T; Gober, P

    2011-10-01

    Uncertainty in future water supplies for the Phoenix Metropolitan Area (Phoenix) are exacerbated by the near certainty of increased, future water demands; water demand may increase eightfold or more by 2030 for some communities. We developed a provider-based water management and planning model for Phoenix termed WaterSim 4.0. The model combines a FORTRAN library with Microsoft C# to simulate the spatial and temporal dynamics of current and projected future water supply and demand as influenced by population demographics, climatic uncertainty, and groundwater availability. This paper describes model development and rationale. Water providers receive surface water, groundwater, or both depending on their portfolio. Runoff from two riverine systems supplies surface water to Phoenix while three alluvial layers that underlie the area provide groundwater. Water demand was estimated using two approaches. One approach used residential density, population projections, water duties, and acreage. A second approach used per capita water consumption and separate population growth estimates. Simulated estimates of initial groundwater for each provider were obtained as outputs from the Arizona Department of Water Resources (ADWR) Salt River Valley groundwater flow model (GFM). We compared simulated estimates of water storage with empirical estimates for modeled reservoirs as a test of model performance. In simulations we modified runoff by 80%-110% of the historical estimates, in 5% intervals, to examine provider-specific responses to altered surface water availability for 33 large water providers over a 25-year period (2010-2035). Two metrics were used to differentiate their response: (1) we examined groundwater reliance (GWR; that proportion of a providers' portfolio dependent upon groundwater) from the runoff sensitivity analysis, and (2) we used 100% of the historical runoff simulations to examine the cumulative groundwater withdrawals for each provider. Four groups of water

  8. The importance of volumetric canopy morphology when modelling drag around riparian vegetation

    Science.gov (United States)

    Boothroyd, Richard; Hardy, Richard; Warburton, Jeff; Marjoribanks, Timothy

    2017-04-01

    Riparian vegetation has a significant impact on the hydraulic functioning of river systems. The bulk of past work concerned with modelling the influence of vegetation on flow has considered vegetation to be morphologically simple, and has generally neglected the complexity and porosity of natural plants, defined herein as the volumetric canopy morphology. However, the volumetric canopy morphology can influence the mean and turbulent properties of the flow, producing spatially heterogeneous downstream velocity fields. By explicitly accounting for this in a computational fluid dynamics (CFD) model, and representing the plant as a porous blockage, complex flow structures and drag can be modelled. For a riparian species, Hebe odora, good agreement with flume measurements are found. Plant shear layer turbulence is shown to be dominated by Kelvin-Helmholtz and Görtler-type vortices, generated through shear instability. Porous representations of the plants, that allow for flow to pass through the plant canopy interior, are compared against fully impermeable plant representations. Penetration of fluid through the canopy in the porous case resembles 'bleed-flow', and this results in a plant wake region that significantly differs from the impermeable case, which is characteristic of wake flow around a traditional bluff body. These results demonstrate the significant effect that the volumetric canopy morphology and porosity of natural plants has on the three-dimensional flow and in-stream drag, and enables a re-evaluation of vegetative flow resistance. The modelled results allow a species dependent Manning's n to be calculated, and this presents an opportunity to move away from the conventional methods of representing vegetation in hydraulic models, in favour of a more physically determined approach. Given the importance of vegetation in river corridor management, and the increasing application of UAV imagery to map riparian vegetation, the numerical scheme developed here

  9. Structure-based vaccines provide protection in a mouse model of ehrlichiosis.

    Directory of Open Access Journals (Sweden)

    Sunil Thomas

    Full Text Available BACKGROUND: Recent advances in bioinformatics have made it possible to predict the B cell and T cell epitopes of antigenic proteins. This has led to design of peptide based vaccines that are more specific, safe, and easy to produce. The obligately intracellular gram negative bacteria Ehrlichia cause ehrlichioses in humans and animals. As yet there are no vaccines to protect against Ehrlichia infection. METHODOLOGY/PRINCIPAL FINDINGS: We applied the principle of structural vaccinology to design peptides to the epitopes of Ehrlichia muris outer membrane P28-19 (OMP-1/P28 and Ehrlichia Heat shock protein 60 (Hsp60/GroEL antigenic proteins. Both P28-19 and Ehrlichia Hsp60 peptides reacted with polyclonal antibodies against E. canis and E. chaffeensis and could be used as a diagnostic tool for ehrlichiosis. In addition, we demonstrated that mice vaccinated with Ehrlichia P28-19 and Hsp60 peptides and later challenged with E. muris were protected against the pathogen. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate the power of structural vaccines and could be a new strategy in the development of vaccines to provide protection against pathogenic microorganisms.

  10. Directed evolution of a model primordial enzyme provides insights into the development of the genetic code.

    Directory of Open Access Journals (Sweden)

    Manuel M Müller

    Full Text Available The contemporary proteinogenic repertoire contains 20 amino acids with diverse functional groups and side chain geometries. Primordial proteins, in contrast, were presumably constructed from a subset of these building blocks. Subsequent expansion of the proteinogenic alphabet would have enhanced their capabilities, fostering the metabolic prowess and organismal fitness of early living systems. While the addition of amino acids bearing innovative functional groups directly enhances the chemical repertoire of proteomes, the inclusion of chemically redundant monomers is difficult to rationalize. Here, we studied how a simplified chorismate mutase evolves upon expanding its amino acid alphabet from nine to potentially 20 letters. Continuous evolution provided an enhanced enzyme variant that has only two point mutations, both of which extend the alphabet and jointly improve protein stability by >4 kcal/mol and catalytic activity tenfold. The same, seemingly innocuous substitutions (Ile→Thr, Leu→Val occurred in several independent evolutionary trajectories. The increase in fitness they confer indicates that building blocks with very similar side chain structures are highly beneficial for fine-tuning protein structure and function.

  11. Genetically engineered K cells provide sufficient insulin to correct hyperglycemia in a nude murine model

    Institute of Scientific and Technical Information of China (English)

    Yiqun Zhang; Liqing Yao; Kuntang Shen; Meidong Xu; Pinghong Zhou; Weige Yang; Xinyuan Liu; Xinyu Qin

    2008-01-01

    A gene therapy-based treatment of type 1 diabetes mellitus requires the development of a surrogate β cell that can synthesize and secrete functionally active insulin in response to physiologically relevant changes in ambient glucose levels. In this study, the murine enteroendocrine cell line STC-1 was genetically modified by stable transfection. Two clone cells were selected (STC-1-2 and STC-1-14) that secreted the highest levels of insulin among the 22 clones expressing insulin from 0 to 157.2 μIU/ml/106 cells/d. After glucose concentration in the culture medium was increased from 1 mM to 10 mM, secreted insulin rose from 40.3±0.8 to 56.3±3.2 μIU/ml (STC-1-2), and from 10.8±0.8 to 23.6±2.3 μIU/ml (STC-1-14). After STC-1-14 cells were implanted into diabetic nude mice, their blood glucose levels were reduced to normal. Body weight loss was also ameliorated. Our data suggested that genetically engineered K cells secrete active insulin in a glucose-regulated manner, and in vivo study showed that hyperglycemia could be reversed by implantation of the cells, suggesting that the use of genetically engineered K cells to express human insulin might provide a glucose-regulated approach to treat diabetic hyperglycemia.

  12. How important is heterogeneous parameter distribution in capturing the catchment response through hydrologic modelling?

    Science.gov (United States)

    Devak, Manjula; Dhanya, Ct

    2017-04-01

    The scrupulous selection of critical spatial and temporal resolution and the evaluation of optimum values for various model parameters are essential aspects in any hydrological modelling study. The accurate assessment of various model parameters is vitally important for the detailed and complete representation of the various physical processes illustrating land-atmosphere interaction. Studies in the past have taken up various auto-calibration and parameter transferability schemes to address these; but the heterogeneity of calibration parameters across grids is greatly ignored often. In many studies, heterogeneity is often compromised through the usual interpolation approaches adopted across grids. In the present study, we focus to analyze the response of a catchment by adopting a heterogeneous and homogeneous parameter distribution in the hydrological model. The semi-distributed hydrological model, Variable Infiltration Capacity (VIC-3L) model, which offers sub-grid variability in soil moisture storage capacity and vegetation classes, is used for this comparison. Nine model parameters are selected for calibrating the VIC-3L model, namely variable infiltration curve parameter (infilt), maximum velocity of base flow for each grid cells (DSmax), fraction of DSmax where non-linear base flow begins (DS, fraction of maximum soil moisture where non-linear base flow occurs (WS), depth of 2nd soil layer (D2), depth of 3rd soil layer (D3), exponent used in baseflow curve (c), advection coefficient (C) and diffusion coefficient (D). Latin-Hypercube sampling is adopted to sample these nine parameters. In homogenous approach, the traditional way of constant soil parameter distribution (HoSCP) is adopted to prepare the parameter set. While, in heterogeneous approach, grid-to-grid variability is ensured by constructing a Heterogeneous Soil Calibration Parameter (HeSCP) set through systematic sampling of already sampled set. The sampling size is made equal to the number of grids

  13. The nature of blast-wave-driven interfacial instabilities - important implications for modeling supernovae explosions

    Science.gov (United States)

    Miles, Aaron

    2004-11-01

    In this talk we discuss the nature of late-time, broad-banded instability development at an interface when a strong blast wave travels from a heavier to lighter fluid, as is the case in a supernova explosion. After a short period of Richtmyer-Meshkov growth, the interface is unstable via the Rayleigh-Taylor mechanism, which rapidly becomes the dominant energy source for growth. This situation is distinct from the classical case in two important ways, both of which can be understood in terms of a bubble merger model we have developed for blast-wave-driven systems. Rather than the constant acceleration feeding the instability to spawn ever larger scales and accelerate the growth, the decaying acceleration in the blast-wave case leads to a decay in the RT growth rate, and a freezing in of a preferred largest scale, which is dependent on the precise details of the system. In the language of bubble-merger models, this can be understood in terms of the time for the generation of the next largest scale being longer than the lifetime of the blast wave. Secondly, the continual expansion behind the blast front precludes the emergence of a self-similar regime, independent of the initial conditions, in the planar case. Self-similarity may be recovered in diverging systems but may be difficult to observe in reality because of rather restrictive conditions that must be met. These observations are borne out by hi-resolution numerical simulations using the higher order Godunov AMR hydrocode Raptor in 2 and 3D, and explain other simulations of instability growth in supernovae explosions; the initial "interfacial" structure is likely very important in determining the late-time growth. The model predictions are also consistent with numerous images of natural and manmade explosions.

  14. Assistance dogs provide a useful behavioral model to enrich communicative skills of assistance robots

    Science.gov (United States)

    Gácsi, Márta; Szakadát, Sára; Miklósi, Ádám

    2013-01-01

    These studies are part of a project aiming to reveal relevant aspects of human–dog interactions, which could serve as a model to design successful human-robot interactions. Presently there are no successfully commercialized assistance robots, however, assistance dogs work efficiently as partners for persons with disabilities. In Study 1, we analyzed the cooperation of 32 assistance dog–owner dyads performing a carrying task. We revealed typical behavior sequences and also differences depending on the dyads' experiences and on whether the owner was a wheelchair user. In Study 2, we investigated dogs' responses to unforeseen difficulties during a retrieving task in two contexts. Dogs displayed specific communicative and displacement behaviors, and a strong commitment to execute the insoluble task. Questionnaire data from Study 3 confirmed that these behaviors could successfully attenuate owners' disappointment. Although owners anticipated the technical competence of future assistance robots to be moderate/high, they could not imagine robots as emotional companions, which negatively affected their acceptance ratings of future robotic assistants. We propose that assistance dogs' cooperative behaviors and problem solving strategies should inspire the development of the relevant functions and social behaviors of assistance robots with limited manual and verbal skills. PMID:24399986

  15. Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model

    Science.gov (United States)

    Garbuzova-Davis, Svitlana; Rodrigues, Maria C. O.; Hernandez-Ontiveros, Diana G.; Tajiri, Naoki; Frisina-Deyo, Aric; Boffeli, Sean M.; Abraham, Jerry V.; Pabon, Mibel; Wagner, Andrew; Ishikawa, Hiroto; Shinozuka, Kazutaka; Haller, Edward; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesario V.

    2013-01-01

    Background Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. Methodology/Principal Findings In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. Conclusions/Significance These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke. PMID:23675488

  16. Blood-brain barrier alterations provide evidence of subacute diaschisis in an ischemic stroke rat model.

    Directory of Open Access Journals (Sweden)

    Svitlana Garbuzova-Davis

    Full Text Available BACKGROUND: Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. METHODOLOGY/PRINCIPAL FINDINGS: In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO, significant BBB alterations characterized by large Evans Blue (EB parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. CONCLUSIONS/SIGNIFICANCE: These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke.

  17. A case study of a team-based, quality-focused compensation model for primary care providers.

    Science.gov (United States)

    Greene, Jessica; Hibbard, Judith H; Overton, Valerie

    2014-06-01

    In 2011, Fairview Health Services began replacing their fee-for-service compensation model for primary care providers (PCPs), which included an annual pay-for-performance bonus, with a team-based model designed to improve quality of care, patient experience, and (eventually) cost containment. In-depth interviews and an online survey of PCPs early after implementation of the new model suggest that it quickly changed the way many PCPs practiced. Most PCPs reported a shift in orientation toward quality of care, working more collaboratively with their colleagues and focusing on their full panel of patients. The majority reported that their quality of care had improved because of the model and that their colleagues' quality had to. The comprehensive change did, however, result in lower fee-for-service billing and reductions in PCP satisfaction. While Fairview's compensation model is still a work in progress, their early experiences can provide lessons for other delivery systems seeking to reform PCP compensation.

  18. Modeling of spatial distribution for scorpions of medical importance in the São Paulo State, Brazil.

    Science.gov (United States)

    Brites-Neto, José; Duarte, Keila Maria Roncato

    2015-07-01

    In this work, we aimed to develop maps of modeling geographic distribution correlating to environmental suitability for the two species of scorpions of medical importance at São Paulo State and to develop spatial configuration parameters for epidemiological surveillance of these species of venomous animals. In this study, 54 georeferenced points for Tityus serrulatus and 86 points for Tityus bahiensis and eight environmental indicators, were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions) version 3.3.3k using 70% of data for training (n=38 to T. serrulatus and n=60 to T. bahiensis) and 30% to test the models (n=16 for T. serrulatus and n=26 for T. bahiensis). The logistic threshold used to cut models in converting the continuous probability model into a binary model was the "maximum test sensitivity plus specificity," provided by Maxent, with results of 0.4143 to T. serrulatus and of 0.3401 to T. bahiensis. The models were evaluated by the area under the curve (AUC), using the omission error and the binomial probability. With the data generated by Maxent, distribution maps were produced using the "ESRI(®) ArcGIS 10.2.2 for Desktop" software. The models had high predictive success (AUC=0.7698±0.0533, omission error=0.2467 and p<0.001 for T. serrulatus and AUC=0.8205±0.0390, omission error=0.1917 and p<0.001 for T. bahiensis) and the resultant maps showed a high environmental suitability in the north, central, and southeast of the state, confirming the increasing spread of these species. The environmental variables that mostly contributed to the scorpions species distribution model were rain precipitation (28.9%) and tree cover (28.2%) for the T. serrulatus and temperature (45.8%) and thermal amplitude (12.6%) for the T. bahiensis. The distribution model of these species of medical importance scorpions in São Paulo State revealed a higher environmental suitability of these species in the

  19. Modeling of spatial distribution for scorpions of medical importance in the São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    José Brites-Neto

    2015-07-01

    Full Text Available Aim: In this work, we aimed to develop maps of modeling geographic distribution correlating to environmental suitability for the two species of scorpions of medical importance at São Paulo State and to develop spatial configuration parameters for epidemiological surveillance of these species of venomous animals. Materials and Methods: In this study, 54 georeferenced points for Tityus serrulatus and 86 points for Tityus bahiensis and eight environmental indicators, were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions version 3.3.3k using 70% of data for training (n=38 to T. serrulatus and n=60 to T. bahiensis and 30% to test the models (n=16 for T. serrulatus and n=26 for T. bahiensis. The logistic threshold used to cut models in converting the continuous probability model into a binary model was the “maximum test sensitivity plus specificity,” provided by Maxent, with results of 0.4143 to T. serrulatus and of 0.3401 to T. bahiensis. The models were evaluated by the area under the curve (AUC, using the omission error and the binomial probability. With the data generated by Maxent, distribution maps were produced using the “ESRI® ArcGIS 10.2.2 for Desktop” software. Results: The models had high predictive success (AUC=0.7698±0.0533, omission error=0.2467 and p<0.001 for T. serrulatus and AUC=0.8205±0.0390, omission error=0.1917 and p<0.001 for T. bahiensis and the resultant maps showed a high environmental suitability in the north, central, and southeast of the state, confirming the increasing spread of these species. The environmental variables that mostly contributed to the scorpions species distribution model were rain precipitation (28.9% and tree cover (28.2% for the T. serrulatus and temperature (45.8% and thermal amplitude (12.6% for the T. bahiensis. Conclusion: The distribution model of these species of medical importance scorpions in São Paulo State

  20. The Charrette Design Model Provides a Means to Promote Collaborative Design in Higher Education

    Directory of Open Access Journals (Sweden)

    Webber Steven B.

    2016-02-01

    Full Text Available Higher education is typically compartmentalized by field and expertise level leading to a lack of collaboration across disciplines and reduced interaction among students of the same discipline that possess varying levels of expertise. The divisions between disciplines and expertise levels can be perforated through the use of a concentrated, short-term design problem called a charrette. The charrette is commonly used in architecture and interior design, and applications in other disciplines are possible. The use of the charrette in an educational context provides design students the opportunity to collaborate in teams where members have varying levels of expertise and consult with experts in allied disciplines in preparation for a profession that will expect the same. In the context of a competitive charrette, this study examines the effectiveness of forming teams of design students that possess a diversity of expertise. This study also looks at the effectiveness of integrating input from professional experts in design-allied disciplines (urban planning, architecture, mechanical and electrical engineering and a design-scenario-specific discipline (medicine into the students' design process. Using a chi-square test of goodness-of-fit, it is possible to determine student preferences in terms of the team configurations as well as their preferences on the experts. In this charrette context, the students indicated that the cross-expertise student team make-up had a positive effect for both the more experienced students and the less experienced students. Overall, the students placed high value on the input from experts in design-allied fields for the charrette. They also perceived a preference of input from external experts that had an immediate and practical implication to their design process. This article will also show student work examples as additional evidence of the successful cross-expertise collaboration among the design students and evidence

  1. miRNA expression in colon polyps provides evidence for a multihit model of colon cancer.

    Directory of Open Access Journals (Sweden)

    Ann L Oberg

    Full Text Available Changes in miRNA expression are a common feature in colon cancer. Those changes occurring in the transition from normal to adenoma and from adenoma to carcinoma, however, have not been well defined. Additionally, miRNA changes among tumor subgroups of colon cancer have also not been adequately evaluated. In this study, we examined the global miRNA expression in 315 samples that included 52 normal colonic mucosa, 41 tubulovillous adenomas, 158 adenocarcinomas with proficient DNA mismatch repair (pMMR selected for stage and age of onset, and 64 adenocarcinomas with defective DNA mismatch repair (dMMR selected for sporadic (n = 53 and inherited colon cancer (n = 11. Sporadic dMMR tumors all had MLH1 inactivation due to promoter hypermethylation. Unsupervised PCA and cluster analysis demonstrated that normal colon tissue, adenomas, pMMR carcinomas and dMMR carcinomas were all clearly discernable. The majority of miRNAs that were differentially expressed between normal and polyp were also differentially expressed with a similar magnitude in the comparison of normal to both the pMMR and dMMR tumor groups, suggesting a stepwise progression for transformation from normal colon to carcinoma. Among the miRNAs demonstrating the largest fold up- or down-regulated changes (≥4, four novel (miR-31, miR-1, miR-9 and miR-99a and two previously reported (miR-137 and miR-135b miRNAs were identified in the normal/adenoma comparison. All but one of these (miR-99a demonstrated similar expression differences in the two normal/carcinoma comparisons, suggesting that these early tumor changes are important in both the pMMR- and dMMR-derived cancers. The comparison between pMMR and dMMR tumors identified four miRNAs (miR-31, miR-552, miR-592 and miR-224 with statistically significant expression differences (≥2-fold change.

  2. miRNA expression in colon polyps provides evidence for a multihit model of colon cancer.

    Science.gov (United States)

    Oberg, Ann L; French, Amy J; Sarver, Aaron L; Subramanian, Subbaya; Morlan, Bruce W; Riska, Shaun M; Borralho, Pedro M; Cunningham, Julie M; Boardman, Lisa A; Wang, Liang; Smyrk, Thomas C; Asmann, Yan; Steer, Clifford J; Thibodeau, Stephen N

    2011-01-01

    Changes in miRNA expression are a common feature in colon cancer. Those changes occurring in the transition from normal to adenoma and from adenoma to carcinoma, however, have not been well defined. Additionally, miRNA changes among tumor subgroups of colon cancer have also not been adequately evaluated. In this study, we examined the global miRNA expression in 315 samples that included 52 normal colonic mucosa, 41 tubulovillous adenomas, 158 adenocarcinomas with proficient DNA mismatch repair (pMMR) selected for stage and age of onset, and 64 adenocarcinomas with defective DNA mismatch repair (dMMR) selected for sporadic (n = 53) and inherited colon cancer (n = 11). Sporadic dMMR tumors all had MLH1 inactivation due to promoter hypermethylation. Unsupervised PCA and cluster analysis demonstrated that normal colon tissue, adenomas, pMMR carcinomas and dMMR carcinomas were all clearly discernable. The majority of miRNAs that were differentially expressed between normal and polyp were also differentially expressed with a similar magnitude in the comparison of normal to both the pMMR and dMMR tumor groups, suggesting a stepwise progression for transformation from normal colon to carcinoma. Among the miRNAs demonstrating the largest fold up- or down-regulated changes (≥4), four novel (miR-31, miR-1, miR-9 and miR-99a) and two previously reported (miR-137 and miR-135b) miRNAs were identified in the normal/adenoma comparison. All but one of these (miR-99a) demonstrated similar expression differences in the two normal/carcinoma comparisons, suggesting that these early tumor changes are important in both the pMMR- and dMMR-derived cancers. The comparison between pMMR and dMMR tumors identified four miRNAs (miR-31, miR-552, miR-592 and miR-224) with statistically significant expression differences (≥2-fold change).

  3. Toward sustainable material usage: evaluating the importance of market motivated agency in modeling material flows.

    Science.gov (United States)

    Gaustad, Gabrielle; Olivetti, Elsa; Kirchain, Randolph

    2011-05-01

    Increasing recycling will be a key strategy for moving toward sustainable materials usage. There are many barriers to increasing recycling, including quality issues in the scrap stream. Repeated recycling can compound this problem through the accumulation of tramp elements over time. This paper explores the importance of capturing recycler decision-making in accurately modeling accumulation and the value of technologies intended to mitigate it. A method was developed combining dynamic material flow analysis with allocation of those materials into production portfolios using blending models. Using this methodology, three scrap allocation methods were explored in the context of a case study of aluminum use: scrap pooling, pseudoclosed loop, and market-based. Results from this case analysis suggest that market-driven decisions and upgrading technologies can partially mitigate the negative impact of accumulation on scrap utilization, thereby increasing scrap use and reducing greenhouse gas emissions. A market-based allocation method for modeling material flows suggests a higher value for upgrading strategies compared to a pseudoclosed loop or pooling allocation method for the scenarios explored.

  4. The Importance of Materials Data and Modelling Parameters in an FE Simulation of Linear Friction Welding

    Directory of Open Access Journals (Sweden)

    R. Turner

    2014-01-01

    Full Text Available Linear friction welding has become a key technology in the aeroengine industry due to its capability to produce blisk components. Finite element (FE simulation of linear friction welding applications has been studied in recent years by a number of institutions, using a variety of software codes. Several codes have been demonstrated to be capable of predicting with reasonable accuracy some or all of the critical outputs of friction welding, namely, the thermal loading, plastic deformation, and residual stresses generated. The importance of reliable material data in performing these calculations is paramount. Available material data in the published literature is often restricted to lower temperatures and strain rate regimes. Extrapolation methods used on this data to estimate high temperature properties can lead to uncertainties in the modelled predictions. This paper reviews the approach to materials modelling, including material datasets and material constitutive laws, for FE simulation work in the literature regarding linear friction welding. Best-practice methods for materials constitutive laws, materials data-sets, and the associated experimental temperatures and strain rates used to gather data are suggested. Finally, successfully validated modelled outcomes—when a robust, reliable, and accurate material database has been selected—are demonstrated for a number of the FE methods considered.

  5. iPSC-derived cancer stem cells provide a model of tumor vasculature

    Science.gov (United States)

    Prieto-Vila, Marta; Yan, Ting; Calle, Anna Sanchez; Nair, Neha; Hurley, Laura; Kasai, Tomonari; Kakuta, Hiroki; Masuda, Junko; Murakami, Hiroshi; Mizutani, Akifumi; Seno, Masaharu

    2016-01-01

    To grow beyond a size of approximately 1-2 mm3, tumor cells activate many processes to develop blood vasculature. Growing evidences indicate that the formation of the tumor vascular network is very complex, and is not restricted to angiogenesis. Cancer cell-derived tumor vasculatures have been recently described. Among them, endothelial differentiation of tumor cells have been directly related to cancer stem cells, which are cells within a tumor that possess the capacity to self-renew, and to exhibit multipotential heterogeneous lineages of cancer cells. Vasculogenic mimicry has been described to be formed by cancer cells expressing stemness markers. Thus, cancer stem cells have been proposed to contribute to vasculogenic mimicry, though its relation is yet to be clarified. Here, we analyzed the tumor vasculature by using a model of mouse cancer stem cells, miPS-LLCcm cells, which we have previously established from mouse induced pluripotent stem cells and we introduced the DsRed gene in miPS-LLCcm to trace them in vivo. Various features of vasculature were evaluated in ovo, in vitro, and in vivo. The tumors formed in allograft nude mice exhibited angiogenesis in chick chorioallantoic membrane assay. In those tumors, along with penetrated host endothelial vessels, we detected endothelial differentiation from cancer stem cells and formation of vasculogenic mimicry. The angiogenic factors such as VEGF-A and FGF2 were expressed predominantly in the cancer stem cells subpopulation of miPS-LLCcm cells. Our results suggested that cancer stem cells play key roles in not only the recruitment of host endothelial vessels into tumor, but also in maturation of endothelial linage of cancer stem cell’s progenies. Furthermore, the undifferentiated subpopulation of the miPS-LLCcm participates directly in the vasculogenic mimicry formation. Collectively, we show that miPS-LLCcm cells have advantages to further study tumor vasculature and to develop novel targeting strategies in

  6. Financial mechanisms and social safety-oriented model of development of the Russian economy (based on import substitution and innovation

    Directory of Open Access Journals (Sweden)

    T. I. Ovchinnikova

    2016-01-01

    Full Text Available In article features of import substitution in the socially oriented model determined as economy with the high level of the state income redistribution of subjects of managing and developed on this basis of system of social protection are considered. Import substitution is considered from the traditional point of view – creation of new productions and technologies which are implemented at the expense of own and borrowed funds of investors. The financial mechanisms for implementation of innovations promoting import substitution are offered: industry plans and road maps as availability of reference points for creation of rational amounts of the budget payments and financial resources of the entities necessary for upgrade of productions, and also the directions of financial resources for implementation of specific most important national priorities and innovative investment projects. The volume of investment into the fixed capital correlated to its cost considerably grew from 3.5% in 2003 to 11.6% in 2009, but value of this indicator isn't enough as degree of depreciation of fixed assets in economy of the region constituted 44.9% in 2009. Direct foreign investments prevail: in Krasnoyarsk Krai their share constituted in 2009 – 45.4%, Krasnodar Region – 40.5%, the Nizhny Novgorod Region – 84.5%. In the Voronezh region such entities as KBHA, Federal State Unitary Enterprise State Research and Production Space Center branch of M. V. Khrunichev the Voronezh Mechanical Plant, JSC Sozvezdiye Concern having the high technologies making safety of the country and especially needing investments function. In plans of urgent strategy of social and economic development of the Voronezh region it is supposed to increase specific weight of innovative products of such entities and to increase the level of innovative activity till 2020. The socially oriented model considering import substitution domestic technologies and products needs strengthening of the

  7. Citicoline and postconditioning provides neuroprotection in a rat model of ischemic spinal cord injury.

    Science.gov (United States)

    Turkkan, Alper; Alkan, Tulin; Goren, Bulent; Kocaeli, Hasan; Akar, Eylem; Korfali, Ender

    2010-06-01

    postconditioning and citicoline group 5. It is thus thought that combining citicoline with postconditioning provides protection by inhibiting the caspase pathway and by increasing the antiapoptotic proteins.

  8. ASSESMENT OF THE DESTINATION IN TERMS OF TOURISM WITH IMPORTANCE-SATISFACTION MODEL: AN IMPLEMENTATION IN EDREMIT

    Directory of Open Access Journals (Sweden)

    Mehmet Sedat İPAR

    2013-06-01

    Full Text Available The major objective of the research is to determine the crucial elements that the local tourists attribute importance to in their decision processes regarding their holidays such as facilities, location and resources of the destination and the tourism services that are provided, while asserting how much they are satisfied in terms of these elements regarding the Edremit destination. As the initial step of the research, the literature was browsed in order to understand the elements that the tourists take into consideration while making a decision on their holiday and their satisfaction levels. The survey obtained in the related literature was used to gauge the importance and satisfaction levels of the tourists. Then the data acquired were analyzed with descriptive statistics and were interpreted by making a distribution on the model developed by Yang (2003a. Both similarities and differences were detected in some elements of the survey, according to the local tourists’ importance and satisfaction. Also some significant insufficiencies in some elements were defined regarding Edremit. If the destination managers and stakeholders take the results of the importance-satisfaction analysis, then the performance of the destination in terms of tourist satisfaction would increase. It is obvious that these findings shall be tested and updated with other researches in the coming period.

  9. Fee-for-service as a business model of growing importance: the academic biobank experience.

    Science.gov (United States)

    McDonald, Sandra A; Sommerkamp, Kara; Egan-Palmer, Maureen; Kharasch, Karen; Holtschlag, Victoria

    2012-10-01

    Biorepositories offer tremendous scientific value to a wide variety of customer groups (academic, commercial, industrial) in their ability to deliver a centralized, standardized service model, encompassing both biospecimen storage and related laboratory services. Generally, the scientific expertise and economies of scale that are offered in centralized, properly resourced research biobanks has yielded value that has been well-recognized by universities, pharmaceutical companies, and other sponsoring institutions. However, like many facets of the economy, biobanks have been under increasing cost pressure in recent years. This has been a particular problem in the academic arena, where direct support from grant sources (both governmental and philanthropic) typically now is more difficult to secure, or provides reduced financial support, relative to previous years. One way to address this challenge is to establish or enhance a well-defined fee-for-service model which is properly calibrated to cover operational costs while still offering competitive value to users. In this model, customers are never charged for the biospecimens themselves, but rather for the laboratory services associated with them. Good communication practices, proper assessment of value, implementation of best practices, and a sound business plan are all needed for this initiative to succeed. Here we summarize our experiences at Washington University School of Medicine in the expectation they will be useful to others.

  10. The importance of health belief models in determining self-care behaviour in diabetes.

    Science.gov (United States)

    Harvey, J N; Lawson, V L

    2009-01-01

    Patients' self-care behaviours have a major role in diabetes management. Diabetes education provides the required knowledge, but despite this, self-care is often suboptimal. The degree to which patients follow advice as regards the various self-care behaviours is determined by their health beliefs (Illness Representations or Personal Models) of diabetes. Psychometric studies have tried to categorize and measure the beliefs about illness that influence patients to adhere to treatment recommendations in diabetes. Various models have been proposed to explain the relationship between beliefs and behaviour. Leventhal's Self-Regulatory Model, which takes account of the emotional as well as the objective rational response to illness, currently seems to offer the best system for identifying the determinants of patient self-care behaviour. A review of interventions indicates those based on psychological theory offer professionals the best chance of maximizing their patients' contribution to diabetes self-management and achieving improved outcomes, both glycaemic and psychosocial. Studies designed specifically to modify illness representations are now being undertaken. This brief review aims to summarize developments in this area of psychological theory over the last 20 years and the implications for promoting better self-care behaviour in diabetes.

  11. Phlebotominae of epidemiological importance in cutaneous leishmaniasis in northwestern Argentina: risk maps and ecological niche models.

    Science.gov (United States)

    Quintana, M; Salomón, O; Guerra, R; De Grosso, M Lizarralde; Fuenzalida, A

    2013-03-01

    In Argentina, 58.2% out of the 8126 Cutaneous Leishmaniasis (CL) incident cases accumulated from 1954 to 2006 were reported in the provinces of Salta and Jujuy. The aim of this study was to develop an exploratory risk map and a potential distribution map of the vector, in order to offer recommendations for CL prevention. A total of 12 079 Phlebotominae (Diptera: Psychodidae) belonging to the species Lutzomyia neivai (Pinto), Lu. migonei (França), Lu. cortelezzii (Brèthes), Lu. shannoni (Dyar), Lu. quinquefer (Dyar) and Brumptomyia spp. (França & Parrot) were captured. Potential distribution models were created for two species, Lu. neivai (incriminated vector of Leishmania braziliensis) and Lu. migonei, associated with domestic animals in Argentina and that in turn could be involved as a link between zoonotic transmission cycles and anthropozoonotic. The Maximum Entropy Modeling System (MaxEnt) was used. The Jackknife test was performed, and the 'rainfall of the driest month' was the variable that best generalized the models. Accuracy was evaluated by the area under the curve (AUC) and validated by the Cohen's kappa index. This approximation provides a new analytical resource of high potential for the prevention of the disease, in order to allocate resources properly and to develop the most suitable strategies for action.

  12. DIAGNOSIS IMPORTANCE OF RURAL DEVELOPMENT OF A MODEL AGROFORESTAL IN PEASANT COMMUNITIES OF SIERRA DE HUAUTLA

    Directory of Open Access Journals (Sweden)

    Miguel Uribe-Gómez

    2015-07-01

    Full Text Available Family agricultural is socioeconomically important in rural areas, but in Mexico, from the 80's this production system presents social stagnation. This type of agriculture presents a dynamic reality in the interests of each producer and limiting access to factors of production (land, labor and capital. In this investigation a methodology for analysis and diagnosis of production systems in rural areas, in two communities in the Country Sierra de Huautla Tepalcingo, Morelos, Mexico was applied. The proposal is based on an assessment of the environmental, historical, technological and socio-economic assessment of different productive activities for different types of units Family Production of the communities studied. The study showed that 40% of Family Production Units fail to exceed the threshold of survival and show impossibility capitalization medium and long term. So it is advisable to implement a model of local agricultural development to improve the socioeconomic conditions of Family Production Units of peasant communities.

  13. A hydrogeomorphic river network model predicts where and why hyporheic exchange is important in large basins

    Science.gov (United States)

    Gomez-Velez, Jesus D.; Harvey, Judson W.

    2014-09-01

    Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data and by models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bed forms rather than lateral exchange through meanders dominates hyporheic fluxes and turnover rates along river corridors. Per kilometer, low-order streams have a biogeochemical potential at least 2 orders of magnitude larger than higher-order streams. However, when biogeochemical potential is examined per average length of each stream order, low- and high-order streams were often found to be comparable. As a result, the hyporheic zone's intrinsic potential for biogeochemical transformations is comparable across different stream orders, but the greater river miles and larger total streambed area of lower order streams result in the highest cumulative impact from low-order streams. Lateral exchange through meander banks may be important in some cases but generally only in large rivers.

  14. Patient-specific induced pluripotent stem cells in neurological disease modeling: the importance of nonhuman primate models

    Directory of Open Access Journals (Sweden)

    Qiu Z

    2013-07-01

    Full Text Available Zhifang Qiu,1,2 Steven L Farnsworth,2 Anuja Mishra,1,2 Peter J Hornsby1,21Geriatric Research Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, USA; 2Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, TX, USAAbstract: The development of the technology for derivation of induced pluripotent stem (iPS cells from human patients and animal models has opened up new pathways to the better understanding of many human diseases, and has created new opportunities for therapeutic approaches. Here, we consider one important neurological disease, Parkinson's, the development of relevant neural cell lines for studying this disease, and the animal models that are available for testing the survival and function of the cells, following transplantation into the central nervous system. Rapid progress has been made recently in the application of protocols for neuroectoderm differentiation and neural patterning of pluripotent stem cells. These developments have resulted in the ability to produce large numbers of dopaminergic neurons with midbrain characteristics for further study. These cells have been shown to be functional in both rodent and nonhuman primate (NHP models of Parkinson's disease. Patient-specific iPS cells and derived dopaminergic neurons have been developed, in particular from patients with genetic causes of Parkinson's disease. For complete modeling of the disease, it is proposed that the introduction of genetic changes into NHP iPS cells, followed by studying the phenotype of the genetic change in cells transplanted into the NHP as host animal, will yield new insights into disease processes not possible with rodent models alone.Keywords: Parkinson's disease, pluripotent cell differentiation, neural cell lines, dopaminergic neurons, cell transplantation, animal models

  15. Importance of calibration for mathematical modeling of self-purification of lotic environments

    Directory of Open Access Journals (Sweden)

    Marcio Ricardo Salla

    Full Text Available Abstract: Aim To demonstrate the importance of calibration in mathematical modeling of self-purification in lotic environments, this study simulated the behavior of various parameters in a river with average annual flows between 4.0 and 32.0 m3.s-1, in a segment downstream from the entry of treated wastewater from a sewage treatment station (average monthly flow of 2.1 m3.s-1. Methods Numerical solution by finite difference of the advection-diffusion equation was used to study the dispersion and to quantify and monitor the evolution over time of the parameters DO, BOD5, Ptotal, NH3, NO3- and the levels of the heavy metals cadmium, chromium, copper, lead and zinc. The longitudinal behavior of the water quality parameters simulated by calibrating the state variables was compared with the behavior of the same parameters simulated via state variables available in the literature. The sensitivity of the state variables was also analyzed. Results The calibration process led to good fits between the simulated and actual data for all the parameters analyzed. On the other hand, the comparison of the water quality model using calibrated state variables with the model based on state variables obtained in the literature revealed inconsistencies regarding the parameters DO, Ptotal, ammonia, nitrate and all the heavy metals. Conclusions Considering the wide threshold ranges of the state variables in the literature and the dearth of studies on calibrating the coefficient of decay and quantifying the release of heavy metals by bottom sediment, this study can serve as a base for future investigations in lotic environments with similar hydraulic and water quality characteristics.

  16. OPR-PPR, a Computer Program for Assessing Data Importance to Model Predictions Using Linear Statistics

    Science.gov (United States)

    Tonkin, Matthew J.; Tiedeman, Claire R.; Ely, D. Matthew; Hill, Mary C.

    2007-01-01

    The OPR-PPR program calculates the Observation-Prediction (OPR) and Parameter-Prediction (PPR) statistics that can be used to evaluate the relative importance of various kinds of data to simulated predictions. The data considered fall into three categories: (1) existing observations, (2) potential observations, and (3) potential information about parameters. The first two are addressed by the OPR statistic; the third is addressed by the PPR statistic. The statistics are based on linear theory and measure the leverage of the data, which depends on the location, the type, and possibly the time of the data being considered. For example, in a ground-water system the type of data might be a head measurement at a particular location and time. As a measure of leverage, the statistics do not take into account the value of the measurement. As linear measures, the OPR and PPR statistics require minimal computational effort once sensitivities have been calculated. Sensitivities need to be calculated for only one set of parameter values; commonly these are the values estimated through model calibration. OPR-PPR can calculate the OPR and PPR statistics for any mathematical model that produces the necessary OPR-PPR input files. In this report, OPR-PPR capabilities are presented in the context of using the ground-water model MODFLOW-2000 and the universal inverse program UCODE_2005. The method used to calculate the OPR and PPR statistics is based on the linear equation for prediction standard deviation. Using sensitivities and other information, OPR-PPR calculates (a) the percent increase in the prediction standard deviation that results when one or more existing observations are omitted from the calibration data set; (b) the percent decrease in the prediction standard deviation that results when one or more potential observations are added to the calibration data set; or (c) the percent decrease in the prediction standard deviation that results when potential information on one

  17. Importance of Field Data for Numerical Modeling to Dam Removal on a Mountain Channel

    Science.gov (United States)

    Kuo, W. C.; Wang, H. W.

    2015-12-01

    In 2011, a 13-m high Chijiawan Dam on Chijiawan Creek was removed due to the safety concern due to aging structure and scoured dam foundation as well as habitat restoration of the endangered Formosan landlocked salmon. Similar to Chijiawan Dam, many dams in Taiwan are located in steep mountainous area with coarser sediment and high sediment yield, and may be removed in the near future. Since the capability of current sediment transport model is insufficient, a systematic planning of field survey and monitoring work can effectively help to decrease data uncertainty in simulation. In this study, we aimed to understand the minimum requirements of data for numerical model to predict channel responses after dam removal, according to the data of pre-project and long term post-project monitoring works from removal of Chijiawan dam. We collected the hourly discharge data of Taipower gaging station located 6.8 km from the dam from 2010 to 2012 and conducted surveys of grain size distributions, cross-sectional and longitudinal profiles. We applied Sedimentation and River Hydraulics (SRH) one-dimensional model to simulate bed elevation changes by different setting of data input, including bed sediment, roughness coefficient, cross-section spacing, and flow discharge. Then, we performed a sensitivity analysis by using Root Mean Square Error (RMSE) to evaluate the minimum requirements of data for predicting to dam removal. The RMSE variability of varied setting of bed sediment, roughness coefficient, cross-section spacing, and flow discharge ranged from 0.02 m, 0.17 m, 0.14 m and 0.09 m, respectively. The results highlight that the simulation is sensitive to roughness coefficient, cross-section spacing, and flow discharge, and less sensitive to bed sediment. We anticipate the results will help decision maker to understand the importance of field data in future removals.

  18. Importance of temporal resolution of meteorological forcings for physics-based snow modeling

    Science.gov (United States)

    Sohrabi, M.; Benjankar, R. M.; Kumar, M.; Marks, D. G.; Kormos, P.; Tonina, D.

    2015-12-01

    In alpine regions, snow delays hydrological responses to precipitation and controls initiation and length of the growing season. Therefore, precise simulations of snow accumulation and melt are crucial for understanding hydrological dynamics and predicting hydrologic response from watersheds. These predictions are important for water resource management and for ecological studies of vegetation distribution, growth and for wildlife habitat. Snow models require fine temporal resolution of meteorological inputs to capture diurnal changes. However, lack of meteorological data at fine-temporal resolution may force the use of coarser than hourly data. The objective of this work is to understand what sort of information can be lost over the watershed depending on the temporal resolution of meteorological inputs, for a range of hydroclimatic and topographic conditions. To address this goal, a spatially distributed and physics-based snow model (iSnobal) was run using 1-, 3- and 6-hourly meteorological inputs for a wet, average and a dry year over Boise River Basin (BRB), Idaho, USA. Simulated snow variables such as Snow Water Equivalent (SWE) and Surface Water Input (SWI - melt draining from the snowcover plus rain on bare ground) were averaged over 3 elevation bands including rain dominated (≤1400m), rain-snow transition (>1400 and ≤1900m) and snow dominated (>1900m). Except at the rain dominated band, using 6-hr inputs causes considerable overestimation of SWE and SWI, particularly in the wet year. The results show that at the rain-snow transition and snow dominated bands at least 3-hr meteorological data are necessary for snow modeling, due to strong diurnal changes in meteorological variables at these elevations. However, using course temporal resolution data for the rain dominated band made only a small difference in results.

  19. A network model shows the importance of coupled processes in the microbial N cycle in the Cape Fear River Estuary

    Science.gov (United States)

    Hines, David E.; Lisa, Jessica A.; Song, Bongkeun; Tobias, Craig R.; Borrett, Stuart R.

    2012-06-01

    Estuaries serve important ecological and economic functions including habitat provision and the removal of nutrients. Eutrophication can overwhelm the nutrient removal capacity of estuaries and poses a widely recognized threat to the health and function of these ecosystems. Denitrification and anaerobic ammonium oxidation (anammox) are microbial processes responsible for the removal of fixed nitrogen and diminish the effects of eutrophication. Both of these microbial removal processes can be influenced by direct inputs of dissolved inorganic nitrogen substrates or supported by microbial interactions with other nitrogen transforming pathways such as nitrification and dissimilatory nitrate reduction to ammonium (DNRA). The coupling of nitrogen removal pathways to other transformation pathways facilitates the removal of some forms of inorganic nitrogen; however, differentiating between direct and coupled nitrogen removal is difficult. Network modeling provides a tool to examine interactions among microbial nitrogen cycling processes and to determine the within-system history of nitrogen involved in denitrification and anammox. To examine the coupling of nitrogen cycling processes, we built a nitrogen budget mass balance network model in two adjacent 1 cm3 sections of bottom water and sediment in the oligohaline portion of the Cape Fear River Estuary, NC, USA. Pathway, flow, and environ ecological network analyses were conducted to characterize the organization of nitrogen flow in the estuary and to estimate the coupling of nitrification to denitrification and of nitrification and DNRA to anammox. Centrality analysis indicated NH4+ is the most important form of nitrogen involved in removal processes. The model analysis further suggested that direct denitrification and coupled nitrification-denitrification had similar contributions to nitrogen removal while direct anammox was dominant to coupled forms of anammox. Finally, results also indicated that partial

  20. On the importance of paleoclimate modelling for improving predictions of future climate change

    Directory of Open Access Journals (Sweden)

    J. C. Hargreaves

    2009-12-01

    Full Text Available We use an ensemble of runs from the MIROC3.2 AGCM with slab-ocean to explore the extent to which mid-Holocene simulations are relevant to predictions of future climate change. The results are compared with similar analyses for the Last Glacial Maximum (LGM and pre-industrial control climate. We suggest that the paleoclimate epochs can provide some independent validation of the models that is also relevant for future predictions. Considering the paleoclimate epochs, we find that the stronger global forcing and hence larger climate change at the LGM makes this likely to be the more powerful one for estimating the large-scale changes that are anticipated due to anthropogenic forcing. The phenomena in the mid-Holocene simulations which are most strongly correlated with future changes (i.e., the mid to high northern latitude land temperature and monsoon precipitation do, however, coincide with areas where the LGM results are not correlated with future changes, and these are also areas where the paleodata indicate significant climate changes have occurred. Thus, these regions and phenomena for the mid-Holocene may be useful for model improvement and validation.

  1. An Extended, Boolean Model of the Septation Initiation Network in S.Pombe Provides Insights into Its Regulation.

    Science.gov (United States)

    Chasapi, Anastasia; Wachowicz, Paulina; Niknejad, Anne; Collin, Philippe; Krapp, Andrea; Cano, Elena; Simanis, Viesturs; Xenarios, Ioannis

    2015-01-01

    Cytokinesis in fission yeast is controlled by the Septation Initiation Network (SIN), a protein kinase signaling network using the spindle pole body as scaffold. In order to describe the qualitative behavior of the system and predict unknown mutant behaviors we decided to adopt a Boolean modeling approach. In this paper, we report the construction of an extended, Boolean model of the SIN, comprising most SIN components and regulators as individual, experimentally testable nodes. The model uses CDK activity levels as control nodes for the simulation of SIN related events in different stages of the cell cycle. The model was optimized using single knock-out experiments of known phenotypic effect as a training set, and was able to correctly predict a double knock-out test set. Moreover, the model has made in silico predictions that have been validated in vivo, providing new insights into the regulation and hierarchical organization of the SIN.

  2. The importance of spatial resolution and convective parameterisation in modelling soil moisture - precipitation feedbacks

    Science.gov (United States)

    Garcia-Carreras, Luis; Taylor, Christopher M.; Roberts, Malcolm; Marsham, John H.

    2017-04-01

    Soil moisture influences low-level temperature and humidity, which can strongly affect convective development. The location of convection in turn alters the soil moisture anomalies present on the following day, providing a feedback mechanism. Satellite observations show that in the tropics afternoon rainfall falls preferentially where the ground is drier than its surroundings. A large number of global weather and climate models, on the other hand, show a positive soil moisture - rainfall feedback, inconsistent with observations. This systematic bias will tend to exaggerate drought impacts in global atmospheric models, and points to missing fundamental processes in the models related to the coupling between the surface and convection. While the source of this error is still unclear, it has been hypothesized that the triggering of parameterisations of convection is excessively sensitive to low-level moisture, leading to convection initiating preferentially over wet soils. Here we quantify the soil-moisture - precipitation feedback sign using the same method as in Taylor et al. (Nature, 2012), which is now part of the ESMValTool model evaluation toolbox. We analyse multi-year global simulations using the Met Office Unified Model (MetUM) with different resolutions and representations of convection. Three simulations are run at 15 km grid-spacing with different representations of convection: 1. the standard operational MetUM parameterisation scheme, 2. 'convection permitting', where the parameterisations of shallow and deep convection are turned off, and 3. only the parameterisation of shallow convection is turned on. The use of the same resolution and setup, except for the representation of convection, allows us to exclude any effects from changing resolution. Additional simulations at 30, 50 and 150 km grid-spacings using the standard MetUM parameterisation of convection scheme are then used to explore the impact of resolution. All simulations show daytime

  3. Investigating Effective Components of Higher Education Marketing and Providing a Marketing Model for Iranian Private Higher Education Institutions

    Science.gov (United States)

    Kasmaee, Roya Babaee; Nadi, Mohammad Ali; Shahtalebi, Badri

    2016-01-01

    Purpose: The purpose of this paper is to study and identify the effective components of higher education marketing and providing a marketing model for Iranian higher education private sector institutions. Design/methodology/approach: This study is a qualitative research. For identifying the effective components of higher education marketing and…

  4. Importance-truncated no-core shell model for fermionic many-body systems

    Energy Technology Data Exchange (ETDEWEB)

    Spies, Helena

    2017-03-15

    The exact solution of quantum mechanical many-body problems is only possible for few particles. Therefore, numerical methods were developed in the fields of quantum physics and quantum chemistry for larger particle numbers. Configuration Interaction (CI) methods or the No-Core Shell Model (NCSM) allow ab initio calculations for light and intermediate-mass nuclei, without resorting to phenomenology. An extension of the NCSM is the Importance-Truncated No-Core Shell Model, which uses an a priori selection of the most important basis states. The importance truncation was first developed and applied in quantum chemistry in the 1970s and latter successfully applied to models of light and intermediate mass nuclei. Other numerical methods for calculations for ultra-cold fermionic many-body systems are the Fixed-Node Diffusion Monte Carlo method (FN-DMC) and the stochastic variational approach with Correlated Gaussian basis functions (CG). There are also such method as the Coupled-Cluster method, Green's Function Monte Carlo (GFMC) method, et cetera, used for calculation of many-body systems. In this thesis, we adopt the IT-NCSM for the calculation of ultra-cold Fermi gases at unitarity. Ultracold gases are dilute, strongly correlated systems, in which the average interparticle distance is much larger than the range of the interaction. Therefore, the detailed radial dependence of the potential is not resolved, and the potential can be replaced by an effective contact interaction. At low energy, s-wave scattering dominates and the interaction can be described by the s-wave scattering length. If the scattering length is small and negative, Cooper-pairs are formed in the Bardeen-Cooper-Schrieffer (BCS) regime. If the scattering length is small and positive, these Cooper-pairs become strongly bound molecules in a Bose-Einstein-Condensate (BEC). In between (for large scattering lengths) is the unitary limit with universal properties. Calculations of the energy spectra

  5. Multivariate Models of Parent-Late Adolescent Gender Dyads: The Importance of Parenting Processes in Predicting Adjustment

    Science.gov (United States)

    McKinney, Cliff; Renk, Kimberly

    2008-01-01

    Although parent-adolescent interactions have been examined, relevant variables have not been integrated into a multivariate model. As a result, this study examined a multivariate model of parent-late adolescent gender dyads in an attempt to capture important predictors in late adolescents' important and unique transition to adulthood. The sample…

  6. The importance of shared mental models and shared situation awareness for transforming robots from tools to teammates

    Science.gov (United States)

    Ososky, Scott; Schuster, David; Jentsch, Florian; Fiore, Stephen; Shumaker, Randall; Lebiere, Christian; Kurup, Unmesh; Oh, Jean; Stentz, Anthony

    2012-06-01

    Current ground robots are largely employed via tele-operation and provide their operators with useful tools to extend reach, improve sensing, and avoid dangers. To move from robots that are useful as tools to truly synergistic human-robot teaming, however, will require not only greater technical capabilities among robots, but also a better understanding of the ways in which the principles of teamwork can be applied from exclusively human teams to mixed teams of humans and robots. In this respect, a core characteristic that enables successful human teams to coordinate shared tasks is their ability to create, maintain, and act on a shared understanding of the world and the roles of the team and its members in it. The team performance literature clearly points towards two important cornerstones for shared understanding of team members: mental models and situation awareness. These constructs have been investigated as products of teams as well; amongst teams, they are shared mental models and shared situation awareness. Consequently, we are studying how these two constructs can be measured and instantiated in human-robot teams. In this paper, we report results from three related efforts that are investigating process and performance outcomes for human robot teams. Our investigations include: (a) how human mental models of tasks and teams change whether a teammate is human, a service animal, or an advanced automated system; (b) how computer modeling can lead to mental models being instantiated and used in robots; (c) how we can simulate the interactions between human and future robotic teammates on the basis of changes in shared mental models and situation assessment.

  7. [The importance of model organisms to study cilia and flagella biology].

    Science.gov (United States)

    Vincensini, Laetitia; Blisnick, Thierry; Bastin, Philippe

    2011-01-01

    Cilia and flagella are ubiquitous organelles that protrude from the surfaces of many cells, and whose architecture is highly conserved from protists to humans. These complex organelles, composed of over 500 proteins, can be either immotile or motile. They are involved in a myriad of biological processes, including sensing (non-motile cilia) and/or cell motility or movement of extracellular fluids (motile cilia). The ever-expanding list of human diseases linked to defective cilia illustrates the functional importance of cilia and flagella. These ciliopathies are characterised by an impressive diversity of symptoms and an often complex genetic etiology. A precise knowledge of cilia and flagella biology is thus critical to better understand these pathologies. However, multi-ciliated cells are terminally differentiated and difficult to manipulate, and a primary cilium is assembled only when the cell exits from the cell cycle. In this context the use of model organisms, that relies on the high degree of structural but also of molecular conservation of these organelles across evolution, is instrumental to decipher the many facets of cilia and flagella biology. In this review, we highlight the specific strengths of the main model organisms to investigate the molecular composition, mode of assembly, sensing and motility mechanisms and functions of cilia and flagella. Pioneering studies carried out in the green alga Chlamydomonas established the link between cilia and several genetic diseases. Moreover, multicellular organisms such as mouse, zebrafish, Xenopus, C. elegans or Drosophila, and protists like Paramecium, Tetrahymena and Trypanosoma or Leishmania each bring specific advantages to the study of cilium biology. For example, the function of genes involved in primary ciliary dyskinesia (due to defects in ciliary motility) can be efficiently assessed in trypanosomes.

  8. Modeling loggerhead turtle movement in the Mediterranean: importance of body size and oceanography.

    Science.gov (United States)

    Eckert, Scott A; Moore, Jeffrey E; Dunn, Daniel C; van Buiten, Ricardo Sagarminaga; Eckert, Karen L; Halpin, Patrick N

    2008-03-01

    Adapting state-space models (SSMs) to telemetry data has been helpful for dealing with location error and for modeling animal movements. We used a combination of two hierarchical Bayesian SSMs to estimate movement pathways from Argos satellite-tag data for 15 juvenile loggerhead turtles (Caretta caretta) in the western Mediterranean Sea, and to probabilistically assign locations to one of two behavioral movement types and relate those behaviors to environmental features. A Monte Carlo procedure helped propagate location uncertainty from the first SSM into the estimation of behavioral states and environment--behavior relationships in the second SSM. Turtles using oceanic habitats of the Balearic Sea (n = 9 turtles) within the western Mediterranean were more likely to exhibit "intensive search" behavior as might occur during foraging, but only larger turtles responded to variations in sea-surface height. This suggests that they were better able than smaller turtles to cue on environmental features that concentrate prey resources or were more dependent on high-quality feeding areas. These findings stress the importance of individual heterogeneity in the analysis of movement behavior and, taken in concert with descriptive studies of Pacific loggerheads, suggest that directed movements toward patchy ephemeral resources may be a general property of larger juvenile loggerheads in different populations. We discovered size-based variation in loggerhead distribution and documented use of the western Mediterranean Sea by turtles larger than previously thought to occur there. With one exception, only individuals > 57 cm curved carapace length used the most westerly basin in the Mediterranean (western Alborán Sea). These observations shed new light on loggerhead migration phenology.

  9. ADAPTIVE ANNEALED IMPORTANCE SAMPLING FOR MULTIMODAL POSTERIOR EXPLORATION AND MODEL SELECTION WITH APPLICATION TO EXTRASOLAR PLANET DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin, E-mail: bins@ieee.org [School of Computer Science and Technology, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China)

    2014-07-01

    We describe an algorithm that can adaptively provide mixture summaries of multimodal posterior distributions. The parameter space of the involved posteriors ranges in size from a few dimensions to dozens of dimensions. This work was motivated by an astrophysical problem called extrasolar planet (exoplanet) detection, wherein the computation of stochastic integrals that are required for Bayesian model comparison is challenging. The difficulty comes from the highly nonlinear models that lead to multimodal posterior distributions. We resort to importance sampling (IS) to estimate the integrals, and thus translate the problem to be how to find a parametric approximation of the posterior. To capture the multimodal structure in the posterior, we initialize a mixture proposal distribution and then tailor its parameters elaborately to make it resemble the posterior to the greatest extent possible. We use the effective sample size (ESS) calculated based on the IS draws to measure the degree of approximation. The bigger the ESS is, the better the proposal resembles the posterior. A difficulty within this tailoring operation lies in the adjustment of the number of mixing components in the mixture proposal. Brute force methods just preset it as a large constant, which leads to an increase in the required computational resources. We provide an iterative delete/merge/add process, which works in tandem with an expectation-maximization step to tailor such a number online. The efficiency of our proposed method is tested via both simulation studies and real exoplanet data analysis.

  10. THE POLISH BUSINESS ENVIRONMENT FOR LANGUAGE SERVICE PROVIDERS IN VIEW OF THE PORTER’S FIVE FORCES MODEL

    OpenAIRE

    Kowalska, Monika

    2014-01-01

    After the Polish accession to the European Union in 2004, language services have considerably grown in importance. Intensive contacts with foreign companies and institutions coupled with information technology developments have increased the role of English as a linguistic medium of international cooperation. The overall aim of this paper is to examine the Polish business environment for Language Service Providers (LSPs) offering specialized English courses and translation services (EN-PL and...

  11. The Main Influencing Factors of Customer Trust in China’s Import Cross-Border E- commerce Business Model

    OpenAIRE

    Zhou, Lu; Liu, Jiaqi; Lu, Yanzhu

    2016-01-01

    China’s import cross-border e-commerce (CICBEC) business model differs from other online shopping business models in both the participators and transaction processes. Government as an important participator has greatly promoted the healthy and rapid development of this business model. As a vital topic in all kinds of businesses, customer trust is also a core research topic in online shopping. Many scholars have studied customer trust in traditional online shopping while few of them focused on...

  12. Evaluating the importance of characterizing soil structure and horizons in parameterizing a hydrologic process model

    Science.gov (United States)

    Mirus, Benjamin B.

    2015-01-01

    Incorporating the influence of soil structure and horizons into parameterizations of distributed surface water/groundwater models remains a challenge. Often, only a single soil unit is employed, and soil-hydraulic properties are assigned based on textural classification, without evaluating the potential impact of these simplifications. This study uses a distributed physics-based model to assess the influence of soil horizons and structure on effective parameterization. This paper tests the viability of two established and widely used hydrogeologic methods for simulating runoff and variably saturated flow through layered soils: (1) accounting for vertical heterogeneity by combining hydrostratigraphic units with contrasting hydraulic properties into homogeneous, anisotropic units and (2) use of established pedotransfer functions based on soil texture alone to estimate water retention and conductivity, without accounting for the influence of pedon structures and hysteresis. The viability of this latter method for capturing the seasonal transition from runoff-dominated to evapotranspiration-dominated regimes is also tested here. For cases tested here, event-based simulations using simplified vertical heterogeneity did not capture the state-dependent anisotropy and complex combinations of runoff generation mechanisms resulting from permeability contrasts in layered hillslopes with complex topography. Continuous simulations using pedotransfer functions that do not account for the influence of soil structure and hysteresis generally over-predicted runoff, leading to propagation of substantial water balance errors. Analysis suggests that identifying a dominant hydropedological unit provides the most acceptable simplification of subsurface layering and that modified pedotransfer functions with steeper soil-water retention curves might adequately capture the influence of soil structure and hysteresis on hydrologic response in headwater catchments.

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

    Science.gov (United States)

    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.

  14. Economic and Social Models in Europe and the Importance of Reform

    Directory of Open Access Journals (Sweden)

    Martin Heipertz

    2008-09-01

    Full Text Available This paper contributes to the ongoing debate on European economic and social models. It provides a comparative assessment of fiscal and regulatory policies in 17 industrialised countries (the EU15, US and Japan and presents the records of these countries in attaining key economic and social objectives. Social and economic systems that feature efficient public sectors and flexible market structures tend to experience reasonably sustainable public finances, high economic growth, education standards and employment, and well-functioning markets. Anglo-Saxon countries broadly fit this mould, albeit, seemingly, at some cost of income equality. A more pronounced emphasis on welfare state policies and the corresponding relatively high levels of public spending bring benefit to income distribution in the Nordic countries while the resulting inefficiencies in their economies are counterbalanced by flexibility in labour and particularly product markets. Also, a number of reform-minded European countries have improved their fiscal and regulatory policies while significantly enhancing the functioning of markets, fiscal sustainability and economic performance. This was generally attained without jeopardising social objectives. On the other hand, those continental and Mediterranean countries that maintain market inefficiencies and at the same time sustain expensive and inefficient welfare states generally suffer from low growth and employment and less well-functioning markets and face serious risks to their economies’ fiscal sustainability. The findings of this note support calls for the comprehensive reform of fiscal policies, as well as of product and labour markets.

  15. On The Importance of A Socio-Culturally Designed Teaching Model in an EFL Writing Classroom

    Directory of Open Access Journals (Sweden)

    Mahdiyeh Abdollahzadeh

    2015-07-01

    Full Text Available Writing is a means of articulating ideas, arousing feelings, persuading and convincing other people, but the procedure of writing has become arduous and labyrinthine for Iranian EFL learners. The educational system in Iran is structure-based and it ignores the communicative role of writing, so students' performance in writing wouldn’t be desirable. To tackle the mentioned problem, the present paper develops a scaffolding environment to maximize students writing dexterities through the application of various scaffolding means coined by Tharp and Gallimore (1988 during the stages of Seow's process model. The purpose was to determine the procedure of teacher guidance in a process- oriented situation and trace the scaffolding means which had a pre-eminent role in enhancing students' writing proficiency by observing the class and conducting an interview. To this end, 15 female students within the age range of 15-18 studying in Be’sat Language Institute in Salmas, Iran participated in this study. The results elucidated that students could benefit from the established situation in different ways during the accomplishment of their writing tasks. At the end, the study provided some pedagogical implications for teachers in terms of teaching writing.

  16. AND/OR Importance Sampling

    OpenAIRE

    Gogate, Vibhav; Dechter, Rina

    2012-01-01

    The paper introduces AND/OR importance sampling for probabilistic graphical models. In contrast to importance sampling, AND/OR importance sampling caches samples in the AND/OR space and then extracts a new sample mean from the stored samples. We prove that AND/OR importance sampling may have lower variance than importance sampling; thereby providing a theoretical justification for preferring it over importance sampling. Our empirical evaluation demonstrates that AND/OR importance sampling is ...

  17. Molecular profiling of breast cancer cell lines defines relevant tumor models and provides a resource for cancer gene discovery.

    Directory of Open Access Journals (Sweden)

    Jessica Kao

    Full Text Available BACKGROUND: Breast cancer cell lines have been used widely to investigate breast cancer pathobiology and new therapies. Breast cancer is a molecularly heterogeneous disease, and it is important to understand how well and which cell lines best model that diversity. In particular, microarray studies have identified molecular subtypes-luminal A, luminal B, ERBB2-associated, basal-like and normal-like-with characteristic gene-expression patterns and underlying DNA copy number alterations (CNAs. Here, we studied a collection of breast cancer cell lines to catalog molecular profiles and to assess their relation to breast cancer subtypes. METHODS: Whole-genome DNA microarrays were used to profile gene expression and CNAs in a collection of 52 widely-used breast cancer cell lines, and comparisons were made to existing profiles of primary breast tumors. Hierarchical clustering was used to identify gene-expression subtypes, and Gene Set Enrichment Analysis (GSEA to discover biological features of those subtypes. Genomic and transcriptional profiles were integrated to discover within high-amplitude CNAs candidate cancer genes with coordinately altered gene copy number and expression. FINDINGS: Transcriptional profiling of breast cancer cell lines identified one luminal and two basal-like (A and B subtypes. Luminal lines displayed an estrogen receptor (ER signature and resembled luminal-A/B tumors, basal-A lines were associated with ETS-pathway and BRCA1 signatures and resembled basal-like tumors, and basal-B lines displayed mesenchymal and stem/progenitor-cell characteristics. Compared to tumors, cell lines exhibited similar patterns of CNA, but an overall higher complexity of CNA (genetically simple luminal-A tumors were not represented, and only partial conservation of subtype-specific CNAs. We identified 80 high-level DNA amplifications and 13 multi-copy deletions, and the resident genes with concomitantly altered gene-expression, highlighting known and

  18. Status study of knowledge management in universities and to provide a suitable model (Case Study: Ferdowsi University of Mashhad)

    Science.gov (United States)

    Jahangir, Mustafa; Asadi, M. Mahdi

    2010-05-01

    During the past two decades to increase the volume of information and knowledge in organizations and the necessity of effective use of it in Organizational decisions is led to the emerging phenomenon of knowledge management. Knowledge management, including all the ways the organization manage their knowledge assets that include how collection, storage, transfer, deployment, update and create knowledge. Universities that type of knowledge based organizations are important sources of knowledge and therefore can be considered as strategic in universities and higher education centers of knowledge management will be more important. In this research The status of knowledge management in universities and a case study of Mashhad University are checked are the problems and challenges are identified and finally as for the features, requirements and conditions to implement a model for universities and deployment of knowledge management is presented in it.Therefore, basic research problem is: the status of knowledge management in universities and the case Mashhad University is how and which model for implementation and deployment of knowledge management is recommended? Importance and necessity of research topicare: Knowledge management experts in the emergence of knowledge management consider four major factors:1) passing the material tangible assets dominated era to the domination of capital in non-palpable, nonetheless organizations. 2) increase the extraordinary volume of information, the electronic storage and increased access to information 3) risk to the story of institutional knowledge due to retirement or exit from the crew 4) become more specialized activities in the organization 5) the emergence of knowledge based organizations and incidence of the most important capital is its knowledge. Knowledge management solutions focus on the entire system, including organization, human resources and technology in the take-the most important tools for solving problems and

  19. A friction model for cold forging of aluminum, steel and stainless steel provided with conversion coating and solid film lubricant

    DEFF Research Database (Denmark)

    Bay, Niels; Eriksen, Morten; Tan, Xincai

    2011-01-01

    Adopting a simulative tribology test system for cold forging the friction stress for aluminum, steel and stainless steel provided with typical lubricants for cold forging has been determined for varying normal pressure, surface expansion, sliding length and tool/work piece interface temperature...... of normal pressure and tool/work piece interface temperature. The model is verified by process testing measuring friction at varying reduction in cold forward rod extrusion....

  20. Fourier power, subjective distance and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Directory of Open Access Journals (Sweden)

    Mark Daniel Lescroart

    2015-11-01

    Full Text Available Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA, Retrosplenial Complex (RSC, and the Occipital Place Area (OPA. It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1 2D features related to Fourier power; (2 3D spatial features such as the distance to objects in a scene; or (3 abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM to BOLD fMRI responses elicited by a set of 1,386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue.

  1. Governance in Health - The Need for Exchange and Evidence Comment on "Governance, Government, and the Search for New Provider Models".

    Science.gov (United States)

    Chanturidze, Tata; Obermann, Konrad

    2016-05-17

    Governance in health is cited as one of the key factors in balancing the concerns of the government and public sector with the interests of civil society/private players, but often remains poorly described and operationalized. Richard Saltman and Antonio Duran look at two aspects in the search for new provider models in a context of health markets signalling liberalisation: (i) the role of the government to balance public and private interests and responsibilities in delivering care through modernised governance arrangements, and (ii) the finding that operational complexities may hinder well-designed provider governance models, unless governance reflects country-specific realities. This commentary builds on the discussion by Saltman and Duran, and argues that the concept of governance needs to be clearly defined and operationalized in order to be helpful for policy debate as well as for the development of an applicable framework for performance improvement. It provides a working definition of governance and includes a reflection on the prevailing cultural norms in an organization or society upon which any governance needs to be build. It proposes to explore whether the "evidence-based governance" concept can be introduced to generate knowledge about innovative and effective governance models, and concludes that studies similar to the one by Saltman and Duran can inform this debate.

  2. Modeling Leptospirosis in Trinidad, West Indies: A Waterborne Zoonosis of Increasing Public Health Importance

    Science.gov (United States)

    Vega, M. C.; Opadeyi, J.

    2012-12-01

    draining soils, percentage of imperfectly draining soils, percentage of impeded draining soils and mean annual rainfall. These covariables together with socio-economic data were used to set up the GWR models. Local model correlation (R^{2}) was 0.78, higher than the global correlation of 0.58 and there was found to be a clear spatial correlation between covariables and leptospirosis cases. Percentage of draining soils and topography were found to be significant (p<0.01 and 0.00) indicating spatial variability in the influence of these factors on the occurrence of leptospirosis in Trinidad communities. Composition of the soils and their lack of drainage may be an important factor influencing leptospirosis occurrence. Leptospires do not have a waterproof membrane therefore for their survival they must remain submersed in water. Previous studies have found leptospires to be associated with soils of high moisture and organic matter content.

  3. Providing a theoretical basis for nanotoxicity risk analysis departing from traditional physiologically-based pharmacokinetic (PBPK) modeling

    Science.gov (United States)

    Yamamoto, Dirk P.

    The same novel properties of engineered nanoparticles that make them attractive may also present unique exposure risks. But, the traditional physiologically-based pharmacokinetic (PBPK) modeling assumption of instantaneous equilibration likely does not apply to nanoparticles. This simulation-based research begins with development of a model that includes diffusion, active transport, and carrier mediated transport. An eigenvalue analysis methodology was developed to examine model behavior to focus future research. Simulations using the physico-chemical properties of size, shape, surface coating, and surface charge were performed and an equation was determined which estimates area under the curve for arterial blood concentration, which is a surrogate of nanoparticle dose. Results show that the cellular transport processes modeled in this research greatly affect the biokinetics of nanoparticles. Evidence suggests that the equation used to estimate area under the curve for arterial blood concentration can be written in terms of nanoparticle size only. The new paradigm established by this research leverages traditional in vitro, in vivo, and PBPK modeling, but includes area under the curve to bridge animal testing results to humans. This new paradigm allows toxicologists and policymakers to then assess risk to a given exposure and assist in setting appropriate exposure limits for nanoparticles. This research provides critical understanding of nanoparticle biokinetics and allows estimation of total exposure at any toxicological endpoint in the body. This effort is a significant contribution as it highlights future research needs and demonstrates how modeling can be used as a tool to advance nanoparticle risk assessment.

  4. A support vector machine model provides an accurate transcript-level-based diagnostic for major depressive disorder

    Science.gov (United States)

    Yu, J S; Xue, A Y; Redei, E E; Bagheri, N

    2016-01-01

    Major depressive disorder (MDD) is a critical cause of morbidity and disability with an economic cost of hundreds of billions of dollars each year, necessitating more effective treatment strategies and novel approaches to translational research. A notable barrier in addressing this public health threat involves reliable identification of the disorder, as many affected individuals remain undiagnosed or misdiagnosed. An objective blood-based diagnostic test using transcript levels of a panel of markers would provide an invaluable tool for MDD as the infrastructure—including equipment, trained personnel, billing, and governmental approval—for similar tests is well established in clinics worldwide. Here we present a supervised classification model utilizing support vector machines (SVMs) for the analysis of transcriptomic data readily obtained from a peripheral blood specimen. The model was trained on data from subjects with MDD (n=32) and age- and gender-matched controls (n=32). This SVM model provides a cross-validated sensitivity and specificity of 90.6% for the diagnosis of MDD using a panel of 10 transcripts. We applied a logistic equation on the SVM model and quantified a likelihood of depression score. This score gives the probability of a MDD diagnosis and allows the tuning of specificity and sensitivity for individual patients to bring personalized medicine closer in psychiatry. PMID:27779627

  5. A Mathematical Model of Metabolism and Regulation Provides a Systems-Level View of How Escherichia coli Responds to Oxygen

    Directory of Open Access Journals (Sweden)

    Michael eEderer

    2014-03-01

    Full Text Available The efficient redesign of bacteria for biotechnological purposes, such as biofuel production, waste disposal or specific biocatalytic functions, requires a quantitative systems-level understanding of energy supply, carbon and redox metabolism. The measurement of transcript levels, metabolite concentrations and metabolic fluxes per se gives an incomplete picture. An appreciation of the interdependencies between the different measurement values is essential for systems-level understanding. Mathematical modeling has the potential to provide a coherent and quantitative description of the interplay between gene expression, metabolite concentrations and metabolic fluxes. Escherichia coli undergoes major adaptations in central metabolism when the availability of oxygen changes. Thus, an integrated description of the oxygen response provides a benchmark of our understanding of carbon, energy and redox metabolism. We present the first comprehensive model of the central metabolism of E. coli that describes steady-state metabolism at different levels of oxygen availability. Variables of the model are metabolite concentrations, gene expression levels, transcription factor activities, metabolic fluxes and biomass concentration. We analyze the model with respect to the production capabilities of central metabolism of E. coli. In particular, we predict how precursor and biomass concentration are affected by product formation.

  6. Simulation with Ideal Switch Models Combined with Measured Loss Data Provides a Good Estimate of Power Loss

    Institute of Scientific and Technical Information of China (English)

    StigMunk-Nielsen; Lucian; N; Tutelea; Ulrik; Jager

    2007-01-01

    Ideally, converter losses should be determined without using an excessive amount of simulation time. State-of-the-art power semiconductor models provide good accuracy,unfortunately they often require a very long simulation time. This paper describes how to estimate power losses from simulation using ideal switches combined with measured power loss data. The semiconductor behavior is put into a look-up table,which replaces the advanced semiconductor models and shortens the simulation time.To extract switching and conduction losses, a converter is simulated and the semiconductor power losses are estimated. Measurement results on a laboratory converter are compared with the estimated losses and a good agreement is shown. Using the ideal switch simulation and the post processing power estimation program,a ten to twenty fold increase in simulation speed is obtained,compared to simulations using advanced models of semiconductors.

  7. Importance of global aerosol modeling including secondary organic aerosol formed from monoterpene

    OpenAIRE

    Goto, Daisuke; Takemura, Toshihiko; Nakajima, Teruyuki

    2008-01-01

    A global three-dimensional aerosol transport-radiation model, coupled to an atmospheric general circulation model (AGCM), has been extended to improve the model process for organic aerosols, particularly secondary organic aerosols (SOA), and to estimate SOA contributions to direct and indirect radiative effects. Because the SOA formation process is complicated and unknown, the results in different model simulations include large differences. In this work, we simulate SOA production assuming v...

  8. An Importance Sampling Scheme for Models in a Strong External Field

    CERN Document Server

    Molkaraie, Mehdi

    2015-01-01

    We propose Monte Carlo methods to estimate the partition function of the two-dimensional Ising model in the presence of an external magnetic field. The estimation is done in the dual of the Forney factor graph representing the model. The proposed methods can efficiently compute an estimate of the partition function in a wide range of model parameters. As an example, we consider models that are in a strong external field.

  9. A Hybrid Artificial Reputation Model Involving Interaction Trust, Witness Information and the Trust Model to Calculate the Trust Value of Service Providers

    Directory of Open Access Journals (Sweden)

    Gurdeep Singh Ransi

    2014-02-01

    Full Text Available Agent interaction in a community, such as the online buyer-seller scenario, is often uncertain, as when an agent comes in contact with other agents they initially know nothing about each other. Currently, many reputation models are developed that help service consumers select better service providers. Reputation models also help agents to make a decision on who they should trust and transact with in the future. These reputation models are either built on interaction trust that involves direct experience as a source of information or they are built upon witness information also known as word-of-mouth that involves the reports provided by others. Neither the interaction trust nor the witness information models alone succeed in such uncertain interactions. In this paper we propose a hybrid reputation model involving both interaction trust and witness information to address the shortcomings of existing reputation models when taken separately. A sample simulation is built to setup buyer-seller services and uncertain interactions. Experiments reveal that the hybrid approach leads to better selection of trustworthy agents where consumers select more reputable service providers, eventually helping consumers obtain more gains. Furthermore, the trust model developed is used in calculating trust values of service providers.

  10. The Mother Teresa Effect: the modulation of spirituality in using the CISM model with mental health service providers.

    Science.gov (United States)

    Newmeyer, Mark; Keyes, Benjamin; Gregory, Sonji; Palmer, Kamala; Buford, Daniel; Mondt, Priscilla; Okai, Benjamin

    2014-01-01

    Mental health service providers are at risk of experiencing compassion fatigue, burnout, and vicarious traumatization as a result of working in difficult contexts or when working with individuals who have experienced trauma. Numerous studies have examined the mitigating factors in professional caregivers' stress and related prevention strategies thought to be associated with professional self-care. This retrospective study examined the impact of debriefing strategies referred to as Critical Incident Stress Management (CISM) and spirituality in 22 mental health service providers working in a stressful, cross-cultural context. Quantitative analysis of pre and post self-report instruments suggests that training and utilization of CISM techniques may be important in preventing future problems. To the surprise of the researchers, spirituality may not only serve as a protective factor in moderating compassion fatigue, but also increases compassion satisfaction among professional caregivers. Thus, the "Mother Teresa Effect".

  11. Modelling both dominance and species distribution provides a more complete picture of changes to mangrove ecosystems under climate change.

    Science.gov (United States)

    Crase, Beth; Vesk, Peter A; Liedloff, Adam; Wintle, Brendan A

    2015-08-01

    Dominant species influence the composition and abundance of other species present in ecosystems. However, forecasts of distributional change under future climates have predominantly focused on changes in species distribution and ignored possible changes in spatial and temporal patterns of dominance. We develop forecasts of spatial changes for the distribution of species dominance, defined in terms of basal area, and for species occurrence, in response to sea level rise for three tree taxa within an extensive mangrove ecosystem in northern Australia. Three new metrics are provided, indicating the area expected to be suitable under future conditions (Eoccupied ), the instability of suitable area (Einstability ) and the overlap between the current and future spatial distribution (Eoverlap ). The current dominance and occurrence were modelled in relation to a set of environmental variables using boosted regression tree (BRT) models, under two scenarios of seedling establishment: unrestricted and highly restricted. While forecasts of spatial change were qualitatively similar for species occurrence and dominance, the models of species dominance exhibited higher metrics of model fit and predictive performance, and the spatial pattern of future dominance was less similar to the current pattern than was the case for the distributions of species occurrence. This highlights the possibility of greater changes in the spatial patterning of mangrove tree species dominance under future sea level rise. Under the restricted seedling establishment scenario, the area occupied by or dominated by a species declined between 42.1% and 93.8%, while for unrestricted seedling establishment, the area suitable for dominance or occurrence of each species varied from a decline of 68.4% to an expansion of 99.5%. As changes in the spatial patterning of dominance are likely to cause a cascade of effects throughout the ecosystem, forecasting spatial changes in dominance provides new and

  12. Kinetic modeling of mechanisms of industrially important organic reactions in gas and liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Vahteristo, K.

    2010-07-01

    This dissertation is based on 5 articles which deal with reaction mechanisms of the following selected industrially important organic reactions: 1. dehydrocyclization of n-butylbenzene to produce naphthalene, 2. dehydrocyclization of 1-(p-tolyl)-2-methylbutane (MB) to produce 2,6-dimethylnaphthalene, 3. esterification of neopentyl glycol (NPG) with different carboxylic acids to produce monoesters, 4. skeletal isomerization of 1-pentene to produce 2-methyl-1-butene and 2-methyl-2-butene. The results of initial- and integral-rate experiments of n-butylbenzene dehydrocyclization over selfmade chromia/alumina catalyst were applied when investigating reaction 2. Reaction 2 was performed using commercial chromia/alumina of different acidity, platina on silica and vanadium/calcium/alumina as catalysts. On all catalysts used for the dehydrocyclization, major reactions were fragmentation of MB and 1-(p-tolyl)-2-methylbutenes (MBes), dehydrogenation of MB, double bond transfer, hydrogenation and 1,6-cyclization of MBes. Minor reactions were 1,5-cyclization of MBes and methyl group fragmentation of 1,6- cyclization products. Esterification reactions of NPG were performed using three different carboxylic acids: propionic, isobutyric and 2-ethylhexanoic acid. Commercial heterogeneous gellular (Dowex 50WX2), macroreticular (Amberlyst 15) type resins and homogeneous para-toluene sulfonic acid were used as catalysts. At first NPG reacted with carboxylic acids to form corresponding monoester and water. Then monoester esterified with carboxylic acid to form corresponding diester. In disproportionation reaction two monoester molecules formed NPG and corresponding diester. All these three reactions can attain equilibrium. Concerning esterification, water was removed from the reactor in order to prevent backward reaction. Skeletal isomerization experiments of 1-pentene were performed over HZSM-22 catalyst. Isomerization reactions of three different kind were detected: double bond, cis

  13. Reduced motor neuron excitability is an important contributor to weakness in a rat model of sepsis.

    Science.gov (United States)

    Nardelli, Paul; Vincent, Jacob A; Powers, Randall; Cope, Tim C; Rich, Mark M

    2016-08-01

    The mechanisms by which sepsis triggers intensive care unit acquired weakness (ICUAW) remain unclear. We previously identified difficulty with motor unit recruitment in patients as a novel contributor to ICUAW. To study the mechanism underlying poor recruitment of motor units we used the rat cecal ligation and puncture model of sepsis. We identified striking dysfunction of alpha motor neurons during repetitive firing. Firing was more erratic, and often intermittent. Our data raised the possibility that reduced excitability of motor neurons was a significant contributor to weakness induced by sepsis. In this study we quantified the contribution of reduced motor neuron excitability and compared its magnitude to the contributions of myopathy, neuropathy and failure of neuromuscular transmission. We injected constant depolarizing current pulses (5s) into the soma of alpha motor neurons in the lumbosacral spinal cord of anesthetized rats to trigger repetitive firing. In response to constant depolarization, motor neurons in untreated control rats fired at steady and continuous firing rates and generated smooth and sustained tetanic motor unit force as expected. In contrast, following induction of sepsis, motor neurons were often unable to sustain firing throughout the 5s current injection such that force production was reduced. Even when firing, motor neurons from septic rats fired erratically and discontinuously, leading to irregular production of motor unit force. Both fast and slow type motor neurons had similar disruption of excitability. We followed rats after recovery from sepsis to determine the time course of resolution of the defect in motor neuron excitability. By one week, rats appeared to have recovered from sepsis as they had no piloerection and appeared to be in no distress. The defects in motor neuron repetitive firing were still striking at 2weeks and, although improved, were present at one month. We infer that rats suffered from weakness due to reduced

  14. Importance of the surface size distribution of erodible material: an improvement on the Dust Entrainment And Deposition (DEAD) Model

    Science.gov (United States)

    Mokhtari, M.; Gomes, L.; Tulet, P.; Rezoug, T.

    2012-05-01

    This paper is based on dust aerosol cycle modelling in the atmospheric model ALADIN (Aire Limitée Adaptation dynamique Développement InterNational) coupled with the EXternalised SURFace scheme SURFEX. Its main goal is to create an appropriate mineral dust emission parameterization compatible with the global database of land surface parameters ECOCLIMAP, and the Food and Agriculture Organization (FAO) soil type database in SURFEX. An improvement on the Dust Entrainment And Deposition scheme (DEAD) is proposed in this paper by introducing the geographical variation of surface soil size distribution, the Marticorena and Bergametti (1995) formulation of horizontal saltation flux and the Shao et al. (1996) formulation of sandblasting efficiency α. To show the importance of the modifications introduced in the DEAD, both sensitivity and comparative studies are conducted in 0 dimensions (0-D) and then in 3 dimensions (3-D) between the old DEAD and the new DEAD. The results of the 0-D simulations indicate that the revised DEAD scheme represents the dust source emission better, particularly in the Bodélé depression, and provides a reasonable friction threshold velocity. In 3-D simulations, small differences are found between the DEAD and the revised DEAD for the simulated Aerosol Optical Depth (AOD) compared with the AErosol RObotic NETwork (AERONET) photometer measurements available in the African Monsoon Multidisciplinary Analyses (AMMA) databases. For the surface concentration, a remarkable improvement is noted for the revised DEAD scheme.

  15. Medicare Provider Data - Hospice Providers

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Hospice Utilization and Payment Public Use File provides information on services provided to Medicare beneficiaries by hospice providers. The Hospice PUF...

  16. Importance of Salmonella Typhi-Responsive CD8+ T Cell Immunity in a Human Typhoid Fever Challenge Model.

    Science.gov (United States)

    Fresnay, Stephanie; McArthur, Monica A; Magder, Laurence S; Darton, Thomas C; Jones, Claire; Waddington, Claire S; Blohmke, Christoph J; Angus, Brian; Levine, Myron M; Pollard, Andrew J; Sztein, Marcelo B

    2017-01-01

    Typhoid fever, caused by the human-restricted organism Salmonella enterica serovar Typhi (S. Typhi), constitutes a major global health problem. The development of improved attenuated vaccines is pressing, but delayed by the lack of appropriate preclinical models. Herein, we report that high levels of S. Typhi-responsive CD8+ T cells at baseline significantly correlate with an increased risk of disease in humans challenged with a high dose (~10(4) CFU) wild-type S. Typhi. Typhoid fever development was associated with higher multifunctional S. Typhi-responsive CD8+ T effector memory cells at baseline. Early decreases of these cells in circulation following challenge were observed in both S. Typhi-responsive integrin α4β7- and integrin α4β7+ CD8+ T effector memory (TEM) cells, suggesting their potential to home to both mucosal and extra-intestinal sites. Participants with higher baseline levels of S. Typhi-responsive CD8+ T memory cells had a higher risk of acquiring disease, but among those who acquired disease, those with a higher baseline responses took longer to develop disease. In contrast, protection against disease was associated with low or absent S. Typhi-responsive T cells at baseline and no changes in circulation following challenge. These data highlight the importance of pre-existing S. Typhi-responsive immunity in predicting clinical outcome following infection with wild-type S. Typhi and provide novel insights into the complex mechanisms involved in protective immunity to natural infection in a stringent human model with a high challenge dose. They also contribute important information on the immunological responses to be assessed in the appraisal and selection of new generation typhoid vaccines.

  17. Importance of Salmonella Typhi-Responsive CD8+ T Cell Immunity in a Human Typhoid Fever Challenge Model

    Science.gov (United States)

    Fresnay, Stephanie; McArthur, Monica A.; Magder, Laurence S.; Darton, Thomas C.; Jones, Claire; Waddington, Claire S.; Blohmke, Christoph J.; Angus, Brian; Levine, Myron M.; Pollard, Andrew J.; Sztein, Marcelo B.

    2017-01-01

    Typhoid fever, caused by the human-restricted organism Salmonella enterica serovar Typhi (S. Typhi), constitutes a major global health problem. The development of improved attenuated vaccines is pressing, but delayed by the lack of appropriate preclinical models. Herein, we report that high levels of S. Typhi-responsive CD8+ T cells at baseline significantly correlate with an increased risk of disease in humans challenged with a high dose (~104 CFU) wild-type S. Typhi. Typhoid fever development was associated with higher multifunctional S. Typhi-responsive CD8+ T effector memory cells at baseline. Early decreases of these cells in circulation following challenge were observed in both S. Typhi-responsive integrin α4β7− and integrin α4β7+ CD8+ T effector memory (TEM) cells, suggesting their potential to home to both mucosal and extra-intestinal sites. Participants with higher baseline levels of S. Typhi-responsive CD8+ T memory cells had a higher risk of acquiring disease, but among those who acquired disease, those with a higher baseline responses took longer to develop disease. In contrast, protection against disease was associated with low or absent S. Typhi-responsive T cells at baseline and no changes in circulation following challenge. These data highlight the importance of pre-existing S. Typhi-responsive immunity in predicting clinical outcome following infection with wild-type S. Typhi and provide novel insights into the complex mechanisms involved in protective immunity to natural infection in a stringent human model with a high challenge dose. They also contribute important information on the immunological responses to be assessed in the appraisal and selection of new generation typhoid vaccines. PMID:28303138

  18. Origin of Individual Differences in Importance Attached to Work: A Model and a Contribution to Its Evaluation.

    Science.gov (United States)

    Sverko, Branimir

    1989-01-01

    Tested model proposing that importance of work for individual depends on individual's perception of possibilities for attainment of personal salient work values through working. Responses from 1,872 high school students, 348 university students, and 344 adults to measures on importance of 20 work values, perceptions of their attainment…

  19. Modeling and monitoring - important elements in a pipeline integrity management system

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Roy; Gartland, Per O. [Force Technology (Norway); Baxandall, Daryl [Force Technology (Canada); Souza Junior, Helio A. de [Corrocean do Brasil Ltda., RJ (Brazil)

    2003-07-01

    A unique model for prediction of corrosion profiles in oil and gas pipelines has been created. The model is based on multiphase flow modeling, water wetting predictions, pH calculations and models of CO{sub 2} and H{sub 2}S corrosion. The input data are typically the pipeline profile, fluid composition data, production rates and data on injected chemicals. It is possible to combine the model with inspection or monitoring data. Based on the uncertainty related to the model and the available data, a probability distribution for the corrosion predictions is established. The result is combined with existing codes for the allowable corrosion attack in pressurized pipes and used to assess the need for pipeline inspection based on the risk of pipeline failure. Detailed example is given for a crude oil pipeline. (author)

  20. Exposure-response modeling of flow-mediated dilation provides an unbiased and informative measure of endothelial function.

    Science.gov (United States)

    Van Brackle, Charles Henry; Harris, Ryan A; Hallow, Karen Melissa

    2016-12-15

    The brachial artery flow-mediated dilation (FMD) test is the most widely utilized, method to evaluate endothelial function non-invasively in humans by calculating the percent change in diameter (FMD%). However, the underutilized velocity and diameter time-course data coupled with confounding influences in shear exposure, noise, and upward bias make the FMD test less desirable. In this study, we developed an exposure-response model-based approach that not only quantifies FMD based on the rich velocity and diameter data, it overcomes previously acknowledged challenges. FMD data were obtained from 15 apparently healthy participants, each exposed to 4 different cuff occlusion durations. The velocity response following cuff release was described by an exponential model with two parameters defining peak velocity and rate of decay. Shear exposure derived from velocity was used to drive the diameter response model, which consists of additive constriction and dilation terms. Three parameters describing distinct aspects of the vascular response to shear (magnitude of the initial constriction response, and magnitude and time constant of the dilation response) were estimated for both the individuals and population. These parameters are independent of shear exposure. Thus, this approach produces identifiable and physiologically meaningful parameters that may provide additional information for comparing differences between experimental groups or over time, and provides a means to completely account for shear exposure.

  1. Realizing the recognition features of model antipsychotic compounds by important protein: Photochemical and computational studies.

    Science.gov (United States)

    Ding, Fei; Peng, Wei; Chao, Ming-Wei; Peng, Yu-Kui

    2015-07-01

    Phenothiazine and its derivatives are the most effective antipsychotic drugs. They have been used in the treatment of serious mental and emotional symptoms including bipolar disorder, organic psychoses, psychotic depression and schizophrenia. However, these drugs cause serious side effects such as akathisia, hyperprolactinaemia and neuroleptic malignant syndrome. In this work we investigated the molecular recognition of two typical phenothiazine compounds, phenosafranin and safranin O by the most pivotal heme protein hemoglobin using steady state and time-resolved fluorescence, extrinsic 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescent probe, circular dichroism (CD) along with computational modeling. Results show phenothiazines complex with protein via formation of adducts at 298 K with moderate strengths of 3.555×10(4) M(-1) and 2.567×10(4) M(-1) for the hemoglobin-phenosafranin and hemoglobin-safranin O, respectively. We also found phenothiazines were effectors at the protein allosteric site, which affects the allosteric equilibrium. Further, time-resolved fluorescence and hydrophobic ANS experiments showed the static mechanism is dominated for the shrinkage in the fluorescence intensity of β-37 Trp residue at the α1β2 interface. The stoichiometric proportion of the protein-drug adduct is 1:1, as derived from Job's plot. Several crucial noncovalent bonds, including hydrogen bonds, π-π stacking and hydrophobic interactions played a major role in stabilizing the noncovalent conjugates. Based on three-dimensional fluorescence, we concluded that the conformation of hemoglobin is partially destabilized after recognition with phenothiazines. These alterations were confirmed by far-UV CD spectra that showed the α-helix of protein decreased from 78.3% in free hemoglobin to 62.8% and 64.8% in hemoglobin-phenosafranin and hemoglobin-safranin O, respectively. Computer-aided molecular docking was consistent, indicating that both phenothiazines are situated

  2. The importance of erosion for debris flow runout modelling from applications to the Swiss Alps

    OpenAIRE

    F. Frank; B. W. McArdell; Huggel, C; A. Vieli

    2015-01-01

    This study describes an investigation of channel-bed erosion of sediment by debris flows. An erosion model, developed using field data from debris flows at the Illgraben catchment, Switzerland, was incorporated into the existing RAMMS debris-flow model, which solves the 2-D shallow-water equations for granular flows. In the erosion model, the relationship between maximum shear stress and measured erosion is used to determine the maximum potential erosion depth. Additionally,...

  3. Extension of CAVS coarse-grained model to phospholipid membranes: The importance of electrostatics.

    Science.gov (United States)

    Shen, Hujun; Deng, Mingsen; Zhang, Yachao

    2017-05-15

    It is evident from experiment that electrostatic potential (or dipole potential) is positive inside PC or PE lipid bilayers in the absence of ions. MARTINI coarse-grained (CG) model, which has been widely used in simulating physical properties of lipid bilayers, fails to reproduce the positive value for the dipole potential in the membrane interior. Although the total dipole potential can be correctly described by the BMW/MARTINI model, the contribution from the ester dipoles, playing a nontrivial role in the electrostatic potential across lipid membranes, is neglected by this hybrid approach. In the ELBA CG model, the role of the ester dipoles is considered, but it is overweighed because various atomistic models have consistently shown that water is actually the leading contributor of dipole potential. Here, we present a CG approach by combining the BMW-like water model (namely CAVS model) with the ELBA-like lipid model proposed in this work. Our CG model was designed not only to correctly reproduce the positive values for the dipole potential inside PC and PE lipid bilayers but also to properly balance the individual contributions from the ester dipoles and water, surmounting the limitations of current CG models in the calculations of dipole potential. © 2017 Wiley Periodicals, Inc.

  4. Impact of GlobalGAP certification on EU banana imports: A gravity modeling approach

    OpenAIRE

    Masood, Amjad; Brümmer, Bernhard

    2014-01-01

    Adopting a gravity framework and using data from 2010 to 2012 for 74 countries, we investigate whether the intensity of GlobalGAP standard adoption has a positive impact on EU banana import values. Intensity is measured by using number of GlobalGAP certified producers and hectares harvested under GlobalGAP certification. Using random and fixed effect estimation we find that intensity of certification, in terms of producers and hectares are associated with higher banana imports. However the es...

  5. Landscape-based population viability models demonstrate importance of strategic conservation planning for birds

    Science.gov (United States)

    Thomas W. Bonnot; Frank R. Thompson; Joshua J. Millspaugh; D. Todd. Jones-Farland

    2013-01-01

    Efforts to conserve regional biodiversity in the face of global climate change, habitat loss and fragmentation will depend on approaches that consider population processes at multiple scales. By combining habitat and demographic modeling, landscape-based population viability models effectively relate small-scale habitat and landscape patterns to regional population...

  6. The importance of accurate muscle modelling for biomechanical analyses: a case study with a lizard skull

    Science.gov (United States)

    Gröning, Flora; Jones, Marc E. H.; Curtis, Neil; Herrel, Anthony; O'Higgins, Paul; Evans, Susan E.; Fagan, Michael J.

    2013-01-01

    Computer-based simulation techniques such as multi-body dynamics analysis are becoming increasingly popular in the field of skull mechanics. Multi-body models can be used for studying the relationships between skull architecture, muscle morphology and feeding performance. However, to be confident in the modelling results, models need to be validated against experimental data, and the effects of uncertainties or inaccuracies in the chosen model attributes need to be assessed with sensitivity analyses. Here, we compare the bite forces predicted by a multi-body model of a lizard (Tupinambis merianae) with in vivo measurements, using anatomical data collected from the same specimen. This subject-specific model predicts bite forces that are very close to the in vivo measurements and also shows a consistent increase in bite force as the bite position is moved posteriorly on the jaw. However, the model is very sensitive to changes in muscle attributes such as fibre length, intrinsic muscle strength and force orientation, with bite force predictions varying considerably when these three variables are altered. We conclude that accurate muscle measurements are crucial to building realistic multi-body models and that subject-specific data should be used whenever possible. PMID:23614944

  7. SEAGRASS STRESS RESPONSE MODEL: THE IMPORTANCE OF LIGHT, TEMPERATURE, SEDIMENTATION AND GEOCHEMISTRY

    Science.gov (United States)

    Our objective is to define interactions between seagrass and water-column and sediment stressors. The model was developed and optimized for sediments in Thalassia testudinum seagrass beds of Lower Laguna Madre, Texas, USA and is composed of a plant sub-model and a sediment diagen...

  8. Importance of fish behaviour in modelling conservation problems: food limitation as an example

    Science.gov (United States)

    Steven Railsback; Bret Harvey

    2011-01-01

    Simulation experiments using the inSTREAM individual-based brown trout Salmo trutta population model explored the role of individual adaptive behaviour in food limitation, as an example of how behaviour can affect managers’ understanding of conservation problems. The model includes many natural complexities in habitat (spatial and temporal variation in characteristics...

  9. Mathematical modeling of the intracellular protein dynamics: the importance of active transport along microtubules.

    Science.gov (United States)

    Szymańska, Zuzanna; Parisot, Martin; Lachowicz, Mirosław

    2014-12-21

    In this paper we propose a mathematical model of protein and mRNA transport inside a cell. The spatio-temporal model takes into account the active transport along microtubules in the cytoplasm as well as diffusion and is able to reproduce the oscillatory changes in protein concentration observed in many experimental data. In the model the protein and the mRNA interact with each other that allows us to classify the model as a simple gene regulatory network. The proposed model is generic and may be adapted to specific signaling pathways. On the basis of numerical simulations, we formulate a new hypothesis that the oscillatory dynamics is allowed by the mRNA active transport along microtubules from the nucleus to distant locations.

  10. The importance of spatial models for estimating the strength of density dependence

    DEFF Research Database (Denmark)

    Thorson, James T.; Skaug, Hans J.; Kristensen, Kasper;

    2014-01-01

    Identifying the existence and magnitude of density dependence is one of the oldest concerns in ecology. Ecologists have aimed to estimate density dependence in population and community data by fitting a simple autoregressive (Gompertz) model for density dependence to time series of abundance...... for an entire population. However, it is increasingly recognized that spatial heterogeneity in population densities has implications for population and community dynamics. We therefore adapt the Gompertz model to approximate local densities over continuous space instead of population-wide abundance......, and to allow productivity to vary spatially. Using simulated data generated from a spatial model, we show that the conventional (nonspatial) Gompertz model will result in biased estimates of density dependence, e.g., identifying oscillatory dynamics when not present. By contrast, the spatial Gompertz model...

  11. Relative importance of fuel management, ignition management and weather for area burned: Evidence from five landscape-fire-succession models

    Science.gov (United States)

    Geoffrey J. Cary; Mike D. Flannigan; Robert E. Keane; Ross A. Bradstock; Ian D. Davies; James M. Lenihan; Chao Li; Kimberley A. Logan; Russell A. Parsons

    2009-01-01

    The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEMLAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets...

  12. NOAA People Empowered Products (PeEP): Combining social media with scientific models to provide eye-witness confirmed products

    Science.gov (United States)

    Codrescu, S.; Green, J. C.; Redmon, R. J.; Minor, K.; Denig, W. F.; Kihn, E. A.

    2013-12-01

    NOAA products and alerts rely on combinations of models and data to provide the public with information regarding space and terrestrial weather phenomena and hazards. This operational paradigm, while effective, neglects an abundant free source of measurements: millions of eyewitnesses viewing weather events. We demonstrate the capabilities of a prototype People Empowered Product (PeEP) that combines the OVATION prime auroral model running at the NOAA National Geophysical Data Center with Twitter reports of observable aurora. We introduce an algorithm for scoring Tweets based on keywords to improve the signal to noise of this dynamic data source. We use the location of the aurora derived from this new database of crowd sourced observations to validate the OVATION model for use in auroral forecasting. The combined product displays the model aurora in real time with markers showing the location and text of tweets from people actually observing the aurora. We discuss how the application might be extended to other space weather products such as radiation related satellite anomalies.

  13. Modeling the Ecosystem Services Provided by Trees in Urban Ecosystems: Using Biome-BGC to Improve i-Tree Eco

    Science.gov (United States)

    Brown, Molly E.; McGroddy, Megan; Spence, Caitlin; Flake, Leah; Sarfraz, Amna; Nowak, David J.; Milesi, Cristina

    2012-01-01

    As the world becomes increasingly urban, the need to quantify the effect of trees in urban environments on energy usage, air pollution, local climate and nutrient run-off has increased. By identifying, quantifying and valuing the ecological activity that provides services in urban areas, stronger policies and improved quality of life for urban residents can be obtained. Here we focus on two radically different models that can be used to characterize urban forests. The i-Tree Eco model (formerly UFORE model) quantifies ecosystem services (e.g., air pollution removal, carbon storage) and values derived from urban trees based on field measurements of trees and local ancillary data sets. Biome-BGC (Biome BioGeoChemistry) is used to simulate the fluxes and storage of carbon, water, and nitrogen in natural environments. This paper compares i-Tree Eco's methods to those of Biome-BGC, which estimates the fluxes and storage of energy, carbon, water and nitrogen for vegetation and soil components of the ecosystem. We describe the two models and their differences in the way they calculate similar properties, with a focus on carbon and nitrogen. Finally, we discuss the implications of further integration of these two communities for land managers such as those in Maryland.

  14. A critical subset model provides a conceptual basis for the high antiviral activity of major HIV drugs.

    Science.gov (United States)

    Shen, Lin; Rabi, S Alireza; Sedaghat, Ahmad R; Shan, Liang; Lai, Jun; Xing, Sifei; Siliciano, Robert F

    2011-07-13

    Control of HIV-1 replication was first achieved with regimens that included a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI); however, an explanation for the high antiviral activity of these drugs has been lacking. Indeed, conventional pharmacodynamic measures like IC(50) (drug concentration causing 50% inhibition) do not differentiate NNRTIs and PIs from less active nucleoside reverse transcriptase inhibitors (NRTIs). Drug inhibitory potential depends on the slope of the dose-response curve (m), which represents how inhibition increases as a function of increasing drug concentration and is related to the Hill coefficient, a measure of intramolecular cooperativity in ligand binding to a multivalent receptor. Although NNRTIs and PIs bind univalent targets, they unexpectedly exhibit cooperative dose-response curves (m > 1). We show that this cooperative inhibition can be explained by a model in which infectivity requires participation of multiple copies of a drug target in an individual life cycle stage. A critical subset of these target molecules must be in the unbound state. Consistent with experimental observations, this model predicts m > 1 for NNRTIs and PIs and m = 1 in situations where a single drug target/virus mediates a step in the life cycle, as is the case with NRTIs and integrase strand transfer inhibitors. This model was tested experimentally by modulating the number of functional drug targets per virus, and dose-response curves for modulated virus populations fit model predictions. This model explains the high antiviral activity of two drug classes important for successful HIV-1 treatment and defines a characteristic of good targets for antiviral drugs in general, namely, intermolecular cooperativity.

  15. Allometry in global models: an important reality check on the growth and biomass of forests

    Science.gov (United States)

    Wolf, A.; Berry, J. A.

    2009-12-01

    Data assimilation incorporates information into a model of nature, and regardless of the algorithm employed the success of DA rests heavily on the quality of both the data and the model. Here we ask the question: if would could assimilate biomass from remote sensing or direct observation, could the models accommodate this information? We find that the state variables that are simulated by land surface models, such as biomass per unit area, are not amenable to developing an "observation operator" necessary for comparison with data. That is, lidar, radar, and multi-angle observations are sensitive to the size and shape of individual trees, whereas most land surface models have no representation of an individual. In addition, most land surface models make no distinction between aboveground and belowground woody biomass. We used the Cannell (1982) forest inventory database to individuate the biomass simulated in land surface models and found that the scaling of biomass pools - leaves, stem, coarse and fine roots - do not obey widely observed empirical and theoretical allometric constraints that are observed for individual trees (Enquist and Niklas, 2002), suggesting that the fractional allocation to these pools and their characteristic turnover times are in error. This discrepancy represents a gap in the translation of research on individual-based allocation to the stand level, where self-pruning and competition are manifest in the observed fluxes and biomass pools per unit area. We develop an approach to synthesize individual-based allocation with area-based flux models using a recent database of component flux and biomass compiled from Fluxnet sites (Luyssaert et al., 2008). We present the size-dependent pattern of allocation and turnover time for forest biomass pools at the spatial scale appropriate for land surface models. We discuss the implications of these results at the global scale for forests with changing size and age structure.

  16. The Importance of Pressure Sampling Frequency in Models for Determination of Critical Wave Loadingson Monolithic Structures

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke; Meinert, Palle

    2008-01-01

    This paper discusses the influence of wave load sampling frequency on calculated sliding distance in an overall stability analysis of a monolithic caisson. It is demonstrated by a specific example of caisson design that for this kind of analyses the sampling frequency in a small scale model could...... be as low as 100 Hz in model scale. However, for design of structure elements like the wave wall on the top of a caisson the wave load sampling frequency must be much higher, in the order of 1000 Hz in the model. Elastic-plastic deformations of foundation and structure were not included in the analysis....

  17. Markov Switching Autoregressive Conditional Heteroscedasticity (SWARCH) Model to Detect Financial Crisis in Indonesia Based on Import and Export Indicators

    Science.gov (United States)

    Sugiyanto; Zukhronah, Etik; Susanti, Yuliana; Rahma Dwi, Sisca

    2017-06-01

    A country is said to be a crisis when the financial system is experiencing a disruption that affects systems that can not function efficiently. The performance efficiency of macroeconomic indicators especially in imports and exports can be used to detect the financial crisis in Indonesia. Based on the import and export indicators from 1987 to 2015, the movement of these indicators can be modelled using SWARCH three states. The results showed that SWARCH (3,1) model was able to detect the crisis that occurred in Indonesia in 1997 and 2008. Using this model, it can be concluded that Indonesia is prone to financial crisis in 2016.

  18. Group Decision-making Models on Determining the Importance Ratings of Technical Characteristics

    Institute of Scientific and Technical Information of China (English)

    GUO Qian; PU Yun; ZHANG Jing

    2011-01-01

    Determining the importance ratings of technical characteristics is a typical group decision-making process. The linguistic-based approach can effectively manage the imprecise and multi-granularity information i;n quality function deployment and facilitate decision-making in deriving the importance ratings. Based on the linguistic weighted averaging (LWA) operator and the linguistic hybrid averaging (LHA) operator, a practical approach is proposed to first aggregate the individual judgments into a collective value for each technical characteristic under linguistic environment, and then measure the deviation degree of linguistic variables to obtain the importance ratings of technical characteristics. A case study shows the application of the proposed method.

  19. Management modelling behaviour: An important prerequisite for the implementation of business ethics

    Directory of Open Access Journals (Sweden)

    E. van Zyl

    2001-08-01

    Full Text Available Researchers agree that ethics and ethical behaviour have become two of the most important topics of the new millennium. Reasons for this can include changing business conditions as well as the growing public demand for quality services, reasonable prices and honest treatment. Furthermore, the present wave of corruption in South African business makes it important to focus on management-related factors that seem to influence employees’ decisions to behave ethically at work. These phenomena will be used as a basis to make practical suggestions on how to improve the situation.

  20. Spinal mechanisms may provide a combination of intermittent and continuous control of human posture: predictions from a biologically based neuromusculoskeletal model.

    Directory of Open Access Journals (Sweden)

    Leonardo Abdala Elias

    2014-11-01

    Full Text Available Several models have been employed to study human postural control during upright quiet stance. Most have adopted an inverted pendulum approximation to the standing human and theoretical models to account for the neural feedback necessary to keep balance. The present study adds to the previous efforts in focusing more closely on modelling the physiological mechanisms of important elements associated with the control of human posture. This paper studies neuromuscular mechanisms behind upright stance control by means of a biologically based large-scale neuromusculoskeletal (NMS model. It encompasses: i conductance-based spinal neuron models (motor neurons and interneurons; ii muscle proprioceptor models (spindle and Golgi tendon organ providing sensory afferent feedback; iii Hill-type muscle models of the leg plantar and dorsiflexors; and iv an inverted pendulum model for the body biomechanics during upright stance. The motor neuron pools are driven by stochastic spike trains. Simulation results showed that the neuromechanical outputs generated by the NMS model resemble experimental data from subjects standing on a stable surface. Interesting findings were that: i an intermittent pattern of muscle activation emerged from this posture control model for two of the leg muscles (Medial and Lateral Gastrocnemius; and ii the Soleus muscle was mostly activated in a continuous manner. These results suggest that the spinal cord anatomy and neurophysiology (e.g., motor unit types, synaptic connectivities, ordered recruitment, along with the modulation of afferent activity, may account for the mixture of intermittent and continuous control that has been a subject of debate in recent studies on postural control. Another finding was the occurrence of the so-called "paradoxical" behaviour of muscle fibre lengths as a function of postural sway. The simulations confirmed previous conjectures that reciprocal inhibition is possibly contributing to this effect, but

  1. Spinal mechanisms may provide a combination of intermittent and continuous control of human posture: predictions from a biologically based neuromusculoskeletal model.

    Science.gov (United States)

    Elias, Leonardo Abdala; Watanabe, Renato Naville; Kohn, André Fabio

    2014-11-01

    Several models have been employed to study human postural control during upright quiet stance. Most have adopted an inverted pendulum approximation to the standing human and theoretical models to account for the neural feedback necessary to keep balance. The present study adds to the previous efforts in focusing more closely on modelling the physiological mechanisms of important elements associated with the control of human posture. This paper studies neuromuscular mechanisms behind upright stance control by means of a biologically based large-scale neuromusculoskeletal (NMS) model. It encompasses: i) conductance-based spinal neuron models (motor neurons and interneurons); ii) muscle proprioceptor models (spindle and Golgi tendon organ) providing sensory afferent feedback; iii) Hill-type muscle models of the leg plantar and dorsiflexors; and iv) an inverted pendulum model for the body biomechanics during upright stance. The motor neuron pools are driven by stochastic spike trains. Simulation results showed that the neuromechanical outputs generated by the NMS model resemble experimental data from subjects standing on a stable surface. Interesting findings were that: i) an intermittent pattern of muscle activation emerged from this posture control model for two of the leg muscles (Medial and Lateral Gastrocnemius); and ii) the Soleus muscle was mostly activated in a continuous manner. These results suggest that the spinal cord anatomy and neurophysiology (e.g., motor unit types, synaptic connectivities, ordered recruitment), along with the modulation of afferent activity, may account for the mixture of intermittent and continuous control that has been a subject of debate in recent studies on postural control. Another finding was the occurrence of the so-called "paradoxical" behaviour of muscle fibre lengths as a function of postural sway. The simulations confirmed previous conjectures that reciprocal inhibition is possibly contributing to this effect, but on the

  2. DEVELOPMENT PROBABILITY-LINGUISTIC MODELS VULNERABILITY ASSESSMENT OF AVIATION SECURITY IMPORTANT TECHNICAL FACILITIES

    National Research Council Canada - National Science Library

    2016-01-01

    ... are justified, and the assessment problem of the protected object vulnerability is formulated. The main advantage of the developed model is the extensive opportunities of formalization of diverse information on the security status of the object...

  3. Total liquid ventilation provides superior respiratory support to conventional mechanical ventilation in a large animal model of severe respiratory failure.

    Science.gov (United States)

    Pohlmann, Joshua R; Brant, David O; Daul, Morgan A; Reoma, Junewai L; Kim, Anne C; Osterholzer, Kathryn R; Johnson, Kent J; Bartlett, Robert H; Cook, Keith E; Hirschl, Ronald B

    2011-01-01

    Total liquid ventilation (TLV) has the potential to provide respiratory support superior to conventional mechanical ventilation (CMV) in the acute respiratory distress syndrome (ARDS). However, laboratory studies are limited to trials in small animals for no longer than 4 hours. The objective of this study was to compare TLV and CMV in a large animal model of ARDS for 24 hours. Ten sheep weighing 53 ± 4 (SD) kg were anesthetized and ventilated with 100% oxygen. Oleic acid was injected into the pulmonary circulation until PaO2:FiO2 ≤ 60 mm Hg, followed by transition to a protective CMV protocol (n = 5) or TLV (n = 5) for 24 hours. Pathophysiology was recorded, and the lungs were harvested for histological analysis. Animals treated with CMV became progressively hypoxic and hypercarbic despite maximum ventilatory support. Sheep treated with TLV maintained normal blood gases with statistically greater PO2 (p < 10(-9)) and lower PCO2 (p < 10(-3)) than the CMV group. Survival at 24 hours in the TLV and CMV groups were 100% and 40%, respectively (p < 0.05). Thus, TLV provided gas exchange superior to CMV in this laboratory model of severe ARDS.

  4. Human neural stem cells over-expressing VEGF provide neuroprotection, angiogenesis and functional recovery in mouse stroke model.

    Directory of Open Access Journals (Sweden)

    Hong J Lee

    Full Text Available BACKGROUND: Intracerebral hemorrhage (ICH is a lethal stroke type. As mortality approaches 50%, and current medical therapy against ICH shows only limited effectiveness, an alternative approach is required, such as stem cell-based cell therapy. Previously we have shown that intravenously transplanted human neural stem cells (NSCs selectively migrate to the brain and induce behavioral recovery in rat ICH model, and that combined administration of NSCs and vascular endothelial growth factor (VEGF results in improved structural and functional outcome from cerebral ischemia. METHODS AND FINDINGS: We postulated that human NSCs overexpressing VEGF transplanted into cerebral cortex overlying ICH lesion could provide improved survival of grafted NSCs, increased angiogenesis and behavioral recovery in mouse ICH model. ICH was induced in adult mice by unilateral injection of bacterial collagenase into striatum. HB1.F3.VEGF human NSC line produced an amount of VEGF four times higher than parental F3 cell line in vitro, and induced behavioral improvement and 2-3 fold increase in cell survival at two weeks and eight weeks post-transplantation. CONCLUSIONS: Brain transplantation of F3 human NSCs over-expressing VEGF near ICH lesion sites provided differentiation and survival of grafted human NSCs and renewed angiogenesis of host brain and functional recovery of ICH animals. These results suggest a possible application of the human neural stem cell line, which is genetically modified to over-express VEGF, as a therapeutic agent for ICH-stroke.

  5. DART: A Community Facility Providing State-of-the-Art, Efficient Ensemble Data Assimilation for Large (Coupled) Geophysical Models

    Science.gov (United States)

    Hoar, T. J.; Anderson, J. L.; Collins, N.; Kershaw, H.; Hendricks, J.; Raeder, K.; Mizzi, A. P.; Barré, J.; Gaubert, B.; Madaus, L. E.; Aydogdu, A.; Raeder, J.; Arango, H.; Moore, A. M.; Edwards, C. A.; Curchitser, E. N.; Escudier, R.; Dussin, R.; Bitz, C. M.; Zhang, Y. F.; Shrestha, P.; Rosolem, R.; Rahman, M.

    2016-12-01

    Strongly-coupled ensemble data assimilation with multiple high-resolution model components requires massive state vectors which need to be efficiently stored and accessed throughout the assimilation process. Supercomputer architectures are tending towards increasing the number of cores per node but have the same or less memory per node. Recent advances in the Data Assimilation Research Testbed (DART), a freely-available community ensemble data assimilation facility that works with dozens of large geophysical models, have addressed the need to run with a smaller memory footprint on a higher node count by utilizing MPI-2 one-sided communication to do non-blocking asynchronous access of distributed data. DART runs efficiently on many computational platforms ranging from laptops through thousands of cores on the newest supercomputers. Benefits of the new DART implementation will be shown. In addition, overviews of the most recently supported models will be presented: CAM-CHEM, WRF-CHEM, CM1, OpenGGCM, FESOM, ROMS, CICE5, TerrSysMP (COSMO, CLM, ParFlow), JULES, and CABLE. DART provides a comprehensive suite of software, documentation, and tutorials that can be used for ensemble data assimilation research, operations, and education. Scientists and software engineers at NCAR are available to support DART users who want to use existing DART products or develop their own applications. Current DART users range from university professors teaching data assimilation, to individual graduate students working with simple models, through national laboratories and state agencies doing operational prediction with large state-of-the-art models.

  6. A review of successful aging models: Proposing proactive coping as an important additional strategy

    NARCIS (Netherlands)

    Ouwehand, C.; Ridder, D.T.D. de; Bensing, J.

    2007-01-01

    Successful aging is an important concept, and one that has been the subject of much research. During the last 15 years, the emphasis of this research has shifted from formulating criteria for successful aging to describing the processes involved in successful aging. The main purpose of the present a

  7. A review of successful aging models: proposing proactive coping as an important additional strategy.

    NARCIS (Netherlands)

    Ouwehand, C.; Ridder, D.T.D. de; Bensing, J.M.

    2007-01-01

    Successful aging is an important concept, and one that has been the subject of much research. During the last 15 years, the emphasis of this research has shifted from formulating criteria for successful aging to describing the processes involved in successful aging. The main purpose of the present a

  8. On the importance of aerosol nitrate over Europe : data analysis and modelling

    NARCIS (Netherlands)

    Schaap, M.

    2003-01-01

    The central theme of this thesis is the nitrate content of aerosols (or particulate matter (PM)). Aerosols play an important role in the climate system by scattering and/or absorbing solar radiation. In the last decades research has been devoted to quantify the radiative forcing of aerosols on clima

  9. Tidal marsh susceptibility to sea-level rise: importance of local-scale models

    Science.gov (United States)

    Thorne, Karen M.; Buffington, Kevin J.; Elliott-Fisk, Deborah L.; Takekawa, John Y.

    2015-01-01

    Increasing concern over sea-level rise impacts to coastal tidal marsh ecosystems has led to modeling efforts to anticipate outcomes for resource management decision making. Few studies on the Pacific coast of North America have modeled sea-level rise marsh susceptibility at a scale relevant to local wildlife populations and plant communities. Here, we use a novel approach in developing an empirical sea-level rise ecological response model that can be applied to key management questions. Calculated elevation change over 13 y for a 324-ha portion of San Pablo Bay National Wildlife Refuge, California, USA, was used to represent local accretion and subsidence processes. Next, we coupled detailed plant community and elevation surveys with measured rates of inundation frequency to model marsh state changes to 2100. By grouping plant communities into low, mid, and high marsh habitats, we were able to assess wildlife species vulnerability and to better understand outcomes for habitat resiliency. Starting study-site conditions were comprised of 78% (253-ha) high marsh, 7% (30-ha) mid marsh, and 4% (18-ha) low marsh habitats, dominated by pickleweed Sarcocornia pacifica and cordgrass Spartina spp. Only under the low sea-level rise scenario (44 cm by 2100) did our models show persistence of some marsh habitats to 2100, with the area dominated by low marsh habitats. Under mid (93 cm by 2100) and high sea-level rise scenarios (166 cm by 2100), most mid and high marsh habitat was lost by 2070, with only 15% (65 ha) remaining, and a complete loss of these habitats by 2080. Low marsh habitat increased temporarily under all three sea-level rise scenarios, with the peak (286 ha) in 2070, adding habitat for the endemic endangered California Ridgway’s rail Rallus obsoletus obsoletus. Under mid and high sea-level rise scenarios, an almost complete conversion to mudflat occurred, with most of the area below mean sea level. Our modeling assumed no marsh migration upslope due to human

  10. Importance of a 3D forward modeling tool for surface wave analysis methods

    Science.gov (United States)

    Pageot, Damien; Le Feuvre, Mathieu; Donatienne, Leparoux; Philippe, Côte; Yann, Capdeville

    2016-04-01

    Since a few years, seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectiveness for sounding and monitoring purposes, e.g., high-resolution tomography of the principal geological units of California or real time monitoring of the Piton de la Fournaise volcano. Historically, these methods are mostly developed under the assumption of semi-infinite 1D layered medium without topography. The forward modeling is generally based on Thomson-Haskell matrix based modeling algorithm and the inversion is driven by Monte-Carlo sampling. Given their efficiency, SWM have been transfered to several scale of which civil engineering structures in order to, e.g., determine the so-called V s30 parameter or assess other critical constructional parameters in pavement engineering. However, at this scale, many structures may often exhibit 3D surface variations which drastically limit the efficiency of SWM application. Indeed, even in the case of an homogeneous structure, 3D geometry can bias the dispersion diagram of Rayleigh waves up to obtain discontinuous phase velocity curves which drastically impact the 1D mean velocity model obtained from dispersion inversion. Taking advantages of high-performance computing center accessibility and wave propagation modeling algorithm development, it is now possible to consider the use of a 3D elastic forward modeling algorithm instead of Thomson-Haskell method in the SWM inversion process. We use a parallelized 3D elastic modeling code based on the spectral element method which allows to obtain accurate synthetic data with very low numerical dispersion and a reasonable numerical cost. In this study, we choose dike embankments as an illustrative example. We first show that their longitudinal geometry may have a significant effect on dispersion diagrams of Rayleigh waves. Then, we demonstrate the necessity of 3D elastic modeling as a forward

  11. Carer and service providers' experiences of individual funding models for children with a disability in rural and remote areas.

    Science.gov (United States)

    Dew, Angela; Bulkeley, Kim; Veitch, Craig; Bundy, Anita; Lincoln, Michelle; Brentnall, Jennie; Gallego, Gisselle; Griffiths, Scott

    2013-07-01

    There is a global movement for people with a disability towards person-centred practices with opportunities for self-determination and choice. Person-centred approaches may involve individual funding (IF) for the purchase of required support. A shift to a person-centred model and IF should allow people with a disability and their carers greater choice in therapy access. However, individuals who live in rural and remote areas have less choice and access to therapy services than their metropolitan counterparts. Drawing on data from a larger study into therapy service delivery in a rural and remote area of New South Wales, Australia, this study describes some benefits and barriers to using IF to access therapy services in rural areas. Ten carers and 60 service providers participated in audio-recorded focus groups and individual interviews during which IF was discussed. Transcribed data were analysed using thematic analysis and constant comparison. Greater access to and choice of therapy providers were identified as benefits of IF. Four barriers were identified: (i) lack of information and advice; (ii) limited local service options and capacity; (iii) higher costs and fewer services and (iv) complexity of self-managing packages. A range of strategies is required to address the barriers to using IF in rural and remote areas. Carers indicated a need for: accessible information; a local contact person for support and guidance; adequate financial compensation to offset additional travel expenses and coordinated eligibility and accountability systems. Service providers required: coordinated cross-sector approaches; local workforce planning to address therapist shortages; certainty around service viability and growth; clear policies and procedures around implementation of IF. This study highlights the need for further discussion and research about how to overcome the barriers to the optimal use of an IF model for those living in rural and remote areas. © 2013 John Wiley

  12. Providing competency-based family medicine residency training in substance abuse in the new millennium: a model curriculum

    Directory of Open Access Journals (Sweden)

    Shellenberger Sylvia

    2010-05-01

    Full Text Available Abstract Background This article, developed for the Betty Ford Institute Consensus Conference on Graduate Medical Education (December, 2008, presents a model curriculum for Family Medicine residency training in substance abuse. Methods The authors reviewed reports of past Family Medicine curriculum development efforts, previously-identified barriers to education in high risk substance use, approaches to overcoming these barriers, and current training guidelines of the Accreditation Council for Graduate Medical Education (ACGME and their Family Medicine Residency Review Committee. A proposed eight-module curriculum was developed, based on substance abuse competencies defined by Project MAINSTREAM and linked to core competencies defined by the ACGME. The curriculum provides basic training in high risk substance use to all residents, while also addressing current training challenges presented by U.S. work hour regulations, increasing international diversity of Family Medicine resident trainees, and emerging new primary care practice models. Results This paper offers a core curriculum, focused on screening, brief intervention and referral to treatment, which can be adapted by residency programs to meet their individual needs. The curriculum encourages direct observation of residents to ensure that core skills are learned and trains residents with several "new skills" that will expand the basket of substance abuse services they will be equipped to provide as they enter practice. Conclusions Broad-based implementation of a comprehensive Family Medicine residency curriculum should increase the ability of family physicians to provide basic substance abuse services in a primary care context. Such efforts should be coupled with faculty development initiatives which ensure that sufficient trained faculty are available to teach these concepts and with efforts by major Family Medicine organizations to implement and enforce residency requirements for

  13. Examining the Support Peer Supporters Provide Using Structural Equation Modeling: Nondirective and Directive Support in Diabetes Management.

    Science.gov (United States)

    Kowitt, Sarah D; Ayala, Guadalupe X; Cherrington, Andrea L; Horton, Lucy A; Safford, Monika M; Soto, Sandra; Tang, Tricia S; Fisher, Edwin B

    2017-04-17

    Little research has examined the characteristics of peer support. Pertinent to such examination may be characteristics such as the distinction between nondirective support (accepting recipients' feelings and cooperative with their plans) and directive (prescribing "correct" choices and feelings). In a peer support program for individuals with diabetes, this study examined (a) whether the distinction between nondirective and directive support was reflected in participants' ratings of support provided by peer supporters and (b) how nondirective and directive support were related to depressive symptoms, diabetes distress, and Hemoglobin A1c (HbA1c). Three hundred fourteen participants with type 2 diabetes provided data on depressive symptoms, diabetes distress, and HbA1c before and after a diabetes management intervention delivered by peer supporters. At post-intervention, participants reported how the support provided by peer supporters was nondirective or directive. Confirmatory factor analysis (CFA), correlation analyses, and structural equation modeling examined the relationships among reports of nondirective and directive support, depressive symptoms, diabetes distress, and measured HbA1c. CFA confirmed the factor structure distinguishing between nondirective and directive support in participants' reports of support delivered by peer supporters. Controlling for demographic factors, baseline clinical values, and site, structural equation models indicated that at post-intervention, participants' reports of nondirective support were significantly associated with lower, while reports of directive support were significantly associated with greater depressive symptoms, altogether (with control variables) accounting for 51% of the variance in depressive symptoms. Peer supporters' nondirective support was associated with lower, but directive support was associated with greater depressive symptoms.

  14. Xenon and sevoflurane provide analgesia during labor and fetal brain protection in a perinatal rat model of hypoxia-ischemia.

    Directory of Open Access Journals (Sweden)

    Ting Yang

    Full Text Available It is not possible to identify all pregnancies at risk of neonatal hypoxic-ischemic encephalopathy (HIE. Many women use some form of analgesia during childbirth and some anesthetic agents have been shown to be neuroprotective when used as analgesics at subanesthetic concentrations. In this study we sought to understand the effects of two anesthetic agents with presumptive analgesic activity and known preconditioning-neuroprotective properties (sevoflurane or xenon, in reducing hypoxia-induced brain damage in a model of intrauterine perinatal asphyxia. The analgesic and neuroprotective effects at subanesthetic levels of sevoflurane (0.35% or xenon (35% were tested in a rat model of intrauterine perinatal asphyxia. Analgesic effects were measured by assessing maternal behavior and spinal cord dorsal horn neuronal activation using c-Fos. In separate experiments, intrauterine fetal asphyxia was induced four hours after gas exposure; on post-insult day 3 apoptotic cell death was measured by caspase-3 immunostaining in hippocampal neurons and correlated with the number of viable neurons on postnatal day (PND 7. A separate cohort of pups was nurtured by a surrogate mother for 50 days when cognitive testing with Morris water maze was performed. Both anesthetic agents provided analgesia as reflected by a reduction in the number of stretching movements and decreased c-Fos expression in the dorsal horn of the spinal cord. Both agents also reduced the number of caspase-3 positive (apoptotic neurons and increased cell viability in the hippocampus at PND7. These acute histological changes were mirrored by improved cognitive function measured remotely after birth on PND 50 compared to control group. Subanesthetic doses of sevoflurane or xenon provided both analgesia and neuroprotection in this model of intrauterine perinatal asphyxia. These data suggest that anesthetic agents with neuroprotective properties may be effective in preventing HIE and should be

  15. Improvement of AEP Predictions Using Diurnal CFD Modelling with Site-Specific Stability Weightings Provided from Mesoscale Simulation

    Science.gov (United States)

    Hristov, Y.; Oxley, G.; Žagar, M.

    2014-06-01

    The Bolund measurement campaign, performed by Danish Technical University (DTU) Wind Energy Department (also known as RISØ), provided significant insight into wind flow modeling over complex terrain. In the blind comparison study several modelling solutions were submitted with the vast majority being steady-state Computational Fluid Dynamics (CFD) approaches with two equation k-epsilon turbulence closure. This approach yielded the most accurate results, and was identified as the state-of-the-art tool for wind turbine generator (WTG) micro-siting. Based on the findings from Bolund, further comparison between CFD and field measurement data has been deemed essential in order to improve simulation accuracy for turbine load and long-term Annual Energy Production (AEP) estimations. Vestas Wind Systems A/S is a major WTG original equipment manufacturer (OEM) with an installed base of over 60GW in over 70 countries accounting for 19% of the global installed base. The Vestas Performance and Diagnostic Centre (VPDC) provides online live data to more than 47GW of these turbines allowing a comprehensive comparison between modelled and real-world energy production data. In previous studies, multiple sites have been simulated with a steady neutral CFD formulation for the atmospheric surface layer (ASL), and wind resource (RSF) files have been generated as a base for long-term AEP predictions showing significant improvement over predictions performed with the industry standard linear WAsP tool. In this study, further improvements to the wind resource file generation with CFD are examined using an unsteady diurnal cycle approach with a full atmospheric boundary layer (ABL) formulation, with the unique stratifications throughout the cycle weighted according to mesoscale simulated sectorwise stability frequencies.

  16. Reply to Comment on "Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model"

    Energy Technology Data Exchange (ETDEWEB)

    Roth, R; Navratil, P

    2008-01-04

    In their comment on our recent Letter [1] Dean et al. [2] criticize the calculations for the ground-state energy of {sup 40}Ca within the importance truncated no-core shell model (NCSM). In particular they address the role of configurations beyond the 3p3h level, which have not been included in the {sup 40}Ca calculations for large N{sub max} {h_bar}{Omega} model spaces. Before responding to this point, the following general statements are in order. For the atomic nucleus as a self-bound system, translational invariance is an important symmetry. The only possibility to preserve translational invariance when working with a Slater determinant basis is to use the harmonic oscillator (HO) basis in conjunction with a basis truncation according to the total HO excitation energy, i.e. N{sub max} {h_bar}{Omega}, as done in the ab initio NCSM. This is important not only for obtaining proper binding or excitation energies, but also for a correct extraction of physical wavefunctions. The spurious center-of-mass components can be exactly removed only if the HO basis and the N{sub max} {h_bar}{Omega} truncation are employed. The minimal violation of the translational invariance was one of the main motivations for developing the importance-truncation scheme introduced in the Letter. In this scheme, we start with the complete N{sub max} {h_bar}{Omega} HO basis space and select important configurations via perturbation theory. All symmetries are under control and our importance-truncated NCSM calculations are completely variational and provide an upper bound of the ground-state energy of the system. The restriction to the 3p3h level, made for computational reasons in the N{sub max} > 8 calculations for {sup 40}Ca, is not inherent to the importance truncation scheme. The explicit inclusion of 4p4h configurations--though computationally more demanding--is straight-forward, even for the largest N{sub max} {h_bar}{Omega} model spaces discussed. To demonstrate this fact we have

  17. Mathematical modeling of drying of potato slices in a forced convective dryer based on important parameters.

    Science.gov (United States)

    Naderinezhad, Samira; Etesami, Nasrin; Poormalek Najafabady, Arefe; Ghasemi Falavarjani, Majid

    2016-01-01

    The effect of air temperature, air velocity, and sample shapes (circle and square with the same cross-sectional area) on kinetic drying of potato slices in a tunnel dryer was investigated experimentally and a suitable drying model was developed. The experiments of drying of potato slices were conducted at an air temperature of 45-70°C with an air velocity 1.60 and 1.81 m sec(-1). Results showed that drying temperature was the most effective parameter in the drying rate. The influence of air velocity was more profound in low temperature. The time for drying square slices was lower compared to the circle ones. Furthermore, drying data were fitted to different empirical models. Among the models, Midilli-Kucuk was the best to explain the single layer drying of potato slices. The parameters of this model were determined as functions of air velocity and temperature by multiple regression analysis for circle and square slices. Various statistical parameters were examined for evaluating the model.

  18. On the importance of modelling the internal spatial dynamics of biological cells.

    Science.gov (United States)

    Sayyid, Faiz; Kalvala, Sara

    2016-07-01

    Spatial effects such as cell shape have very often been considered negligible in models of cellular pathways, and many existing simulation infrastructures do not take such effects into consideration. Recent experimental results are reversing this judgement by showing that very small spatial variations can make a big difference in the fate of a cell. This is particularly the case when considering eukaryotic cells, which have a complex physical structure and many subtle control mechanisms, but bacteria are also interesting for the huge variation in shape both between species and in different phases of their lifecycle. In this work we perform simulations that measure the effect of three common bacterial shapes on the behaviour of model cellular pathways. To perform these experiments we develop ReDi-Cell, a highly scalable GPGPU cell simulation infrastructure for the modelling of cellular pathways in spatially detailed environments. ReDi-Cell is validated against known-good simulations, prior to its use in new work. We then use ReDi-Cell to conduct novel experiments that demonstrate the effect that three common bacterial shapes (Cocci, Bacilli and Spirilli) have on the behaviour of model cellular pathways. Pathway wavefront shape, pathway concentration gradients, and chemical species distribution are measured in the three different shapes. We also quantify the impact of internal cellular clutter on the same pathways. Through this work we show that variations in the shape or configuration of these common cell shapes alter model cell behaviour.

  19. A Novel Protocol to Differentiate Induced Pluripotent Stem Cells by Neuronal microRNAs to Provide a Suitable Cellular Model.

    Science.gov (United States)

    Zare, Mehrak; Soleimani, Masoud; Akbarzadeh, Abolfazl; Bakhshandeh, Behnaz; Aghaee-Bakhtiari, Seyed Hamid; Zarghami, Nosratollah

    2015-08-01

    Neurodegenerative diseases are one of the most challenging subjects in medicine. Investigation of their underlying genetic or epigenetic factors is hampered by lack of suitable models. Patient-specific induced pluripotent stem cells (iPS cells) represent a valuable approach to provide a proper model for poorly understood mechanisms of neuronal diseases and the related drug screenings. miR-124 and miR-128 are the two brain-enriched miRNAs with different time-points of expression during neuronal development. Herein, we transduced human iPS cells with miR-124 and miR-128 harboring lentiviruses sequentially. The transduced plasmids contained GFP and puromycin antibiotic-resistant genes for easier selection and identification. Morphological assessment and immunocytochemistry (overexpressions of beta-tubulin and neuron-specific enolase) confirmed that induced hiPS cells by miR-124 and miR-128 represent similar characteristics to those of mature neurons. In addition, the upregulation of neuron-specific enolase, beta-tubulin, Map2, GFAP, and BDNF was detected by quantitative real-time PCR. In conclusion, it seems that our novel protocol remarks the combinatorial effect of miR-124 and miR-128 on neural differentiation in the absence of any extrinsic factor. Moreover, such cellular models could be used in personalized drug screening and applied for more effective therapies.

  20. THE MODEL OF PREVENTION OF VANDAL BEHAVIOR PROVIDED BY THE DEFORMATIONS AND DESTRUCTIONS OF VALUABLE SPHERE OF YOUTH

    Directory of Open Access Journals (Sweden)

    Irina V. Vorobyeva

    2015-01-01

    model involves personal values that are considered as a dynamic system. Fundamentally new approach to prevention interventions is realised: the model focuses not so much on sanctions actions as on technologies of psychological influences on the problem personality; and formation of steady prosocial strategy of person’s behaviour. Practical significance. The research findings and the application of the proposed model can be useful while planning of educative work in terms of educational institutions by the teachers, administrators and parents, as it provides the possibility to organize selective and point events to prevent destructive behavior of pupils and students, taking into account the characteristics of their value and the scope of actual problems in the manifestation of activity.  

  1. Important issues facing model-based approaches to tunneling transport in molecular junctions

    CERN Document Server

    Baldea, Ioan

    2015-01-01

    Extensive studies on thin films indicated a generic cubic current-voltage $I-V$ dependence as a salient feature of charge transport by tunneling. A quick glance at $I-V$ data for molecular junctions suggests a qualitatively similar behavior. This would render model-based studies almost irrelevant, since, whatever the model, its parameters can always be adjusted to fit symmetric (asymmetric) $I-V$ curves characterized by two (three) expansion coefficients. Here, we systematically examine popular models based on tunneling barrier or tight-binding pictures and demonstrate that, for a quantitative description at biases of interest ($V$ slightly higher than the transition voltage $V_t$), cubic expansions do not suffice. A detailed collection of analytical formulae as well as their conditions of applicability are presented to facilitate experimentalists colleagues to process and interpret their experimental data by obtained by measuring currents in molecular junctions. We discuss in detail the limits of applicabili...

  2. On the importance of observational data properties when assessing regional climate model performance of extreme precipitation

    DEFF Research Database (Denmark)

    Sunyer Pinya, Maria Antonia; Sørup, Hjalte Jomo Danielsen; Christensen, Ole Bøssing

    2013-01-01

    In recent years, there has been an increase in the number of climate studies addressing changes in extreme precipitation. A common step in these studies involves the assessment of the climate model performance. This is often measured by comparing climate model output with observational data....... In the majority of such studies the characteristics and uncertainties of the observational data are neglected. This study addresses the influence of using different observational datasets to assess the climate model performance. Four different datasets covering Denmark using different gauge systems and comprising...... both networks of point measurements and gridded datasets are considered. Additionally, the influence of using different performance indices and metrics is addressed. A set of indices ranging from mean to extreme precipitation properties is calculated for all the datasets. For each of the observational...

  3. Mathematical modelling of methanogenic reactor start-up: Importance of volatile fatty acids degrading population.

    Science.gov (United States)

    Jabłoński, Sławomir J; Łukaszewicz, Marcin

    2014-12-01

    Development of balanced community of microorganisms is one of the obligatory for stable anaerobic digestion. Application of mathematical models might be helpful in development of reliable procedures during the process start-up period. Yet, the accuracy of forecast depends on the quality of input and parameters. In this study, the specific anaerobic activity (SAA) tests were applied in order to estimate microbial community structure. Obtained data was applied as input conditions for mathematical model of anaerobic digestion. The initial values of variables describing the amount of acetate and propionate utilizing microorganisms could be calculated on the basis of SAA results. The modelling based on those optimized variables could successfully reproduce the behavior of a real system during the continuous fermentation.

  4. Modified release itraconazole amorphous solid dispersion to treat Aspergillus fumigatus: importance of the animal model selection.

    Science.gov (United States)

    Maincent, Julien P; Najvar, Laura K; Kirkpatrick, William R; Huang, Siyuan; Patterson, Thomas F; Wiederhold, Nathan P; Peters, Jay I; Williams, Robert O

    2017-02-01

    Previously, modified release itraconazole in the form of a melt-extruded amorphous solid dispersion based on a pH dependent enteric polymer combined with hydrophilic additives (HME-ITZ), exhibited improved in vitro dissolution properties. These properties agreed with pharmacokinetic results in rats showing high and sustained itraconazole (ITZ) systemic levels. The objective of the present study was to better understand the best choice of rodent model for evaluating the pharmacokinetic and efficacy of this orally administered modified release ITZ dosage form against invasive Aspergillus fumigatus. A mouse model and a guinea pig model were investigated and compared to results previously published. In the mouse model, despite similar levels as previously reported values, plasma and lung levels were variable and fungal burden was not statistically different for placebo controls, HME-ITZ and Sporanox(®) (ITZ oral solution). This study demonstrated that the mouse model is a poor choice for studying modified release ITZ dosage forms based on pH dependent enteric polymers due to low fluid volume available for dissolution and low intestinal pH. To the contrary, guinea pig was a suitable model to evaluate modified release ITZ dosage forms. Indeed, a significant decrease in lung fungal burden as a result of high and sustained ITZ tissue levels was measured. Sufficiently high intestinal pH and fluids available for dissolution likely facilitated the dissolution process. Despite high ITZ tissue level, the primary therapeutic agent voriconazole exhibited an even more pronounced decrease in fungal burden due to its reported higher clinical efficacy specifically against Aspergillus fumigatus.

  5. The iconographic model of the Minerva from Collippo and its historic importance

    Directory of Open Access Journals (Sweden)

    Virgílio Hipólito Correia

    2014-12-01

    Full Text Available A statue head representing Minerva from the ancient Collippo (S. Sebastião do Freixo, Batalha is studied and its iconographic model is identified in a similar piece from the temple of Apollo Sosianus in Rome; other pieces of the same model are identified.It is proposed that this piece represents a remain of an intervention in the forum of the ancient town probably dating from the Claudio‑neronian period and its relation to similar processes occurring in the capital of the province of Lusitania is discussed.http://dx.doi.org/10.14195/2183-1718_66_16

  6. DIAGNOSIS IMPORTANCE OF RURAL DEVELOPMENT OF A MODEL AGROFORESTAL IN PEASANT COMMUNITIES OF SIERRA DE HUAUTLA

    OpenAIRE

    Miguel Uribe-Gómez; Artemio Cruz-León; Dionicio Juárez-Ramón; Alejandro Lara-Bueno; José L. Romo-Lozano; Ramón Valdivia-Alcalá; Marcos Portillo-Vázquez

    2015-01-01

    Family agricultural is socioeconomically important in rural areas, but in Mexico, from the 80's this production system presents social stagnation. This type of agriculture presents a dynamic reality in the interests of each producer and limiting access to factors of production (land, labor and capital). In this investigation a methodology for analysis and diagnosis of production systems in rural areas, in two communities in the Country Sierra de Huautla Tepalcingo, Morelos, Mexico was applied...

  7. Immunization with lipopolysaccharide-deficient whole cells provides protective immunity in an experimental mouse model of Acinetobacter baumannii infection.

    Science.gov (United States)

    García-Quintanilla, Meritxell; Pulido, Marina R; Pachón, Jerónimo; McConnell, Michael J

    2014-01-01

    The increasing clinical importance of infections caused by multidrug resistant Acinetobacter baumannii warrants the development of novel approaches for prevention and treatment. In this context, vaccination of certain patient populations may contribute to reducing the morbidity and mortality caused by this pathogen. Vaccines against Gram-negative bacteria based on inactivated bacterial cells are highly immunogenic and have been shown to produce protective immunity against a number of bacterial species. However, the high endotoxin levels present in these vaccines due to the presence of lipopolysaccharide complicates their use in human vaccination. In the present study, we used a laboratory-derived strain of A. baumannii that completely lacks lipopolysaccharide due to a mutation in the lpxD gene (IB010), one of the genes involved in the first steps of lipopolysaccharide biosynthesis, for vaccination. We demonstrate that IB010 has greatly reduced endotoxin content (infection tissue bacterial loads and significantly lower serum levels of the pro-inflammatory cytokines IL-1β, TNF-α and IL-6 compared to control mice in a mouse model of disseminated A. baumannii infection. Importantly, immunized mice were protected from infection with the ATCC 19606 strain and an A. baumannii clinical isolate. These data suggest that immunization with inactivated A. baumannii whole cells deficient in lipopolysaccharide could serve as the basis for a vaccine for the prevention of infection caused by A. baumannii.

  8. Modeling the effects of chemical exposure on avian seasonal productivity: Importance of differences in breeding strategies

    Science.gov (United States)

    Agencies that regulate the use of chemicals are increasingly interested in understanding the magnitude of effects of those chemicals on wildlife populations. While laboratory toxicity tests provide insights into the types of effects caused by chemical exposure, they do not alway...

  9. Comparison of expert modeling versus voice-over PowerPoint lecture and presimulation readings on novice nurses' competence of providing care to multiple patients.

    Science.gov (United States)

    Franklin, Ashley E; Sideras, Stephanie; Gubrud-Howe, Paula; Lee, Christopher S

    2014-11-01

    Due to today's complex needs of hospitalized patients, nurses' competence and strategies to improve competence are of growing importance. Simulation is commonly used to influence competence, but little evidence exists for comparing how presimulation assignments influence competence. A randomized control trial was used to compare the efficacy of three simulation preparation methods (expert modeling/intervention, voice-over PowerPoint/active control, and reading assignments/passive control) on improving competence for providing care to multiple patients among senior undergraduate novice nurses. Competence was measured at two time points (baseline and following a 5-week intervention) by two blinded raters using the Creighton Simulation Evaluation Instrument. Twenty novice nurses participated in the trial. No significant differences were noted in raw improvements in competence among the three groups, but the expert modeling (Cohen's d=0.413) and voice-over PowerPoint methods (Cohen's d=0.226) resulted in greater improvements in competence, compared with the passive control.

  10. Important Physiological Parameters and Physical Activity Data for Evaluating Exposure Modeling Performance: a Synthesis

    Science.gov (United States)

    The purpose of this report is to develop a database of physiological parameters needed for understanding and evaluating performance of the APEX and SHEDS exposure/intake dose rate model used by the Environmental Protection Agency (EPA) as part of its regulatory activities. The A...

  11. An Ecological Risk Model for Early Childhood Anxiety: The Importance of Early Child Symptoms and Temperament

    Science.gov (United States)

    Mian, Nicholas D.; Wainwright, Laurel; Briggs-Gowan, Margaret J.; Carter, Alice S.

    2011-01-01

    Childhood anxiety is impairing and associated with later emotional disorders. Studying risk factors for child anxiety may allow earlier identification of at-risk children for prevention efforts. This study applied an ecological risk model to address how early childhood anxiety symptoms, child temperament, maternal anxiety and depression symptoms,…

  12. Numerical considerations for Lagrangian stochastic dispersion models: Eliminating rogue trajectories, and the importance of numerical accuracy

    Science.gov (United States)

    When Lagrangian stochastic models for turbulent dispersion are applied to complex flows, some type of ad hoc intervention is almost always necessary to eliminate unphysical behavior in the numerical solution. This paper discusses numerical considerations when solving the Langevin-based particle velo...

  13. Importance of interfaces in governing thermal transport in composite materials: modeling and experimental perspectives.

    Science.gov (United States)

    Roy, Ajit K; Farmer, Barry L; Varshney, Vikas; Sihn, Sangwook; Lee, Jonghoon; Ganguli, Sabyasachi

    2012-02-01

    Thermal management in polymeric composite materials has become increasingly critical in the air-vehicle industry because of the increasing thermal load in small-scale composite devices extensively used in electronics and aerospace systems. The thermal transport phenomenon in these small-scale heterogeneous systems is essentially controlled by the interface thermal resistance because of the large surface-to-volume ratio. In this review article, several modeling strategies are discussed for different length scales, complemented by our experimental efforts to tailor the thermal transport properties of polymeric composite materials. Progress in the molecular modeling of thermal transport in thermosets is reviewed along with a discussion on the interface thermal resistance between functionalized carbon nanotube and epoxy resin systems. For the thermal transport in fiber-reinforced composites, various micromechanics-based analytical and numerical modeling schemes are reviewed in predicting the transverse thermal conductivity. Numerical schemes used to realize and scale the interface thermal resistance and the finite mean free path of the energy carrier in the mesoscale are discussed in the frame of the lattice Boltzmann-Peierls-Callaway equation. Finally, guided by modeling, complementary experimental efforts are discussed for exfoliated graphite and vertically aligned nanotubes based composites toward improving their effective thermal conductivity by tailoring interface thermal resistance.

  14. Comparing Modeled and Measured Mercury Speciation in Contaminated Groundwater: Importance of Dissolved Organic Matter Composition.

    Science.gov (United States)

    Richard, Jan-Helge; Bischoff, Cornelia; Biester, Harald

    2016-07-19

    In addition to analytical speciation, reliable Hg species modeling is crucial for predicting the mobility and toxicity of Hg, but geochemical speciation codes have not yet been tested for their prediction accuracy. Our study compares analyses of Hg species in highly Hg-contaminated groundwater (Hgtot: 0.02-4 μmol·L(-1)) at three sites with predictions of Hg speciation obtained from three geochemical codes (WHAM, Visual MINTEQ, PHREEQC) with and without implementation of Hg complexation by dissolved organic matter (DOM). Samples were analyzed for chemical composition, elemental, inorganic, and DOM-bound Hg (Hg(0), Hginorg, HgDOM). Hg-DOM complexation was modeled using three approaches: binding to humic/fulvic acids, binding to thiol-groups, or a combination of both. Results of Hg(0) modeling were poor in all scenarios. Prediction accuracy for Hginorg and HgDOM strongly depended on the assumed DOM composition. Best results were achieved when weaker binding sites, simulated by WHAMs DOM submodel, were combined with strongly binding thiol groups. Indications were found that thiol-DOM ratios in groundwater are likely to be lower than in surface water, highlighting the need for analytical thiol quantification in groundwater DOM. This study shows that DOM quality is a crucial parameter for prediction of Hg speciation in groundwater by means of geochemical modeling.

  15. Importance of cytochromes in cyclization reactions: quantum chemical study on a model reaction of proguanil to cycloguanil.

    Science.gov (United States)

    Arfeen, Minhajul; Patel, Dhilon S; Abbat, Sheenu; Taxak, Nikhil; Bharatam, Prasad V

    2014-10-30

    Proguanil, an anti-malarial prodrug, undergoes cytochrome P450 catalyzed biotransformation to the pharmacologically active triazine metabolite (cycloguanil), which inhibits plasmodial dihydrofolate reductase. This cyclization is catalyzed by CYP2C19 and many anti-malarial lead compounds are being designed and synthesized to exploit this pathway. Quantum chemical calculations were performed using the model species (Cpd I for active species of cytochrome and N4-isopropyl-N6-methylbiguanide for proguanil) to elucidate the mechanism of the cyclization pathway. The overall reaction involves the loss of a water molecule, and is exothermic by approximately 55 kcal/mol, and involves a barrier of approximately 17 kcal/mol. The plausible reaction pathway involves the initial H-radical abstraction from the isopropyl group by Cpd I, followed by two alternative paths- (i) oxygen rebound to provide hydroxyl derivative and (ii) loss of additional H-radical to yield 1,3,5-triazatriene, which undergoes cyclization. This study helped in understanding the role of the active species of cytochromes in this important cyclization reaction. Copyright © 2014 Wiley Periodicals, Inc.

  16. On the importance of measurement error correlations in data assimilation for integrated hydrological models

    Science.gov (United States)

    Camporese, Matteo; Botto, Anna

    2017-04-01

    Data assimilation is becoming increasingly popular in hydrological and earth system modeling, as it allows us to integrate multisource observation data in modeling predictions and, in doing so, to reduce uncertainty. For this reason, data assimilation has been recently the focus of much attention also for physically-based integrated hydrological models, whereby multiple terrestrial compartments (e.g., snow cover, surface water, groundwater) are solved simultaneously, in an attempt to tackle environmental problems in a holistic approach. Recent examples include the joint assimilation of water table, soil moisture, and river discharge measurements in catchment models of coupled surface-subsurface flow using the ensemble Kalman filter (EnKF). One of the typical assumptions in these studies is that the measurement errors are uncorrelated, whereas in certain situations it is reasonable to believe that some degree of correlation occurs, due for example to the fact that a pair of sensors share the same soil type. The goal of this study is to show if and how the measurement error correlations between different observation data play a significant role on assimilation results in a real-world application of an integrated hydrological model. The model CATHY (CATchment HYdrology) is applied to reproduce the hydrological dynamics observed in an experimental hillslope. The physical model, located in the Department of Civil, Environmental and Architectural Engineering of the University of Padova (Italy), consists of a reinforced concrete box containing a soil prism with maximum height of 3.5 m, length of 6 m, and width of 2 m. The hillslope is equipped with sensors to monitor the pressure head and soil moisture responses to a series of generated rainfall events applied onto a 60 cm thick sand layer overlying a sandy clay soil. The measurement network is completed by two tipping bucket flow gages to measure the two components (subsurface and surface) of the outflow. By collecting

  17. A new glucocerebrosidase-deficient neuronal cell model provides a tool to probe pathophysiology and therapeutics for Gaucher disease.

    Science.gov (United States)

    Westbroek, Wendy; Nguyen, Matthew; Siebert, Marina; Lindstrom, Taylor; Burnett, Robert A; Aflaki, Elma; Jung, Olive; Tamargo, Rafael; Rodriguez-Gil, Jorge L; Acosta, Walter; Hendrix, An; Behre, Bahafta; Tayebi, Nahid; Fujiwara, Hideji; Sidhu, Rohini; Renvoise, Benoit; Ginns, Edward I; Dutra, Amalia; Pak, Evgenia; Cramer, Carole; Ory, Daniel S; Pavan, William J; Sidransky, Ellen

    2016-07-01

    Glucocerebrosidase is a lysosomal hydrolase involved in the breakdown of glucosylceramide. Gaucher disease, a recessive lysosomal storage disorder, is caused by mutations in the gene GBA1 Dysfunctional glucocerebrosidase leads to accumulation of glucosylceramide and glycosylsphingosine in various cell types and organs. Mutations in GBA1 are also a common genetic risk factor for Parkinson disease and related synucleinopathies. In recent years, research on the pathophysiology of Gaucher disease, the molecular link between Gaucher and Parkinson disease, and novel therapeutics, have accelerated the need for relevant cell models with GBA1 mutations. Although induced pluripotent stem cells, primary rodent neurons, and transfected neuroblastoma cell lines have been used to study the effect of glucocerebrosidase deficiency on neuronal function, these models have limitations because of challenges in culturing and propagating the cells, low yield, and the introduction of exogenous mutant GBA1 To address some of these difficulties, we established a high yield, easy-to-culture mouse neuronal cell model with nearly complete glucocerebrosidase deficiency representative of Gaucher disease. We successfully immortalized cortical neurons from embryonic null allele gba(-/-) mice and the control littermate (gba(+/+)) by infecting differentiated primary cortical neurons in culture with an EF1α-SV40T lentivirus. Immortalized gba(-/-) neurons lack glucocerebrosidase protein and enzyme activity, and exhibit a dramatic increase in glucosylceramide and glucosylsphingosine accumulation, enlarged lysosomes, and an impaired ATP-dependent calcium-influx response; these phenotypical characteristics were absent in gba(+/+) neurons. This null allele gba(-/-) mouse neuronal model provides a much-needed tool to study the pathophysiology of Gaucher disease and to evaluate new therapies. © 2016. Published by The Company of Biologists Ltd.

  18. A new glucocerebrosidase-deficient neuronal cell model provides a tool to probe pathophysiology and therapeutics for Gaucher disease

    Directory of Open Access Journals (Sweden)

    Wendy Westbroek

    2016-07-01

    Full Text Available Glucocerebrosidase is a lysosomal hydrolase involved in the breakdown of glucosylceramide. Gaucher disease, a recessive lysosomal storage disorder, is caused by mutations in the gene GBA1. Dysfunctional glucocerebrosidase leads to accumulation of glucosylceramide and glycosylsphingosine in various cell types and organs. Mutations in GBA1 are also a common genetic risk factor for Parkinson disease and related synucleinopathies. In recent years, research on the pathophysiology of Gaucher disease, the molecular link between Gaucher and Parkinson disease, and novel therapeutics, have accelerated the need for relevant cell models with GBA1 mutations. Although induced pluripotent stem cells, primary rodent neurons, and transfected neuroblastoma cell lines have been used to study the effect of glucocerebrosidase deficiency on neuronal function, these models have limitations because of challenges in culturing and propagating the cells, low yield, and the introduction of exogenous mutant GBA1. To address some of these difficulties, we established a high yield, easy-to-culture mouse neuronal cell model with nearly complete glucocerebrosidase deficiency representative of Gaucher disease. We successfully immortalized cortical neurons from embryonic null allele gba−/− mice and the control littermate (gba+/+ by infecting differentiated primary cortical neurons in culture with an EF1α-SV40T lentivirus. Immortalized gba−/− neurons lack glucocerebrosidase protein and enzyme activity, and exhibit a dramatic increase in glucosylceramide and glucosylsphingosine accumulation, enlarged lysosomes, and an impaired ATP-dependent calcium-influx response; these phenotypical characteristics were absent in gba+/+ neurons. This null allele gba−/− mouse neuronal model provides a much-needed tool to study the pathophysiology of Gaucher disease and to evaluate new therapies.

  19. A 3D porous media liver lobule model: the importance of vascular septa and anisotropic permeability for homogeneous perfusion.

    Science.gov (United States)

    Debbaut, Charlotte; Vierendeels, Jan; Siggers, Jennifer H; Repetto, Rodolfo; Monbaliu, Diethard; Segers, Patrick

    2014-01-01

    The hepatic blood circulation is complex, particularly at the microcirculatory level. Previously, 2D liver lobule models using porous media and a 3D model using real sinusoidal geometries have been developed. We extended these models to investigate the role of vascular septa (VS) and anisotropic permeability. The lobule was modelled as a hexagonal prism (with or without VS) and the tissue was treated as a porous medium (isotropic or anisotropic permeability). Models were solved using computational fluid dynamics. VS inclusion resulted in more spatially homogeneous perfusion. Anisotropic permeability resulted in a larger axial velocity component than isotropic permeability. A parameter study revealed that results are most sensitive to the lobule size and radial pressure drop. Our model provides insight into hepatic microhaemodynamics, and suggests that inclusion of VS in the model leads to perfusion patterns that are likely to reflect physiological reality. The model has potential for applications to unphysiological and pathological conditions.

  20. The Hispanic Clinic for Pediatric Surgery: A model to improve parent-provider communication for Hispanic pediatric surgery patients.

    Science.gov (United States)

    Jaramillo, Joshua; Snyder, Elizabeth; Dunlap, Jonathan L; Wright, Robert; Mendoza, Fernando; Bruzoni, Matias

    2016-04-01

    26 million Americans have limited English proficiency (LEP). It is well established that language barriers adversely affect health and health care. Despite growing awareness of language barriers, there is essentially a void in the medical literature regarding the influence of language disparity on pediatric surgery patients. This study was designed to assess the impact of patient-provider language concordance on question-asking behavior and patient satisfaction for pediatric surgery patients. Participants included families of patients in a General Pediatric Surgery Clinic categorized into 3 groups by patient-provider language concordance: concordant English-speaking, LEP concordant Spanish-speaking, and LEP discordant Spanish-speaking using an interpreter. Clinical visits were audio recorded and the number of patient-initiated questions and the length of clinical encounter were measured. Families were administered a surgery-specific, 5-point Likert scale questionnaire modeled after validated surveys concerning communication, trust, perceived discrimination and patient-provider language concordance. Regression models were performed to analyze associations between language concordance and patient's question-asking behavior and between language concordance and survey results. A total of 156 participants were enrolled including 57 concordant-English, 52 LEP concordant-Spanish and 47 LEP-discordant-Spanish. There was significant variation in the mean number of patient-initiated questions among the groups (p=0.002). Both the English and Spanish concordant groups asked a similar number of questions (p=0.9), and they both asked more questions compared to the Spanish-discordant participants (p=0.002 and p=0.001). Language discordance was associated with fewer questions asked after adjustment for socioeconomic status. Language concordant participants rated higher scores of communication. Both Spanish-concordant and Spanish-discordant patients reported significantly increased

  1. A Dynamic Neuro-Fuzzy Model Providing Bio-State Estimation and Prognosis Prediction for Wearable Intelligent Assistants

    Directory of Open Access Journals (Sweden)

    Winters Jack M

    2005-06-01

    Full Text Available Abstract Background Intelligent management of wearable applications in rehabilitation requires an understanding of the current context, which is constantly changing over the rehabilitation process because of changes in the person's status and environment. This paper presents a dynamic recurrent neuro-fuzzy system that implements expert-and evidence-based reasoning. It is intended to provide context-awareness for wearable intelligent agents/assistants (WIAs. Methods The model structure includes the following types of signals: inputs, states, outputs and outcomes. Inputs are facts or events which have effects on patients' physiological and rehabilitative states; different classes of inputs (e.g., facts, context, medication, therapy have different nonlinear mappings to a fuzzy "effect." States are dimensionless linguistic fuzzy variables that change based on causal rules, as implemented by a fuzzy inference system (FIS. The FIS, with rules based on expertise and evidence, essentially defines the nonlinear state equations that are implemented by nuclei of dynamic neurons. Outputs, a function of weighing of states and effective inputs using conventional or fuzzy mapping, can perform actions, predict performance, or assist with decision-making. Outcomes are scalars to be extremized that are a function of outputs and states. Results The first example demonstrates setup and use for a large-scale stroke neurorehabilitation application (with 16 inputs, 12 states, 5 outputs and 3 outcomes, showing how this modelling tool can successfully capture causal dynamic change in context-relevant states (e.g., impairments, pain as a function of input event patterns (e.g., medications. The second example demonstrates use of scientific evidence to develop rule-based dynamic models, here for predicting changes in muscle strength with short-term fatigue and long-term strength-training. Conclusion A neuro-fuzzy modelling framework is developed for estimating

  2. Recent Advances in the Use of Drosophila melanogaster as a Model to Study Immunopathogenesis of Medically Important Filamentous Fungi

    Directory of Open Access Journals (Sweden)

    Georgios Hamilos

    2012-01-01

    Full Text Available Airborne opportunistic fungi, including Aspergillus and other less common saprophytic molds, have recently emerged as important causes of mortality in immunocompromised individuals. Understanding the molecular mechanisms of host-fungal interplay in robust experimental pathosystems is becoming a research priority for development of novel therapeutics to combat these devastating infections. Over the past decade, invertebrate hosts with evolutionarily conserved innate immune signaling pathways and powerful genetics, such as Drosophila melanogaster, have been employed as a means to overcome logistic restrains associated with the use mammalian models of fungal infections. Recent studies in Drosophila models of filamentous fungi demonstrated that several genes implicated in fungal virulence in mammals also play a similarly important pathogenic role in fruit flies, and important host-related aspects in fungal pathogenesis are evolutionarily conserved. In view of recent advances in Drosophila genetics, fruit flies will become an invaluable surrogate model to study immunopathogenesis of fungal diseases.

  3. Boolean modeling identifies Greatwall/MASTL as an important regulator in the AURKA network of neuroblastoma.

    Science.gov (United States)

    Dahlhaus, Meike; Burkovski, Andre; Hertwig, Falk; Mussel, Christoph; Volland, Ruth; Fischer, Matthias; Debatin, Klaus-Michael; Kestler, Hans A; Beltinger, Christian

    2016-02-01

    Aurora Kinase A (AURKA) is often overexpressed in neuroblastoma (NB) with poor outcome. The causes of AURKA overexpression in NB are unknown. Here, we describe a gene regulatory network consisting of core regulators of AURKA protein expression and activation during mitosis to identify potential causes. This network was transformed to a dynamic Boolean model. Simulated activation of the serine/threonine protein kinase Greatwall (GWL, encoded by MASTL) that attenuates the pivotal AURKA inhibitor PP2A, predicted stabilization of AURKA. Consistent with this notion, gene set enrichment analysis showed enrichment of mitotic spindle assembly genes and MYCN target genes in NB with high GWL/MASTL expression. In line with the prediction of GWL/MASTL enhancing AURKA, elevated expression of GWL/MASTL was associated with NB risk factors and poor survival of patients. These results establish Boolean network modeling of oncogenic pathways in NB as a useful means for guided discovery in this enigmatic cancer.

  4. On determining important aspects of mathematical models: Application to problems in physics and chemistry

    Science.gov (United States)

    Rabitz, Herschel

    1987-01-01

    The use of parametric and functional gradient sensitivity analysis techniques is considered for models described by partial differential equations. By interchanging appropriate dependent and independent variables, questions of inverse sensitivity may be addressed to gain insight into the inversion of observational data for parameter and function identification in mathematical models. It may be argued that the presence of a subset of dominantly strong coupled dependent variables will result in the overall system sensitivity behavior collapsing into a simple set of scaling and self similarity relations amongst elements of the entire matrix of sensitivity coefficients. These general tools are generic in nature, but herein their application to problems arising in selected areas of physics and chemistry is presented.

  5. Why Knowledge Modeling is Important for Business and for a Danish Terminology and Knowledge Bank

    DEFF Research Database (Denmark)

    Erdman Thomsen, Hanne; Madsen, Bodil Nistrup

    2011-01-01

    Businesses and organizations, including public authorities, have a growing need for organizing and handling large amounts of data. In order to manage complex knowledge, knowledge must be modeled and structured. One very powerful method used for structuring knowledge is the use of ontologies....... Businesses and organizations need efficient tools for building domain-specific ontologies and systems for managing knowledge. Most medium-sized and large Danish businesses and organizations operate in a bilingual or multilingual environment, where knowledge is transferred and stored in Danish and/or English...... the foundation for a national terminology and knowledge bank. Furthermore, I will briefly introduce our plans for teaching within the field of knowledge modeling at Copenhagen Business School, CBS....

  6. The right time, the right place: will targeting human cancer-associated mutations to the mouse provide the perfect preclinical model?

    Science.gov (United States)

    Blyth, Karen; Morton, Jennifer P; Sansom, Owen J

    2012-02-01

    Over the past 10 years the realisation that genetic mouse models of cancer may play a key role in preclinical drug development has gained strong momentum. Moreover sequencing studies of human tumours have provided key insights into the mutational complexity of epithelial cancer, unleashing important clues for researchers to generate accurate genetically engineered mouse (GEM) models of cancer. Thus by targeting multiple cancer associated human mutations to the appropriate murine epithelia, mice develop tumours that more closely recapitulate the human disease. As a number of excellent models now exist, the next 5-10 years will ascertain whether these models will predict response of human cancer to intervention. If so they might become the 'gold standard' where all drugs are required to be tested in mouse models of disease before proceeding into the patient. However, although this principle is very attractive, it is relatively untested and here, using examples of prevalent human cancers, we will review the latest data on preclinical GEM studies and comment on what challenges are left to overcome.

  7. Client value models provide a framework for rational library planning (or, phrasing the answer in the form of a question).

    Science.gov (United States)

    Van Moorsel, Guillaume

    2005-01-01

    Libraries often do not know how clients value their product/ service offerings. Yet at a time when the mounting costs for library support are increasingly difficult to justify to the parent institution, the library's ability to gauge the value of its offerings to clients has never been more critical. Client Value Models (CVMs) establish a common definition of value elements-or a "value vocabulary"-for libraries and their clients, thereby providing a basis upon which to make rational planning decisions regarding product/service acquisition and development. The CVM concept is borrowed from business and industry, but its application has a natural fit in libraries. This article offers a theoretical consideration and practical illustration of CVM application in libraries.

  8. Two-dimensional modelling of internal arc effects in an enclosed MV cell provided with a protection porous filter

    Energy Technology Data Exchange (ETDEWEB)

    Rochette, D [Laboratoire Arc Electrique et Plasmas Thermiques, CNRS UMR 6069, Universite Blaise Pascal, IUT de Montlucon, Avenue Aristide Briand, BP 2235, 03101 Montlucon Cedex (France); Clain, S [Laboratoire de Mathematiques pour l' Industrie et la Physique, CNRS UMR 5640, Universite Paul Sabatier Toulouse 3, 118 route de Narbonne, 31062 Toulouse Cedex 4 (France); Andre, P [Laboratoire Arc Electrique et Plasmas Thermiques, CNRS UMR 6069, Universite Blaise Pascal, IUT de Montlucon, Avenue Aristide Briand, BP 2235, 03101 Montlucon Cedex (France); Bussiere, W [Laboratoire Arc Electrique et Plasmas Thermiques, CNRS UMR 6069, Universite Blaise Pascal, IUT de Montlucon, Avenue Aristide Briand, BP 2235, 03101 Montlucon Cedex (France); Gentils, F [Schneider Electric-Science and Technology Division-Research Center A2, 38050 Grenoble Cedex 9 (France)

    2007-05-21

    Medium voltage (MV) cells have to respect standards (for example IEC ones (IEC TC 17C 2003 IEC 62271-200 High Voltage Switchgear and Controlgear-Part 200 1st edn)) that define security levels against internal arc faults such as an accidental electrical arc occurring in the apparatus. New protection filters based on porous materials are developed to provide better energy absorption properties and a higher protection level for people. To study the filter behaviour during a major electrical accident, a two-dimensional model is proposed. The main point is the use of a dedicated numerical scheme for a non-conservative hyperbolic problem. We present a numerical simulation of the process during the first 0.2 s when the safety valve bursts and we compare the numerical results with tests carried out in a high power test laboratory on real electrical apparatus.

  9. Mitral leaflet modeling: Importance of in vivo shape and material properties.

    Science.gov (United States)

    Stevanella, Marco; Krishnamurthy, Gaurav; Votta, Emiliano; Swanson, Julia C; Redaelli, Alberto; Ingels, Neil B

    2011-08-11

    The anterior mitral leaflet (AML) is a thin membrane that withstands high left ventricular (LV) pressure pulses 100,000 times per day. The presence of contractile cells determines AML in vivo stiffness and complex geometry. Until recently, mitral valve finite element (FE) models have neglected both of these aspects. In this study we assess their effect on AML strains and stresses, hypothesizing that these will differ significantly from those reported in literature. Radiopaque markers were sewn on the LV, the mitral annulus, and AML in sheep hearts, and their four-dimensional coordinates obtained with biplane video fluoroscopy. Employing in vivo data from three representative hearts, AML FE models were created from the marker coordinates at the end of isovolumic relaxation assumed as the unloaded reference state. AML function was simulated backward through systole, applying the measured trans-mitral pressure on AML LV surface and marker displacements on AML boundaries. Simulated AML displacements and curvatures were consistent with in vivo measurements, confirming model accuracy. AML circumferential strains were mostly tensile (1-3%), despite being compressive (-1%) near the commissures. Radial strains were compressive in the belly (-1 to -0.2%), and tensile (2-8%) near the free edge. These results differ significantly from those of previous FE models. They reflect the synergy of high tissue stiffness, which limits tensile circumferential strains, and initial compound curvature, which forces LV pressure to compress AML radially. The obtained AML shape may play a role not only in preventing mitral regurgitation, but also in optimizing LV outflow fluid dynamics.

  10. The importance of nature's invisible fabric: food web structure mediates modeled responses to river restoration

    Science.gov (United States)

    Bellmore, R.; Benjamin, J.; Newsom, M.; Bountry, J.; Dombroski, D.

    2016-12-01

    Restoration is frequently aimed at the recovery of target species, but also influences the larger food web in which these species participate. Effects of restoration on this broader network of organisms can influence target species both directly and indirectly via changes in energy flow through food webs. To help incorporate these complexities into river restoration planning we constructed a food web model that links river food web dynamics to in-stream physical habitat and riparian vegetation conditions. We present an application of this model to the Methow River, Washington (USA), a location of on-going restoration aimed at recovering salmon. Three restoration strategies were simulated: riparian vegetation restoration, nutrient augmentation via salmon carcass addition, and floodplain reconnection. To explore how food web structure mediates responses to these actions, we modified the food web by adding populations of invasive aquatic snails and nonnative fish. Simulations suggest that floodplain reconnection may be a better strategy than carcass addition and vegetation planting for improving conditions for salmon in this river segment. However, modeled responses were strongly sensitive to changes in the structure of the food web. The addition of invasive snails and nonnative fishes modified pathways of energy through the food web, which negated restoration improvements. This finding illustrates that forecasting responses to restoration may require accounting for the structure of food webs, and that changes in this structure—as might be expected with the spread of invasive species—could compromise restoration outcomes. By elucidating the direct and indirect pathways by which restoration affects target species, dynamic food web models can improve restoration planning by fostering a deeper understanding of system connectedness and dynamics.

  11. Pole tide Love number - an important parameter for polar motion modeling

    Science.gov (United States)

    Kirschner, S.; Schmidt, M. G.; Seitz, F.

    2013-12-01

    The Euler-Liouville equation is the basic physical model to describe Earth rotation. It is based on the balance of angular momentum in the Earth system. The pole tide Love number is needed to characterize the rotational deformation effect, which depends on the internal structure and rheology of the Earth. There is a direct dependency between the pole tide Love number and the period and damping of the Chandler oscillation. Here we estimate the pole tide Love number on the basis of an inversion of the Euler-Liouville equation. The Earth orientation parameters are used as input parameters. They have been observed precisely over several decades by geodetic methods (C01 and C04 time series). It will be shown that the estimated pole tide Love number leads to significantly better results for polar motion compared to the original value taken from the Conventions of the International Earth Rotation and Reference System Service (IERS). Nevertheless the estimation is dependent on the input models for the subsystems (e.g. atmosphere and ocean models), applied estimation approach and time frame. These aspects are analyzed and discussed in detail.

  12. The importance of land cover change across urban-rural typologies for climate modeling.

    Science.gov (United States)

    Vargo, Jason; Habeeb, Dana; Stone, Brian

    2013-01-15

    Land cover changes affect local surface energy balances by changing the amount of solar energy reflected, the magnitude and duration over which absorbed energy is released as heat, and the amount of energy that is diverted to non-heating fluxes through evaporation. However, such local influences often are only crudely included in climate modeling exercises, if at all. A better understanding of local land conversion dynamics can serve to inform inputs for climate models and increase the role for land use planning in climate management policy. Here we present a new approach for projecting and incorporating metropolitan land cover change into mesoscale climate and other environmental assessment models. Our results demonstrate the relative contributions of different land development patterns to land cover change and conversion and suggest that regional growth management strategies serving to increase settlement densities over time can have a significant influence on the rate of deforestation per unit of population growth. Employing the approach presented herein, the impacts of land conversion on climate change and on parallel environmental systems and services, such as ground water recharge, habitat provision, and food production, may all be investigated more closely and managed through land use planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. PCBs in the Arctic atmosphere: determining important driving forces using a global atmospheric transport model

    Directory of Open Access Journals (Sweden)

    C. L. Friedman

    2015-11-01

    Full Text Available We present a spatially and temporally resolved global atmospheric PCB model, driven by meteorological data, that is skilled at simulating mean atmospheric PCB concentrations and seasonal cycles in the Northern Hemisphere mid-latitudes, and mean Arctic concentrations. However, the model does not capture the observed Arctic summer maximum in atmospheric PCBs. We use the model to estimate global budgets for the International Council for the Exploration of the Sea 7 PCBs, and demonstrate that congeners that deposit more readily show lower potential for long-range transport, consistent with a recently-described "differential removal hypothesis" regarding the hemispheric transport of PCBs. Using sensitivity simulations to assess processes within, outside, or transport to the Arctic, we examine the influence of climate- and emissions-driven processes on Arctic concentrations and their effect on improving the simulated Arctic seasonal cycle. We find evidence that processes occurring outside the Arctic have a greater influence on Arctic atmospheric PCB levels than processes that occur within the Arctic. Our simulations suggest that re-emissions from sea ice melting or from the Arctic Ocean during summer would have to be unrealistically high in order to capture observed temporal trends of PCBs in the Arctic atmosphere. We conclude that mid-latitude processes are likely to have a greater effect on the Arctic under global change scenarios than re-emissions within the Arctic.

  14. Phase diagram and spin correlations of the Kitaev-Heisenberg model: Importance of quantum effects

    Science.gov (United States)

    Gotfryd, Dorota; Rusnačko, Juraj; Wohlfeld, Krzysztof; Jackeli, George; Chaloupka, Jiří; Oleś, Andrzej M.

    2017-01-01

    We explore the phase diagram of the Kitaev-Heisenberg model with nearest neighbor interactions on the honeycomb lattice using the exact diagonalization of finite systems combined with the cluster mean field approximation, and supplemented by the insights from analytic approaches: the linear spin-wave and second-order perturbation theories. This study confirms that by varying the balance between the Heisenberg and Kitaev term, frustrated exchange interactions stabilize in this model either one of four phases with magnetic long range order: Néel phase, ferromagnetic phase, and two other phases with coexisting antiferromagnetic and ferromagnetic bonds, zigzag and stripy phase, or one of two distinct spin-liquid phases. Out of these latter disordered phases, the one with ferromagnetic Kitaev interactions has a substantially broader range of stability as the neighboring competing ordered phases, ferromagnetic and stripy, have very weak quantum fluctuations. Focusing on the quantum spin-liquid phases, we study spatial spin correlations and dynamic spin structure factor of the model by the exact diagonalization technique, and discuss the evolution of gapped low-energy spin response across the quantum phase transitions between the disordered spin liquid and phases with long range magnetic order.

  15. Modeling organic aerosols during MILAGRO: importance of biogenic secondary organic aerosols

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2009-09-01

    Full Text Available The meso-scale chemistry-transport model CHIMERE is used to assess our understanding of major sources and formation processes leading to a fairly large amount of organic aerosols – OA, including primary OA (POA and secondary OA (SOA – observed in Mexico City during the MILAGRO field project (March 2006. Chemical analyses of submicron aerosols from aerosol mass spectrometers (AMS indicate that organic particles found in the Mexico City basin contain a large fraction of oxygenated organic species (OOA which have strong correspondence with SOA, and that their production actively continues downwind of the city. The SOA formation is modeled here by the one-step oxidation of anthropogenic (i.e. aromatics, alkanes, biogenic (i.e. monoterpenes and isoprene, and biomass-burning SOA precursors and their partitioning into both organic and aqueous phases. Conservative assumptions are made for uncertain parameters to maximize the amount of SOA produced by the model. The near-surface model evaluation shows that predicted OA correlates reasonably well with measurements during the campaign, however it remains a factor of 2 lower than the measured total OA. Fairly good agreement is found between predicted and observed POA within the city suggesting that anthropogenic and biomass burning emissions are reasonably captured. Consistent with previous studies in Mexico City, large discrepancies are encountered for SOA, with a factor of 2–10 model underestimate. When only anthropogenic SOA precursors were considered, the model was able to reproduce within a factor of two the sharp increase in OOA concentrations during the late morning at both urban and near-urban locations but the discrepancy increases rapidly later in the day, consistent with previous results, and is especially obvious when the column-integrated SOA mass is considered instead of the surface concentration. The increase in the missing SOA mass in the afternoon coincides with the sharp drop in POA

  16. The Importance of High Temporal Resolution in Modeling Renewable Energy Penetration Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Nicolosi, Marco; Mills, Andrew D; Wiser, Ryan H

    2010-10-08

    Traditionally, modeling investment and dispatch problems in electricity economics has been limited by computation power. Due to this limitation, simplifications are applied. One common practice, for example, is to reduce the temporal resolution of the dispatch by clustering similar load levels. The increase of intermittent electricity from renewable energy sources (RES-E) changes the validity of this assumption. RES-E already cover a certain amount of the total demand. This leaves an increasingly volatile residual demand to be matched by the conventional power market. This paper quantifies differences in investment decisions by applying three different time-resolution residual load patterns in an investment and dispatch power system model. The model optimizes investment decisions in five year steps between today and 2030 with residual load levels for 8760, 288 and 16 time slices per year. The market under consideration is the four zone ERCOT market in Texas. The results show that investment decisions significantly differ across the three scenarios. In particular, investments into base-load technologies are substantially reduced in the high resolution scenario (8760 residual load levels) relative to the scenarios with lower temporal resolution. Additionally, the amount of RES-E curtailment and the market value of RES-E exhibit noteworthy differences.

  17. Supplementary Material for: Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody

    2016-01-01

    Abstract Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel

  18. Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody

    2016-03-23

    Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel resistance

  19. Does the macaque monkey provide a good model for studying human executive control? A comparative behavioral study of task switching.

    Directory of Open Access Journals (Sweden)

    Luana Caselli

    Full Text Available The ability to swiftly and smoothly switch from one task set to another is central to intelligent behavior, because it allows an organism to flexibly adapt to ever changing environmental conditions and internal needs. For this reason, researchers interested in executive control processes have often relied on task-switching paradigms as powerful tools to uncover the underlying cognitive and brain architecture. In order to gather fundamental information at the single-cell level, it would be greatly helpful to demonstrate that non-human primates, especially the macaque monkey, share with us similar behavioral manifestations of task-switching and therefore, in all likelihood, similar underlying brain mechanisms. Unfortunately, prior attempts have provided negative results (e.g., Stoet & Snyder, 2003b, in that it was reported that macaques do not show the typical signature of task-switching operations at the behavioral level, represented by switch costs. If confirmed, this would indicate that the macaque cannot be used as a model approach to explore human executive control mechanisms by means of task-switching paradigms. We have therefore decided to re-explore this issue, by conducting a comparative experiment on a group of human participants and two macaque monkeys, whereby we measured and compared performance costs linked to task switching and resistance to interference across the two species. Contrary to what previously reported, we found that both species display robust task switching costs, thus supporting the claim that macaque monkeys provide an exquisitely suitable model to study the brain mechanisms responsible for maintaining and switching task sets.

  20. Does the macaque monkey provide a good model for studying human executive control? A comparative behavioral study of task switching.

    Science.gov (United States)

    Caselli, Luana; Chelazzi, Leonardo

    2011-01-01

    The ability to swiftly and smoothly switch from one task set to another is central to intelligent behavior, because it allows an organism to flexibly adapt to ever changing environmental conditions and internal needs. For this reason, researchers interested in executive control processes have often relied on task-switching paradigms as powerful tools to uncover the underlying cognitive and brain architecture. In order to gather fundamental information at the single-cell level, it would be greatly helpful to demonstrate that non-human primates, especially the macaque monkey, share with us similar behavioral manifestations of task-switching and therefore, in all likelihood, similar underlying brain mechanisms. Unfortunately, prior attempts have provided negative results (e.g., Stoet & Snyder, 2003b), in that it was reported that macaques do not show the typical signature of task-switching operations at the behavioral level, represented by switch costs. If confirmed, this would indicate that the macaque cannot be used as a model approach to explore human executive control mechanisms by means of task-switching paradigms. We have therefore decided to re-explore this issue, by conducting a comparative experiment on a group of human participants and two macaque monkeys, whereby we measured and compared performance costs linked to task switching and resistance to interference across the two species. Contrary to what previously reported, we found that both species display robust task switching costs, thus supporting the claim that macaque monkeys provide an exquisitely suitable model to study the brain mechanisms responsible for maintaining and switching task sets.

  1. Targeted delivery of the hydroxylase inhibitor DMOG provides enhanced efficacy with reduced systemic exposure in a murine model of colitis.

    Science.gov (United States)

    Tambuwala, Murtaza M; Manresa, Mario C; Cummins, Eoin P; Aversa, Vincenzo; Coulter, Ivan S; Taylor, Cormac T

    2015-11-10

    Targeting hypoxia-sensitive pathways has recently been proposed as a new therapeutic approach to the treatment of intestinal inflammation. HIF-hydroxylases are enzymes which confer hypoxic-sensitivity upon the hypoxia-inducible factor (HIF), a major regulator of the adaptive response to hypoxia. Previous studies have shown that systemic (intraperitoneal) administration of hydroxylase inhibitors such as dimethyloxalylglycine (DMOG) is profoundly protective in multiple models of colitis, however the therapeutic potential of this approach is limited due to potential side-effects associated with systemic drug exposure and the fact that orally delivered DMOG is ineffective (likely due to drug inactivation by gastric acid). In order to overcome these issues, we formulated DMOG in a liquid emulsion drug delivery system which, when coated with specific polymer coatings, permits oral delivery of a reduced dose which is released locally throughout the colon. This colon-targeted DMOG formulation demonstrated increased relative colonic bioactivity with reduced systemic exposure and provided a similar degree of protection to systemic (intraperitoneal) administration at a 40-fold lower dose in DSS-induced colitis. In summary, targeted delivery of DMOG to the colon provides local protection resulting in enhanced efficacy with reduced systemic exposure in the treatment of colitis. This novel approach to targeting hydroxylase inhibitors to specific diseased regions of the GI tract may improve it's potential as a new therapeutic in inflammatory bowel diseases such as ulcerative colitis.

  2. A new model for providing cell-free DNA and risk assessment for chromosome abnormalities in a public hospital setting.

    Science.gov (United States)

    Wallerstein, Robert; Jelks, Andrea; Garabedian, Matthew J

    2014-01-01

    Cell-free DNA (cfDNA) offers highly accurate noninvasive screening for Down syndrome. Incorporating it into routine care is complicated. We present our experience implementing a novel program for cfDNA screening, emphasizing patient education, genetic counseling, and resource management. Beginning in January 2013, we initiated a new patient care model in which high-risk patients for aneuploidy received genetic counseling at 12 weeks of gestation. Patients were presented with four pathways for aneuploidy risk assessment and diagnosis: (1) cfDNA; (2) integrated screening; (3) direct-to-invasive testing (chorionic villus sampling or amniocentesis); or (4) no first trimester diagnostic testing/screening. Patients underwent follow-up genetic counseling and detailed ultrasound at 18-20 weeks to review first trimester testing and finalize decision for amniocentesis. Counseling and second trimester detailed ultrasound were provided to 163 women. Most selected cfDNA screening (69%) over integrated screening (0.6%), direct-to-invasive testing (14.1%), or no screening (16.6%). Amniocentesis rates decreased following implementation of cfDNA screening (19.0% versus 13.0%, P < 0.05). When counseled about screening options, women often chose cfDNA over integrated screening. This program is a model for patient-directed, efficient delivery of a newly available high-level technology in a public health setting. Genetic counseling is an integral part of patient education and determination of plan of care.

  3. A model to identify mathematics topics in MXit lingo to provide tutors quick access to supporting documentation

    Directory of Open Access Journals (Sweden)

    Laurie Butgereit

    2011-11-01

    Full Text Available Dr MathTM is a mobile, online tutoring system where learners can use MXitTM on their mobile phones to receive help with their mathematics homework from volunteer tutors. These conversations between learners and Dr Math are held in MXit lingo. MXit lingo is a heavily abbreviated, English-like language that is evolving between users of mobile phones that communicate using MXit. The Dr Math project has been running since January 2007 and uses volunteer tutors who are mostly university students who readily understand and use MXit lingo. However, due to the large number of simultaneous conversations that the tutors are often involved in and the diversity of topics discussed, it would often be beneficial to provide assistance regarding the mathematics topic to the tutors. This article explains how the μ model identifies the mathematics topic in the conversation. The model identifies appropriate mathematics topics in just over 75% of conversations in a corpus of conversations identified to be about mathematics topics in the school curriculum.

  4. A Multi-Period Optimization Model for Service Providers Using Online Reservation Systems: An Application to Hotels.

    Science.gov (United States)

    Xu, Ming; Jiao, Yan; Li, Xiaoming; Cao, Qingfeng; Wang, Xiaoyang

    2015-01-01

    This paper presents a multi-period optimization model for high margin and zero salvage products in online distribution channels with classifying customers based on number of products required. Taking hotel customers as an example, one is regular customers who reserve rooms for one day, and the other is long term stay (LTS) customers who reserve rooms for a number of days. LTS may guarantee a specific amount of demand and generate opportunity income for a certain number of periods, meanwhile with risk of punishment incurred by overselling. By developing an operational optimization model and exploring the effects of parameters on optimal decisions, we suggest that service providers should make decisions based on the types of customers, number of products required, and duration of multi-period to reduce the loss of reputation and obtain more profit; at the same time, multi-period buying customers should buy products early. Finally, the paper conducts a numerical experiment, and the results are consistent with prevailing situations.

  5. A Multi-Period Optimization Model for Service Providers Using Online Reservation Systems: An Application to Hotels

    Science.gov (United States)

    Xu, Ming; Jiao, Yan; Li, Xiaoming; Cao, Qingfeng; Wang, Xiaoyang

    2015-01-01

    This paper presents a multi-period optimization model for high margin and zero salvage products in online distribution channels with classifying customers based on number of products required. Taking hotel customers as an example, one is regular customers who reserve rooms for one day, and the other is long term stay (LTS) customers who reserve rooms for a number of days. LTS may guarantee a specific amount of demand and generate opportunity income for a certain number of periods, meanwhile with risk of punishment incurred by overselling. By developing an operational optimization model and exploring the effects of parameters on optimal decisions, we suggest that service providers should make decisions based on the types of customers, number of products required, and duration of multi-period to reduce the loss of reputation and obtain more profit; at the same time, multi-period buying customers should buy products early. Finally, the paper conducts a numerical experiment, and the results are consistent with prevailing situations. PMID:26147663

  6. A Multi-Period Optimization Model for Service Providers Using Online Reservation Systems: An Application to Hotels.

    Directory of Open Access Journals (Sweden)

    Ming Xu

    Full Text Available This paper presents a multi-period optimization model for high margin and zero salvage products in online distribution channels with classifying customers based on number of products required. Taking hotel customers as an example, one is regular customers who reserve rooms for one day, and the other is long term stay (LTS customers who reserve rooms for a number of days. LTS may guarantee a specific amount of demand and generate opportunity income for a certain number of periods, meanwhile with risk of punishment incurred by overselling. By developing an operational optimization model and exploring the effects of parameters on optimal decisions, we suggest that service providers should make decisions based on the types of customers, number of products required, and duration of multi-period to reduce the loss of reputation and obtain more profit; at the same time, multi-period buying customers should buy products early. Finally, the paper conducts a numerical experiment, and the results are consistent with prevailing situations.

  7. A New Model for Providing Cell-Free DNA and Risk Assessment for Chromosome Abnormalities in a Public Hospital Setting

    Directory of Open Access Journals (Sweden)

    Robert Wallerstein

    2014-01-01

    Full Text Available Objective. Cell-free DNA (cfDNA offers highly accurate noninvasive screening for Down syndrome. Incorporating it into routine care is complicated. We present our experience implementing a novel program for cfDNA screening, emphasizing patient education, genetic counseling, and resource management. Study Design. Beginning in January 2013, we initiated a new patient care model in which high-risk patients for aneuploidy received genetic counseling at 12 weeks of gestation. Patients were presented with four pathways for aneuploidy risk assessment and diagnosis: (1 cfDNA; (2 integrated screening; (3 direct-to-invasive testing (chorionic villus sampling or amniocentesis; or (4 no first trimester diagnostic testing/screening. Patients underwent follow-up genetic counseling and detailed ultrasound at 18–20 weeks to review first trimester testing and finalize decision for amniocentesis. Results. Counseling and second trimester detailed ultrasound were provided to 163 women. Most selected cfDNA screening (69% over integrated screening (0.6%, direct-to-invasive testing (14.1%, or no screening (16.6%. Amniocentesis rates decreased following implementation of cfDNA screening (19.0% versus 13.0%, P<0.05. Conclusion. When counseled about screening options, women often chose cfDNA over integrated screening. This program is a model for patient-directed, efficient delivery of a newly available high-level technology in a public health setting. Genetic counseling is an integral part of patient education and determination of plan of care.

  8. Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity.

    Directory of Open Access Journals (Sweden)

    Naomi J Fox

    Full Text Available Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes

  9. An Architectural Model to Provide QoS in a Home Network and its Evaluation in a Real Testbed

    Directory of Open Access Journals (Sweden)

    Francesca Cuomo

    2008-06-01

    Full Text Available Home networks are an evolution of office local area networks, answering the need for residential distribution of broadband services. The design of a home network must strive to keep low costs, easy installation and maintenance while at the same time providing a large variety of services, from voice and data applications to multimedia streaming. A successful platform for home networking must put together simple interfaces for the users and sophisticated mechanisms for managing the distribution of the desired broadband services. In this paper we propose mechanisms to support flows with different Quality of Service (QoS requirements in a home network whose architectural model has been defined in the framework of the European IST ePerSpace project. The model is based on a centralized Residential Gateway (RG, which connects and coordinates different network technologies to support home services. The proposed mechanisms are simple to be implemented since they can be installed on top of existing home network technologies, without modifying them.We implement the whole model and our mechanisms in a real testbed and we perform an extensive performance evaluation over it. The performance evaluation allows us to understand the effect of different settings both on the wired and on the wireless interfaces of the RG, to comprehend which are the key aspects that influence the overall performance and to propose some RG configurations which turn out to be very effective in achieving the desired performance. Special attention is devoted to the wireless support of home services on IEEE 802.11b devices.

  10. Formative evaluation of a telemedicine model for delivering clinical neurophysiology services part I: Utility, technical performance and service provider perspective

    Directory of Open Access Journals (Sweden)

    Breen Patricia

    2010-09-01

    Full Text Available Abstract Background Formative evaluation is conducted in the early stages of system implementation to assess how it works in practice and to identify opportunities for improving technical and process performance. A formative evaluation of a teleneurophysiology service was conducted to examine its technical and sociological dimensions. Methods A teleneurophysiology service providing routine EEG investigation was established. Service use, technical performance and satisfaction of clinical neurophysiology personnel were assessed qualitatively and quantitatively. These were contrasted with a previously reported analysis of the need for teleneurophysiology, and examination of expectation and satisfaction with clinical neurophysiology services in Ireland. A preliminary cost-benefit analysis was also conducted. Results Over the course of 40 clinical sessions during 20 weeks, 142 EEG investigations were recorded and stored on a file server at a satellite centre which was 130 miles away from the host clinical neurophysiology department. Using a virtual private network, the EEGs were accessed by a consultant neurophysiologist at the host centre for interpretation. The model resulted in a 5-fold increase in access to EEG services as well as reducing average waiting times for investigation by a half. Technically the model worked well, although a temporary loss of virtual private network connectivity highlighted the need for clarity in terms of responsibility for troubleshooting and repair of equipment problems. Referral quality, communication between host and satellite centres, quality of EEG recordings, and ease of EEG review and reporting indicated that appropriate organisational processes were adopted by the service. Compared to traditional CN service delivery, the teleneurophysiology model resulted in a comparable unit cost per EEG. Conclusion Observations suggest that when traditional organisational boundaries are crossed challenges associated with the

  11. Regional input-output models and the treatment of imports in the European System of Accounts

    OpenAIRE

    Kronenberg, Tobias

    2011-01-01

    Input-output models are often used in regional science due to their versatility and their ability to capture many of the distinguishing features of a regional economy. Input-output tables are available for all EU member countries, but they are hard to find at the regional level, since many regional governments lack the resources or the will to produce reliable, survey-based regional input-output tables. Therefore, in many cases researchers adopt nonsurvey techniques to derive regional input-o...

  12. Business model for an International Trade Agent : Importing apparel, footwear and accessories from Colombia

    OpenAIRE

    Peña Archila, Jorge Andres

    2014-01-01

    This thesis proposes a business model for a start-up business that will act as an International Trade agent, the aim of which will be to enhance trade relations between Colombia and Finland due to a free trade agreement between the European Union and Colombia. The scope of this thesis was limited to the products of apparel, footwear and accessories. The primary research was conducted in the form of an unstructured interview with an entrepreneur who has more than two decades of experience ...

  13. Model selection emphasises the importance of non-chromosomal information in genetic studies.

    Directory of Open Access Journals (Sweden)

    Reda Rawi

    Full Text Available Ever since the case of the missing heritability was highlighted some years ago, scientists have been investigating various possible explanations for the issue. However, none of these explanations include non-chromosomal genetic information. Here we describe explicitly how chromosomal and non-chromosomal modifiers collectively influence the heritability of a trait, in this case, the growth rate of yeast. Our results show that the non-chromosomal contribution can be large, adding another dimension to the estimation of heritability. We also discovered, combining the strength of LASSO with model selection, that the interaction of chromosomal and non-chromosomal information is essential in describing phenotypes.

  14. Imported family models? Cohabitation patterns of Latin American women in Spain

    Directory of Open Access Journals (Sweden)

    Clara CORTINA TRILLA

    2010-09-01

    Full Text Available During the last decade, international immigration flows have undergone a dramatic growth in Spain. In this particular context, the purpose of this article is to analyze whether Latin American female migrants residing in Spain largely maintain nuptial and reproductive patterns from their countries of origin. To analyze the prevalence of consensual unions we use three different databases: the Spanish Immigration Survey, the Spanish Labour Force Survey and birth records, all of them corresponding to 2007 and collected by the Spanish Statistical Institute. The study documents the high prevalence of consensual unions among Latin American migrants. Regarding the socio-demographic factors influencing cohabitation, our results show important similarities between Spanish and Latin American women, except for educational attainment.

  15. Using a computerized provider order entry system to meet the unique prescribing needs of children: description of an advanced dosing model

    Directory of Open Access Journals (Sweden)

    Schellenberger Patricia

    2011-02-01

    Full Text Available Abstract Background It is well known that the information requirements necessary to safely treat children with therapeutic medications cannot be met with the same approaches used in adults. Over a 1-year period, Duke University Hospital engaged in the challenging task of enhancing an established computerized provider order entry (CPOE system to address the unique medication dosing needs of pediatric patients. Methods An advanced dosing model (ADM was designed to interact with our existing CPOE application to provide decision support enabling complex pediatric dose calculations based on chronological age, gestational age, weight, care area in the hospital, indication, and level of renal impairment. Given that weight is a critical component of medication dosing that may change over time, alerting logic was added to guard against erroneous entry or outdated weight information. Results Pediatric CPOE was deployed in a staggered fashion across 6 care areas over a 14-month period. Safeguards to prevent miskeyed values became important in allowing providers the flexibility to override the ADM logic if desired. Methods to guard against over- and under-dosing were added. The modular nature of our model allows us to easily add new dosing scenarios for specialized populations as the pediatric population and formulary change over time. Conclusions The medical needs of pediatric patients vary greatly from those of adults, and the information systems that support those needs require tailored approaches to design and implementation. When a single CPOE system is used for both adults and pediatrics, safeguards such as redirection and suppression must be used to protect children from inappropriate adult medication dosing content. Unlike other pediatric dosing systems, our model provides active dosing assistance and dosing process management, not just static dosing advice.

  16. Report: the current situation of sanitary landfills in Brazil and the importance of the application of economic models.

    Science.gov (United States)

    Neto, Raul Oliveira; Petter, Carlos Otávio; Cortina, José Luis

    2009-12-01

    We present the development stage of the sanitary landfills in Brazil in the context of urban solid residue management, demonstrating the necessity and importance of the employment of economic models. In the article, a cost estimate model is proposed as the basis for studies to be applied by sector management, including the city council, companies, consultants and engineers, contributing to the choice of new areas, public bids, municipal consortia and private public partnerships.

  17. Report: the current situation of sanitary landfills in Brazil and the importance of the application of economic models

    OpenAIRE

    Oliveira Neto, Raúl; Otávio Petter, Carlos; Cortina Pallás, José Luís

    2009-01-01

    We present the development stage of the sanitary landfills in Brazil in the context of urban solid residue management, demonstrating the necessity and importance of the employment of economic models. In the article, a cost estimate model is proposed as the basis for studies to be applied by sector management, including the city council, companies, consultants and engineers, contributing to the choice of new areas, public bids, municipal consortia and private public partnerships. Peer Re...

  18. Flatworm models in pharmacological research: the importance of compound stability testing.

    Science.gov (United States)

    Stalmans, Sofie; Willems, Maxime; Adriaens, Els; Remon, Jean-Paul; D'Hondt, Matthias; De Spiegeleer, Bart

    2014-10-01

    Flatworms possess adult pluripotent stem cells, which make them extraordinary experimental model organisms to assess in vivo the undesirable effects of substances on stem cells. Currently, quality practices, implying evaluation of the stability of the test compound under the proposed experimental conditions, are uncommon in this research field. Nevertheless, performing a stability study during the rational design of in vivo assay protocols will result in more reliable assay results. To illustrate the influence of the stability of the test substance on the final experimental outcome, we performed a short-term International Conference on Harmonization (ICH)-based stability study of cyclophosphamide in the culture medium, to which a marine flatworm model Macrostomum lignano is exposed. Using a validated U(H)PLC method, it was demonstrated that the cyclophosphamide concentration in the culture medium at 20°C is lowered to 80% of the initial concentration after 21days. The multiwell plates, flatworms and diatoms, as well as light exposure, did not influence significantly the cyclophosphamide concentration in the medium. The results of the stability study have practical implications on the experimental set-up of the carcinogenicity assay like the frequency of medium renewal. This case study demonstrates the benefits of applying appropriate quality guidelines already during fundamental research increasing the credibility of the results.

  19. The importance of topographically corrected null models for analyzing ecological point processes.

    Science.gov (United States)

    McDowall, Philip; Lynch, Heather J

    2017-07-01

    Analyses of point process patterns and related techniques (e.g., MaxEnt) make use of the expected number of occurrences per unit area and second-order statistics based on the distance between occurrences. Ecologists working with point process data often assume that points exist on a two-dimensional x-y plane or within a three-dimensional volume, when in fact many observed point patterns are generated on a two-dimensional surface existing within three-dimensional space. For many surfaces, however, such as the topography of landscapes, the projection from the surface to the x-y plane preserves neither area nor distance. As such, when these point patterns are implicitly projected to and analyzed in the x-y plane, our expectations of the point pattern's statistical properties may not be met. When used in hypothesis testing, we find that the failure to account for the topography of the generating surface may bias statistical tests that incorrectly identify clustering and, furthermore, may bias coefficients in inhomogeneous point process models that incorporate slope as a covariate. We demonstrate th