Evaluation and prioritization of rice production practices and constraints under temperate climatic conditions using Fuzzy Analytical Hierarchy Process (FAHP)

International Nuclear Information System (INIS)

Mir, S.A.; Padma, T.

2016-01-01

Due to overwhelming complex and vague nature of interactions between multiple factors describing agriculture, Multi-Criteria Decision Making (MCDM) methods are widely used from farm to fork to facilitate systematic and transparent decision support, figure out multiple decision outcomes and equip decision maker with confident decision choices in order to choose best alternative. This research proposes a Fuzzy Analytical Hierarchy Process (FAHP) based decision support to evaluate and prioritize important factors of rice production practices and constraints under temperate climatic conditions and provides estimate of weightings, which measure relative importance of critical factors of the crop under biotic, abiotic, socio-economic and technological settings. The results envisage that flood, drought, water logging, late sali, temperature and rainfall are important constraints. However, regulating transplantation time; maintaining planting density; providing training to the educated farmers; introducing high productive varieties like Shalimar Rice-1 and Jhelum; better management of nutrients, weeds and diseases are most important opportunities to enhance rice production in the region. Therefore, the proposed system supplements farmers with precise decision information about important rice production practices, opportunities and constraints.

Evaluation and prioritization of rice production practices and constraints under temperate climatic conditions using Fuzzy Analytical Hierarchy Process (FAHP

Directory of Open Access Journals (Sweden)

Shabir A. Mir

2016-12-01

Full Text Available Due to overwhelming complex and vague nature of interactions between multiple factors describing agriculture, Multi-Criteria Decision Making (MCDM methods are widely used from farm to fork to facilitate systematic and transparent decision support, figure out multiple decision outcomes and equip decision maker with confident decision choices in order to choose best alternative. This research proposes a Fuzzy Analytical Hierarchy Process (FAHP based decision support to evaluate and prioritize important factors of rice production practices and constraints under temperate climatic conditions and provides estimate of weightings, which measure relative importance of critical factors of the crop under biotic, abiotic, socio-economic and technological settings. The results envisage that flood, drought, water logging, late sali, temperature and rainfall are important constraints. However, regulating transplantation time; maintaining planting density; providing training to the educated farmers; introducing high productive varieties like Shalimar Rice-1 and Jhelum; better management of nutrients, weeds and diseases are most important opportunities to enhance rice production in the region. Therefore, the proposed system supplements farmers with precise decision information about important rice production practices, opportunities and constraints.

Evaluation and prioritization of rice production practices and constraints under temperate climatic conditions using Fuzzy Analytical Hierarchy Process (FAHP)

Energy Technology Data Exchange (ETDEWEB)

Mir, S.A.; Padma, T.

2016-07-01

Due to overwhelming complex and vague nature of interactions between multiple factors describing agriculture, Multi-Criteria Decision Making (MCDM) methods are widely used from farm to fork to facilitate systematic and transparent decision support, figure out multiple decision outcomes and equip decision maker with confident decision choices in order to choose best alternative. This research proposes a Fuzzy Analytical Hierarchy Process (FAHP) based decision support to evaluate and prioritize important factors of rice production practices and constraints under temperate climatic conditions and provides estimate of weightings, which measure relative importance of critical factors of the crop under biotic, abiotic, socio-economic and technological settings. The results envisage that flood, drought, water logging, late sali, temperature and rainfall are important constraints. However, regulating transplantation time; maintaining planting density; providing training to the educated farmers; introducing high productive varieties like Shalimar Rice-1 and Jhelum; better management of nutrients, weeds and diseases are most important opportunities to enhance rice production in the region. Therefore, the proposed system supplements farmers with precise decision information about important rice production practices, opportunities and constraints.

Improving non-communicable disease remediation outcomes in Tonga: the importance of domestic fruit production systems: an analysis

Directory of Open Access Journals (Sweden)

Steven J. R. Underhill

2017-04-01

Full Text Available Non-communicable diseases (NCD are the leading cause of mortality in the Pacific Island nation of Tonga. Current remedial strategies have focused on promoting healthy food choices based on increased intake of fruits and vegetables. While researchers seek to overcome complex social, gender and cultural practices that impede dietary transition, discontinuous domestic fruit supply chains undermine this effort. With the view to supporting a more holistic approach to NCD remediation in Tonga, this paper provides a preliminary assessment of domestic horticultural supply chains constraints, in support of diversification and expansion of local fruit production. Current impediments and constraints to enhanced local fruit production are presented and possible strategies to increased domestic fruit supply discussed. We present a case for a more consumer-centric approach to industry development, with an emphasis on production systems that are compatible with existing social structures, customary land ownership constraints, and local nutritional needs.

DELPHI ANALYSIS OF CONSTRAINTS TO MAIZE PRODUCTION IN ...

African Journals Online (AJOL)

A descriptive Delphi study was conducted to: identify constraints to maize production on SNL from the perspectives of crop researchers, extension officers and farmers; categorise the constraints; rank them in order of importance; and identify ways of addressing them. A total of 33 constraint items were identified and ...

Misconceptions and constraints

International Nuclear Information System (INIS)

Whitten, M.; Mahon, R.

2005-01-01

In theory, the sterile insect technique (SIT) is applicable to a wide variety of invertebrate pests. However, in practice, the approach has been successfully applied to only a few major pests. Chapters in this volume address possible reasons for this discrepancy, e.g. Klassen, Lance and McInnis, and Robinson and Hendrichs. The shortfall between theory and practice is partly due to the persistence of some common misconceptions, but it is mainly due to one constraint, or a combination of constraints, that are biological, financial, social or political in nature. This chapter's goal is to dispel some major misconceptions, and view the constraints as challenges to overcome, seeing them as opportunities to exploit. Some of the common misconceptions include: (1) released insects retain residual radiation, (2) females must be monogamous, (3) released males must be fully sterile, (4) eradication is the only goal, (5) the SIT is too sophisticated for developing countries, and (6) the SIT is not a component of an area-wide integrated pest management (AW-IPM) strategy. The more obvious constraints are the perceived high costs of the SIT, and the low competitiveness of released sterile males. The perceived high up-front costs of the SIT, their visibility, and the lack of private investment (compared with alternative suppression measures) emerge as serious constraints. Failure to appreciate the true nature of genetic approaches, such as the SIT, may pose a significant constraint to the wider adoption of the SIT and other genetically-based tactics, e.g. transgenic genetically modified organisms (GMOs). Lack of support for the necessary underpinning strategic research also appears to be an important constraint. Hence the case for extensive strategic research in ecology, population dynamics, genetics, and insect behaviour and nutrition is a compelling one. Raising the competitiveness of released sterile males remains the major research objective of the SIT. (author)

A review on important maize diseases and their management in Nepal

Directory of Open Access Journals (Sweden)

Subash Subedi

2015-12-01

Full Text Available In Nepal, maize ranks second after rice both in area and production. In recent years, maize area and production has shown a steady increase, but productivity has been low (2.46 t/ha. The major maize producing regions in Nepal are mid hill (72.85%, terai (17.36% and high hill (9.79% respectively. A literature review was carried out to explore major maize diseases and their management in Nepal. The omnipresent incidence of diseases at the pre harvest stage has been an important bottleneck in increasing production. Till now, a total of 78 (75 fungal and 3 bacterial species are pathogenic to maize crop in Nepal. The major and economically important maize diseases reported are Gray leaf spot, Northern leaf blight, Southern leaf Blight, Banded leaf and sheath blight, Ear rot, Stalk rot, Head smut, Common rust, Downy mildew and Brown spot. Information on bacterial and virus diseases, nematodes and yield loss assessment is also given. Description of the major maize diseases, their causal organisms, distribution, time and intensity of disease incidence, symptoms, survival, spreads, environmental factors for disease development, yield losses and various disease management strategies corresponded to important maize diseases of Nepal are gathered and compiled thoroughly from the available publications. Concerted efforts of NARC commodity programs, divisions, ARS and RARS involving research on maize pathology and their important outcomes are mentioned. The use of disease management methods focused on host resistance has also been highlighted.

A Survey of Myanmar Rice Production and Constraints

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T.A.A. Naing

2008-10-01

Full Text Available Although modern high yielding varieties were introduced into Myanmar in the early 1980s, the national average of rice grain yield has stagnated at 3.2-3.4 t ha-1. To identify yield constraints, input intensities and the general practices of rice cultivation in Myanmar, a survey was conducted during the wet seasons of 2001 and 2002. A total of 98 farmers from five townships in Upper Myanmar and 16 in Lower Myanmar representing the most important areas of rice production were questioned on their management practices, yields, and perceived yield constraints over the previous four years. There was a recent decrease in the overall average rate of fertilizer application, an increase in the prevalence of rice-legume cropping systems, and only localized insect pest or disease problems. Additionally, rice yields were found to be higher in Upper Myanmar, likely the results of more suitable weather conditions, better irrigation, and ready market access. Furthermore, a number of critical factors affecting production are identified and possible solutions discussed.

The functional importance of disease-associated mutation

Directory of Open Access Journals (Sweden)

Klein Teri E

2002-09-01

Full Text Available Abstract Background For many years, scientists believed that point mutations in genes are the genetic switches for somatic and inherited diseases such as cystic fibrosis, phenylketonuria and cancer. Some of these mutations likely alter a protein's function in a manner that is deleterious, and they should occur in functionally important regions of the protein products of genes. Here we show that disease-associated mutations occur in regions of genes that are conserved, and can identify likely disease-causing mutations. Results To show this, we have determined conservation patterns for 6185 non-synonymous and heritable disease-associated mutations in 231 genes. We define a parameter, the conservation ratio, as the ratio of average negative entropy of analyzable positions with reported mutations to that of every analyzable position in the gene sequence. We found that 84.0% of the 231 genes have conservation ratios less than one. 139 genes had eleven or more analyzable mutations and 88.0% of those had conservation ratios less than one. Conclusions These results indicate that phylogenetic information is a powerful tool for the study of disease-associated mutations. Our alignments and analysis has been made available as part of the database at http://cancer.stanford.edu/mut-paper/. Within this dataset, each position is annotated with the analysis, so the most likely disease-causing mutations can be identified.

Constraint Differentiation

DEFF Research Database (Denmark)

Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca

2010-01-01

We introduce constraint differentiation, a powerful technique for reducing search when model-checking security protocols using constraint-based methods. Constraint differentiation works by eliminating certain kinds of redundancies that arise in the search space when using constraints to represent...... results show that constraint differentiation substantially reduces search and considerably improves the performance of OFMC, enabling its application to a wider class of problems....

Constraint-based scheduling applying constraint programming to scheduling problems

CERN Document Server

Baptiste, Philippe; Nuijten, Wim

2001-01-01

Constraint Programming is a problem-solving paradigm that establishes a clear distinction between two pivotal aspects of a problem: (1) a precise definition of the constraints that define the problem to be solved and (2) the algorithms and heuristics enabling the selection of decisions to solve the problem. It is because of these capabilities that Constraint Programming is increasingly being employed as a problem-solving tool to solve scheduling problems. Hence the development of Constraint-Based Scheduling as a field of study. The aim of this book is to provide an overview of the most widely used Constraint-Based Scheduling techniques. Following the principles of Constraint Programming, the book consists of three distinct parts: The first chapter introduces the basic principles of Constraint Programming and provides a model of the constraints that are the most often encountered in scheduling problems. Chapters 2, 3, 4, and 5 are focused on the propagation of resource constraints, which usually are responsibl...

Participatory diagnosis and prioritization of constraints to cattle production in some smallholder farming areas of Zimbabwe.

Science.gov (United States)

Chatikobo, P; Choga, T; Ncube, C; Mutambara, J

2013-05-01

A participatory epidemiological study was conducted to identify and prioritize constraints to livestock health and production on smallholder farms in Sanyati and Gokwe districts of Zimbabwe. Questionnaires were administered to 294 randomly selected livestock owners across the two districts. Livestock diseases (29% of the respondents), high cost of drugs (18.21%), weak veterinary extension (15.18%), inadequate grazing (13.60%), inadequate water (13.54%), and livestock thefts (10.44%) were the major livestock health and production constraints identified. The number of diseases reported varied (Pdomestic chicken, donkeys, and guinea fowls, respectively. Seven (19.4%) of the 36 diseases including rabies and foot and mouth disease were those listed by the OIE. Thirty-four percent of the respondents rated bovine dermatophilosis as the most important livestock disease. Respondents rated, in descending order, other diseases including tick borne diseases (21%); a previously unreported disease, "Magwiriri" or "Ganda renzou" in vernacular (14%); mastitis (11%); parafilariosis (11%); and blackleg (9%). Cattle skin samples from "Magwiriri" cases had Besnoitia besnoiti parasites. Overall, this study revealed factors and diseases that limit livestock production in Zimbabwe and are of global concern; in addition, the study showed that the skin diseases, bovine dermatophilosis and besnoitiosis, have recently emerged and appear to be spreading, likely a consequence of ectoparasite control demise in smallholder farming areas of Zimbabwe over the last 15 years. Copyright © 2012 Elsevier B.V. All rights reserved.

Is exercise important in chronic obstructive pulmonary disease?

Science.gov (United States)

Make, Barry; Casaburi, Richard

2007-09-01

Chronic obstructive pulmonary disease impairs the ability of patients to perform maximal physical exercise, particularly in patients with severe lung disease. However, differing perceptions of the meaning and importance of exercise to patients and caregivers is likely to impair patient-physician communication about current medical status and outcomes of therapeutic interventions. Other outcomes of importance to patients including actual performance of functional activity during daily life and health-related quality of life may also be affected by impaired exercise capacity. However, the relationships between exercise, activity, and quality of life are inconsistent. Thus, measurement of physiologic and patient-centered outcomes may provide the best approach to assessing responses to therapeutic interventions. These concepts were explored in a conference sponsored by Boehringer Ingelheim Pharmaceuticals, Inc. and Pfizer Inc and reviewed in the articles generated from the symposium in this issue of COPD.

Parallel handling of integrity constraints on fragmented relations

NARCIS (Netherlands)

Grefen, P.W.P.J.; Apers, Peter M.G.

A short introduction to the important aspects of the PRISMA DBMS (database management system) and to the notation and terminology used is presented. It is shown how integrity constraints formulated in terms of global relations can be translated into a fragmented form. The strategy for constraint

Ring power balance observing plasma stability constraints

International Nuclear Information System (INIS)

Campbell, R.B.; Logan, B.G.

1982-01-01

Ring power balance is performed for an E-ring stabilized tandem mirror reactor, taking into account constraints imposed by plasma stability. The two most important criteria are the stability of the core interchange and hot electron interchange modes. The former determines the ring thickness, the latter determines the minimum hot electron temperature; both quantities are important for power balance. The combination of the hot electron interchange constraint and the fact that the barrier density is low places the operating point on the synchrotron dominated branch of power balance. The reference case considered here requires a reasonable 34 MW of heating power deposited in the rings. We also have examined the sensitivity of the required ring power on uncertainties in the numerical coefficients of the stability constraints. We have found that the heating power is strongly affected

[Clinical microbiology laboratory and imported parasitic diseases].

Science.gov (United States)

Martín-Rabadán, Pablo; Martínez-Ruiz, Rocío; Cuadros, Juan; Cañavate, Carmen

2010-12-01

Imported parasitosis represents an increasingly frequent diagnostic challenge for microbiology laboratories. A surge in immigration and international travel has led to a rise in the number of imported cases of parasitosis, and this trend is expected to continue in the future. The present article addresses this challenge by reviewing recommended diagnostic approaches and tests. Currently, microscopy is always recommended when analysing blood samples for parasites. If malaria is suspected, rapid antigen testing (including at least HRP2 antigen) should also be performed. The work-up for suspected leishmaniasis should include serology, culture, and in selected cases detection of antigen in urine. In suspected Chagas disease, two different serological tests should be performed. PCR for blood protozoa is highly sensitive, although it cannot be used to rule out Chagas disease, since this condition may be present without parasitemia. Accurate diagnosis of intestinal amebiasis usually requires PCR or antigen detection tests. In helminthiasis, traditional microscopy may need to be complemented with other tests, such as agar plate culture for strongyloidiasis, Og4C3 antigen detection for bancroftian filariasis, and antibody detection test for filariasis and schistosomiasis. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Constraints and Logic Programming in Grammars and Language Analysis

DEFF Research Database (Denmark)

Christiansen, Henning

2014-01-01

Constraints are an important notion in grammars and language analysis, and constraint programming techniques have been developed concurrently for solving a variety of complex problems. In this chapter we consider the synthesis of these branches into practical and effective methods for language...... methods that combine constraints with logic grammars such as Definite Clause Grammars and CHR Grammars, and show also a direct relationship to abductive reasoning....

Medical image segmentation by means of constraint satisfaction neural network

International Nuclear Information System (INIS)

Chen, C.T.; Tsao, C.K.; Lin, W.C.

1990-01-01

This paper applies the concept of constraint satisfaction neural network (CSNN) to the problem of medical image segmentation. Constraint satisfaction (or constraint propagation), the procedure to achieve global consistency through local computation, is an important paradigm in artificial intelligence. CSNN can be viewed as a three-dimensional neural network, with the two-dimensional image matrix as its base, augmented by various constraint labels for each pixel. These constraint labels can be interpreted as the connections and the topology of the neural network. Through parallel and iterative processes, the CSNN will approach a solution that satisfies the given constraints thus providing segmented regions with global consistency

Selective constraint on noncoding regions of hominid genomes.

Directory of Open Access Journals (Sweden)

Eliot C Bush

2005-12-01

Full Text Available An important challenge for human evolutionary biology is to understand the genetic basis of human-chimpanzee differences. One influential idea holds that such differences depend, to a large extent, on adaptive changes in gene expression. An important step in assessing this hypothesis involves gaining a better understanding of selective constraint on noncoding regions of hominid genomes. In noncoding sequence, functional elements are frequently small and can be separated by large nonfunctional regions. For this reason, constraint in hominid genomes is likely to be patchy. Here we use conservation in more distantly related mammals and amniotes as a way of identifying small sequence windows that are likely to be functional. We find that putatively functional noncoding elements defined in this manner are subject to significant selective constraint in hominids.

Selective Constraint on Noncoding Regions of Hominid Genomes.

Directory of Open Access Journals (Sweden)

2005-12-01

Full Text Available An important challenge for human evolutionary biology is to understand the genetic basis of human-chimpanzee differences. One influential idea holds that such differences depend, to a large extent, on adaptive changes in gene expression. An important step in assessing this hypothesis involves gaining a better understanding of selective constraint on noncoding regions of hominid genomes. In noncoding sequence, functional elements are frequently small and can be separated by large nonfunctional regions. For this reason, constraint in hominid genomes is likely to be patchy. Here we use conservation in more distantly related mammals and amniotes as a way of identifying small sequence windows that are likely to be functional. We find that putatively functional noncoding elements defined in this manner are subject to significant selective constraint in hominids.

Computing group cardinality constraint solutions for logistic regression problems.

Science.gov (United States)

Zhang, Yong; Kwon, Dongjin; Pohl, Kilian M

2017-01-01

We derive an algorithm to directly solve logistic regression based on cardinality constraint, group sparsity and use it to classify intra-subject MRI sequences (e.g. cine MRIs) of healthy from diseased subjects. Group cardinality constraint models are often applied to medical images in order to avoid overfitting of the classifier to the training data. Solutions within these models are generally determined by relaxing the cardinality constraint to a weighted feature selection scheme. However, these solutions relate to the original sparse problem only under specific assumptions, which generally do not hold for medical image applications. In addition, inferring clinical meaning from features weighted by a classifier is an ongoing topic of discussion. Avoiding weighing features, we propose to directly solve the group cardinality constraint logistic regression problem by generalizing the Penalty Decomposition method. To do so, we assume that an intra-subject series of images represents repeated samples of the same disease patterns. We model this assumption by combining series of measurements created by a feature across time into a single group. Our algorithm then derives a solution within that model by decoupling the minimization of the logistic regression function from enforcing the group sparsity constraint. The minimum to the smooth and convex logistic regression problem is determined via gradient descent while we derive a closed form solution for finding a sparse approximation of that minimum. We apply our method to cine MRI of 38 healthy controls and 44 adult patients that received reconstructive surgery of Tetralogy of Fallot (TOF) during infancy. Our method correctly identifies regions impacted by TOF and generally obtains statistically significant higher classification accuracy than alternative solutions to this model, i.e., ones relaxing group cardinality constraints. Copyright © 2016 Elsevier B.V. All rights reserved.

Modifier constraint in alkali borophosphate glasses using topological constraint theory

Energy Technology Data Exchange (ETDEWEB)

Li, Xiang [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zeng, Huidan, E-mail: hdzeng@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Jiang, Qi [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhao, Donghui [Unifrax Corporation, Niagara Falls, NY 14305 (United States); Chen, Guorong [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Wang, Zhaofeng; Sun, Luyi [Department of Chemical & Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269 (United States); Chen, Jianding [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2016-12-01

In recent years, composition-dependent properties of glasses have been successfully predicted using the topological constraint theory. The constraints of the glass network are derived from two main parts: network formers and network modifiers. The constraints of the network formers can be calculated on the basis of the topological structure of the glass. However, the latter cannot be accurately calculated in this way, because of the existing of ionic bonds. In this paper, the constraints of the modifier ions in phosphate glasses were thoroughly investigated using the topological constraint theory. The results show that the constraints of the modifier ions are gradually increased with the addition of alkali oxides. Furthermore, an improved topological constraint theory for borophosphate glasses is proposed by taking the composition-dependent constraints of the network modifiers into consideration. The proposed theory is subsequently evaluated by analyzing the composition dependence of the glass transition temperature in alkali borophosphate glasses. This method is supposed to be extended to other similar glass systems containing alkali ions.

Route constraints model based on polychromatic sets

Science.gov (United States)

Yin, Xianjun; Cai, Chao; Wang, Houjun; Li, Dongwu

2018-03-01

With the development of unmanned aerial vehicle (UAV) technology, the fields of its application are constantly expanding. The mission planning of UAV is especially important, and the planning result directly influences whether the UAV can accomplish the task. In order to make the results of mission planning for unmanned aerial vehicle more realistic, it is necessary to consider not only the physical properties of the aircraft, but also the constraints among the various equipment on the UAV. However, constraints among the equipment of UAV are complex, and the equipment has strong diversity and variability, which makes these constraints difficult to be described. In order to solve the above problem, this paper, referring to the polychromatic sets theory used in the advanced manufacturing field to describe complex systems, presents a mission constraint model of UAV based on polychromatic sets.

Graphical constraints: a graphical user interface for constraint problems

OpenAIRE

Vieira, Nelson Manuel Marques

2015-01-01

A constraint satisfaction problem is a classical artificial intelligence paradigm characterized by a set of variables (each variable with an associated domain of possible values), and a set of constraints that specify relations among subsets of these variables. Solutions are assignments of values to all variables that satisfy all the constraints. Many real world problems may be modelled by means of constraints. The range of problems that can use this representation is very diverse and embrace...

Financial Constraints: Explaining Your Position.

Science.gov (United States)

Cargill, Jennifer

1988-01-01

Discusses the importance of educating library patrons about the library's finances and the impact of budget constraints and the escalating cost of serials on materials acquisition. Steps that can be taken in educating patrons by interpreting and publicizing financial information are suggested. (MES)

Management practices and production constraints of central ...

African Journals Online (AJOL)

management practices of central highland goats and their major constraints. ... tance to improve the goat production potential and livelihood of the farmers in the study ... ing the productivity and income from keeping goats, there is a study gap in ..... and day time, possibly increasing the chance of getting contagious diseases.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.

[The Nature and Issues of Drug Addiction Treatment under Constraint].

Science.gov (United States)

Quirion, Bastien

This article is exploring different forms of constraint that are exerted in the field of drug addiction treatment. The objective of this article is to establish benchmarks and to stimulate reflection about the ethical and clinical implications of those constraints in the field of drug addiction treatment. This article is presenting a critical review of different forms of constraint that can be exerted in Canada in regard to the treatment of drug addiction. In the first section of the article, a definition of therapeutic intervention is proposed, that includes the dimension of power, which justifies the importance of considering the coercive aspects of treatment. The second section, which represents the core section of the paper, is devoted to the presentation of different levels of constraint that can be distinguished in regard to drug addicts who are under treatment. Three levels of constraint are exposed: judicial constraint, institutional constraint and relational constraint. The coercive aspect of treatment can then be recognized as a combination of all tree levels of constraint. Judicial constraint refers to any form of constraint in which the court or the judge is imposing or recommending treatment. This particular level of constraint can take different forms, such as therapeutic remands, conditions of a probation order, conditions of a conditional sentence of imprisonment, and coercive treatment such as the ones provided through drug courts. Institutional constraint refers to any form of constraint exerted within any institutional setting, such as correctional facilities and programs offered in community. Correctional facilities being limited by their own specific mission, it might have a major impact on the way the objectives of treatment are defined. Those limitations can then be considered as a form of constraint, in which drug users don't have much space to express their personal needs. Finally, relational constraint refers to any form of constraint in

Time Optimal Run-time Evaluation of Distributed Timing Constraints in Process Control Software

DEFF Research Database (Denmark)

Drejer, N.; Kristensen, C.H.

1993-01-01

This paper considers run-time evaluation of an important class of constraints; Timing constraints. These appear extensively in process control systems. Timing constraints are considered in distributed systems, i.e. systems consisting of multiple autonomous nodes......

Intertemporal consumption and credit constraints

DEFF Research Database (Denmark)

Leth-Petersen, Søren

2010-01-01

There is continuing controversy over the importance of credit constraints. This paper investigates whether total household expenditure and debt is affected by an exogenous increase in access to credit provided by a credit market reform that enabled Danish house owners to use housing equity...

Rodent-borne diseases and their public health importance in Iran.

Directory of Open Access Journals (Sweden)

Mohammad Hasan Rabiee

2018-04-01

Full Text Available Rodents are reservoirs and hosts for several zoonotic diseases such as plague, leptospirosis, and leishmaniasis. Rapid development of industry and agriculture, as well as climate change throughout the globe, has led to change or increase in occurrence of rodent-borne diseases. Considering the distribution of rodents throughout Iran, the aim of this review is to assess the risk of rodent-borne diseases in Iran.We searched Google Scholar, PubMed, Science Direct, Scientific Information Database (SID, and Magiran databases up to September 2016 to obtain articles reporting occurrence of rodent-borne diseases in Iran and extract information from them. Out of 70 known rodent-borne diseases, 34 were reported in Iran: 17 (50% parasitic diseases, 13 (38% bacterial diseases, and 4 (12% viral diseases. Twenty-one out of 34 diseases were reported from both humans and rodents. Among the diseases reported in the rodents of Iran, plague, leishmaniasis, and hymenolepiasis were the most frequent. The most infected rodents were Rattus norvegicus (16 diseases, Mus musculus (14 diseases, Rattus rattus (13 diseases, Meriones persicus (7 diseases, Apodemus spp. (5 diseases, Tatera indica (4 diseases, Meriones libycus (3 diseases, Rhombomys opimus (3 diseases, Cricetulus migratorius (3 diseases, and Nesokia indica (2 diseases.The results of this review indicate the importance of rodent-borne diseases in Iran. Considering notable diversity of rodents and their extensive distribution throughout the country, it is crucial to pay more attention to their role in spreading infectious diseases for better control of the diseases.

Rodent-borne diseases and their public health importance in Iran

Science.gov (United States)

Mahmoudi, Ahmad; Siahsarvie, Roohollah; Kryštufek, Boris; Mostafavi, Ehsan

2018-01-01

Background Rodents are reservoirs and hosts for several zoonotic diseases such as plague, leptospirosis, and leishmaniasis. Rapid development of industry and agriculture, as well as climate change throughout the globe, has led to change or increase in occurrence of rodent-borne diseases. Considering the distribution of rodents throughout Iran, the aim of this review is to assess the risk of rodent-borne diseases in Iran. Methodology/Principal finding We searched Google Scholar, PubMed, Science Direct, Scientific Information Database (SID), and Magiran databases up to September 2016 to obtain articles reporting occurrence of rodent-borne diseases in Iran and extract information from them. Out of 70 known rodent-borne diseases, 34 were reported in Iran: 17 (50%) parasitic diseases, 13 (38%) bacterial diseases, and 4 (12%) viral diseases. Twenty-one out of 34 diseases were reported from both humans and rodents. Among the diseases reported in the rodents of Iran, plague, leishmaniasis, and hymenolepiasis were the most frequent. The most infected rodents were Rattus norvegicus (16 diseases), Mus musculus (14 diseases), Rattus rattus (13 diseases), Meriones persicus (7 diseases), Apodemus spp. (5 diseases), Tatera indica (4 diseases), Meriones libycus (3 diseases), Rhombomys opimus (3 diseases), Cricetulus migratorius (3 diseases), and Nesokia indica (2 diseases). Conclusions/Significance The results of this review indicate the importance of rodent-borne diseases in Iran. Considering notable diversity of rodents and their extensive distribution throughout the country, it is crucial to pay more attention to their role in spreading infectious diseases for better control of the diseases. PMID:29672510

Urban and peri-urban family-based pig-keeping in Cambodia: Characteristics, management and perceived benefits and constraints.

Directory of Open Access Journals (Sweden)

Gunilla Ström

Full Text Available Keeping pigs in urban and peri-urban areas may not only provide many benefits for the urban households, but may also be challenging and a potential health hazard. The aim of this cross-sectional study was to describe household characteristics and to evaluate perceived benefits and constraints among pig-keepers in the urban and peri-urban areas of Phnom Penh, Cambodia. The study included 204 households and a structured questionnaire was used to interview the household member responsible for taking care of the pigs. Descriptive analyses showed that most households kept between 5 and 15 pigs and that all households kept their pigs in confinement. About 97% of the households owned the pigs themselves and the pigs were generally managed by female household members (43%. Pigs were mainly kept for commercial purposes and more than 60% of the households stated that income from pig-keeping was the main or one of the main sources of revenue for the household. More than 82% reported that they had experienced disease outbreaks among their pigs during the past three years and disease outbreaks were more commonly reported in households with lower socio-economic position (P = 0.025. Disease outbreaks were considered one of the main constraints, along with expensive feed and low payment prices for the slaughter pigs, but few households considered sanitary or other public health issues problematic. Thus, pig-keeping makes an important contribution to the livelihoods of urban and peri-urban households, but many households face external constraints on their production, such as diseases and low revenues, which may have a negative impact on their livelihoods.

Constraint Embedding Technique for Multibody System Dynamics

Science.gov (United States)

Woo, Simon S.; Cheng, Michael K.

2011-01-01

Multibody dynamics play a critical role in simulation testbeds for space missions. There has been a considerable interest in the development of efficient computational algorithms for solving the dynamics of multibody systems. Mass matrix factorization and inversion techniques and the O(N) class of forward dynamics algorithms developed using a spatial operator algebra stand out as important breakthrough on this front. Techniques such as these provide the efficient algorithms and methods for the application and implementation of such multibody dynamics models. However, these methods are limited only to tree-topology multibody systems. Closed-chain topology systems require different techniques that are not as efficient or as broad as those for tree-topology systems. The closed-chain forward dynamics approach consists of treating the closed-chain topology as a tree-topology system subject to additional closure constraints. The resulting forward dynamics solution consists of: (a) ignoring the closure constraints and using the O(N) algorithm to solve for the free unconstrained accelerations for the system; (b) using the tree-topology solution to compute a correction force to enforce the closure constraints; and (c) correcting the unconstrained accelerations with correction accelerations resulting from the correction forces. This constraint-embedding technique shows how to use direct embedding to eliminate local closure-loops in the system and effectively convert the system back to a tree-topology system. At this point, standard tree-topology techniques can be brought to bear on the problem. The approach uses a spatial operator algebra approach to formulating the equations of motion. The operators are block-partitioned around the local body subgroups to convert them into aggregate bodies. Mass matrix operator factorization and inversion techniques are applied to the reformulated tree-topology system. Thus in essence, the new technique allows conversion of a system with

Banana Cultivar Mapping and Constraints Identification With Farmers in Southwest Kenya

International Nuclear Information System (INIS)

Onyago, M.; Makworo, S.; Njue, E.; Rees, D.

1999-01-01

Southwest Kenya is one of the major banana growing ares of Kenya and contributes about 40% of the country's production. Banana is an important crop in Kenya providing the small-scale resource poor farmers with food and the much-needed income. In southwest Kenya, Banana is a priority crop that is grown in a wide range of farms from backyard gardens to medium farms. Rapid Rural Appraisal (RRP) and Participatory Rural Appraisal (PRA) were conducted between January, 1996 and December 1997. The overall objective was to identify major constraints in specific areas, rank them with farmers and determine suitable interventions. The RRA and PRA revealed that farmers grow banana as a pure stand, intercropped with crops like maize, beans and groundnuts, in addition along the contour lines for soil conservation purpose. Diverse banana cultivars are grown in the region, of which some are localised while others are widespread. The major cultivars grown include 'Ekeganda', Kisukari', 'Ng'ombe' and 'Pisang Awak'. Pisang Awak was found prevalent in drier areas of Kendu Bay (LM 3 ) and very cold areas of Bomet (LH 1 ). Ekeganda is the most popular cooking type while Kisukari is a dessert type and is the second most popular banana cultivar in the region. Some of the constraints cut across the AEZs and include a complex of pests and diseases, poor orchard management, soil exhaustion because of land pressure, lack of superior cultivars and socioeconomic factors such as poor infrastructure. Panama disease, nematodes and banana weevil are prevalent at the medium and lower AEZs while moles are menace in the upper midlands and highland areas. To address some of the major constraints, on-farm banana cultivar evaluation trials were initiated in four AEZs namely LM 3-4 , LH 1 , UM 1 and LM 2 , respectively. Monitoring and evaluation of these cultivars by both researchers, extension and farmers is on-going

Constraints, Trade-offs and the Currency of Fitness.

Science.gov (United States)

Acerenza, Luis

2016-03-01

Understanding evolutionary trajectories remains a difficult task. This is because natural evolutionary processes are simultaneously affected by various types of constraints acting at the different levels of biological organization. Of particular importance are constraints where correlated changes occur in opposite directions, called trade-offs. Here we review and classify the main evolutionary constraints and trade-offs, operating at all levels of trait hierarchy. Special attention is given to life history trade-offs and the conflict between the survival and reproduction components of fitness. Cellular mechanisms underlying fitness trade-offs are described. At the metabolic level, a linear trade-off between growth and flux variability was found, employing bacterial genome-scale metabolic reconstructions. Its analysis indicates that flux variability can be considered as the currency of fitness. This currency is used for fitness transfer between fitness components during adaptations. Finally, a discussion is made regarding the constraints which limit the increase in the amount of fitness currency during evolution, suggesting that occupancy constraints are probably the main restrictions.

Challenges and constraints to vaccination in developing countries.

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Alders, R G; Bagnol, B; Young, M P; Ahlers, C; Brum, E; Rushton, J

2007-01-01

The challenges and constraints to vaccinating poultry in areas where adequate infrastructure and human resources are lacking are addressed in both a technical and a socioeconomic framework. The key issues discussed are: (1) selection of an appropriate vaccine and vaccination technique, including the advantages and disadvantages of a combined vaccine against highly pathogenic avian influenza (HPAI) and Newcastle disease and addressing the differences between endemic disease and emergency disease control; (2) vaccine conservation and distribution; (3) evaluation of the flocks to be vaccinated in terms of their disease status, immunocompetence and production systems; (4) design of effective information, education and communication materials and methods with and for veterinary and extension staff as well as commercial and smallholder producers and community vaccinators in rural areas; (5) evaluation and monitoring systems for technical and socioeconomic factors that affect vaccination; (6) support and coordination of and by relevant public and private agencies; (7) the role of simultaneous implementation of other control activities in addition to vaccination; (8) the importance of assessing the costs and cost-effectiveness of various approaches to the control of HPAI, including the prevention of other endemic killer diseases and options for cost-sharing; (9) evaluation of the incentives for poultry-holders, vaccinators and vaccine producers to contribute to and participate in effective vaccination campaigns; and (10) policy development and the organizational framework for short- and long-term implementation and communication to decision-makers.

From physical dose constraints to equivalent uniform dose constraints in inverse radiotherapy planning

International Nuclear Information System (INIS)

Thieke, Christian; Bortfeld, Thomas; Niemierko, Andrzej; Nill, Simeon

2003-01-01

Optimization algorithms in inverse radiotherapy planning need information about the desired dose distribution. Usually the planner defines physical dose constraints for each structure of the treatment plan, either in form of minimum and maximum doses or as dose-volume constraints. The concept of equivalent uniform dose (EUD) was designed to describe dose distributions with a higher clinical relevance. In this paper, we present a method to consider the EUD as an optimization constraint by using the method of projections onto convex sets (POCS). In each iteration of the optimization loop, for the actual dose distribution of an organ that violates an EUD constraint a new dose distribution is calculated that satisfies the EUD constraint, leading to voxel-based physical dose constraints. The new dose distribution is found by projecting the current one onto the convex set of all dose distributions fulfilling the EUD constraint. The algorithm is easy to integrate into existing inverse planning systems, and it allows the planner to choose between physical and EUD constraints separately for each structure. A clinical case of a head and neck tumor is optimized using three different sets of constraints: physical constraints for all structures, physical constraints for the target and EUD constraints for the organs at risk, and EUD constraints for all structures. The results show that the POCS method converges stable and given EUD constraints are reached closely

Beyond mechanistic interaction: Value-based constraints on meaning in language

Directory of Open Access Journals (Sweden)

Joanna eRączaszek-Leonardi

2015-10-01

Full Text Available According to situated, embodied, distributed approaches to cognition, language is a crucial means for structuring social interactions. Recent approaches that emphasize the coordinative function of language treat language as a system of replicable constraints that work both on individuals and on interactions. In this paper we argue that the integration of replicable constraints approach to language with the ecological view on values allows for a deeper insight into processes of meaning creation in interaction. Such synthesis of these frameworks draws attention to important sources of structuring interactions beyond the sheer efficiency of a collective system in its current task situation. Most importantly the workings of linguistic constraints will be shown as embedded in more general fields of values, which are realized on multiple time-scales. Since the ontogenetic timescale offers a convenient window into a process of the emergence of linguistic constraints, we present illustrations of concrete mechanisms through which values may become embodied in language use in development.

Beyond mechanistic interaction: value-based constraints on meaning in language.

Science.gov (United States)

Rączaszek-Leonardi, Joanna; Nomikou, Iris

2015-01-01

According to situated, embodied, and distributed approaches to cognition, language is a crucial means for structuring social interactions. Recent approaches that emphasize this coordinative function treat language as a system of replicable constraints on individual and interactive dynamics. In this paper, we argue that the integration of the replicable-constraints approach to language with the ecological view on values allows for a deeper insight into processes of meaning creation in interaction. Such a synthesis of these frameworks draws attention to important sources of structuring interactions beyond the sheer efficiency of a collective system in its current task situation. Most importantly, the workings of linguistic constraints will be shown as embedded in more general fields of values, which are realized on multiple timescales. Because the ontogenetic timescale offers a convenient window into the emergence of linguistic constraints, we present illustrations of concrete mechanisms through which values may become embodied in language use in development.

Energy constraints and organizational change in US production

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

There is still considerable uncertainty about the way in which energy-supply constraints affect industrial thinking and activity. Yet, this is an important issue in determining the effectiveness of conservation programs and in formulating energy policy. The authors expand on a survey of US business attitudes and responses to energy constraints first published in the September 1979 Energy Policy with the results of further analysis of their survey. In particular, they examine correlations between perceived causes and preferred solutions of energy problems, organizational adjustments to energy constraints in energy-intensive industries, and the ways in which production operations have changed in response to supply problems. 5 references, 5 tables.

q-Virasoro constraints in matrix models

Energy Technology Data Exchange (ETDEWEB)

Nedelin, Anton [Dipartimento di Fisica, Università di Milano-Bicocca and INFN, sezione di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy); Department of Physics and Astronomy, Uppsala university,Box 516, SE-75120 Uppsala (Sweden); Zabzine, Maxim [Department of Physics and Astronomy, Uppsala university,Box 516, SE-75120 Uppsala (Sweden)

2017-03-20

The Virasoro constraints play the important role in the study of matrix models and in understanding of the relation between matrix models and CFTs. Recently the localization calculations in supersymmetric gauge theories produced new families of matrix models and we have very limited knowledge about these matrix models. We concentrate on elliptic generalization of hermitian matrix model which corresponds to calculation of partition function on S{sup 3}×S{sup 1} for vector multiplet. We derive the q-Virasoro constraints for this matrix model. We also observe some interesting algebraic properties of the q-Virasoro algebra.

Producing Satisfactory Solutions to Scheduling Problems: An Iterative Constraint Relaxation Approach

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Chien, S.; Gratch, J.

1994-01-01

One drawback to using constraint-propagation in planning and scheduling systems is that when a problem has an unsatisfiable set of constraints such algorithms typically only show that no solution exists. While, technically correct, in practical situations, it is desirable in these cases to produce a satisficing solution that satisfies the most important constraints (typically defined in terms of maximizing a utility function). This paper describes an iterative constraint relaxation approach in which the scheduler uses heuristics to progressively relax problem constraints until the problem becomes satisfiable. We present empirical results of applying these techniques to the problem of scheduling spacecraft communications for JPL/NASA antenna resources.

Field management of Phytophthora blight disease of cocoyam ...

African Journals Online (AJOL)

Cocoyam (Colocasia esculenta L). is an important edible tuber crop, but taro leaf blight caused by Phytophthora colocasiae has been the greatest constraint to cocoyam production in Nigeria since 2009. Field trials were conducted to determine the effect of fungicides and the spray regimes on leaf growth, disease incidence, ...

[Ticks and transmission of some important diseases by ticks].

Science.gov (United States)

Gazyağci, Aycan Nuriye; Aydenızöz, Meral

2010-01-01

Ticks which are commonly found all around the world are ectoparasites which are obliged to suck blood from vertebrates such as mammals and birds during all of their periods of develeopment. They may cause toxicities and paralyses in the course of blood sucking through saliva injection and the attachment sites may become ports of entry for secondary agents. Healthy animals that are severely infested by ticks can show a decreased yield and anemia. Young and sick animals can even die. Besides this, ticks are both biological and mechanical vectors for viruses, bacteria, rickettsias, spirochaetas, protozoons and helminths. Ten percent of the ticks identified in the world are associated with 200 diseases. In this review the taxonomy and morphology of ticks, some of the important diseases they carry and the diagnosis and treatment of these diseases are mentioned.

Implications of water constraints for electricity capacity expansion in the United States

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Liu, L.; Hejazi, M. I.; Iyer, G.; Forman, B. A.

2017-12-01

U.S. electricity generation is vulnerable to water supply since water is required for cooling. Constraints on the availability of water will therefore necessitate adaptive planning by the power generation sector. Hence, it is important to integrate restrictions in water availability in electricity capacity planning in order to better understand the economic viability of alternative capacity planning options. The study of the implications of water constraints for the U.S. power generation system is limited in terms of scale and robustness. We extend previous studies by including physical water constraints in a state-level model of the U.S. energy system embedded within a global integrated assessment model (GCAM-USA). We focus on the implications of such constraints for the U.S. electricity capacity expansion, integrating both supply and demand effects under a consistent framework. Constraints on the availability of water have two general effects across the U.S. First, water availability constraints increase the cost of electricity generation, resulting in reduced electrification of end-use sectors. Second, water availability constraints result in forced retirements of water-intensive technologies such as thermoelectric coal- and gas- fired technologies before the end of their natural lifetimes. The demand for electricity is then met by an increase in investments in less water-dependent technologies such as wind and solar photovoltaic. Our results show that the regional patterns of the above effects are heterogeneous across the U.S. In general, the impacts of water constraints on electricity capacity expansion are more pronounced in the West than in the East. This is largely because of lower water availability in the West compared to the East due to lower precipitation in the Western states. Constraints on the availability of water might also have important implications for U.S. electricity trade. For example, under severe constraints on the availability of water

Constraint-based reachability

Directory of Open Access Journals (Sweden)

Arnaud Gotlieb

2013-02-01

Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

Modeling the main fungal diseases of winter wheat: constraints and possible solutions

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The first step in the formulation of disease management strategy for any cropping system is to identify the most important risk factors among those on the long list of possible candidates. This is facilitated by basic epidemiological studies of pathogen life cycles, and an understanding of the way i...

The relative importance of geophysical constraints, amenity values, and farm-related factors in the dynamics of grassland set-aside

DEFF Research Database (Denmark)

Odgaard, Mette Vestergaard; Moeslund, Jesper Erenskjold; Bøcher, Peder Klith

2013-01-01

This study aimed at quantifying the spatial distribution of set-aside – highly valuable biodiversity reservoirs – in a typical lowland agricultural region (Denmark), just before and after the set-aside policy change (years 2007 and 2008), to assess which factors drive farmers’ set-aside priorities......, and to elaborate the potential consequence of the set-aside spatial transformation from 2007 to 2008 on nature. Multiple regressions were used to test if and how set-aside is linked to three potential groups of drivers: (1) geophysical constraints (topographic and edaphic constraints on the farming......-suitability of an area), (2) amenity values (nature conservation and aesthetic values), and (3) farming-related factors (e.g., field size and livestock density). The spatial distribution of set-aside was influenced by both geophysical constraints and amenity values and only some extent farming-related factors. More...

Constraints Faced by the Dairy Farmers in Nagpur District while Adopting Animal Managenment Practices

Directory of Open Access Journals (Sweden)

A.P.Patil

2009-06-01

Full Text Available The present study was carried out to analyse the constraints faced by the dairy farmers in Nagpur district. This study was conducted in 15 villages from 3 talukas of Nagpur district by personally interviewing 225 dairy farmers. Here, majority of the respondents (72.44% stated their constraint as low milk production from the local breeds, 45.33% as shortage of green fodder and 41.33% as lack of clean water while 25.33% stated lack of preservation facility as their constraint. Referring to the financial constraints, 78.22% respondents stated their constraint as delay in milk payment,63.11% as inadequate money and lack of loan facility whereas high cost of concentrates as the constraint by 56.44% of the respondents. As regards technical constraints, majority of the respondents (68.00% have stated their constraint as inadequate knowledge of diseases, their prevention and control while 56.89% have referred their constraint as non-availability of veterinary services. [Vet. World 2009; 2(3.000: 111-112

Web-based GIS: the vector-borne disease airline importation risk (VBD-AIR) tool.

Science.gov (United States)

Huang, Zhuojie; Das, Anirrudha; Qiu, Youliang; Tatem, Andrew J

2012-08-14

Over the past century, the size and complexity of the air travel network has increased dramatically. Nowadays, there are 29.6 million scheduled flights per year and around 2.7 billion passengers are transported annually. The rapid expansion of the network increasingly connects regions of endemic vector-borne disease with the rest of the world, resulting in challenges to health systems worldwide in terms of vector-borne pathogen importation and disease vector invasion events. Here we describe the development of a user-friendly Web-based GIS tool: the Vector-Borne Disease Airline Importation Risk Tool (VBD-AIR), to help better define the roles of airports and airlines in the transmission and spread of vector-borne diseases. Spatial datasets on modeled global disease and vector distributions, as well as climatic and air network traffic data were assembled. These were combined to derive relative risk metrics via air travel for imported infections, imported vectors and onward transmission, and incorporated into a three-tier server architecture in a Model-View-Controller framework with distributed GIS components. A user-friendly web-portal was built that enables dynamic querying of the spatial databases to provide relevant information. The VBD-AIR tool constructed enables the user to explore the interrelationships among modeled global distributions of vector-borne infectious diseases (malaria. dengue, yellow fever and chikungunya) and international air service routes to quantify seasonally changing risks of vector and vector-borne disease importation and spread by air travel, forming an evidence base to help plan mitigation strategies. The VBD-AIR tool is available at http://www.vbd-air.com. VBD-AIR supports a data flow that generates analytical results from disparate but complementary datasets into an organized cartographical presentation on a web map for the assessment of vector-borne disease movements on the air travel network. The framework built provides a flexible

Constraint Logic Programming approach to protein structure prediction

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Fogolari Federico

2004-11-01

Full Text Available Abstract Background The protein structure prediction problem is one of the most challenging problems in biological sciences. Many approaches have been proposed using database information and/or simplified protein models. The protein structure prediction problem can be cast in the form of an optimization problem. Notwithstanding its importance, the problem has very seldom been tackled by Constraint Logic Programming, a declarative programming paradigm suitable for solving combinatorial optimization problems. Results Constraint Logic Programming techniques have been applied to the protein structure prediction problem on the face-centered cube lattice model. Molecular dynamics techniques, endowed with the notion of constraint, have been also exploited. Even using a very simplified model, Constraint Logic Programming on the face-centered cube lattice model allowed us to obtain acceptable results for a few small proteins. As a test implementation their (known secondary structure and the presence of disulfide bridges are used as constraints. Simplified structures obtained in this way have been converted to all atom models with plausible structure. Results have been compared with a similar approach using a well-established technique as molecular dynamics. Conclusions The results obtained on small proteins show that Constraint Logic Programming techniques can be employed for studying protein simplified models, which can be converted into realistic all atom models. The advantage of Constraint Logic Programming over other, much more explored, methodologies, resides in the rapid software prototyping, in the easy way of encoding heuristics, and in exploiting all the advances made in this research area, e.g. in constraint propagation and its use for pruning the huge search space.

Constraint Logic Programming approach to protein structure prediction.

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Dal Palù, Alessandro; Dovier, Agostino; Fogolari, Federico

2004-11-30

The protein structure prediction problem is one of the most challenging problems in biological sciences. Many approaches have been proposed using database information and/or simplified protein models. The protein structure prediction problem can be cast in the form of an optimization problem. Notwithstanding its importance, the problem has very seldom been tackled by Constraint Logic Programming, a declarative programming paradigm suitable for solving combinatorial optimization problems. Constraint Logic Programming techniques have been applied to the protein structure prediction problem on the face-centered cube lattice model. Molecular dynamics techniques, endowed with the notion of constraint, have been also exploited. Even using a very simplified model, Constraint Logic Programming on the face-centered cube lattice model allowed us to obtain acceptable results for a few small proteins. As a test implementation their (known) secondary structure and the presence of disulfide bridges are used as constraints. Simplified structures obtained in this way have been converted to all atom models with plausible structure. Results have been compared with a similar approach using a well-established technique as molecular dynamics. The results obtained on small proteins show that Constraint Logic Programming techniques can be employed for studying protein simplified models, which can be converted into realistic all atom models. The advantage of Constraint Logic Programming over other, much more explored, methodologies, resides in the rapid software prototyping, in the easy way of encoding heuristics, and in exploiting all the advances made in this research area, e.g. in constraint propagation and its use for pruning the huge search space.

Inflammatory pathways of importance for management of inflammatory bowel disease

DEFF Research Database (Denmark)

Pedersen, Jannie; Coskun, Mehmet; Soendergaard, Christoffer

2014-01-01

Inflammatory bowel disease (IBD) is a group of chronic disorders of the gastrointestinal tract comprising Crohn's disease (CD) and ulcerative colitis (UC). Their etiologies are unknown, but they are characterised by an imbalanced production of pro-inflammatory mediators, e.g., tumor necrosis factor......-inflammatory cytokines, antibodies targeting integrins, and small anti-adhesion molecules that block adhesion between leukocytes and the intestinal vascular endothelium, reducing their infiltration into the inflamed mucosa. In this review we have elucidated the major signaling pathways of clinical importance for IBD...

Reduction of Constraints: Applicability of the Homogeneity Constraint for Macrobatch 3

International Nuclear Information System (INIS)

Peeler, D.K.

2001-01-01

The Product Composition Control System (PCCS) is used to determine the acceptability of each batch of Defense Waste Processing Facility (DWPF) melter feed in the Slurry Mix Evaporator (SME). This control system imposes several constraints on the composition of the contents of the SME to define acceptability. These constraints relate process or product properties to composition via prediction models. A SME batch is deemed acceptable if its sample composition measurements lead to acceptable property predictions after accounting for modeling, measurement and analytic uncertainties. The baseline document guiding the use of these data and models is ''SME Acceptability Determination for DWPF Process Control (U)'' by Brown and Postles [1996]. A minimum of three PCCS constraints support the prediction of the glass durability from a given SME batch. The Savannah River Technology Center (SRTC) is reviewing all of the PCCS constraints associated with durability. The purpose of this review is to revisit these constraints in light of the additional knowledge gained since the beginning of radioactive operations at DWPF and to identify any supplemental studies needed to amplify this knowledge so that redundant or overly conservative constraints can be eliminated or replaced by more appropriate constraints

Exploring the roles of cannot-link constraint in community detection via Multi-variance Mixed Gaussian Generative Model

Science.gov (United States)

Ge, Meng; Jin, Di; He, Dongxiao; Fu, Huazhu; Wang, Jing; Cao, Xiaochun

2017-01-01

Due to the demand for performance improvement and the existence of prior information, semi-supervised community detection with pairwise constraints becomes a hot topic. Most existing methods have been successfully encoding the must-link constraints, but neglect the opposite ones, i.e., the cannot-link constraints, which can force the exclusion between nodes. In this paper, we are interested in understanding the role of cannot-link constraints and effectively encoding pairwise constraints. Towards these goals, we define an integral generative process jointly considering the network topology, must-link and cannot-link constraints. We propose to characterize this process as a Multi-variance Mixed Gaussian Generative (MMGG) Model to address diverse degrees of confidences that exist in network topology and pairwise constraints and formulate it as a weighted nonnegative matrix factorization problem. The experiments on artificial and real-world networks not only illustrate the superiority of our proposed MMGG, but also, most importantly, reveal the roles of pairwise constraints. That is, though the must-link is more important than cannot-link when either of them is available, both must-link and cannot-link are equally important when both of them are available. To the best of our knowledge, this is the first work on discovering and exploring the importance of cannot-link constraints in semi-supervised community detection. PMID:28678864

Culture and National Well-Being: Should Societies Emphasize Freedom or Constraint?

Science.gov (United States)

Harrington, Jesse R; Boski, Pawel; Gelfand, Michele J

2015-01-01

Throughout history and within numerous disciplines, there exists a perennial debate about how societies should best be organized. Should they emphasize individual freedom and autonomy or security and constraint? Contrary to proponents who tout the benefits of one over the other, we demonstrate across 32 nations that both freedom and constraint exhibit a curvilinear relationship with many indicators of societal well-being. Relative to moderate nations, very permissive and very constrained nations exhibit worse psychosocial outcomes (lower happiness, greater dysthymia, higher suicide rates), worse health outcomes (lower life expectancy, greater mortality rates from cardiovascular disease and diabetes) and poorer economic and political outcomes (lower gross domestic product per capita, greater risk for political instability). This supports the notion that a balance between freedom and constraint results in the best national outcomes. Accordingly, it is time to shift the debate away from either constraint or freedom and focus on both in moderation.

Momentum constraint relaxation

International Nuclear Information System (INIS)

Marronetti, Pedro

2006-01-01

Full relativistic simulations in three dimensions invariably develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. Recently, we introduced a numerical method (Hamiltonian relaxation) that greatly reduces the Hamiltonian constraint violation and helps improve the quality of the numerical model. We present here a method that controls the violation of the momentum constraint. The method is based on the addition of a longitudinal component to the traceless extrinsic curvature A ij -tilde, generated by a vector potential w i , as outlined by York. The components of w i are relaxed to solve approximately the momentum constraint equations, slowly pushing the evolution towards the space of solutions of the constraint equations. We test this method with simulations of binary neutron stars in circular orbits and show that it effectively controls the growth of the aforementioned violations. We also show that a full numerical enforcement of the constraints, as opposed to the gentle correction of the momentum relaxation scheme, results in the development of instabilities that stop the runs shortly

A survey of major constraints limiting commercial poultry production ...

African Journals Online (AJOL)

In a survey of major constraints limiting commercial poultry production in Gombe metropolis, 2,121 poultry cases were presented at the Gombe State Veterinary Clinic between January 1995 and December 2004. Out of the total number of cases presented, Newcastle disease (ND) accounted for 14.66%, chronic respiratory ...

Currently important animal disease management issues in sub-Saharan Africa.

Science.gov (United States)

Thomson, G R

2009-03-01

The present international approach to management of transboundary animal diseases (TADs) is based on the assumption that most can be eradicated; consequently, that is the usual objective adopted by international organizations concerned with animal health. However, for sub-Saharan Africa and southern Africa more particularly, eradication of most TADs is impossible for the foreseeable future for a variety of technical, financial and logistical reasons. Compounding this, the present basis for access to international markets for products derived from animals requires that the area of origin (country or zone) is free from trade-influencing TADs. The ongoing development of transfrontier conservation areas (TFCAs), extending across huge areas of southern Africa, therefore presents a development conundrum because it makes creation of geographic areas free from TADs more difficult and brings development based on wildlife conservation on the one hand and that based on livestock production on the other into sharp conflict. Sub-Saharan Africa is consequently confronted by a complex problem that contributes significantly to retarded rural development which, in turn, impedes poverty alleviation. In southern Africa specifically, foot-and-mouth disease (FMD) presents the greatest problem in relation to access to international markets for animal products. However, it is argued that this problem could be overcome by a combination between (1) implementation of a commodity-based approach to trade in products derived from animals and (2) amendment of the international standards for FMD specifically (i.e. the FMD chapter in the Terrestrial Animal Health Code of the World Organisation for Animal Health [OIE]) so that occurrence of SAT serotype viruses in free-living African buffalo need not necessarily mean exclusion of areas where buffalo occur from international markets for animal products. This would overcome a presently intractable constraint to market access for southern African

A comparison of Heuristic method and Llewellyn’s rules for identification of redundant constraints

Science.gov (United States)

Estiningsih, Y.; Farikhin; Tjahjana, R. H.

2018-03-01

Important techniques in linear programming is modelling and solving practical optimization. Redundant constraints are consider for their effects on general linear programming problems. Identification and reduce redundant constraints are for avoidance of all the calculations associated when solving an associated linear programming problems. Many researchers have been proposed for identification redundant constraints. This paper a compararison of Heuristic method and Llewellyn’s rules for identification of redundant constraints.

Culture and National Well-Being: Should Societies Emphasize Freedom or Constraint?

Directory of Open Access Journals (Sweden)

Jesse R Harrington

Full Text Available Throughout history and within numerous disciplines, there exists a perennial debate about how societies should best be organized. Should they emphasize individual freedom and autonomy or security and constraint? Contrary to proponents who tout the benefits of one over the other, we demonstrate across 32 nations that both freedom and constraint exhibit a curvilinear relationship with many indicators of societal well-being. Relative to moderate nations, very permissive and very constrained nations exhibit worse psychosocial outcomes (lower happiness, greater dysthymia, higher suicide rates, worse health outcomes (lower life expectancy, greater mortality rates from cardiovascular disease and diabetes and poorer economic and political outcomes (lower gross domestic product per capita, greater risk for political instability. This supports the notion that a balance between freedom and constraint results in the best national outcomes. Accordingly, it is time to shift the debate away from either constraint or freedom and focus on both in moderation.

REVIEW ON IMPORTANT HELMINTHIC DISEASES IN ANIMAL IN INDONESIA

Directory of Open Access Journals (Sweden)

I.G. P. Suweta

2012-09-01

Full Text Available Helminthic diseases are widely spread throughout the world. In Indonesia, the cases in animals are primarily associated with the condition of the field, although the intensity of the infestations are also affected by various factors inside the body of the host. In general, the tropical and humid conditions in Indonesia, optimally support the development and spreading of the parasites, so that the prevalence of the infestations are usually high except in the very dry areas. In Indonesia, important helminthic diseases found in livestock are mostly caused by nematodes and trematodes, and there is a lack of information regarding cestode infestations, except infestation by immature stages of the worm such as cysticercosis in ruminants and swine. On the other hand, dogs and cats are usually infested by cestodes and nematodes. Here, the negative influence of helminthic infestation on live stock is mostiy shown by failure of growth, decrease of body weight and body resistance, damage of organs infested by the parasites, but it is not rare that the disease cause death of the infested animals such as haemonchiasis in sheep, ascariasis in young swine and calves, etc. The integrated system of farming combined with periodic anthelminthic treatments were favourable in the effort of controlling the disease.

Hyper-spectral frequency selection for the classification of vegetation diseases

OpenAIRE

Dijkstra, Klaas; van de Loosdrecht, Jaap; Schomaker, Lambert; Wiering, Marco

2017-01-01

Reducing the use of pesticides by early visual detection of diseases in precision agriculture is important. Because of the color similarity between potato-plant diseases, narrow band hyper-spectral imaging is required. Payload constraints on unmanned aerial vehicles require reduc- tion of spectral bands. Therefore, we present a methodology for per-patch classification combined with hyper-spectral band selection. In controlled experiments performed on a set of individual leaves, we measure the...

Important considerations in the management of Graves' disease in pregnant women.

Science.gov (United States)

Okosieme, Onyebuchi E; Lazarus, John H

2015-01-01

Graves' disease is an autoimmune disorder in which autoantibodies to the thyroid-stimulating hormone receptor cause hyperthyroidism through unregulated stimulation of the thyroid-stimulating hormone receptor. Effective management of Graves' disease in pregnancy must address the competing fetal and maternal priorities of controlling hyperthyroidism in the mother on the one hand, and on the other, minimizing the impact of maternal disease and antithyroid drugs on the well-being of the fetus. Optimal strategies for achieving this intricate balance are currently a source of continued debate among thyroid experts and studies in recent decades are now providing greater clarity into the risk posed to the unborn baby by the combination of biochemical, immunological and pharmacological hazards arising from Graves' disease and its therapy. This review summarizes the current best practice and highlights important considerations and areas of uncertainty in the management of Graves' disease in pregnant women.

78 FR 11521 - Control of Communicable Disease; Foreign-Requirements for Importers of Nonhuman Primates (NHP)

Science.gov (United States)

2013-02-15

... Part 71 Control of Communicable Disease; Foreign--Requirements for Importers of Nonhuman Primates (NHP... Primates (NHP) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health and Human... live nonhuman primates (NHPs) by extending existing requirements for the importation of Macaca...

About some types of constraints in problems of routing

Science.gov (United States)

Petunin, A. A.; Polishuk, E. G.; Chentsov, A. G.; Chentsov, P. A.; Ukolov, S. S.

2016-12-01

Many routing problems arising in different applications can be interpreted as a discrete optimization problem with additional constraints. The latter include generalized travelling salesman problem (GTSP), to which task of tool routing for CNC thermal cutting machines is sometimes reduced. Technological requirements bound to thermal fields distribution during cutting process are of great importance when developing algorithms for this task solution. These requirements give rise to some specific constraints for GTSP. This paper provides a mathematical formulation for the problem of thermal fields calculating during metal sheet thermal cutting. Corresponding algorithm with its programmatic implementation is considered. The mathematical model allowing taking such constraints into account considering other routing problems is discussed either.

Generalizing Backtrack-Free Search: A Framework for Search-Free Constraint Satisfaction

Science.gov (United States)

Jonsson, Ari K.; Frank, Jeremy

2000-01-01

Tractable classes of constraint satisfaction problems are of great importance in artificial intelligence. Identifying and taking advantage of such classes can significantly speed up constraint problem solving. In addition, tractable classes are utilized in applications where strict worst-case performance guarantees are required, such as constraint-based plan execution. In this work, we present a formal framework for search-free (backtrack-free) constraint satisfaction. The framework is based on general procedures, rather than specific propagation techniques, and thus generalizes existing techniques in this area. We also relate search-free problem solving to the notion of decision sets and use the result to provide a constructive criterion that is sufficient to guarantee search-free problem solving.

Towards first principle medical diagnostics: on the importance of disease-disease and sign-sign interactions

Science.gov (United States)

Ramezanpour, Abolfazl; Mashaghi, Alireza

2017-07-01

A fundamental problem in medicine and biology is to assign states, e.g. healthy or diseased, to cells, organs or individuals. State assignment or making a diagnosis is often a nontrivial and challenging process and, with the advent of omics technologies, the diagnostic challenge is becoming more and more serious. The challenge lies not only in the increasing number of measured properties and dynamics of the system (e.g. cell or human body) but also in the co-evolution of multiple states and overlapping properties, and degeneracy of states. We develop, from first principles, a generic rational framework for state assignment in cell biology and medicine, and demonstrate its applicability with a few simple theoretical case studies from medical diagnostics. We show how disease-related statistical information can be used to build a comprehensive model that includes the relevant dependencies between clinical and laboratory findings (signs) and diseases. In particular, we include disease-disease and sign-sign interactions and study how one can infer the probability of a disease in a patient with given signs. We perform comparative analysis with simple benchmark models to check the performances of our models. We find that including interactions can significantly change the statistical importance of the signs and diseases. This first principles approach, as we show, facilitates the early diagnosis of disease by taking interactions into accounts, and enables the construction of consensus diagnostic flow charts. Additionally, we envision that our approach will find applications in systems biology, and in particular, in characterizing the phenome via the metabolome, the proteome, the transcriptome, and the genome.

Analysis on the contributions of and constraints to camel production in Shinile and Jijiga zones, eastern Ethiopia

Directory of Open Access Journals (Sweden)

Eyassu Seifu

2011-11-01

Full Text Available Contributions of the dromedary camel and constraints to camel production in Jijiga and Shinile zones of eastern Ethiopia were assessed. A total of 73 households were interviewed on the significance of the dromedary camel and constraints associated to camel production in the area using a single-visit-multiple-subject diagnostic survey. All the households interviewed owned camels and milk production was the primary reason for keeping camels in the area. The major contributions rendered by dromedary camels in the study area were milk production and transportation, while the major constraints associated with camel production in the area were feed shortage and prevalence of disease. Camels in these areas feed mainly on poor-quality natural vegetation. Cactus and acacia were the dominant plant species consumed by camels in the area. Camels were not given supplementary feed except salt and/or mineral soil. Dromedary camels play an important role to the livelihood and survival of nomadic pastoralists in the study areas. Thus, development interventions aimed at improving the productivity of camels in the study areas should take into account the major socio-economic contributions of camels and the prevailing problems in the area.

Fundamental constraints on some event data

International Nuclear Information System (INIS)

Watson, I.A.

1986-01-01

A modified version of Searle's theory of the structure of human action has been explained and applied to man machine interaction. The comprehensiveness of the theory has been demonstrated, in particular its explanation of human performance and that its consistency with current theories of human error for which it provides an overall setting. The importance of the mental component of human error is highlighted and the constraints that this puts on the collection analysis and use of human error data. Examples have been given to illustrate and apply the theory ranging from considerations of the tenuousness of the link between safety goals and data to simple valve operations. Two approaches which recognise the constraints shown by the theory have been explained. (orig./DG)

Potential importance of B cells in aging and aging-associated neurodegenerative diseases.

Science.gov (United States)

Biragyn, Arya; Aliseychik, Maria; Rogaev, Evgeny

2017-04-01

Our understanding of B cells as merely antibody producers is slowly changing. Alone or in concert with antibody, they control outcomes of seemingly different diseases such as cancer, rheumatoid arthritis, diabetes, and multiple sclerosis. While their role in activation of effector immune cells is beneficial in cancer but bad in autoimmune diseases, their immunosuppressive and regulatory subsets (Bregs) inhibit autoimmune and anticancer responses. These pathogenic and suppressive functions are not static and appear to be regulated by the nature and strength of inflammation. Although aging increases inflammation and changes the composition and function of B cells, surprisingly, little is known whether the change affects aging-associated neurodegenerative disease, such as Alzheimer's disease (AD). Here, by analyzing B cells in cancer and autoimmune and neuroinflammatory diseases, we elucidate their potential importance in AD and other aging-associated neuroinflammatory diseases.

Constraints in the Adoption of Eco Friendly Conservation Practices

Directory of Open Access Journals (Sweden)

L. Murali Krishnan

2016-05-01

Insect pest and diseases management, Lack of awareness of agro environmental problems and farmer’s attitude towards the Eco Friendly Conservation Practices are the major constraints in the adoption of Eco Friendly Conservation Practices.The study suggests educational, extension & training strategies for fostering the adopted of ECO friendly Conservation Practices.

Automatic Constraint Detection for 2D Layout Regularization.

Science.gov (United States)

Jiang, Haiyong; Nan, Liangliang; Yan, Dong-Ming; Dong, Weiming; Zhang, Xiaopeng; Wonka, Peter

2016-08-01

In this paper, we address the problem of constraint detection for layout regularization. The layout we consider is a set of two-dimensional elements where each element is represented by its bounding box. Layout regularization is important in digitizing plans or images, such as floor plans and facade images, and in the improvement of user-created contents, such as architectural drawings and slide layouts. To regularize a layout, we aim to improve the input by detecting and subsequently enforcing alignment, size, and distance constraints between layout elements. Similar to previous work, we formulate layout regularization as a quadratic programming problem. In addition, we propose a novel optimization algorithm that automatically detects constraints. We evaluate the proposed framework using a variety of input layouts from different applications. Our results demonstrate that our method has superior performance to the state of the art.

Automatic Constraint Detection for 2D Layout Regularization

KAUST Repository

Jiang, Haiyong

2015-09-18

In this paper, we address the problem of constraint detection for layout regularization. As layout we consider a set of two-dimensional elements where each element is represented by its bounding box. Layout regularization is important for digitizing plans or images, such as floor plans and facade images, and for the improvement of user created contents, such as architectural drawings and slide layouts. To regularize a layout, we aim to improve the input by detecting and subsequently enforcing alignment, size, and distance constraints between layout elements. Similar to previous work, we formulate the layout regularization as a quadratic programming problem. In addition, we propose a novel optimization algorithm to automatically detect constraints. In our results, we evaluate the proposed framework on a variety of input layouts from different applications, which demonstrates our method has superior performance to the state of the art.

Contact structure, mobility, environmental impact and behaviour: the importance of social forces to infectious disease dynamics and disease ecology.

Science.gov (United States)

Arthur, Ronan F; Gurley, Emily S; Salje, Henrik; Bloomfield, Laura S P; Jones, James H

2017-05-05

Human factors, including contact structure, movement, impact on the environment and patterns of behaviour, can have significant influence on the emergence of novel infectious diseases and the transmission and amplification of established ones. As anthropogenic climate change alters natural systems and global economic forces drive land-use and land-cover change, it becomes increasingly important to understand both the ecological and social factors that impact infectious disease outcomes for human populations. While the field of disease ecology explicitly studies the ecological aspects of infectious disease transmission, the effects of the social context on zoonotic pathogen spillover and subsequent human-to-human transmission are comparatively neglected in the literature. The social sciences encompass a variety of disciplines and frameworks for understanding infectious diseases; however, here we focus on four primary areas of social systems that quantitatively and qualitatively contribute to infectious diseases as social-ecological systems. These areas are social mixing and structure, space and mobility, geography and environmental impact, and behaviour and behaviour change. Incorporation of these social factors requires empirical studies for parametrization, phenomena characterization and integrated theoretical modelling of social-ecological interactions. The social-ecological system that dictates infectious disease dynamics is a complex system rich in interacting variables with dynamically significant heterogeneous properties. Future discussions about infectious disease spillover and transmission in human populations need to address the social context that affects particular disease systems by identifying and measuring qualitatively important drivers.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

Constraints on trait combinations explain climatic drivers of biodiversity: the importance of trait covariance in community assembly.

Science.gov (United States)

Dwyer, John M; Laughlin, Daniel C

2017-07-01

Trade-offs maintain diversity and structure communities along environmental gradients. Theory indicates that if covariance among functional traits sets a limit on the number of viable trait combinations in a given environment, then communities with strong multidimensional trait constraints should exhibit low species diversity. We tested this prediction in winter annual plant assemblages along an aridity gradient using multilevel structural equation modelling. Univariate and multivariate functional diversity measures were poorly explained by aridity, and were surprisingly poor predictors of community richness. By contrast, the covariance between maximum height and seed mass strengthened along the aridity gradient, and was strongly associated with richness declines. Community richness had a positive effect on local neighbourhood richness, indicating that climate effects on trait covariance indirectly influence diversity at local scales. We present clear empirical evidence that declines in species richness along gradients of environmental stress can be due to increasing constraints on multidimensional phenotypes. © 2017 John Wiley & Sons Ltd/CNRS.

A review on important maize diseases and their management in Nepal

OpenAIRE

Subash Subedi

2015-01-01

In Nepal, maize ranks second after rice both in area and production. In recent years, maize area and production has shown a steady increase, but productivity has been low (2.46 t/ha). The major maize producing regions in Nepal are mid hill (72.85%), terai (17.36%) and high hill (9.79%) respectively. A literature review was carried out to explore major maize diseases and their management in Nepal. The omnipresent incidence of diseases at the pre harvest stage has been an important bottleneck ...

Constraint-based deadlock checking of high-level specifications

DEFF Research Database (Denmark)

Hallerstede, Stefan; Leuschel, Michael

2011-01-01

Establishing the absence of deadlocks is important in many applications of formal methods. The use of model checking for finding deadlocks in formal models is limited because in many industrial applications the state space is either infinite or much too large to be explored exhaustively. In this ......Establishing the absence of deadlocks is important in many applications of formal methods. The use of model checking for finding deadlocks in formal models is limited because in many industrial applications the state space is either infinite or much too large to be explored exhaustively......B's Prolog kernel, such as reification of membership and arithmetic constraints. ProB typically finds counter examples to deadlock-freedom constraints, a formula of about 900 partly nested conjunctions and disjunction among them 80 arithmetic and 150 set-theoretic predicates (in total a formula of 30 pages...

Crack-tip constraint analyses and constraint-dependent LBB curves for circumferential through-wall cracked pipes

Energy Technology Data Exchange (ETDEWEB)

Chen, Y.L.; Wang, G.Z., E-mail: gzwang@ecust.edu.cn; Xuan, F.Z.; Tu, S.T.

2015-04-15

Highlights: • Solution of constraint parameter τ* for through-wall cracked pipes has been obtained. • Constraint increases with increasing crack length and radius–thickness ratio of pipes. • Constraint-dependent LBB curve for through-wall cracked pipes has been constructed. • For increasing accuracy of LBB assessments, constraint effect should be considered. - Abstract: The leak-before-break (LBB) concept has been widely applied in the structural integrity assessments of pressured pipes in nuclear power plants. However, the crack-tip constraint effects in LBB analyses and designs cannot be incorporated. In this paper, by using three-dimensional finite element calculations, the modified load-independent T-stress constraint parameter τ* for circumferential through-wall cracked pipes with different geometries and crack sizes has been analyzed under different loading conditions, and the solutions of the crack-tip constraint parameter τ* have been obtained. Based on the τ* solutions and constraint-dependent J–R curves of a steel, the constraint-dependent LBB (leak-before-break) curves have been constructed. The results show that the constraint τ* increases with increasing crack length θ, mean radius R{sub m} and radius–thickness ratio R{sub m}/t of the pipes. In LBB analyses, the critical crack length calculated by the J–R curve of the standard high constraint specimen for pipes with shorter cracks is over-conservative, and the degree of conservatism increases with decreasing crack length θ, R{sub m} and R{sub m}/t. Therefore, the constraint-dependent LBB curves should be constructed to modify the over-conservatism and increase accuracy of LBB assessments.

Institutional constraints on alternative water for energy: a guidebook for regional assessments

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

Basic information is presented about the legal, political, and social constraints faced by energy developers in the acquisition of water from underground, irrigation return flow, municipal waste, and saline sources. It is a guide to those institutional constraints which are general and pronounced enough to be important for regional assessments. First, attention was focused on the acquisition phase of the water use cycle. Second, constraints were analyzed primarily from a regional, rather than state-by-state, perspective. Emphasis was placed generally on the West - particularly the synfuel-rich Rocky Mountain states, the East, and Mid-West, in that order. Alaska and Hawaii were not surveyed. Third, the study focuses on the constraints associated with groundwater, municipal waste, irrigation return flow, and sea water, in that order. The phrase, institutional constraints, as used in the study, means legal, social, economic, and political restrictions, requirements, circumstances, or conditions that must be anticipated or responded to in order to acquire water for energy development. The study focuses primarily on legal constraints and secondarily on political constraints, because they tend to encompass or reflect other forms of institutional constraints.

Optimal consumption—portfolio problem with CVaR constraints

International Nuclear Information System (INIS)

Zhang, Qingye; Gao, Yan

2016-01-01

The optimal portfolio selection is a fundamental issue in finance, and its two most important ingredients are risk and return. Merton's pioneering work in dynamic portfolio selection emphasized only the expected utility of the consumption and the terminal wealth. To make the optimal portfolio strategy be achievable, risk control over bankruptcy during the investment horizon is an indispensable ingredient. So, in this paper, we consider the consumption-portfolio problem coupled with a dynamic risk control. More specifically, different from the existing literature, we impose a dynamic relative CVaR constraint on it. By the stochastic dynamic programming techniques, we derive the corresponding Hamilton–Jacobi–Bellman (HJB) equation. Moreover, by the Lagrange multiplier method, the closed form solution is provided when the utility function is a logarithmic one. At last, an illustrative empirical study is given. The results show the distinct difference of the portfolio strategies with and without the CVaR constraints: the proportion invested in the risky assets is reduced over time with CVaR constraint instead of being constant without CVaR constraints. This can provide a good decision-making reference for the investors.

Toward First Principle Medical Diagnostics: On the Importance of Disease-Disease and Sign-Sign Interactions

Directory of Open Access Journals (Sweden)

Abolfazl Ramezanpour

2017-07-01

Full Text Available A fundamental problem in medicine and biology is to assign states, e.g., healthy or diseased, to cells, organs or individuals. State assignment or making a diagnosis is often a nontrivial and challenging process and, with the advent of omics technologies, the diagnostic challenge is becoming more and more serious. The challenge lies not only in the increasing number of measured properties and dynamics of the system (e.g., cell or human body but also in the co-evolution of multiple states and overlapping properties, and degeneracy of states. We develop, from first principles, a generic rational framework for state assignment in cell biology and medicine, and demonstrate its applicability with a few simple theoretical case studies from medical diagnostics. We show how disease–related statistical information can be used to build a comprehensive model that includes the relevant dependencies between clinical and laboratory findings (signs and diseases. In particular, we include disease-disease and sign–sign interactions and study how one can infer the probability of a disease in a patient with given signs. We perform comparative analysis with simple benchmark models to check the performances of our models. We find that including interactions can significantly change the statistical importance of the signs and diseases. This first principles approach, as we show, facilitates the early diagnosis of disease by taking interactions into accounts, and enables the construction of consensus diagnostic flow charts. Additionally, we envision that our approach will find applications in systems biology, and in particular, in characterizing the phenome via the metabolome, the proteome, the transcriptome, and the genome.

Constraints and Creativity in NPD - Testing the Impact of 'Late Constraints'

DEFF Research Database (Denmark)

Onarheim, Balder; Valgeirsdóttir, Dagný

experiment was conducted, involving 12 teams of industrial designers from three different countries, each team working on two 30 minutes design tasks. In one condition all constraints were given at the start, and in the other one new radical constraint was added after 12 minutes. The output from all 24 tasks......The aim of the presented work is to investigate how the timing of project constraints can influence the creativity of the output in New Product Development (NPD) projects. When seeking to produce a creative output, is it beneficial to know all constraints when initiating a project...... was assessed for creativity using the Consensual Assessment Technique (CAT), and a comparative within-subjects analysis found no significant different between the two conditions. Controlling for task and assessor a small but non-significant effect was found, in favor of the ‘late constraint’ condition. Thus...

The importance of waterborne disease outbreak surveillance in the United States

Directory of Open Access Journals (Sweden)

Gunther Franz Craun

2012-12-01

Full Text Available Analyses of the causes of disease outbreaks associated with contaminated drinking water in the United States have helped inform prevention efforts at the national, state, and local levels. This article describes the changing nature of disease outbreaks in public water systems during 1971-2008 and discusses the importance of a collaborative waterborne outbreak surveillance system established in 1971. Increasing reports of outbreaks throughout the early 1980s emphasized that microbial contaminants remained a health-risk challenge for suppliers of drinking water. Outbreak investigations identified the responsible etiologic agents and deficiencies in the treatment and distribution of drinking water, especially the high risk associated with unfiltered surface water systems. Surveillance information was important in establishing an effective research program that guided government regulations and industry actions to improve drinking water quality. Recent surveillance statistics suggest that prevention efforts based on these research findings have been effective in reducing outbreak risks especially for surface water systems.

Financing Constraints and Firm Growth in Emerging Europe

Directory of Open Access Journals (Sweden)

Leitner Sandra M.

2016-04-01

Full Text Available The paper aims to shed light on the effects of different types of financing constraints on firm sales and employment growth in Emerging Europe before and after the onset of the financial crisis. It analyzes the group of emerging NMS-10 economies (plus Turkey and the group of economically and financially lagging Western Balkan countries. The paper demonstrates that financing constraints significantly obstruct firm growth, particularly in the Western Balkan countries, which calls for policy intervention to ensure swifter job-rich growth and catching-up with the rest of Europe. It also emphasizes that particular firm characteristics are essential for growth in Emerging Europe and demonstrates that exporting only and innovating are recipes for faster firm growth, while importing only and a high foreign ownership share seriously retard firm growth. Finally, it stresses the importance of the particular institutional environment for firms to thrive.

Giant Panda Maternal Care: A Test of the Experience Constraint Hypothesis

Science.gov (United States)

Snyder, Rebecca J.; Perdue, Bonnie M.; Zhang, Zhihe; Maple, Terry L.; Charlton, Benjamin D.

2016-01-01

The body condition constraint and the experience condition constraint hypotheses have both been proposed to account for differences in reproductive success between multiparous (experienced) and primiparous (first-time) mothers. However, because primiparous mothers are typically characterized by both inferior body condition and lack of experience when compared to multiparous mothers, interpreting experience related differences in maternal care as support for either the body condition constraint hypothesis or the experience constraint hypothesis is extremely difficult. Here, we examined maternal behaviour in captive giant pandas, allowing us to simultaneously control for body condition and provide a rigorous test of the experience constraint hypothesis in this endangered animal. We found that multiparous mothers spent more time engaged in key maternal behaviours (nursing, grooming, and holding cubs) and had significantly less vocal cubs than primiparous mothers. This study provides the first evidence supporting the experience constraint hypothesis in the order Carnivora, and may have utility for captive breeding programs in which it is important to monitor the welfare of this species’ highly altricial cubs, whose survival is almost entirely dependent on receiving adequate maternal care during the first few weeks of life. PMID:27272352

Interactions between social structure, demography, and transmission determine disease persistence in primates.

Science.gov (United States)

Ryan, Sadie J; Jones, James H; Dobson, Andrew P

2013-01-01

Catastrophic declines in African great ape populations due to disease outbreaks have been reported in recent years, yet we rarely hear of similar disease impacts for the more solitary Asian great apes, or for smaller primates. We used an age-structured model of different primate social systems to illustrate that interactions between social structure and demography create 'dynamic constraints' on the pathogens that can establish and persist in primate host species with different social systems. We showed that this varies by disease transmission mode. Sexually transmitted infections (STIs) require high rates of transmissibility to persist within a primate population. In particular, for a unimale social system, STIs require extremely high rates of transmissibility for persistence, and remain at extremely low prevalence in small primates, but this is less constrained in longer-lived, larger-bodied primates. In contrast, aerosol transmitted infections (ATIs) spread and persist at high prevalence in medium and large primates with moderate transmissibility;, establishment and persistence in small-bodied primates require higher relative rates of transmissibility. Intragroup contact structure - the social network - creates different constraints for different transmission modes, and our model underscores the importance of intragroup contacts on infection prior to intergroup movement in a structured population. When alpha males dominate sexual encounters, the resulting disease transmission dynamics differ from when social interactions are dominated by mother-infant grooming events, for example. This has important repercussions for pathogen spread across populations. Our framework reveals essential social and demographic characteristics of primates that predispose them to different disease risks that will be important for disease management and conservation planning for protected primate populations.

Transgenic approaches for development of disease resistance in banana

International Nuclear Information System (INIS)

Shekhawat, Upendra K.S.; Ghag, Siddhesh B.; Ganapathi, Thumballi R.

2014-01-01

Banana (Musa spp.) is an important food and cash crop worldwide. Diseases and pests pose the most serious constraint to banana cultivation. Among the diseases, Fusarium wilt and Banana Bunchy Top Virus (BBTV) are the most important economically. We have explored different transgenic approaches for development of efficient resistance in banana against these two diseases. For countering Fusarium wilt, we have over expressed Petunia floral defensins using a strong constitutive promoter in transgenic banana plants. We have also tested a host induced gene silencing strategy targeting two vital fungal genes to obtain Fusarium resistant banana plants. For development of BBTV resistant banana plants also, we have used a host-induced gene silencing approach utilizing the full and partial coding sequence of the viral replication initiation protein. Successful bioassays performed in controlled greenhouse conditions have shown the efficacy of using these strategies to develop disease resistant banana plants. (author)

Topological constraints and their breakdown in dynamical evolution

International Nuclear Information System (INIS)

Goldstein, Raymond E; Moffatt, H Keith; Pesci, Adriana I

2012-01-01

A variety of physical and biological systems exhibit dynamical behaviour that has some explicit or implicit topological features. Here, the term ‘topological’ is meant to convey the idea of structures, e.g. physical knots, links or braids, that have some measure of invariance under continuous deformation. Dynamical evolution is then subject to the topological constraints that express this invariance. The simplest problem arising in these systems is the determination of minimum-energy structures (and routes towards these structures) permitted by such constraints, and elucidation of mechanisms by which the constraints may be broken. In more complex nonequilibrium cases there can be recurring singularities associated with topological rearrangements driven by continuous injection of energy. In this brief overview, motivated by an upcoming program on ‘Topological Dynamics in the Physical and Biological Sciences’ at the Isaac Newton Institute for Mathematical Sciences, we present a summary of this class of dynamical systems and discuss examples of important open problems. (invited articles)

The importance of international collaboration for rare diseases research: a European perspective.

Science.gov (United States)

Julkowska, D; Austin, C P; Cutillo, C M; Gancberg, D; Hager, C; Halftermeyer, J; Jonker, A H; Lau, L P L; Norstedt, I; Rath, A; Schuster, R; Simelyte, E; van Weely, S

2017-09-01

Over the last two decades, important contributions were made at national, European and international levels to foster collaboration into rare diseases research. The European Union (EU) has put much effort into funding rare diseases research, encouraging national funding organizations to collaborate together in the E-Rare program, setting up European Reference Networks for rare diseases and complex conditions, and initiating the International Rare Diseases Research Consortium (IRDiRC) together with the National Institutes of Health in the USA. Co-ordination of the activities of funding agencies, academic researchers, companies, regulatory bodies, and patient advocacy organizations and partnerships with, for example, the European Research Infrastructures maximizes the collective impact of global investments in rare diseases research. This contributes to accelerating progress, for example, in faster diagnosis through enhanced discovery of causative genes, better understanding of natural history of rare diseases through creation of common registries and databases and boosting of innovative therapeutic approaches. Several examples of funded pre-clinical and clinical gene therapy projects show that integration of multinational and multidisciplinary expertize generates new knowledge and can result in multicentre gene therapy trials. International collaboration in rare diseases research is key to improve the life of people living with a rare disease.

Searching for genomic constraints

Energy Technology Data Exchange (ETDEWEB)

Lio` , P [Cambridge, Univ. (United Kingdom). Genetics Dept.; Ruffo, S [Florence, Univ. (Italy). Fac. di Ingegneria. Dipt. di Energetica ` S. Stecco`

1998-01-01

The authors have analyzed general properties of very long DNA sequences belonging to simple and complex organisms, by using different correlation methods. They have distinguished those base compositional rules that concern the entire genome which they call `genomic constraints` from the rules that depend on the `external natural selection` acting on single genes, i. e. protein-centered constraints. They show that G + C content, purine / pyrimidine distributions and biological complexity of the organism are the most important factors which determine base compositional rules and genome complexity. Three main facts are here reported: bacteria with high G + C content have more restrictions on base composition than those with low G + C content; at constant G + C content more complex organisms, ranging from prokaryotes to higher eukaryotes (e.g. human) display an increase of repeats 10-20 nucleotides long, which are also partly responsible for long-range correlations; work selection of length 3 to 10 is stronger in human and in bacteria for two distinct reasons. With respect to previous studies, they have also compared the genomic sequence of the archeon Methanococcus jannaschii with those of bacteria and eukaryotes: it shows sometimes an intermediate statistical behaviour.

Searching for genomic constraints

International Nuclear Information System (INIS)

Lio', P.; Ruffo, S.

1998-01-01

The authors have analyzed general properties of very long DNA sequences belonging to simple and complex organisms, by using different correlation methods. They have distinguished those base compositional rules that concern the entire genome which they call 'genomic constraints' from the rules that depend on the 'external natural selection' acting on single genes, i. e. protein-centered constraints. They show that G + C content, purine / pyrimidine distributions and biological complexity of the organism are the most important factors which determine base compositional rules and genome complexity. Three main facts are here reported: bacteria with high G + C content have more restrictions on base composition than those with low G + C content; at constant G + C content more complex organisms, ranging from prokaryotes to higher eukaryotes (e.g. human) display an increase of repeats 10-20 nucleotides long, which are also partly responsible for long-range correlations; work selection of length 3 to 10 is stronger in human and in bacteria for two distinct reasons. With respect to previous studies, they have also compared the genomic sequence of the archeon Methanococcus jannaschii with those of bacteria and eukaryotes: it shows sometimes an intermediate statistical behaviour

Creativity from Constraints in Engineering Design

DEFF Research Database (Denmark)

Onarheim, Balder

2012-01-01

This paper investigates the role of constraints in limiting and enhancing creativity in engineering design. Based on a review of literature relating constraints to creativity, the paper presents a longitudinal participatory study from Coloplast A/S, a major international producer of disposable...... and ownership of formal constraints played a crucial role in defining their influence on creativity – along with the tacit constraints held by the designers. The designers were found to be highly constraint focused, and four main creative strategies for constraint manipulation were observed: blackboxing...

Epidemics on adaptive networks with geometric constraints

Science.gov (United States)

Shaw, Leah; Schwartz, Ira

2008-03-01

When a population is faced with an epidemic outbreak, individuals may modify their social behavior to avoid exposure to the disease. Recent work has considered models in which the contact network is rewired dynamically so that susceptibles avoid contact with infectives. We consider extensions in which the rewiring is subject to constraints that preserve key properties of the social network structure. Constraining to a fixed degree distribution destroys previously observed bistable behavior. The most effective rewiring strategy is found to depend on the spreading rate.

Infrared Constraint on Ultraviolet Theories

Energy Technology Data Exchange (ETDEWEB)

Tsai, Yuhsin [Cornell Univ., Ithaca, NY (United States)

2012-08-01

While our current paradigm of particle physics, the Standard Model (SM), has been extremely successful at explaining experiments, it is theoretically incomplete and must be embedded into a larger framework. In this thesis, we review the main motivations for theories beyond the SM (BSM) and the ways such theories can be constrained using low energy physics. The hierarchy problem, neutrino mass and the existence of dark matter (DM) are the main reasons why the SM is incomplete . Two of the most plausible theories that may solve the hierarchy problem are the Randall-Sundrum (RS) models and supersymmetry (SUSY). RS models usually suffer from strong flavor constraints, while SUSY models produce extra degrees of freedom that need to be hidden from current experiments. To show the importance of infrared (IR) physics constraints, we discuss the flavor bounds on the anarchic RS model in both the lepton and quark sectors. For SUSY models, we discuss the difficulties in obtaining a phenomenologically allowed gaugino mass, its relation to R-symmetry breaking, and how to build a model that avoids this problem. For the neutrino mass problem, we discuss the idea of generating small neutrino masses using compositeness. By requiring successful leptogenesis and the existence of warm dark matter (WDM), we can set various constraints on the hidden composite sector. Finally, to give an example of model independent bounds from collider experiments, we show how to constrain the DM–SM particle interactions using collider results with an effective coupling description.

Active Surveillance of Hansen's Disease (Leprosy): Importance for Case Finding among Extra-domiciliary Contacts

Science.gov (United States)

Moura, Maria L. N.; Dupnik, Kathryn M.; Sampaio, Gabriel A. A.; Nóbrega, Priscilla F. C.; Jeronimo, Ana K.; do Nascimento-Filho, Jose M.; Miranda Dantas, Roberta L.; Queiroz, Jose W.; Barbosa, James D.; Dias, Gutemberg; Jeronimo, Selma M. B.; Souza, Marcia C. F.; Nobre, Maurício L.

2013-01-01

Hansen's disease (leprosy) remains an important health problem in Brazil, where 34,894 new cases were diagnosed in 2010, corresponding to 15.3% of the world's new cases detected in that year. The purpose of this study was to use home visits as a tool for surveillance of Hansen's disease in a hyperendemic area in Brazil. A total of 258 residences were visited with 719 individuals examined. Of these, 82 individuals had had a previous history of Hansen's disease, 209 were their household contacts and 428 lived in neighboring residences. Fifteen new Hansen's disease cases were confirmed, yielding a detection rate of 2.0% of people examined. There was no difference in the detection rate between household and neighbor contacts (p = 0.615). The two groups had the same background in relation to education (p = 0.510), household income (p = 0.582), and the number of people living in the residence (p = 0.188). Spatial analysis showed clustering of newly diagnosed cases and association with residential coordinates of previously diagnosed multibacillary cases. Active case finding is an important tool for Hansen's disease control in hyperendemic areas, enabling earlier diagnosis, treatment, decrease in disability from Hansen's disease and potentially less spread of Mycobacterium leprae. PMID:23516645

Deepening Contractions and Collateral Constraints

DEFF Research Database (Denmark)

Jensen, Henrik; Ravn, Søren Hove; Santoro, Emiliano

and occasionally non-binding credit constraints. Easier credit access increases the likelihood that constraints become slack in the face of expansionary shocks, while contractionary shocks are further amplified due to tighter constraints. As a result, busts gradually become deeper than booms. Based...

Control of articulated snake robot under dynamic active constraints.

Science.gov (United States)

Kwok, Ka-Wai; Vitiello, Valentina; Yang, Guang-Zhong

2010-01-01

Flexible, ergonomically enhanced surgical robots have important applications to transluminal endoscopic surgery, for which path-following and dynamic shape conformance are essential. In this paper, kinematic control of a snake robot for motion stabilisation under dynamic active constraints is addressed. The main objective is to enable the robot to track the visual target accurately and steadily on deforming tissue whilst conforming to pre-defined anatomical constraints. The motion tracking can also be augmented with manual control. By taking into account the physical limits in terms of maximum frequency response of the system (manifested as a delay between the input of the manipulator and the movement of the end-effector), we show the importance of visual-motor synchronisation for performing accurate smooth pursuit movements. Detailed user experiments are performed to demonstrate the practical value of the proposed control mechanism.

Histological variability and the importance of clinicopathological correlation in cutaneous Rosai-Dorfman disease.

Science.gov (United States)

Gameiro, Ana; Gouveia, Miguel; Cardoso, José Carlos; Tellechea, Oscar

2016-01-01

Rosai-Dorfman disease is a benign histiocytic proliferative disorder of unknown etiology. The disease mainly affects lymph node tissue, although it is rarely confined to the skin. Here, we describe a 53-year-old woman with purely cutaneous Rosai-Dorfman disease. The patient presented with a large pigmented plaque on her left leg, and sparse erythematous papules on her face and arms. A complete clinical response was achieved with thalidomide, followed by recurrence at the initial site one year later. The histological examination displayed the typical features of Rosai-Dorfman disease in the recent lesions but not in the older lesions. In the setting of no lymphadenopathy, the histopathological features of Rosai-Dorfman disease are commonly misinterpreted. Therefore, awareness of the histological aspects present at different stages, not always featuring the hallmark microscopic signs of Rosai-Dorfman disease, is particularly important for a correct diagnosis of this rare disorder.

Congenital heart disease screening: which referral factors are most important

International Nuclear Information System (INIS)

Fayyaz, A.; Ahmed, W.

2013-01-01

To identify the referral factors for fetal echocardiography which are associated with congenital cardiac defects in the fetus. Study Design: Cross-sectional descriptive study. Place and Duration of Study: Radiology Department, CMH, Rawalpindi, from January 2007 to November 2010. Methodology: All patients referred for fetal echocardiography with one or more risk factors for the development of congenital heart disease, and those patients with incidental discovery of congenital heart disease on antenatal ultrasound were evaluated. Patients with no risk factors who were found to have normal fetal echocardiography were excluded from the study. Univariate logistic regression analysis was carried out for each variable. The variables with statistical significance of less than 0.05 were subjected to multivariate logistic regression. Fetal echocardiographic diagnosis was taken as the dependent variable and all other variables were the independent variables. Results: Two hundred and sixty four patients were evaluated by fetal echocardiography for congenital heart disease. The statistically significant factor was detection of congenital heart disease on routine ultrasound examination. Conclusion: A routine obstetric scan should include evaluation of the heart with four-chamber and base-of-heart views to exclude cardiac anomalies. A cardiac anomaly picked up on routine ultrasound scan is the most important indication for referral for fetal echocardiography. Fetal arrhythmias and echogenic focus in the left ventricle do not have a significant association with structural cardiac malformation. (author)

Occupational dose constraint

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

2005-01-01

The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

Specifying and implementing constraints in GIS - with examples from a Geo-Virtual Reality system

NARCIS (Netherlands)

Louwsma, J.; Zlatanova, S.; Lammeren, van R.J.A.; Oosterom, van P.

2006-01-01

Constraints are important elements of every modelling process, but until now they have been treated in an ad hoc manner, depending on the specific application domain and the capabilities of the tools used. In GIS and GeoVR applications, constraints are conditions which always have to be valid (true)

Solar constraints

International Nuclear Information System (INIS)

Provost, J.

1984-01-01

Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

Temporal Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Valencia Posso, Frank Dan

2002-01-01

The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...... reflect the reactive interactions between concurrent constraint processes and their environment, as well as internal interactions between individual processes. Relationships between the suggested notions are studied, and they are all proved to be decidable for a substantial fragment of the calculus...

The importance of continuity in inhaler device choice for asthma and chronic obstructive pulmonary disease.

Science.gov (United States)

Bjermer, Leif

2014-01-01

Inhaled therapies are central to the treatment of asthma and chronic obstructive pulmonary disease. Physicians consider many factors when selecting the most appropriate inhaler device, including device efficacy and the cost to the health care system. This review aims to discuss the factors that are important when considering inhaler devices and the importance of continuity in the choice of inhaler device. A large number of factors can contribute to therapeutic outcomes with inhalation devices. The inhalation technique is critical to treatment success and differs substantially between inhaler devices. Misuse of an inhaler is common, and thorough training of patients and physicians is important to ensure correct utilization. Patient satisfaction is an important consideration because it is significantly correlated with compliance and better outcomes. Financial pressures contribute to decision making: although selecting the less expensive inhaler device might reduce direct treatment costs, it can have a large impact on disease control and the patient's well-being. Switching may be associated with a poor inhalation technique, reduced disease control and quality of life, increased use of other treatments and health care resources, and a greater chance of unsuccessful treatment. Nonconsensual switches can result in patient discontent, reduced confidence in the medication, and uncertainty regarding the degree of disease control. It is recommended that patients with stable disease remain on their current device. If a switch is considered, the patient should be consulted and the physician should take into account the patient's preference, their ability to correctly use the device, and the availability of the preferred drug in the preferred device.

Enforcement of entailment constraints in distributed service-based business processes.

Science.gov (United States)

Hummer, Waldemar; Gaubatz, Patrick; Strembeck, Mark; Zdun, Uwe; Dustdar, Schahram

2013-11-01

A distributed business process is executed in a distributed computing environment. The service-oriented architecture (SOA) paradigm is a popular option for the integration of software services and execution of distributed business processes. Entailment constraints, such as mutual exclusion and binding constraints, are important means to control process execution. Mutually exclusive tasks result from the division of powerful rights and responsibilities to prevent fraud and abuse. In contrast, binding constraints define that a subject who performed one task must also perform the corresponding bound task(s). We aim to provide a model-driven approach for the specification and enforcement of task-based entailment constraints in distributed service-based business processes. Based on a generic metamodel, we define a domain-specific language (DSL) that maps the different modeling-level artifacts to the implementation-level. The DSL integrates elements from role-based access control (RBAC) with the tasks that are performed in a business process. Process definitions are annotated using the DSL, and our software platform uses automated model transformations to produce executable WS-BPEL specifications which enforce the entailment constraints. We evaluate the impact of constraint enforcement on runtime performance for five selected service-based processes from existing literature. Our evaluation demonstrates that the approach correctly enforces task-based entailment constraints at runtime. The performance experiments illustrate that the runtime enforcement operates with an overhead that scales well up to the order of several ten thousand logged invocations. Using our DSL annotations, the user-defined process definition remains declarative and clean of security enforcement code. Our approach decouples the concerns of (non-technical) domain experts from technical details of entailment constraint enforcement. The developed framework integrates seamlessly with WS-BPEL and the Web

Alkaptonuria: An example of a "fundamental disease"--A rare disease with important lessons for more common disorders.

Science.gov (United States)

Gallagher, James A; Dillon, Jane P; Sireau, Nicolas; Timmis, Oliver; Ranganath, Lakshminarayan R

2016-04-01

"Fundamental diseases" is a term introduced by the charity Findacure to describe rare genetic disorders that are gateways to understanding common conditions and human physiology. The concept that rare diseases have important lessons for biomedical science has been recognised by some of the great figures in the history of medical research, including Harvey, Bateson and Garrod. Here we describe some of the recently discovered lessons from the study of the iconic genetic disease alkaptonuria (AKU), which have shed new light on understanding the pathogenesis of osteoarthritis. In AKU, ochronotic pigment is deposited in cartilage when collagen fibrils become susceptible to attack by homogentisic acid (HGA). When HGA binds to collagen, cartilage matrix becomes stiffened, resulting in the aberrant transmission of loading to underlying subchondral bone. Aberrant loading leads to the formation of pathophysiological structures including trabecular excrescences and high density mineralised protrusions (HDMPs). These structures initially identified in AKU have subsequently been found in more common osteoarthritis and appear to play a role in joint destruction in both diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

The algebraic-hyperbolic approach to the linearized gravitational constraints on a Minkowski background

International Nuclear Information System (INIS)

Winicour, Jeffrey

2017-01-01

An algebraic-hyperbolic method for solving the Hamiltonian and momentum constraints has recently been shown to be well posed for general nonlinear perturbations of the initial data for a Schwarzschild black hole. This is a new approach to solving the constraints of Einstein’s equations which does not involve elliptic equations and has potential importance for the construction of binary black hole data. In order to shed light on the underpinnings of this approach, we consider its application to obtain solutions of the constraints for linearized perturbations of Minkowski space. In that case, we find the surprising result that there are no suitable Cauchy hypersurfaces in Minkowski space for which the linearized algebraic-hyperbolic constraint problem is well posed. (note)

Theory of Constraints (TOC)

DEFF Research Database (Denmark)

Michelsen, Aage U.

2004-01-01

Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process.......Tankegangen bag Theory of Constraints samt planlægningsprincippet Drum-Buffer-Rope. Endvidere skitse af The Thinking Process....

Innovating Without Information Constraints: Organizations, Communities, and Innovation When Information Costs Approach Zero

OpenAIRE

Elizabeth J. Altman; Frank Nagle; Michael L. Tushman

2013-01-01

Innovation traditionally takes place within an organization's boundaries and with selected partners. This Chandlerian approach is rooted in transaction costs, organizational boundaries, and information challenges. Information processing, storage, and communication costs have been an important constraint on innovation and a reason why innovation takes place inside the organization. However, exponential technological progress is dramatically decreasing information constraints, and in many conte...

Constraint Embedding for Multibody System Dynamics

Science.gov (United States)

Jain, Abhinandan

2009-01-01

This paper describes a constraint embedding approach for the handling of local closure constraints in multibody system dynamics. The approach uses spatial operator techniques to eliminate local-loop constraints from the system and effectively convert the system into tree-topology systems. This approach allows the direct derivation of recursive O(N) techniques for solving the system dynamics and avoiding the expensive steps that would otherwise be required for handling the closedchain dynamics. The approach is very effective for systems where the constraints are confined to small-subgraphs within the system topology. The paper provides background on the spatial operator O(N) algorithms, the extensions for handling embedded constraints, and concludes with some examples of such constraints.

Selection of new constraints

International Nuclear Information System (INIS)

Sugier, A.

2003-01-01

The selected new constraints should be consistent with the scale of concern i.e. be expressed roughly as fractions or multiples of the average annual background. They should take into account risk considerations and include the values of the currents limits, constraints and other action levels. The recommendation is to select four leading values for the new constraints: 500 mSv ( single event or in a decade) as a maximum value, 0.01 mSv/year as a minimum value; and two intermediate values: 20 mSv/year and 0.3 mSv/year. This new set of dose constraints, representing basic minimum standards of protection for the individuals taking into account the specificity of the exposure situations are thus coherent with the current values which can be found in ICRP Publications. A few warning need however to be noticed: There is no more multi sources limit set by ICRP. The coherence between the proposed value of dose constraint (20 mSv/year) and the current occupational dose limit of 20 mSv/year is valid only if the workers are exposed to one single source. When there is more than one source, it will be necessary to apportion. The value of 1000 mSv lifetimes used for relocation can be expressed into annual dose, which gives approximately 10 mSv/year and is coherent with the proposed dose constraint. (N.C.)

Major emerging vector-borne zoonotic diseases of public health importance in Canada.

Science.gov (United States)

Kulkarni, Manisha A; Berrang-Ford, Lea; Buck, Peter A; Drebot, Michael A; Lindsay, L Robbin; Ogden, Nicholas H

2015-06-10

In Canada, the emergence of vector-borne diseases may occur via international movement and subsequent establishment of vectors and pathogens, or via northward spread from endemic areas in the USA. Re-emergence of endemic vector-borne diseases may occur due to climate-driven changes to their geographic range and ecology. Lyme disease, West Nile virus (WNV), and other vector-borne diseases were identified as priority emerging non-enteric zoonoses in Canada in a prioritization exercise conducted by public health stakeholders in 2013. We review and present the state of knowledge on the public health importance of these high priority emerging vector-borne diseases in Canada. Lyme disease is emerging in Canada due to range expansion of the tick vector, which also signals concern for the emergence of human granulocytic anaplasmosis, babesiosis, and Powassan virus. WNV has been established in Canada since 2001, with epidemics of varying intensity in following years linked to climatic drivers. Eastern equine encephalitis virus, Jamestown Canyon virus, snowshoe hare virus, and Cache Valley virus are other mosquito-borne viruses endemic to Canada with the potential for human health impact. Increased surveillance for emerging pathogens and vectors and coordinated efforts among sectors and jurisdictions will aid in early detection and timely public health response.

Overview on urban and peri-urban agriculture: definition, impact on human health, constraints and policy issues.

Science.gov (United States)

Kang'ethe, E K; Grace, D; Randolph, T F

2007-11-01

To collate and synthesize current knowledge of components of urban agriculture (UA) with a thematic emphasis on human health impact and a geographic emphasis on East Africa. Data management followed a structured approach in which key issues were first identified and then studies selected through literature search and personal communication. Evidence-based principles. Urban agriculture is an important source of food security for urban dwellers in East Africa. Descriptors of UA are location, areas, activities, scale, products, destinations, stakeholders and motivation. Many zoonotic and food-borne diseases have been associated with UA but evidence on human health impact and management is lacking. Major constraints to UA are illegality and lack of access to input and market; policy options have been developed for overcoming these. Urban agriculture is an important activity and likely to remain so. Both positive and negative human health impacts are potentially important but more research is needed to understand these and set appropriate policy and support levels.

Minimal Flavor Constraints for Technicolor

DEFF Research Database (Denmark)

Sakuma, Hidenori; Sannino, Francesco

2010-01-01

We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self-coupling and mas......We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self...

Temporal Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Palamidessi, Catuscia; Valencia, Frank Dan

2002-01-01

The ntcc calculus is a model of non-deterministic temporal concurrent constraint programming. In this paper we study behavioral notions for this calculus. In the underlying computational model, concurrent constraint processes are executed in discrete time intervals. The behavioral notions studied...

Disease-associated mutations disrupt functionally important regions of intrinsic protein disorder.

Directory of Open Access Journals (Sweden)

Vladimir Vacic

Full Text Available The effects of disease mutations on protein structure and function have been extensively investigated, and many predictors of the functional impact of single amino acid substitutions are publicly available. The majority of these predictors are based on protein structure and evolutionary conservation, following the assumption that disease mutations predominantly affect folded and conserved protein regions. However, the prevalence of the intrinsically disordered proteins (IDPs and regions (IDRs in the human proteome together with their lack of fixed structure and low sequence conservation raise a question about the impact of disease mutations in IDRs. Here, we investigate annotated missense disease mutations and show that 21.7% of them are located within such intrinsically disordered regions. We further demonstrate that 20% of disease mutations in IDRs cause local disorder-to-order transitions, which represents a 1.7-2.7 fold increase compared to annotated polymorphisms and neutral evolutionary substitutions, respectively. Secondary structure predictions show elevated rates of transition from helices and strands into loops and vice versa in the disease mutations dataset. Disease disorder-to-order mutations also influence predicted molecular recognition features (MoRFs more often than the control mutations. The repertoire of disorder-to-order transition mutations is limited, with five most frequent mutations (R→W, R→C, E→K, R→H, R→Q collectively accounting for 44% of all deleterious disorder-to-order transitions. As a proof of concept, we performed accelerated molecular dynamics simulations on a deleterious disorder-to-order transition mutation of tumor protein p63 and, in agreement with our predictions, observed an increased α-helical propensity of the region harboring the mutation. Our findings highlight the importance of mutations in IDRs and refine the traditional structure-centric view of disease mutations. The results of this study

Spatial decoupling of agricultural production and consumption: quantifying dependences of countries on food imports due to domestic land and water constraints

International Nuclear Information System (INIS)

Fader, Marianela; Gerten, Dieter; Lucht, Wolfgang; Krause, Michael; Cramer, Wolfgang

2013-01-01

In our globalizing world, the geographical locations of food production and consumption are becoming increasingly disconnected, which increases reliance on external resources and their trade. We quantified to what extent water and land constraints limit countries’ capacities, at present and by 2050, to produce on their own territory the crop products that they currently import from other countries. Scenarios of increased crop productivity and water use, cropland expansion (excluding areas prioritized for other uses) and population change are accounted for. We found that currently 16% of the world population use the opportunities of international trade to cover their demand for agricultural products. Population change may strongly increase the number of people depending on ex situ land and water resources up to about 5.2 billion (51% of world population) in the SRES A2r scenario. International trade will thus have to intensify if population growth is not accompanied by dietary change towards less resource-intensive products, by cropland expansion, or by productivity improvements, mainly in Africa and the Middle East. Up to 1.3 billion people may be at risk of food insecurity in 2050 in present low-income economies (mainly in Africa), if their economic development does not allow them to afford productivity increases, cropland expansion and/or imports from other countries. (letter)

Immediate sensitivity to structural constraints in pronoun resolution

Directory of Open Access Journals (Sweden)

Wing Yee eChow

2014-06-01

Full Text Available Real-time interpretation of pronouns is sometimes sensitive to the presence of grammatically-illicit antecedents, and sometimes not. This occasional sensitivity has been taken as evidence that structural constraints do not immediately impact the initial antecedent retrieval for pronoun interpretation. We argue that it is important to separate effects that reflect the initial antecedent retrieval process from those that reflect later processes. We present results from five reading comprehension experiments. Both the current results and previous evidence support the hypothesis that agreement features and structural constraints immediately constrain the antecedent retrieval process for pronoun interpretation. Occasional sensitivity to grammatically-illicit antecedents may be due to repair processes triggered when the initial retrieval fails to return a grammatical antecedent.

Efficient Searching with Linear Constraints

DEFF Research Database (Denmark)

Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

2000-01-01

We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint. This pr...

Constraint qualifications and optimality conditions for optimization problems with cardinality constraints

Czech Academy of Sciences Publication Activity Database

Červinka, Michal; Kanzow, Ch.; Schwartz, A.

2016-01-01

Roč. 160, č. 1 (2016), s. 353-377 ISSN 0025-5610 R&D Projects: GA ČR GAP402/12/1309; GA ČR GA15-00735S Institutional support: RVO:67985556 Keywords : Cardinality constraints * Constraint qualifications * Optimality conditions * KKT conditions * Strongly stationary points Subject RIV: BA - General Mathematics Impact factor: 2.446, year: 2016 http://library.utia.cas.cz/separaty/2016/MTR/cervinka-0461165.pdf

Constraint Specialisation in Horn Clause Verification

DEFF Research Database (Denmark)

Kafle, Bishoksan; Gallagher, John Patrick

2015-01-01

We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query-answer transformation of a given set of clauses and a goal. The effect is to propagate the constraints from the goal top......-down and propagate answer constraints bottom-up. Our approach does not unfold the clauses at all; we use the constraints from the model to compute a specialised version of each clause in the program. The approach is independent of the abstract domain and the constraints theory underlying the clauses. Experimental...

Constraint specialisation in Horn clause verification

DEFF Research Database (Denmark)

Kafle, Bishoksan; Gallagher, John Patrick

2017-01-01

We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query–answer transformed version of a given set of clauses and a goal. The constraints from the model are then used to compute...... a specialised version of each clause. The effect is to propagate the constraints from the goal top-down and propagate answer constraints bottom-up. The specialisation procedure can be repeated to yield further specialisation. The approach is independent of the abstract domain and the constraint theory...

Environmental constraints and call evolution in torrent-dwelling frogs.

Science.gov (United States)

Goutte, Sandra; Dubois, Alain; Howard, Samuel D; Marquez, Rafael; Rowley, Jodi J L; Dehling, J Maximilian; Grandcolas, Philippe; Rongchuan, Xiong; Legendre, Frédéric

2016-04-01

Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Democratic Constraints and Adherence to the Classical Gold Standard

NARCIS (Netherlands)

Kramer, Bert S.; Milionis, Petros

We study how domestic politics affected the decisions of countries to adhere to the classical gold standard. Using a variety of econometric techniques and controlling for a wide range of economic factors, we demonstrate that political constraints were important in the decision of countries to adopt

[Challenge and strategy of prevention and control of important parasitic diseases under the Belt and Road Initiative].

Science.gov (United States)

Chun-Li, Cao; Jia-Gang, Guo

2018-04-17

China was once a country with the heaviest burden of parasitic diseases. Under the leadership of the Communist Party and national authority, after more than 60 years' efforts of prevention and control, the remarkable results have been achieved in China. However, affected by the social and economic development and environmental changes, the prevention and control of parasitic diseases, especially imported parasitic diseases, are facing new challenges, and the parasitic diseases, such as malaria, schistosomiasis, leishmaniasis, filariasis and trypanosomiasis, appear increasingly. With the development of the Belt and Road Initiative, the transmission risks of these diseases are more increased. The purpose of this paper is to describe the experience and results of parasitic disease prevention and control in China, understand the present parasitic disease epidemic situation of the Belt and Road Initiative related countries, analyze the transmission risks of important parasitic diseases, and present some relevant suggestions, so as to provide the evidence for the health administrative department formulating the prevention and control strategies of such parasitic diseases timely and effectively.

Reduction Of Constraints For Coupled Operations

International Nuclear Information System (INIS)

Raszewski, F.; Edwards, T.

2009-01-01

The homogeneity constraint was implemented in the Defense Waste Processing Facility (DWPF) Product Composition Control System (PCCS) to help ensure that the current durability models would be applicable to the glass compositions being processed during DWPF operations. While the homogeneity constraint is typically an issue at lower waste loadings (WLs), it may impact the operating windows for DWPF operations, where the glass forming systems may be limited to lower waste loadings based on fissile or heat load limits. In the sludge batch 1b (SB1b) variability study, application of the homogeneity constraint at the measurement acceptability region (MAR) limit eliminated much of the potential operating window for DWPF. As a result, Edwards and Brown developed criteria that allowed DWPF to relax the homogeneity constraint from the MAR to the property acceptance region (PAR) criterion, which opened up the operating window for DWPF operations. These criteria are defined as: (1) use the alumina constraint as currently implemented in PCCS (Al 2 O 3 (ge) 3 wt%) and add a sum of alkali constraint with an upper limit of 19.3 wt% (ΣM 2 O 2 O 3 constraint to 4 wt% (Al 2 O 3 (ge) 4 wt%). Herman et al. previously demonstrated that these criteria could be used to replace the homogeneity constraint for future sludge-only batches. The compositional region encompassing coupled operations flowsheets could not be bounded as these flowsheets were unknown at the time. With the initiation of coupled operations at DWPF in 2008, the need to revisit the homogeneity constraint was realized. This constraint was specifically addressed through the variability study for SB5 where it was shown that the homogeneity constraint could be ignored if the alumina and alkali constraints were imposed. Additional benefit could be gained if the homogeneity constraint could be replaced by the Al 2 O 3 and sum of alkali constraint for future coupled operations processing based on projections from Revision 14 of

Transmission and capacity pricing and constraints

International Nuclear Information System (INIS)

Fusco, M.

1999-01-01

A series of overhead viewgraphs accompanied this presentation which discussed the following issues regarding the North American electric power industry: (1) capacity pricing transmission constraints, (2) nature of transmission constraints, (3) consequences of transmission constraints, and (4) prices as market evidence. Some solutions suggested for pricing constraints included the development of contingent contracts, back-up power in supply regions, and new line capacity construction. 8 tabs., 20 figs

Constraints to Agricultural Mechanization in Sub-Saharan Africa ...

African Journals Online (AJOL)

However, unlike other developing countries in Asia, the level of agricultural mechanization in Sub-‐Sahara Africa is still very low and is faced with a number of constraints. It is important for the attention of governments and other institutions to be drawn to these for immediate intervention to be taken. The objective of this ...

Tracking cashew economically important diseases in the West African region using metagenomics

Science.gov (United States)

Monteiro, Filipa; Romeiras, Maria M.; Figueiredo, Andreia; Sebastiana, Mónica; Baldé, Aladje; Catarino, Luís; Batista, Dora

2015-01-01

During the last decades, agricultural land-uses in West Africa were marked by dramatic shifts in the coverage of individual crops. Nowadays, cashew (Anacardium occidentale L.) is one of the most export-oriented horticulture crops, notably in Guinea-Bissau. Relying heavily on agriculture to increase their income, developing countries have been following a strong trend of moving on from traditional farming systems toward commercial production. Emerging infectious diseases, driven either by adaptation to local conditions or inadvertent importation of plant pathogens, are able to cause tremendous cashew production losses, with economic and social impact of which, in developing countries is often underestimated. Presently, plant genomics with metagenomics as an emergent tool, presents an enormous potential to better characterize diseases by providing extensive knowledge on plant pathogens at a large scale. In this perspective, we address metagenomics as a promising genomic tool to identify cashew fungal associated diseases as well as to discriminate the causal pathogens, aiming at obtaining tools to help design effective strategies for disease control and thus promote the sustainable production of cashew in West African Region. PMID:26175748

Tracking cashew economically important diseases in the West African region using metagenomics

Directory of Open Access Journals (Sweden)

Filipa eMonteiro

2015-06-01

Full Text Available During the last decades, agricultural land-uses in West Africa were marked by dramatic shifts in the coverage of individual crops. Nowadays, cashew (Anacardium occidentale L. is one of the most export-oriented horticulture crops, notably in Guinea-Bissau. Relying heavily on agriculture to increase their income, developing countries have been following a strong trend of moving on from traditional farming systems towards commercial production. Emerging infectious diseases, driven either by adaptation to local conditions or inadvertent importation of plant pathogens, are able to cause tremendous cashew production losses, with economic and social impact of which, in developing countries is often underestimated. Presently, plant genomics with metagenomics as an emergent tool, presents an enormous potential to better characterize diseases by providing extensive knowledge on plant pathogens at a large scale. In this perspective, we address metagenomics as a promising genomic tool to identify cashew fungal associated diseases as well as to discriminate the causal pathogens, aiming at obtaining tools to help design effective strategies for disease control and thus promote the sustainable production of cashew in West African region.

Evaluating Distributed Timing Constraints

DEFF Research Database (Denmark)

Kristensen, C.H.; Drejer, N.

1994-01-01

In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems.......In this paper we describe a solution to the problem of implementing time-optimal evaluation of timing constraints in distributed real-time systems....

Private sector involvement in times of armed conflict: What are the constraints for trading medical equipment?

Science.gov (United States)

Schmidt, Georg

Today, healthcare facilities are highly dependent on the private sector to keep their medical equipment functioning. Moreover, private sector involvement becomes particularly important for the supply of spare parts and consumables. However, in times of armed conflict, the capacity of the corporate world appears to be seriously hindered. Subsequently, this study researches the influence of armed conflict on the private medical equipment sector. This study follows a qualitative approach by conducting 19 interviews with representatives of the corporate world in an active conflict zone. A semistructured interview guide, consisting of 10 questions, was used to examine the constraints of this sector. The results reveal that the lack of skilled personnel, complicated importation procedures, and a decrease in financial capacity are the major constraints faced by private companies dealing in medical equipment in conflict zones. Even when no official sanctions and embargoes for medical items exist, constraints for trading medical equipment are clearly recognizable. Countries at war would benefit from a centralized structure that deals with the importation procedures for medical items, to assist local companies in their purchasing procedures. A high degree of adaption is needed to continue operating, despite the emerging constraints of armed conflict. Future studies might research the constraints for manufacturers outside the conflict to export medical items to the country of war.

Thermomechanical constraints and constitutive formulations in thermoelasticity

Directory of Open Access Journals (Sweden)

Baek S.

2003-01-01

Full Text Available We investigate three classes of constraints in a thermoelastic body: (i a deformation-temperature constraint, (ii a deformation-entropy constraint, and (iii a deformation-energy constraint. These constraints are obtained as limits of unconstrained thermoelastic materials and we show that constraints (ii and (iii are equivalent. By using a limiting procedure, we show that for the constraint (i, the entropy plays the role of a Lagrange multiplier while for (ii and (iii, the absolute temperature plays the role of Lagrange multiplier. We further demonstrate that the governing equations for materials subject to constraint (i are identical to those of an unconstrained material whose internal energy is an affine function of the entropy, while those for materials subject to constraints (ii and (iii are identical to those of an unstrained material whose Helmholtz potential is affine in the absolute temperature. Finally, we model the thermoelastic response of a peroxide-cured vulcanizate of natural rubber and show that imposing the constraint in which the volume change depends only on the internal energy leads to very good predictions (compared to experimental results of the stress and temperature response under isothermal and isentropic conditions.

Global epidemiology of phytoplasma diseases of economic importance in Southeast Europe

OpenAIRE

Mitrev, Sasa

2007-01-01

The network ‘Global epidemiology of phytoplasma diseases of economic importance in Southeast Europe’ will coordinate the efforts of plant pathologists, microbiologists and entomologists of Southeast European countries to better monitor phytoplasma strains propagation through nurseries and insect vectors, at the European scale. This will be investigated both in plants and insects using up to date molecular typing tools and real-time PCR detection technology. In addition, the network will initi...

Exploring the Constraint Profile of Winter Sports Resort Tourist Segments.

Science.gov (United States)

Priporas, Constantinos-Vasilios; Vassiliadis, Chris A; Bellou, Victoria; Andronikidis, Andreas

2015-09-01

Many studies have confirmed the importance of market segmentation both theoretically and empirically. Surprisingly though, no study has so far addressed the issue from the perspective of leisure constraints. Since different consumers face different barriers, we look at participation in leisure activities as an outcome of the negotiation process that winter sports resort tourists go through, to balance between related motives and constraints. This empirical study reports the findings on the applicability of constraining factors in segmenting the tourists who visit winter sports resorts. Utilizing data from 1,391 tourists of winter sports resorts in Greece, five segments were formed based on their constraint, demographic, and behavioral profile. Our findings indicate that such segmentation sheds light on factors that could potentially limit the full utilization of the market. To maximize utilization, we suggest customizing marketing to the profile of each distinct winter sports resort tourist segment that emerged.

Exploring the Constraint Profile of Winter Sports Resort Tourist Segments

Science.gov (United States)

Priporas, Constantinos-Vasilios; Vassiliadis, Chris A.; Bellou, Victoria; Andronikidis, Andreas

2014-01-01

Many studies have confirmed the importance of market segmentation both theoretically and empirically. Surprisingly though, no study has so far addressed the issue from the perspective of leisure constraints. Since different consumers face different barriers, we look at participation in leisure activities as an outcome of the negotiation process that winter sports resort tourists go through, to balance between related motives and constraints. This empirical study reports the findings on the applicability of constraining factors in segmenting the tourists who visit winter sports resorts. Utilizing data from 1,391 tourists of winter sports resorts in Greece, five segments were formed based on their constraint, demographic, and behavioral profile. Our findings indicate that such segmentation sheds light on factors that could potentially limit the full utilization of the market. To maximize utilization, we suggest customizing marketing to the profile of each distinct winter sports resort tourist segment that emerged. PMID:29708114

Present scenario, constraints and strategies for improvement of mungbean-production in Pakistan

International Nuclear Information System (INIS)

Haqqani, A.M.; Zubair, M.; Malik, M.R.

2004-01-01

Mungbean is one of the important Kharif pulses of Pakistan. It is also grown during spring season, mainly in southern Punjab and Sindh provinces. During 1999-2000, it was planted on an area of 202.7 hectares, with the production of 94.8 tones. Punjab is the mungbean-growing province that alone accounted for 85.6% area and 83% of the total mungbean production, respectively. Cultivation is concentrated in the districts of Layyah, Bhakkar, Mianwali and Rawalpindi. It is mainly grown in Kharif season (July October). Although it is grown in different crop rotations, about 75% cultivation follows mungbean - wheat crop rotation. With the development of short duration and uniform maturing varieties, mungbean can be fitted in various cropping systems. Presently the production of mungbean has increase due to expansion in area but not by the increase in productivity. Among the major constraints, weeds, insect damage and lack of seed production are the most important ones. Research activities on mungbean have mainly focused on the development of high-yielding varieties with wider adaptability, resistance to diseases like mungbean yellow mosaic virus (MYMV) and Cercospora Leaf Spot (CLS), early maturity and insensitivity to photo period. The breeding improvement of mungbean was limited, until 1970, due to the selection from land races, which were of trailing types. Research on this crop like other pulses gained momentum from 1980 when Coordinated Pulses Research Program was started at federal level by PARC, in collaboration with provincial research institutes. This program, through generation of funds, short-term and long-term training, exchange of germplasm/research materials (with National and International Research Institute) and evaluation of new improved lines, strengthened research on pulses. From 1985-86 to date, about ten improved varieties have been released for general cultivation in country. New improved varieties have the potential to increase mungbean production

Legal, ethical,and economic constraints

International Nuclear Information System (INIS)

Libassi, F.P.; Donaldson, L.F.

1980-01-01

This paper considers the legal, ethical, and economic constraints to developing a comprehensive knowledge of the biological effects of ionizing radiation. These constraints are not fixed and immutable; rather they are determined by the political process. Political issues cannot be evaded. The basic objective of developing a comprehensive knowledge about the biological effects of ionizing radiation exists as an objective not only because we wish to add to the store of human knowledge but also because we have important use for that knowledge. It will assist our decision-makers to make choices that affect us all. These choices require both hard factual information and application of political judgment. Research supplies some of the hard factual information and should be as free as possible from political influence in its execution. At the same time, the political choices that must be made influence the direction and nature of the research program as a whole. Similarly, the legal, ethical, and economic factors that constrain our ability to expand knowledge through research reflect a judgment by political agents that values other than expansion of knowledge should be recognized and given effect

Machine tongues. X. Constraint languages

Energy Technology Data Exchange (ETDEWEB)

Levitt, D.

Constraint languages and programming environments will help the designer produce a lucid description of a problem domain, and then of particular situations and problems in it. Early versions of these languages were given descriptions of real world domain constraints, like the operation of electrical and mechanical parts. More recently, the author has automated a vocabulary for describing musical jazz phrases, using constraint language as a jazz improviser. General constraint languages will handle all of these domains. Once the model is in place, the system will connect built-in code fragments and algorithms to answer questions about situations; that is, to help solve problems. Bugs will surface not in code, but in designs themselves. 15 references.

Prospects for nuclear terrorism: psychological motivations and constraints

International Nuclear Information System (INIS)

Post, J.M.

1987-01-01

In considering the implications of psychological understandings to the specific case of nuclear terrorism, it is emphasized that distorted decision making does not equate to totally irrational decision making. In certain circumstances, however, the distorted individual and group decision-making psychology could influence the group toward a high-risk option such as nuclear terrorism. For terrorists operating within their own national boundaries, a terrorist act producing mass casualties would generally be counterproductive. For groups acting across national boundaries, however, this constraint does not apply to nearly the same degree. Although the opprobrium of the West will be a constraint for some, it will not be equally so for all terrorist groups. The degree of disincentive will relate in particular to the major audience of influence. Also, there are the terrorist losers who are being shunted aside and losing the recognition they seek. Such a group could justify a terrorist spectacular in order to regain influence on the basis of a what have we got to lose rationale. In thinking about the possibility of nuclear terrorism, it is important to distinguish between the actual detonation of a device and the use of a device for extortion and influence. The constraints against the latter are significantly reduced in contrast to acts producing mass casualties. The constraints are even more reduced in the case of the plausible nuclear hoax, an option that can be expected to become more frequent

Cosmological constraints with clustering-based redshifts

Science.gov (United States)

Kovetz, Ely D.; Raccanelli, Alvise; Rahman, Mubdi

2017-07-01

We demonstrate that observations lacking reliable redshift information, such as photometric and radio continuum surveys, can produce robust measurements of cosmological parameters when empowered by clustering-based redshift estimation. This method infers the redshift distribution based on the spatial clustering of sources, using cross-correlation with a reference data set with known redshifts. Applying this method to the existing Sloan Digital Sky Survey (SDSS) photometric galaxies, and projecting to future radio continuum surveys, we show that sources can be efficiently divided into several redshift bins, increasing their ability to constrain cosmological parameters. We forecast constraints on the dark-energy equation of state and on local non-Gaussianity parameters. We explore several pertinent issues, including the trade-off between including more sources and minimizing the overlap between bins, the shot-noise limitations on binning and the predicted performance of the method at high redshifts, and most importantly pay special attention to possible degeneracies with the galaxy bias. Remarkably, we find that once this technique is implemented, constraints on dynamical dark energy from the SDSS imaging catalogue can be competitive with, or better than, those from the spectroscopic BOSS survey and even future planned experiments. Further, constraints on primordial non-Gaussianity from future large-sky radio-continuum surveys can outperform those from the Planck cosmic microwave background experiment and rival those from future spectroscopic galaxy surveys. The application of this method thus holds tremendous promise for cosmology.

Coronary artery anomalies and clinically important anatomy in patients with congenital heart disease: multislice CT findings

International Nuclear Information System (INIS)

Goo, Hyun Woo; Seo, Dong-Man; Yun, Tae-Jin; Park, Jeong-Jun; Park, In-Sook; Ko, Jae Kon; Kim, Young Hwee

2009-01-01

In patients with congenital heart disease, coronary artery anomalies are common and have different clinical importance from individuals with structurally normal hearts. Visibility of the coronary arteries by CT has markedly improved due to high temporal resolution and ECG-synchronized data acquisition. In this article we describe current multislice CT techniques for coronary artery imaging and illustrate coronary artery anomalies and clinically important coronary artery anatomy from the point of view of congenital heart disease. (orig.)

Coronary artery anomalies and clinically important anatomy in patients with congenital heart disease: multislice CT findings

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea); Seo, Dong-Man; Yun, Tae-Jin; Park, Jeong-Jun [University of Ulsan College of Medicine, Department of Pediatric Cardiac Surgery, Asan Medical Center, Seoul (Korea); Park, In-Sook; Ko, Jae Kon; Kim, Young Hwee [University of Ulsan College of Medicine, Department of Pediatric Cardiology, Asan Medical Center, Seoul (Korea)

2009-03-15

In patients with congenital heart disease, coronary artery anomalies are common and have different clinical importance from individuals with structurally normal hearts. Visibility of the coronary arteries by CT has markedly improved due to high temporal resolution and ECG-synchronized data acquisition. In this article we describe current multislice CT techniques for coronary artery imaging and illustrate coronary artery anomalies and clinically important coronary artery anatomy from the point of view of congenital heart disease. (orig.)

Appreciate the Appreciation: Imported Inputs and Concern Over Dutch Disease

Directory of Open Access Journals (Sweden)

Wardah Naim

2013-03-01

Full Text Available If anything is to blame for a higher dollar having negative effects on the Central Canadian manufacturing sector, you are not likely to find it in any “Dutch Disease” supposedly caused by Alberta’s oil sands. Contrary to popular belief, the higher value of the Canadian dollar may even help Central Canadian manufacturers grow stronger, cut costs, and create jobs. The idea that a booming, commodity-driven dollar is hurting Canadian goods exports, afflicting the country with so-called Dutch Disease, may be popular among certain politicians, including federal Opposition leader Thomas Mulcair and former Premier of Ontario Dalton McGuinty, but is not supported by the facts. It turns out that the simple economic theory these politicians have in mind is incomplete. A more thorough, data-driven look at the nation’s manufacturing sector reveals that Canadian businesses rely very heavily on imported materials and equipment as inputs in the manufacturing process. Canadian industry overall has one of the highest import ratios for such intermediate goods in the OECD, roughly twice as high as that of the U.S., the European Union and Japan. Compared to all other sectors, manufacturers are the heaviest users of imported materials and equipment, with more than 40 per cent of their inputs coming from other countries. A higher dollar may make it more expensive for foreign buyers to purchase Canadian manufactured goods, but that effect appears to be more than offset by the savings that Canadian producers enjoy with a higher dollar that makes possible cheaper imported-inputs and lower cost of production, which have a lowering effect on prices. The net result is that Canadian manufacturers actually get more benefit from a higher dollar, and the regions that get the biggest boost from it are the Central Canadian provinces of Ontario and Quebec. Policy-makers looking to aid the Canadian economy as a whole, and the manufacturing sector in particular, should stop

Ant colony optimization and constraint programming

CERN Document Server

Solnon, Christine

2013-01-01

Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

Competition as a source of constraint on life history evolution in natural populations.

Science.gov (United States)

Wilson, A J

2014-01-01

Competition among individuals is central to our understanding of ecology and population dynamics. However, it could also have major implications for the evolution of resource-dependent life history traits (for example, growth, fecundity) that are important determinants of fitness in natural populations. This is because when competition occurs, the phenotype of each individual will be causally influenced by the phenotypes, and so the genotypes, of competitors. Theory tells us that indirect genetic effects arising from competitive interactions will give rise to the phenomenon of 'evolutionary environmental deterioration', and act as a source of evolutionary constraint on resource-dependent traits under natural selection. However, just how important this constraint is remains an unanswered question. This article seeks to stimulate empirical research in this area, first highlighting some patterns emerging from life history studies that are consistent with a competition-based model of evolutionary constraint, before describing several quantitative modelling strategies that could be usefully applied. A recurrent theme is that rigorous quantification of a competition's impact on life history evolution will require an understanding of the causal pathways and behavioural processes by which genetic (co)variance structures arise. Knowledge of the G-matrix among life history traits is not, in and of itself, sufficient to identify the constraints caused by competition.

Motion and deformation estimation from medical imagery by modeling sub-structure interaction and constraints

KAUST Repository

Sundaramoorthi, Ganesh

2012-09-13

This paper presents a novel medical image registration algorithm that explicitly models the physical constraints imposed by objects or sub-structures of objects that have differing material composition and border each other, which is the case in most medical registration applications. Typical medical image registration algorithms ignore these constraints and therefore are not physically viable, and to incorporate these constraints would require prior segmentation of the image into regions of differing material composition, which is a difficult problem in itself. We present a mathematical model and algorithm for incorporating these physical constraints into registration / motion and deformation estimation that does not require a segmentation of different material regions. Our algorithm is a joint estimation of different material regions and the motion/deformation within these regions. Therefore, the segmentation of different material regions is automatically provided in addition to the image registration satisfying the physical constraints. The algorithm identifies differing material regions (sub-structures or objects) as regions where the deformation has different characteristics. We demonstrate the effectiveness of our method on the analysis of cardiac MRI which includes the detection of the left ventricle boundary and its deformation. The experimental results indicate the potential of the algorithm as an assistant tool for the quantitative analysis of cardiac functions in the diagnosis of heart disease.

Causality Constraints in Conformal Field Theory

CERN Multimedia

CERN. Geneva

2015-01-01

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂φ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinni...

Causality constraints in conformal field theory

Energy Technology Data Exchange (ETDEWEB)

Hartman, Thomas; Jain, Sachin; Kundu, Sandipan [Department of Physics, Cornell University,Ithaca, New York (United States)

2016-05-17

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂ϕ){sup 4} coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning operators.

Micro-compression testing: A critical discussion of experimental constraints

International Nuclear Information System (INIS)

Kiener, D.; Motz, C.; Dehm, G.

2009-01-01

Micro-compression testing is a promising technique for determining mechanical properties at small length scales since it has several benefits over nanoindentation. However, as for all new techniques, experimental constraints influencing the results of such a micro-mechanical test must be considered. Here we investigate constraints imposed by the sample geometry, the pile-up of dislocations at the sample top and base, and the lateral stiffness of the testing setup. Using a focused ion beam milling setup, single crystal Cu specimens with different geometries and crystal orientations were fabricated. Tapered samples served to investigate the influence of strain gradients, while stiff sample top coatings and undeformable substrates depict the influence of dislocation pile-ups at these interfaces. The lateral system stiffness was reduced by placing specimens on top of needles. Samples were loaded using an in situ indenter in a scanning electron microscope in load controlled or displacement controlled mode. The observed differences in the mechanical response with respect to the experimental imposed constraints are discussed and lead to the conclusion that controlling the lateral system stiffness is the most important point

Importance of prumycin produced by Bacillus amyloliquefaciens SD-32 in biocontrol against cucumber powdery mildew disease.

Science.gov (United States)

Tanaka, Keijitsu; Fukuda, Mutsumi; Amaki, Yusuke; Sakaguchi, Takatoshi; Inai, Koji; Ishihara, Atsushi; Nakajima, Hiromitsu

2017-12-01

Powdery mildew disease of cucurbits is caused mainly by Podosphaera fusca, which is one of the most important limiting factors in cucurbit production worldwide. Previously we reported that Bacillus amyloliquefaciens biocontrol strain SD-32 produces C 17 bacillomycin D and [Ile 2002]surfactin, and that these metabolites play important roles in SD-32's biocontrol over cucumber gray mold disease. Our further investigation demonstrated that the culture broth and its supernatant suppressed cucumber powdery mildew disease in greenhouse experiments. However, the active principle(s) remained unknown. The active compound was isolated from the culture supernatant after anti-powdery mildew disease activity-guided purification and identified as prumycin. Prumycin significantly suppressed the disease, whereas bacillomycin D and [Ile 2002]surfactin did not. Prumycin did not induce the expression of plant defense genes (PR1a and VSP1), suggesting that it does not act via plant defense response. Light microscopic observations of prumycin-treated cucumber cotyledon suggested that prumycin inhibits the conidial germination of P. fusca. This study demonstrates that prumycin is a major factor in SD-32's suppression of cucumber powdery mildew disease. Our findings shed light for the first time on prumycin's role in biocontrol by Bacillus against this disease. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Cardiovascular magnetic resonance in pericardial diseases

Directory of Open Access Journals (Sweden)

Francone Marco

2009-05-01

Full Text Available Abstract The pericardium and pericardial diseases in particular have received, in contrast to other topics in the field of cardiology, relatively limited interest. Today, despite improved knowledge of pathophysiology of pericardial diseases and the availability of a wide spectrum of diagnostic tools, the diagnostic challenge remains. Not only the clinical presentation may be atypical, mimicking other cardiac, pulmonary or pleural diseases; in developed countries a shift for instance in the epidemiology of constrictive pericarditis has been noted. Accurate decision making is crucial taking into account the significant morbidity and mortality caused by complicated pericardial diseases, and the potential benefit of therapeutic interventions. Imaging herein has an important role, and cardiovascular magnetic resonance (CMR is definitely one of the most versatile modalities to study the pericardium. It fuses excellent anatomic detail and tissue characterization with accurate evaluation of cardiac function and assessment of the haemodynamic consequences of pericardial constraint on cardiac filling. This review focuses on the current state of knowledge how CMR can be used to study the most common pericardial diseases.

Learning and Parallelization Boost Constraint Search

Science.gov (United States)

Yun, Xi

2013-01-01

Constraint satisfaction problems are a powerful way to abstract and represent academic and real-world problems from both artificial intelligence and operations research. A constraint satisfaction problem is typically addressed by a sequential constraint solver running on a single processor. Rather than construct a new, parallel solver, this work…

A global analysis of NMR distance constraints from the PDB

International Nuclear Information System (INIS)

Vranken, Wim

2007-01-01

Information obtained from Nuclear Magnetic Resonance (NMR) experiments is encoded as a set of constraint lists when calculating three-dimensional structures for a protein. With the amount of constraint data from the world wide Protein Data Bank (wwPDB) that is now available, it is possible to do a global, large-scale analysis using only information from the constraints, without taking the coordinate information into account. This article describes such an analysis of distance constraints from NOE data based on a set of 1834 NMR PDB entries containing 1909 protein chains. In order to best represent the quality and extent of the data that is currently deposited at the wwPDB, only the original data as deposited by the authors was used, and no attempt was made to 'clean up' and further interpret this information. Because the constraint lists provide a single set of data, and not an ensemble of structural solutions, they are easier to analyse and provide a reduced form of structural information that is relevant for NMR analysis only. The online resource resulting from this analysis makes it possible to check, for example, how often a particular contact occurs when assigning NOESY spectra, or to find out whether a particular sequence fragment is likely to be difficult to assign. In this respect it formalises information that scientists with experience in spectrum analysis are aware of but cannot necessarily quantify. The analysis described here illustrates the importance of depositing constraints (and all other possible NMR derived information) along with the structure coordinates, as this type of information can greatly assist the NMR community

Fuzzy Constraint-Based Agent Negotiation

Institute of Scientific and Technical Information of China (English)

Menq-Wen Lin; K. Robert Lai; Ting-Jung Yu

2005-01-01

Conflicts between two or more parties arise for various reasons and perspectives. Thus, resolution of conflicts frequently relies on some form of negotiation. This paper presents a general problem-solving framework for modeling multi-issue multilateral negotiation using fuzzy constraints. Agent negotiation is formulated as a distributed fuzzy constraint satisfaction problem (DFCSP). Fuzzy constrains are thus used to naturally represent each agent's desires involving imprecision and human conceptualization, particularly when lexical imprecision and subjective matters are concerned. On the other hand, based on fuzzy constraint-based problem-solving, our approach enables an agent not only to systematically relax fuzzy constraints to generate a proposal, but also to employ fuzzy similarity to select the alternative that is subject to its acceptability by the opponents. This task of problem-solving is to reach an agreement that benefits all agents with a high satisfaction degree of fuzzy constraints, and move towards the deal more quickly since their search focuses only on the feasible solution space. An application to multilateral negotiation of a travel planning is provided to demonstrate the usefulness and effectiveness of our framework.

Constraint-based scheduling

Science.gov (United States)

Zweben, Monte

1993-01-01

The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

Financing Constraints And Inventory Investment: A Comparative Study With High-Frequency Panel Data

OpenAIRE

Robert E. Carpenter; Steven M. Fazzari; Bruce C. Petersen

1998-01-01

This study provides new evidence of the importance of financing constraints for explaining the dramatic cycles in inventory investment. We compare the empirical performance of different financial variables (coverage ratio, cash stocks, and cash flow) used in previous research to test for the presence of financing constraints. The comparison is undertaken in a common framework with an identical sample and high-frequency (quarterly) firm panel data. Cash flow is much more successful than cash s...

An effective heuristic for combined heat-and-power production planning with power ramp constraints

International Nuclear Information System (INIS)

Rong, Aiying; Lahdelma, Risto

2007-01-01

Combined heat-and-power (CHP) production is an increasingly important technology for its efficient utilization of primary-energy resources and for reducing CO 2 emissions. In the CHP plant, the generation of heat-and-power follows a joint characteristic, which makes the determination of both the marginal power production cost (MPPC) and the feasible operating region for the plant more complicated than for the power-only generation plant. Due to the interdependence between heat and power production, the power-ramp constraints, which limit how much the power production of a CHP plant may increase or decrease between two successive periods, may also imply constraints on the heat production. In this paper, we investigate the impact of power-ramp constraints on CHP production planning and develop a robust heuristic for dealing with the power-ramp constraints based on the solution to the problem with relaxed ramp-constraints (RRC). Numerical results based on realistic production models show that the heuristic can generate high-quality solutions efficiently. (author)

Estimating cross-validatory predictive p-values with integrated importance sampling for disease mapping models.

Science.gov (United States)

Li, Longhai; Feng, Cindy X; Qiu, Shi

2017-06-30

An important statistical task in disease mapping problems is to identify divergent regions with unusually high or low risk of disease. Leave-one-out cross-validatory (LOOCV) model assessment is the gold standard for estimating predictive p-values that can flag such divergent regions. However, actual LOOCV is time-consuming because one needs to rerun a Markov chain Monte Carlo analysis for each posterior distribution in which an observation is held out as a test case. This paper introduces a new method, called integrated importance sampling (iIS), for estimating LOOCV predictive p-values with only Markov chain samples drawn from the posterior based on a full data set. The key step in iIS is that we integrate away the latent variables associated the test observation with respect to their conditional distribution without reference to the actual observation. By following the general theory for importance sampling, the formula used by iIS can be proved to be equivalent to the LOOCV predictive p-value. We compare iIS and other three existing methods in the literature with two disease mapping datasets. Our empirical results show that the predictive p-values estimated with iIS are almost identical to the predictive p-values estimated with actual LOOCV and outperform those given by the existing three methods, namely, the posterior predictive checking, the ordinary importance sampling, and the ghosting method by Marshall and Spiegelhalter (2003). Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

ATC calculation with steady-state security constraints using Benders decomposition

International Nuclear Information System (INIS)

Shaaban, M.; Yan, Z.; Ni, Y.; Wu, F.; Li, W.; Liu, H.

2003-01-01

Available transfer capability (ATC) is an important indicator of the usable amount of transmission capacity accessible by assorted parties for commercial trading, ATC calculation is nontrivial when steady-state security constraints are included. In hie paper, Benders decomposition method is proposed to partition the AC problem with steady-state security constraints into a base case master problem and a series of subproblems relevant to various contingencies to include their impacts on ATC. The mathematical model is formulated and the two solution schemes are presented. Computer testing on the 4-bus system and IEEE 30-bus system shows the effectiveness of the proposed method and the solution schemes. (Author)

Acorn: A grid computing system for constraint based modeling and visualization of the genome scale metabolic reaction networks via a web interface

Directory of Open Access Journals (Sweden)

Bushell Michael E

2011-05-01

Full Text Available Abstract Background Constraint-based approaches facilitate the prediction of cellular metabolic capabilities, based, in turn on predictions of the repertoire of enzymes encoded in the genome. Recently, genome annotations have been used to reconstruct genome scale metabolic reaction networks for numerous species, including Homo sapiens, which allow simulations that provide valuable insights into topics, including predictions of gene essentiality of pathogens, interpretation of genetic polymorphism in metabolic disease syndromes and suggestions for novel approaches to microbial metabolic engineering. These constraint-based simulations are being integrated with the functional genomics portals, an activity that requires efficient implementation of the constraint-based simulations in the web-based environment. Results Here, we present Acorn, an open source (GNU GPL grid computing system for constraint-based simulations of genome scale metabolic reaction networks within an interactive web environment. The grid-based architecture allows efficient execution of computationally intensive, iterative protocols such as Flux Variability Analysis, which can be readily scaled up as the numbers of models (and users increase. The web interface uses AJAX, which facilitates efficient model browsing and other search functions, and intuitive implementation of appropriate simulation conditions. Research groups can install Acorn locally and create user accounts. Users can also import models in the familiar SBML format and link reaction formulas to major functional genomics portals of choice. Selected models and simulation results can be shared between different users and made publically available. Users can construct pathway map layouts and import them into the server using a desktop editor integrated within the system. Pathway maps are then used to visualise numerical results within the web environment. To illustrate these features we have deployed Acorn and created a

Notes on Timed Concurrent Constraint Programming

DEFF Research Database (Denmark)

Nielsen, Mogens; Valencia, Frank D.

2004-01-01

and program reactive systems. This note provides a comprehensive introduction to the background for and central notions from the theory of tccp. Furthermore, it surveys recent results on a particular tccp calculus, ntcc, and it provides a classification of the expressive power of various tccp languages.......A constraint is a piece of (partial) information on the values of the variables of a system. Concurrent constraint programming (ccp) is a model of concurrency in which agents (also called processes) interact by telling and asking information (constraints) to and from a shared store (a constraint...

Constraint and loneliness in agoraphobia: an empirical investigation.

Science.gov (United States)

Pehlivanidis, A; Koulis, S; Papakostas, Y

2014-01-01

While progress in the aetiopathology and treatment of panic disorder is indisputable, research regarding agoraphobia lacks behind. One significant-yet untested- theory by Guidano and Liotti, suggests the existence of inner representations of fear of "constraint" and fear of "loneliness" as two major schemata, important in the pathogenesis and manifestation of agoraphobia. Activation of these schemata may occur in situations in which the patient: (a) feels as in an inescapable trap (constraint) or (b) alone, unprotected and helpless (loneliness). Upon activation, the "constraint" schema elicits such symptoms as asphyxiation, chest pain, difficult breathing, motor agitation and muscular tension, while the "loneliness" schema elicits such symptoms as sensation of tachycardia, weakness of limbs, trembling or fainting. Activation of these schemata by content-compatible stimuli is expected to trigger various, yet distinct, response patterns, both of which are indiscriminately described within the term "agoraphobia". In order to investigate this hypothesis and its possible clinical applications, several mental and physical probes were applied to 20 patients suffering primarily from agoraphobia, and their responses and performance were recorded. Subjects also completed the "10-item Agoraphobia Questionnaire" prepared by our team aiming at assessing cognitions related to Guidano and Liotti's notion of "loneliness" and "constraint". Breath holding (BH) and Hyperventilation (HV) were selected as physical probes. BH was selected as an easily administered hypercapnea - induced clinical procedure, because of its apparent resemblance to the concept of "constraint". Subjects were instructed to hold their breath for as long as they could and stop at will. Similarly, it was hypothesized that HV might represent a physical "loneliness" probe, since it can elicit such symptoms as dizziness, paraesthesias, stiff muscles, cold hands or feet and trembling, reminiscent of a "collapsing

Importance of viral diseases in irradiated persons

International Nuclear Information System (INIS)

Blaha, M.; Jebavy, L.; Merka, V.; Horacek, J.

1988-01-01

A preliminary study was performed aimed at establishing the incidence of some viral diseases in radiation syndrome patients and the significance of the diseases for prognosis. In the study, 77 patients with syndromologically identical acute hematological forms of radiation sickness, mainly leukemic patients suffering from severe blood formation suppression and/or hematoblastosis were examined for concurrent herpes simplex virus and cytomegalovirus infections. Active viruses were isolated in almost 30% of the patients; nearly 90% of the patients were serologically positive, shedding antibodies. The findings thus confirmed the view that viral disease, especially in immunocompromised patients, has a critical effect on the survival of radiation sickness sufferers. (L.O.). 12 refs

The constraints

International Nuclear Information System (INIS)

Jones, P.M.S.

1987-01-01

There are considerable incentives for the use of nuclear in preference to other sources for base load electricity generation in most of the developed world. These are economic, strategic, environmental and climatic. However, there are two potential constraints which could hinder the development of nuclear power to its full economic potential. These are public opinion and financial regulations which distort the nuclear economic advantage. The concerns of the anti-nuclear lobby are over safety, (especially following the Chernobyl accident), the management of radioactive waste, the potential effects of large scale exposure of the population to radiation and weapons proliferation. These are discussed. The financial constraint is over two factors, the availability of funds and the perception of cost, both of which are discussed. (U.K.)

Fixed-Point Approximations of Bandwidth-Sharing Networks with Rate Constraints

NARCIS (Netherlands)

M. Frolkova (Masha); J. Reed (Josh); A.P. Zwart (Bert)

2011-01-01

htmlabstractBandwidth-sharing networks are important flow level models of communication networks. We focus on the fact that it takes a signicant number of users to saturate a link, necessitating the inclusion of individual rate constraints. In particular we extend work of Reed & Zwart on fluid

Convolutional Encoder and Viterbi Decoder Using SOPC For Variable Constraint Length

DEFF Research Database (Denmark)

Kulkarni, Anuradha; Dnyaneshwar, Mantri; Prasad, Neeli R.

2013-01-01

Convolution encoder and Viterbi decoder are the basic and important blocks in any Code Division Multiple Accesses (CDMA). They are widely used in communication system due to their error correcting capability But the performance degrades with variable constraint length. In this context to have...... detailed analysis, this paper deals with the implementation of convolution encoder and Viterbi decoder using system on programming chip (SOPC). It uses variable constraint length of 7, 8 and 9 bits for 1/2 and 1/3 code rates. By analyzing the Viterbi algorithm it is seen that our algorithm has a better...

Research in constraint-based layout, visualization, CAD, and related topics : a bibliographical survey

OpenAIRE

Hower, Walter; Graf, Winfried H.

1995-01-01

The present work compiles numerous papers in the area of computer-aided design, graphics, layout configuration, and user interfaces in general. There is nearly no conference on graphics, multimedia, and user interfaces that does not include a section on constraint-based graphics; on the other hand most conferences on constraint processing favour applications in graphics. This work of bibliographical pointers may serve as a basis for a detailed and comprehensive survey of this important and ch...

Developmental constraints on behavioural flexibility.

Science.gov (United States)

Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

2013-05-19

We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

Generalized Pauli constraints in small atoms

DEFF Research Database (Denmark)

Schilling, Christian; Altunbulak, Murat; Knecht, Stefan

2018-01-01

investigations have found evidence that these constraints are exactly saturated in several physically relevant systems, e.g., in a certain electronic state of the beryllium atom. It has been suggested that, in such cases, the constraints, rather than the details of the Hamiltonian, dictate the system......'s qualitative behavior. Here, we revisit this question with state-of-the-art numerical methods for small atoms. We find that the constraints are, in fact, not exactly saturated, but that they lie much closer to the surface defined by the constraints than the geometry of the problem would suggest. While...

Learning With Mixed Hard/Soft Pointwise Constraints.

Science.gov (United States)

Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

2015-09-01

A learning paradigm is proposed and investigated, in which the classical framework of learning from examples is enhanced by the introduction of hard pointwise constraints, i.e., constraints imposed on a finite set of examples that cannot be violated. Such constraints arise, e.g., when requiring coherent decisions of classifiers acting on different views of the same pattern. The classical examples of supervised learning, which can be violated at the cost of some penalization (quantified by the choice of a suitable loss function) play the role of soft pointwise constraints. Constrained variational calculus is exploited to derive a representer theorem that provides a description of the functional structure of the optimal solution to the proposed learning paradigm. It is shown that such an optimal solution can be represented in terms of a set of support constraints, which generalize the concept of support vectors and open the doors to a novel learning paradigm, called support constraint machines. The general theory is applied to derive the representation of the optimal solution to the problem of learning from hard linear pointwise constraints combined with soft pointwise constraints induced by supervised examples. In some cases, closed-form optimal solutions are obtained.

Short-sale Constraints and Credit Runs

DEFF Research Database (Denmark)

Venter, Gyuri

), creditors with high private signals are more lenient to roll over debt, and a bank with lower asset quality remains solvent. This leads to higher allocative efficiency in the real economy. My result thus implies that the decrease in average informativeness due to short-sale constraints can be more than......This paper studies how short-sale constraints affect the informational efficiency of market prices and the link between prices and economic activity. I show that under short-sale constraints security prices contain less information. However, short-sale constraints increase the informativeness...... the price of an asset the bank holds. I show that short-selling constraints in the financial market lead to the revival of self-fulfilling beliefs about the beliefs and actions of others, and create multiple equilibria. In the equilibrium where agents rely more on public information (i.e., the price...

Hamiltonian constraint in polymer parametrized field theory

International Nuclear Information System (INIS)

Laddha, Alok; Varadarajan, Madhavan

2011-01-01

Recently, a generally covariant reformulation of two-dimensional flat spacetime free scalar field theory known as parametrized field theory was quantized using loop quantum gravity (LQG) type ''polymer'' representations. Physical states were constructed, without intermediate regularization structures, by averaging over the group of gauge transformations generated by the constraints, the constraint algebra being a Lie algebra. We consider classically equivalent combinations of these constraints corresponding to a diffeomorphism and a Hamiltonian constraint, which, as in gravity, define a Dirac algebra. Our treatment of the quantum constraints parallels that of LQG and obtains the following results, expected to be of use in the construction of the quantum dynamics of LQG: (i) the (triangulated) Hamiltonian constraint acts only on vertices, its construction involves some of the same ambiguities as in LQG and its action on diffeomorphism invariant states admits a continuum limit, (ii) if the regulating holonomies are in representations tailored to the edge labels of the state, all previously obtained physical states lie in the kernel of the Hamiltonian constraint, (iii) the commutator of two (density weight 1) Hamiltonian constraints as well as the operator correspondent of their classical Poisson bracket converge to zero in the continuum limit defined by diffeomorphism invariant states, and vanish on the Lewandowski-Marolf habitat, (iv) the rescaled density 2 Hamiltonian constraints and their commutator are ill-defined on the Lewandowski-Marolf habitat despite the well-definedness of the operator correspondent of their classical Poisson bracket there, (v) there is a new habitat which supports a nontrivial representation of the Poisson-Lie algebra of density 2 constraints.

Treatment of Anorexia Nervosa: The Importance of Disease Progression in the Prognosis.

Science.gov (United States)

Andrade, Rodrigo; Gonçalves-Pinho, Manuel; Roma-Torres, António; Brandão, Isabel

2017-08-31

Anorexia nervosa is a severe, usually chronic, life-threatening disease of complex etiology characterized by food restriction, overestimation of the importance of body weight and image, intense fear of weight gain and distortion of body image. Anorexia nervosa is associated with high rates of mortality, suicide and decreased quality of life. Our aim is to present an anorexia nervosa treatment program offered in a major university hospital in Portugal, and to determine the impact of illness duration before admission on the outcome. Our hypothesis is that patients with greater disease longevity may have worse prognosis and poorer outcome. The sample included data from case records of 169 patients seen consecutively and for the first time at Centro Hospitalar São João, between 2010 and 2015. We performed a retrospective observational study which included data collected at admission and from later follow-up years. From the initially selected patients, 14.8% reached total remission, 16% accomplished partial remission and 14.2% ended up with exacerbation/stagnation of the disease. The dropout rate was of 55% throughout our study period. We found significant differences on outcome rates between distinct illness duration groups (p = 0.007). There are several factors frequently associated with poor outcome for anorexia nervosa. The interpretation of outcome findings was limited by the high rate of dropout and lack of consistent definition criteria. Our results support the idea that illness duration has an important role on the outcome and prognostic features of these patients.

Strongest experimental constraints on SU(5)×U(1) supergravity models

Science.gov (United States)

Lopez, Jorge L.; Nanopoulos, D. V.; Park, Gye T.; Zichichi, A.

1994-01-01

We consider a class of well-motivated string-inspired flipped SU(5) supergravity models which include four supersymmetry-breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are needed to describe all new phenomena (mt,tanβ,mg~). We show that the CERN LEP precise measurements of the electroweak parameters in the form of the ɛ1 variable and the CLEO II allowed range for B(b-->sγ) are at present the most important experimental constraints on this class of models. For mt>~155 (165) GeV, the ɛ1 constraint [at 90 (95)% C.L.] requires the presence of light charginos (m+/-χ1360 GeV, mq~sγ) constraint excludes a significant fraction of the otherwise allowed region in the (m+/-χ1,tanβ) plane (irrespective of the magnitude of the chargino mass), while future experimental improvements will result in decisive tests of these models. In light of the ɛ1 constraint, we conclude that the outlook for chargino and selectron detection at LEP II and at DESY HERA is quite favorable in this class of models.

Constraint-based Word Segmentation for Chinese

DEFF Research Database (Denmark)

Christiansen, Henning; Bo, Li

2014-01-01

-hoc and statistically based methods. In this paper, we show experiments of implementing different approaches to CWSP in the framework of CHR Grammars [Christiansen, 2005] that provides a constraint solving approach to language analysis. CHR Grammars are based upon Constraint Handling Rules, CHR [Frühwirth, 1998, 2009......], which is a declarative, high-level programming language for specification and implementation of constraint solvers....

Cacao diseases: important threats to chocolate production worldwide.

Science.gov (United States)

Ploetz, Randy C

2007-12-01

ABSTRACT Theobroma cacao, cacao, is an ancient, neotropical domesticate. It is now grown throughout the humid, lowland tropics and is the basis of a multibillion dollar confectionary trade. Diverse diseases impact production of the crop. They reduce yields by ca. 20%, but could cause far greater losses if certain highly damaging diseases were to become more widely distributed. Among the most potentially dangerous of these diseases are frosty pod, caused by Moniliophthora roreri, and witches' broom, caused by M. perniciosa (previously Crinipellis perniciosa). These two diseases occur only in the Western Hemisphere, and severe losses would follow their introduction to West Africa and Asia, where ca. 86% of all cacao production occurs. Elsewhere, Cacao swollen shoot virus and the damaging black pod agent, Phytophthora megakarya, are found in Western Africa; whereas vascular streak dieback, caused by Oncobasidium theobromae, is present only in Asia. Breeding programs are challenged by minimal resistance to some of the diseases. Progress that has been made is threatened by the "emergence" of other serious diseases, such as Ceratocystis wilt (Ceratocystis cacaofunesta). During this symposium, new insights are discussed on the biology, origins, pathology and phylogeny of the pathogens; as well as the biological, chemical and genetic management of the diseases that they cause.

Evaluation of pig production practices, constraints and opportunities for improvement in smallholder production systems in Kenya.

Science.gov (United States)

Mbuthia, Jackson Mwenda; Rewe, Thomas Odiwuor; Kahi, Alexander Kigunzu

2015-02-01

This study evaluated pig production practices by smallholder farmers in two distinct production systems geared towards addressing their constraints and prospects for improvement. The production systems evaluated were semi-intensive and extensive and differed in remoteness, market access, resource availability and pig production intensity. Data were collected using structured questionnaires where a total of 102 pig farmers were interviewed. Qualitative and quantitative research methods were employed to define the socioeconomic characteristics of the production systems, understanding the different roles that pigs play, marketing systems and constraints to production. In both systems, regular cash income and insurance against emergencies were ranked as the main reasons for rearing pigs. Marketing of pigs was mainly driven by the type of production operation. Finances, feeds and housing were identified as the major constraints to production. The study provides important parameters and identifies constraints important for consideration in design of sustainable production improvement strategies. Feeding challenges can be improved through understanding the composition and proper utilization of local feed resources. Provision of adequate housing would improve the stocking rates and control mating.

Can We Finish the Revolution? Gender, Work-Family Ideals, and Institutional Constraint.

Science.gov (United States)

Pedulla, David S; Thébaud, Sarah

2015-02-01

Why has progress toward gender equality in the workplace and at home stalled in recent decades? A growing body of scholarship suggests that persistently gendered workplace norms and policies limit men's and women's ability to create gender egalitarian relationships at home. In this article, we build on and extend prior research by examining the extent to which institutional constraints, including workplace policies, affect young, unmarried men's and women's preferences for their future work-family arrangements. We also examine how these effects vary across levels of education. Drawing on original survey-experimental data, we ask respondents how they would like to structure their future relationships while experimentally manipulating the degree of institutional constraint under which they state their preferences. Two clear patterns emerge. First, as constraints are removed and men and women can opt for an egalitarian relationship, the majority of them choose this option, regardless of gender or education level. Second, women's relationship structure preferences are more malleable to the removal of institutional constraints via supportive work-family policy interventions than are men's. These findings shed light on important questions about the role of institutions in shaping work-family preferences, underscoring the notion that seemingly gender-traditional work-family decisions are largely contingent on the constraints of current workplaces.

The importance of ecological constraints on the control of multi-species treeline dynamics in eastern Nunavik, Quebec.

Science.gov (United States)

Dufour-Tremblay, Geneviève; De Vriendt, Laurent; Lévesque, Esther; Boudreau, Stéphane

2012-10-01

Treelines are temperature-sensitive ecotones that should be able to expand in response to global warming; however, they are also controlled by ecological constraints. These constraints can create bottlenecks for tree regeneration, hindering treeline advances. Near Kangiqsualujjuaq (Nunavik, subarctic Québec), previous studies suggested successful recruitment of Larix laricina above the altitudinal treeline, while Picea mariana establishment remains scarce. We studied regeneration of both species to identify factors responsible for such contrasting responses. • We measured seeds and wings to evaluate species dispersal potential. We compared seed viability and tolerance to shrub leachates with germination trials. To evaluate seedbed preferences, we compared seedling occurrence on the different seedbeds with seedbed relative abundance in the field. • Seed germination was similar between L. laricina and P. mariana, whereas dispersal potential was higher for the latter. Germination of P. mariana seeds was more strongly inhibited by shrub leachates than were L. laricina seeds. In the field, we found only a few Picea seedlings, but numerous seedlings of Larix had established disproportionally on several seedbeds. While Betula glandulosa, mosses, and Vaccinium uliginosim impeded Larix establishment, numerous seedlings were found on lichens, mineral soil, and liverworts. The low occurrence of suitable seedbeds for Picea, mainly mineral soil, could explain the seedling scarcity of this species. • This study highlighted that allelopathy and unsuitable seedbeds could contribute to regeneration failure of P. mariana in eastern Nunavik and emphasizes the need to consider ecological preferences of species before predicting treeline expansion under a warmer climate.

A Hybrid Method for Modeling and Solving Supply Chain Optimization Problems with Soft and Logical Constraints

Directory of Open Access Journals (Sweden)

Paweł Sitek

2016-01-01

Full Text Available This paper presents a hybrid method for modeling and solving supply chain optimization problems with soft, hard, and logical constraints. Ability to implement soft and logical constraints is a very important functionality for supply chain optimization models. Such constraints are particularly useful for modeling problems resulting from commercial agreements, contracts, competition, technology, safety, and environmental conditions. Two programming and solving environments, mathematical programming (MP and constraint logic programming (CLP, were combined in the hybrid method. This integration, hybridization, and the adequate multidimensional transformation of the problem (as a presolving method helped to substantially reduce the search space of combinatorial models for supply chain optimization problems. The operation research MP and declarative CLP, where constraints are modeled in different ways and different solving procedures are implemented, were linked together to use the strengths of both. This approach is particularly important for the decision and combinatorial optimization models with the objective function and constraints, there are many decision variables, and these are summed (common in manufacturing, supply chain management, project management, and logistic problems. The ECLiPSe system with Eplex library was proposed to implement a hybrid method. Additionally, the proposed hybrid transformed model is compared with the MILP-Mixed Integer Linear Programming model on the same data instances. For illustrative models, its use allowed finding optimal solutions eight to one hundred times faster and reducing the size of the combinatorial problem to a significant extent.

Growth Status of Iranian Children with Hemodynamically Important Congenital Heart Disease

Directory of Open Access Journals (Sweden)

Mohammad Dalili

2011-02-01

Full Text Available The relationship between congenital heart disease (CHD and growth retardation is well documented. We investigated the growth condition of Iranian children with several types of congenital heart disease (CHD and compared it with worldwide researches. Growth condition was investigated in 469 patients with important CHD aged from 1 month to 18 years. The patients were divided into two groups; infants (aged 12 months or less, and children (1-18 yrs of age. Children with hemodynamically unimportant small VSDs or small ASDs were not studied. Other exclusion criteria were prematurity, known genetic disorders and neurologic disease affecting growthd. All patients' cardiac diagnoses were made on the basis of clinical and laboratory examinations; including electrocardiography, echocardiography, cardiac catheterization, and angiography. Body weight and height of all patients were measured using conventional methods and compared with standard growth charts. In all patients body weights and heights were significantly lower than normal population. This difference was greater in the weight of female children. Other risk factors for growth failure were large left-to-right intracardiac shunts, pulmonary hypertension and cyanosis. Iranian children with CHD have growth failure somewhat different from other countries. Lower body weights of cyanotic patients and female children indicated that these patients need more nutritional and psychosocial attention.

Generalized Pauli constraints in small atoms

Science.gov (United States)

Schilling, Christian; Altunbulak, Murat; Knecht, Stefan; Lopes, Alexandre; Whitfield, James D.; Christandl, Matthias; Gross, David; Reiher, Markus

2018-05-01

The natural occupation numbers of fermionic systems are subject to nontrivial constraints, which include and extend the original Pauli principle. A recent mathematical breakthrough has clarified their mathematical structure and has opened up the possibility of a systematic analysis. Early investigations have found evidence that these constraints are exactly saturated in several physically relevant systems, e.g., in a certain electronic state of the beryllium atom. It has been suggested that, in such cases, the constraints, rather than the details of the Hamiltonian, dictate the system's qualitative behavior. Here, we revisit this question with state-of-the-art numerical methods for small atoms. We find that the constraints are, in fact, not exactly saturated, but that they lie much closer to the surface defined by the constraints than the geometry of the problem would suggest. While the results seem incompatible with the statement that the generalized Pauli constraints drive the behavior of these systems, they suggest that the qualitatively correct wave-function expansions can in some systems already be obtained on the basis of a limited number of Slater determinants, which is in line with numerical evidence from quantum chemistry.

University Course Timetabling using Constraint Programming

Directory of Open Access Journals (Sweden)

Hadi Shahmoradi

2017-03-01

Full Text Available University course timetabling problem is a challenging and time-consuming task on the overall structure of timetable in every academic environment. The problem deals with many factors such as the number of lessons, classes, teachers, students and working time, and these are influenced by some hard and soft constraints. The aim of solving this problem is to assign courses and classes to teachers and students, so that the restrictions are held. In this paper, a constraint programming method is proposed to satisfy maximum constraints and expectation, in order to address university timetabling problem. For minimizing the penalty of soft constraints, a cost function is introduced and AHP method is used for calculating its coefficients. The proposed model is tested on department of management, University of Isfahan dataset using OPL on the IBM ILOG CPLEX Optimization Studio platform. A statistical analysis has been conducted and shows the performance of the proposed approach in satisfying all hard constraints and also the satisfying degree of the soft constraints is on maximum desirable level. The running time of the model is less than 20 minutes that is significantly better than the non-automated ones.

Psychological constraints on egalitarianism

DEFF Research Database (Denmark)

Kasperbauer, Tyler Joshua

2015-01-01

processes motivating people to resist various aspects of egalitarianism. I argue for two theses, one normative and one descriptive. The normative thesis holds that egalitarians must take psychological constraints into account when constructing egalitarian ideals. I draw from non-ideal theories in political...... philosophy, which aim to construct moral goals with current social and political constraints in mind, to argue that human psychology must be part of a non-ideal theory of egalitarianism. The descriptive thesis holds that the most fundamental psychological challenge to egalitarian ideals comes from what......Debates over egalitarianism for the most part are not concerned with constraints on achieving an egalitarian society, beyond discussions of the deficiencies of egalitarian theory itself. This paper looks beyond objections to egalitarianism as such and investigates the relevant psychological...

Constraint Programming for Context Comprehension

DEFF Research Database (Denmark)

Christiansen, Henning

2014-01-01

A close similarity is demonstrated between context comprehension, such as discourse analysis, and constraint programming. The constraint store takes the role of a growing knowledge base learned throughout the discourse, and a suitable con- straint solver does the job of incorporating new pieces...

Some cosmological constraints on gauge theories

International Nuclear Information System (INIS)

Schramm, D.N.

1983-01-01

In these lectures, a review is made of various constraints cosmology may place on gauge theories. Particular emphasis is placed on those constraints obtainable from Big Bang Nucleosynthesis, with only brief mention made of Big Bang Baryosynthesis. There is also a considerable discussion of astrophysical constraints on masses and lifetimes of neutrinos with specific mention of the 'missing mass (light)' problem of galactic dynamics. (orig./HSI)

The economics of managing Verticillium wilt, an imported disease in California lettuce

Directory of Open Access Journals (Sweden)

Christine L. Carroll

2017-09-01

Full Text Available Verticillium dahliae is a soilborne fungus that is introduced to the soil via infested spinach seeds and that causes lettuce to be afflicted with Verticillium wilt. This disease has spread rapidly through the Salinas Valley, the prime lettuce production region of California. Verticillium wilt can be prevented or controlled by the grower by fumigating, planting broccoli, or not planting spinach. Because these control options require long-term investment for future gain, renters might not take the steps needed to control Verticillium wilt. Verticillium wilt can also be prevented or controlled by a spinach seed company through testing and cleaning the spinach seeds. However, seed companies are unwilling to test or clean spinach seeds, as they are not affected by this disease. We discuss our research on the externalities that arise with renters, and between seed companies and growers, due to Verticillium wilt. These externalities have important implications for the management of Verticillium wilt in particular, and for the management of diseases in agriculture in general.

Dynamics and causality constraints

International Nuclear Information System (INIS)

Sousa, Manoelito M. de

2001-04-01

The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Causality in field theory are kinematical constraints dynamically implemented via solutions of the field equation, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away with deep implications to the nature of physicals interactions. (author)

Design variables and constraints in fashion store design processes

DEFF Research Database (Denmark)

Haug, Anders; Borch Münster, Mia

2015-01-01

is to identify the most important store design variables, organise these variables into categories, understand the design constraints between categories, and determine the most influential stakeholders. Design/methodology/approach: – Based on a discussion of existing literature, the paper defines a framework...... into categories, provides an understanding of constraints between categories of variables, and identifies the most influential stakeholders. The paper demonstrates that the fashion store design task can be understood through a system perspective, implying that the store design task becomes a matter of defining......Purpose: – Several frameworks of retail store environment variables exist, but as shown by this paper, they are not particularly well-suited for supporting fashion store design processes. Thus, in order to provide an improved understanding of fashion store design, the purpose of this paper...

Data assimilation with inequality constraints

Science.gov (United States)

Thacker, W. C.

If values of variables in a numerical model are limited to specified ranges, these restrictions should be enforced when data are assimilated. The simplest option is to assimilate without regard for constraints and then to correct any violations without worrying about additional corrections implied by correlated errors. This paper addresses the incorporation of inequality constraints into the standard variational framework of optimal interpolation with emphasis on our limited knowledge of the underlying probability distributions. Simple examples involving only two or three variables are used to illustrate graphically how active constraints can be treated as error-free data when background errors obey a truncated multi-normal distribution. Using Lagrange multipliers, the formalism is expanded to encompass the active constraints. Two algorithms are presented, both relying on a solution ignoring the inequality constraints to discover violations to be enforced. While explicitly enforcing a subset can, via correlations, correct the others, pragmatism based on our poor knowledge of the underlying probability distributions suggests the expedient of enforcing them all explicitly to avoid the computationally expensive task of determining the minimum active set. If additional violations are encountered with these solutions, the process can be repeated. Simple examples are used to illustrate the algorithms and to examine the nature of the corrections implied by correlated errors.

Mast cells are important modifiers of autoimmune disease: With so much evidence, why is there controversy?

Directory of Open Access Journals (Sweden)

Melissa Ann Brown

2012-06-01

Full Text Available There is abundant evidence that mast cells are active participants in events that mediate tissue damage in autoimmune disease. Disease-associated increases in mast cell numbers accompanied by mast cell degranulation and elaboration of numerous mast cell mediators at sites of inflammation are commonly observed in many human autoimmune diseases including multiple sclerosis, rheumatoid arthritis and bullous pemphigoid. In animal models, treatment with mast cell stabilizing drugs or mast cell ablation can result in diminished disease. A variety of receptors including those engaged by antibody, complement, pathogens and intrinsic danger signals are implicated in mast cell activation in disease. Similar to their role as first responders in infection settings, mast cells likely orchestrate early recruitment of immune cells, including neutrophils, to the sites of autoimmune destruction. This co-localization promotes cellular crosstalk and activation and results in the amplification of the local inflammatory response thereby promoting and sustaining tissue damage. Despite the evidence, there is still a debate regarding the relative role of mast cells in these processes. However, by definition, mast cells can only act as accessory cells to the self-reactive T and/or antibody driven autoimmune responses. Thus, when evaluating mast cell involvement using existing and somewhat imperfect animal models of disease, their importance is sometimes obscured. However, these potent immune cells are undoubtedly major contributors to autoimmunity and should be considered as important targets for therapeutic disease intervention.

Market liberalization in the European Natural Gas Market. The importance of capacity constraints and efficiency differences

Energy Technology Data Exchange (ETDEWEB)

Brakman, S. [University of Groningen, Faculty of Economics, Department of International Economics and Business, P.O. Box 800, 9700 AV Groningen (Netherlands); Van Marrewijk, C.; Van Witteloostuijn, A. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

2009-06-15

In the European Union, energy markets are increasingly being liberalized. A case in point is the European natural gas industry. The general expectation is that more competition will lead to lower prices and higher volumes, and hence higher welfare. This paper indicates that this might not happen for at least two reasons. First, energy markets, including the market for natural gas, are characterized by imperfect competition and increasing costs to develop new energy sources. As a result, new entrants in the market are less efficient than incumbent firms. Second, energy markets, again including the market for natural gas, are associated with capacity constraints. Prices are determined in residual markets where the least efficient firms are active. This is likely to lead to price increases, rather than decreases.

Use of dose constraints in public exposure

International Nuclear Information System (INIS)

Tageldein, Amged

2015-02-01

An overview of the dose constraints in public exposures has been carried out in this project. The establishment, development and the application of the concept of dose constraints are reviewed with regards to public exposure. The role of dose constraints in the process of optimization of radiation protection was described and has been showed that the concept of the dose constraints along with many other concept of radiation protection is widely applied in the optimization of exposure to radiation. From the beginning of the establishment of dose constraints as a concept in radiation protection, the International Commission of Radiological Protection (ICRP) has published a number of documents that provides detailed application related to radiation protection and safety of public exposure from ionizing radiation. This work provides an overview of such publications and related documents with special emphasis on optimization of public exposure using dose constraints. (au)

HRCT patterns of the most important interstitial lung diseases; HRCT-Muster der wichtigsten interstitiellen Lungenerkrankungen

Energy Technology Data Exchange (ETDEWEB)

Schaefer-Prokop, C. [Meander Medisch Centrum, Abt. Radiologie, Amersfoort (Netherlands); Radboud Universitaet, Abt. Radiologie und Nuklearmedizin, Nijmegen (Netherlands)

2014-12-15

Interstitial lung diseases are a mixed group of diffuse parenchymal lung diseases which can have an acute or chronic course. Idiopathic diseases and diseases with an underlying cause (e.g. collagen vascular diseases) share the same patterns. Thin section computed tomography (CT) plays a central role in the diagnostic work-up. The article describes the most important interstitial lung diseases following a four pattern approach with a predominant nodular or reticular pattern or a pattern with increased or decreased lung density. (orig.) [German] Interstitielle Lungenerkrankungen stellen eine gemischte Gruppe diffuser Lungenparenchymerkrankungen dar, die einen akuten oder chronischen Verlauf haben koennen. Idiopathische Erkrankungen und Erkrankungen mit definierter Ursache (z. B. kollagenvaskulaere Erkrankungen) weisen ein gemeinsames Muster auf. Die Duennschichtcomputertomographie spielt eine zentrale Rolle in der diagnostischen Abklaerung. In dem vorliegenden Beitrag werden die wichtigsten interstitiellen Lungenerkrankungen beschrieben. Dabei gibt es 4 Grundmuster: ueberwiegend nodulaere Verdichtungen, vorwiegend retikulaere Verdichtungen, erhoehte oder erniedrigte Lungenparenchymdichte. (orig.)

GROWTH, LIQUIDITY CONSTRAINTS, CREDIBILITY AND THE EFFECTS OF SHOCKS UNDER A NON-CREDIBLE GOVERNMENT

Directory of Open Access Journals (Sweden)

DURMUŞ ÖZDEMİR

2013-06-01

Full Text Available This paper presents an overlapping generations model for a small open economy. The model is calibrated to fit data for Turkey. Simulations suggest that for a fairly open economy such as Turkey, credibility and liquidity constraints matter and the choice of income taxation rate, the mix of government spending and the long-run government debt/GDP ratio can all significantly affect the economic growth. The paper also examines the effectiveness of fiscal policy under different levels of liquidity constraint in an open economy within a dynamic framework. It shows that liquidity constraints can affect the outcome of any fiscal policy. Hence fiscal policy is even more important for the less developed economies of the world.

Facilitators and constraints at each stage of the migration decision process.

Science.gov (United States)

Kley, Stefanie

2017-10-01

Behavioural models of migration emphasize the importance of migration decision-making for the explanation of subsequent behaviour. But empirical migration research regularly finds considerable gaps between those who intend to migrate and those who actually realize their intention. This paper applies the Theory of Planned Behaviour, enriched by the Rubicon model, to test specific hypotheses about distinct effects of facilitators and constraints on specific stages of migration decision-making and behaviour. The data come from a tailor-made panel survey based on random samples of people drawn from two German cities in 2006-07. The results show that in conventional models the effects of facilitators and constraints on migration decision-making are likely to be underestimated. Splitting the process of migration decision-making into a pre-decisional and a pre-actional phase helps to avoid bias in the estimated effects of facilitators and constraints on both migration decision-making and migration behaviour.

Uncertainty management by relaxation of conflicting constraints in production process scheduling

Science.gov (United States)

Dorn, Juergen; Slany, Wolfgang; Stary, Christian

1992-01-01

Mathematical-analytical methods as used in Operations Research approaches are often insufficient for scheduling problems. This is due to three reasons: the combinatorial complexity of the search space, conflicting objectives for production optimization, and the uncertainty in the production process. Knowledge-based techniques, especially approximate reasoning and constraint relaxation, are promising ways to overcome these problems. A case study from an industrial CIM environment, namely high-grade steel production, is presented to demonstrate how knowledge-based scheduling with the desired capabilities could work. By using fuzzy set theory, the applied knowledge representation technique covers the uncertainty inherent in the problem domain. Based on this knowledge representation, a classification of jobs according to their importance is defined which is then used for the straightforward generation of a schedule. A control strategy which comprises organizational, spatial, temporal, and chemical constraints is introduced. The strategy supports the dynamic relaxation of conflicting constraints in order to improve tentative schedules.

Evolution of female carotenoid coloration by sexual constraint in Carduelis finches

Directory of Open Access Journals (Sweden)

Cardoso Gonçalo C

2010-03-01

Full Text Available Abstract Background Females often express the same ornaments as males to a similar or lesser degree. Female ornaments can be adaptive, but little is known regarding their origins and mode of evolution. Current utility does not imply evolutionary causation, and therefore it is possible that female ornamentation evolved due to selection on females, as a correlated response to selection on males (sexual constraint, or a combination of both. We tested these ideas simulating simple models for the evolution of male and female correlated traits, and compared their predictions against the coloration of finches in the genus Carduelis. Results For carotenoid-based ornamental coloration, a model of sexual constraint on females fits the Carduelis data well. The two alternative models (sexual constraint on males, and mutual constraint were rejected as causing the similarities in carotenoid coloration between males and females. For melanin coloration, the correlation between the sexes was weaker, indicating that males and females evolved independently to a greater extent. Conclusions This indicates that sexual constraint on females was an important mechanism for the evolution of ornamental carotenoid coloration in females, but less so for melanin coloration. This does not mean that female carotenoid coloration is non-adaptive or maladaptive, because sexual dichromatism could evolve if it were maladaptive. It suggests, however, that most evolution of female carotenoid coloration was male-driven and, when adaptive, may not be an adaptation stricto sensu.

A general treatment of dynamic integrity constraints

NARCIS (Netherlands)

de Brock, EO

This paper introduces a general, set-theoretic model for expressing dynamic integrity constraints, i.e., integrity constraints on the state changes that are allowed in a given state space. In a managerial context, such dynamic integrity constraints can be seen as representations of "real world"

An Introduction to 'Creativity Constraints'

DEFF Research Database (Denmark)

Onarheim, Balder; Biskjær, Michael Mose

2013-01-01

Constraints play a vital role as both restrainers and enablers in innovation processes by governing what the creative agent/s can and cannot do, and what the output can and cannot be. Notions of constraints are common in creativity research, but current contributions are highly dispersed due to n...

Market segmentation using perceived constraints

Science.gov (United States)

Jinhee Jun; Gerard Kyle; Andrew Mowen

2008-01-01

We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

Health and management constraints to family poultry development in Morocco

International Nuclear Information System (INIS)

Faouzi, K.; El Omari, N.; Tmiri, N.; Jaouzi, T.

2002-01-01

A field survey was carried out in 73 farms from 11 villages distributed in 2 areas of Morocco during the dry season 1999 and the wet season 2000. Data on husbandry, farm socio-economics and health status of the flocks were collected. Flocks were clinically examined and sick/dead birds were subjected to pathological and parasitological investigations. The results showed that most flocks were raised in a traditional extensive system with a low stock density and weak production records. The management system was precarious and labour and financial input was very poor in most of the surveyed farms. Feeding system was poor, unreliable and arbitrary. Mortality was high and reached 70% in some flocks. Gumboro disease and Newcastle disease were among the major diseases diagnosed besides helminth and ectoparasite infestations. All constraints were prevailing in the absence of any institutional or corporate interventions. (author)

Constraint Handling Rules with Binders, Patterns and Generic Quantification

NARCIS (Netherlands)

Serrano, Alejandro; Hage, J.

2017-01-01

Constraint Handling Rules provide descriptions for constraint solvers. However, they fall short when those constraints specify some binding structure, like higher-rank types in a constraint-based type inference algorithm. In this paper, the term syntax of constraints is replaced by λ-tree syntax, in

Analysis of an Internet Community about Pneumothorax and the Importance of Accurate Information about the Disease.

Science.gov (United States)

Kim, Bong Jun; Lee, Sungsoo

2018-04-01

The huge improvements in the speed of data transmission and the increasing amount of data available as the Internet has expanded have made it easy to obtain information about any disease. Since pneumothorax frequently occurs in young adolescents, patients often search the Internet for information on pneumothorax. This study analyzed an Internet community for exchanging information on pneumothorax, with an emphasis on the importance of accurate information and doctors' role in providing such information. This study assessed 599,178 visitors to the Internet community from June 2008 to April 2017. There was an average of 190 visitors, 2.2 posts, and 4.5 replies per day. A total of 6,513 posts were made, and 63.3% of them included questions about the disease. The visitors mostly searched for terms such as 'pneumothorax,' 'recurrent pneumothorax,' 'pneumothorax operation,' and 'obtaining a medical certification of having been diagnosed with pneumothorax.' However, 22% of the pneumothorax-related posts by visitors contained inaccurate information. Internet communities can be an important source of information. However, incorrect information about a disease can be harmful for patients. We, as doctors, should try to provide more in-depth information about diseases to patients and to disseminate accurate information about diseases in Internet communities.

Connectionism, parallel constraint satisfaction processes, and gestalt principles: (re) introducing cognitive dynamics to social psychology.

Science.gov (United States)

Read, S J; Vanman, E J; Miller, L C

1997-01-01

We argue that recent work in connectionist modeling, in particular the parallel constraint satisfaction processes that are central to many of these models, has great importance for understanding issues of both historical and current concern for social psychologists. We first provide a brief description of connectionist modeling, with particular emphasis on parallel constraint satisfaction processes. Second, we examine the tremendous similarities between parallel constraint satisfaction processes and the Gestalt principles that were the foundation for much of modem social psychology. We propose that parallel constraint satisfaction processes provide a computational implementation of the principles of Gestalt psychology that were central to the work of such seminal social psychologists as Asch, Festinger, Heider, and Lewin. Third, we then describe how parallel constraint satisfaction processes have been applied to three areas that were key to the beginnings of modern social psychology and remain central today: impression formation and causal reasoning, cognitive consistency (balance and cognitive dissonance), and goal-directed behavior. We conclude by discussing implications of parallel constraint satisfaction principles for a number of broader issues in social psychology, such as the dynamics of social thought and the integration of social information within the narrow time frame of social interaction.

Perceived stress as a mediator between social constraints and sleep quality among Chinese American breast cancer survivors.

Science.gov (United States)

Yeung, Nelson C Y; Ramirez, Jeffrey; Lu, Qian

2017-07-01

Previous studies primarily fo c used on how disease- and treatment-related variables affect cancer survivors' sleep quality. Little is known about the impact of the psychosocial factors on their sleep quality. Social constraints are perceived negative social interactions inhibiting one's disclosure. This study examined the association between social constraints and Chinese American breast cancer survivors' (BCS) sleep quality and tested perceived stress as a mediator explaining the association. Chinese American BCS (n = 94) were recruited from Southern California. Participants' social constraints, perceived stress, and sleep quality were measured in a questionnaire package. Social constraints were associated with higher perceived stress (r = 0.32, p = .002) and poorer sleep quality (r = 0.33, p stress was associated with poorer sleep quality (r = 0.47, p social constraints to poor sleep quality (indicated by the Pittsburgh Sleep Quality Index; PSQI) via perceived stress was significant (β = 0.20; 95% confidence intervals (CI) = 0.06, 0.40). The path coefficient for direct effect from social constraints to PSQI significantly dropped from β = 0.32 (95% CI = 0.11, 0.51) to β = 0.13 (95% CI = -0.12, 0.35) after considering perceived stress as a mediator, suggesting a mediation effect. This study implied that social constraints may worsen sleep quality among Chinese American BCS through increasing perceived stress. Interventions to reduce social constraints and perceived stress may improve sleep quality.

Supergravity constraints on monojets

International Nuclear Information System (INIS)

Nandi, S.

1986-01-01

In the standard model, supplemented by N = 1 minimal supergravity, all the supersymmetric particle masses can be expressed in terms of a few unknown parameters. The resulting mass relations, and the laboratory and the cosmological bounds on these superpartner masses are used to put constraints on the supersymmetric origin of the CERN monojets. The latest MAC data at PEP excludes the scalar quarks, of masses up to 45 GeV, as the origin of these monojets. The cosmological bounds, for a stable photino, excludes the mass range necessary for the light gluino-heavy squark production interpretation. These difficulties can be avoided by going beyond the minimal supergravity theory. Irrespective of the monojets, the importance of the stable γ as the source of the cosmological dark matter is emphasized

Toward an automaton Constraint for Local Search

Directory of Open Access Journals (Sweden)

Jun He

2009-10-01

Full Text Available We explore the idea of using finite automata to implement new constraints for local search (this is already a successful technique in constraint-based global search. We show how it is possible to maintain incrementally the violations of a constraint and its decision variables from an automaton that describes a ground checker for that constraint. We establish the practicality of our approach idea on real-life personnel rostering problems, and show that it is competitive with the approach of [Pralong, 2007].

Why Are Omics Technologies Important to Understanding the Role of Nutrition in Inflammatory Bowel Diseases?

Directory of Open Access Journals (Sweden)

Lynnette R. Ferguson

2016-10-01

Full Text Available For many years, there has been confusion about the role that nutrition plays in inflammatory bowel diseases (IBD. It is apparent that good dietary advice for one individual may prove inappropriate for another. As with many diseases, genome-wide association studies across large collaborative groups have been important in revealing the role of genetics in IBD, with more than 200 genes associated with susceptibility to the disease. These associations provide clues to explain the differences in nutrient requirements among individuals. In addition to genes directly involved in the control of inflammation, a number of the associated genes play roles in modulating the gut microbiota. Cell line models enable the generation of hypotheses as to how various bioactive dietary components might be especially beneficial for certain genetic groups. Animal models are necessary to mimic aspects of the complex aetiology of IBD, and provide an important link between tissue culture studies and human trials. Once we are sufficiently confident of our hypotheses, we can then take modified diets to an IBD population that is stratified according to genotype. Studies in IBD patients fed a Mediterranean-style diet have been important in validating our hypotheses and as a proof-of-principle for the application of these sensitive omics technologies to aiding in the control of IBD symptoms.

Intelligence Constraints on Terrorist Network Plots

Science.gov (United States)

Woo, Gordon

Since 9/11, the western intelligence and law enforcement services have managed to interdict the great majority of planned attacks against their home countries. Network analysis shows that there are important intelligence constraints on the number and complexity of terrorist plots. If two many terrorists are involved in plots at a given time, a tipping point is reached whereby it becomes progressively easier for the dots to be joined and for the conspirators to be arrested, and for the aggregate evidence to secure convictions. Implications of this analysis are presented for the campaign to win hearts and minds.

Constraint-based Attribute and Interval Planning

Science.gov (United States)

Jonsson, Ari; Frank, Jeremy

2013-01-01

In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We then show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. In addition, we de ne compatibilities, a compact mechanism for describing planning domains. We describe how this framework can incorporate the use of constraint reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework.

Crohn's disease.

LENUS (Irish Health Repository)

Shanahan, Fergus

2012-02-03

Crohn\\'s disease is a disorder mediated by T lymphocytes which arises in genetically susceptible individuals as a result of a breakdown in the regulatory constraints on mucosal immune responses to enteric bacteria. Regulation of immune reactivity to enteric antigens has improved understanding of the pathophysiological mechanisms of Crohn\\'s disease, and has expanded therapeutic options for patients with this disorder. Disease heterogeneity is probable, with various underlying defects associated with a similar pathophysiological outcome. Although most conventional drug treatments are directed at modification of host response, therapeutic manipulation of the enteric flora is becoming a realistic option.

Disease resistance in sugarcane – An overview

Directory of Open Access Journals (Sweden)

A. Ramesh Sundar

2015-12-01

Full Text Available Sugarcane is one of the important commercial crops cultivated world-wide both under tropical and sub-tropical conditions. The crop gains economic importance by virtue of its industrial potential in terms of products like crystal white sugar, bagasse, pressmud, power etc. Among the various production constraints of the crop, diseases are seen as a major threat for sustaining the productivity of sugarcane. Conventional Breeding is a lengthy process and it involves almost more than 10 years for the release of a commercial variety. Many varieties with superior agronomical traits have succumbed to diseases like red rot and smut during the course of cultivation, which hitherto at the time of release were rated to be resistant. The breakdown of disease resistance is attributed to the possible emergence of new virulent pathotypes. This situation has warranted a pertinent need to have a thorough understanding on inheritance pattern and mechanism of disease resistance in sugarcane, which would aid for quick screening of disease resistant clones and successful management of the diseases, respectively. Overall, there is a paradigm shift in the understanding of plant disease resistance, thanks to the advent of robust molecular tools. An integration of the tools of “Omics” namely genomics, proteomics, metabolomics etc. has further strengthened in deciphering plant-pathogen interactions at the molecular level. With the accomplishments in elucidating sugarcane ESTs, which was ably supported by employing the next generation sequencing platforms to unlock the secrets of pathogenomics in sugarcane, it is now made possible to further improve our understanding on disease resistance in sugarcane. Giving the scenario, the future looks evenmore promising, wherein convincing results are in the offing to thoroughly unravel the enigmatic relationship between sugarcane and its important pathogens.

Constraints on stress-energy perturbations in general relativity

International Nuclear Information System (INIS)

Traschen, J.

1985-01-01

Conditions are found for the existence of integral constraints on stress-energy perturbations in general relativity. The integral constraints can be thought of as a general-relativistic generalization of the conservation of energy and momentum of matter perturbations in special relativity. The constraints are stated in terms of a vector field V, and the Robertson-Walker spacetimes are shown to have such constraint vectors. Although in general V is not a Killing vector, in a vacuum spacetime the constraint vectors are precisely the Killing vectors

On Lifecycle Constraints of Artifact-Centric Workflows

Science.gov (United States)

Kucukoguz, Esra; Su, Jianwen

Data plays a fundamental role in modeling and management of business processes and workflows. Among the recent "data-aware" workflow models, artifact-centric models are particularly interesting. (Business) artifacts are the key data entities that are used in workflows and can reflect both the business logic and the execution states of a running workflow. The notion of artifacts succinctly captures the fluidity aspect of data during workflow executions. However, much of the technical dimension concerning artifacts in workflows is not well understood. In this paper, we study a key concept of an artifact "lifecycle". In particular, we allow declarative specifications/constraints of artifact lifecycle in the spirit of DecSerFlow, and formulate the notion of lifecycle as the set of all possible paths an artifact can navigate through. We investigate two technical problems: (Compliance) does a given workflow (schema) contain only lifecycle allowed by a constraint? And (automated construction) from a given lifecycle specification (constraint), is it possible to construct a "compliant" workflow? The study is based on a new formal variant of artifact-centric workflow model called "ArtiNets" and two classes of lifecycle constraints named "regular" and "counting" constraints. We present a range of technical results concerning compliance and automated construction, including: (1) compliance is decidable when workflow is atomic or constraints are regular, (2) for each constraint, we can always construct a workflow that satisfies the constraint, and (3) sufficient conditions where atomic workflows can be constructed.

Block Pickard Models for Two-Dimensional Constraints

DEFF Research Database (Denmark)

Forchhammer, Søren; Justesen, Jørn

2009-01-01

In Pickard random fields (PRF), the probabilities of finite configurations and the entropy of the field can be calculated explicitly, but only very simple structures can be incorporated into such a field. Given two Markov chains describing a boundary, an algorithm is presented which determines...... for the domino tiling constraint represented by a quaternary alphabet. PRF models are also presented for higher order constraints, including the no isolated bits (n.i.b.) constraint, and a minimum distance 3 constraint by defining super symbols on blocks of binary symbols....

Departure time choice: Modelling individual preferences, intention and constraints

DEFF Research Database (Denmark)

Thorhauge, Mikkel

by nearly all studies within departure time. More importantly it shows that the underlying psychological processes are more complex than simply accounting for attitudes and perceptions which are typically used in other areas. The work in this PhD thesis accounts for the full Theory of Planned Behaviour......, but can also be perceived by the individuals as barriers towards participating in activities. Perceived constraints affect the departure time choice through the individual intention of being on time. This PhD thesis also contributes to the departure time literature by discussing the problem of collecting...... whether they are constrained. The thesis also provides empirical evidences of the policy implication of not accounting for other activities and their constraints. Thirdly, the thesis shows that the departure time choice can be partly explained by psychological factors, which have previously been neglected...

«La vida alegre». How Important is Condom Used for Sexually Transmitted Diseases Prevention

Directory of Open Access Journals (Sweden)

Emilio PINTOR HOLGUÍN

2015-10-01

Full Text Available Action takes place in Spain in the mid?eighties (1987 with the change in Spanish society and the appearance of the first cases of AIDS in our country. From a comical sight, the adventures of a dermatologist particularly interested on sexually transmitted diseases prevention; especially in patients with risk behaviors, such as homosexuals, prostitutes and drug addicts injecting. The entire film revolves around the importance of condom use in preventing all sexually transmitted diseases.

CD4+ T-cell epitope prediction using antigen processing constraints.

Science.gov (United States)

Mettu, Ramgopal R; Charles, Tysheena; Landry, Samuel J

2016-05-01

T-cell CD4+ epitopes are important targets of immunity against infectious diseases and cancer. State-of-the-art methods for MHC class II epitope prediction rely on supervised learning methods in which an implicit or explicit model of sequence specificity is constructed using a training set of peptides with experimentally tested MHC class II binding affinity. In this paper we present a novel method for CD4+ T-cell eptitope prediction based on modeling antigen-processing constraints. Previous work indicates that dominant CD4+ T-cell epitopes tend to occur adjacent to sites of initial proteolytic cleavage. Given an antigen with known three-dimensional structure, our algorithm first aggregates four types of conformational stability data in order to construct a profile of stability that allows us to identify regions of the protein that are most accessible to proteolysis. Using this profile, we then construct a profile of epitope likelihood based on the pattern of transitions from unstable to stable regions. We validate our method using 35 datasets of experimentally measured CD4+ T cell responses of mice bearing I-Ab or HLA-DR4 alleles as well as of human subjects. Overall, our results show that antigen processing constraints provide a significant source of predictive power. For epitope prediction in single-allele systems, our approach can be combined with sequence-based methods, or used in instances where little or no training data is available. In multiple-allele systems, sequence-based methods can only be used if the allele distribution of a population is known. In contrast, our approach does not make use of MHC binding prediction, and is thus agnostic to MHC class II genotypes. Copyright © 2016 Elsevier B.V. All rights reserved.

Revisiting the simplicity constraints and coherent intertwiners

International Nuclear Information System (INIS)

Dupuis, Maite; Livine, Etera R

2011-01-01

In the context of loop quantum gravity and spinfoam models, the simplicity constraints are essential in that they allow one to write general relativity as a constrained topological BF theory. In this work, we apply the recently developed U(N) framework for SU(2) intertwiners to the issue of imposing the simplicity constraints to spin network states. More particularly, we focus on solving on individual intertwiners in the 4D Euclidean theory. We review the standard way of solving the simplicity constraints using coherent intertwiners and we explain how these fit within the U(N) framework. Then we show how these constraints can be written as a closed u(N) algebra and we propose a set of U(N) coherent states that solves all the simplicity constraints weakly for an arbitrary Immirzi parameter.

Economic losses due to important diseases of bovines in central India

Directory of Open Access Journals (Sweden)

Dhananjay Singh

2014-08-01

Full Text Available Aim: To analyze the factors associated with morbidity and mortality rates as well as to evaluate economic losses due to important diseases of bovines, viz. mastitis, HS and surra in Purvanchal Region of Uttar Pradesh. Materials and Methods: A sample of 300 livestock owners were selected from each of five divisions of Purvanchal region of the state of Uttar Pradesh using multistage stratified sampling with simple random sampling without replacement at village level. The morbidity, mortality and case fatality rates due to different diseases were determined using standard statistical indices. Association between cattle morbidity and mortality rates and different factors was calculated by χ2 Test. The total economic loss due to diseases in bovines was worked out as sum of mortality loss, loss in milk yield and cost of treatment of affected animals. Results: The overall morbidity rates of mastitis, HS and surra in cattle and buffaloes were 15.5%, 7.1% and 5.3%, respectively. The mortality and case fatality due to HS was found higher in the young calves as compared to the adults in case of both buffaloes and cattle. Mortality and case fatality due to surra was greater in the adult animals as compared to the younger ones in case of both buffaloes and cattle. Total losses due to mastitis per lactation in ND cow, CB cow and buffalo were INR 868.34, INR 1, 314.10 and INR 1, 272.36, respectively. Total losses due to HS per animal in ND cows, CB cows and buffaloes were INR 2, 355.78, INR 3, 228.52 and INR 4, 262.57, respectively. Total losses due to surra per animal in ND cow, CB cow and buffalo were INR 3, 328.18, INR 6, 193 and INR 9, 872.33, respectively. Conclusion: The study thus revealed significant losses due to diseases in large ruminants on. There is thus ample scope for preventive measures to control the disease bovines.

The Ambiguous Role of Constraints in Creativity

DEFF Research Database (Denmark)

Biskjær, Michael Mose; Onarheim, Balder; Wiltschnig, Stefan

2011-01-01

The relationship between creativity and constraints is often described in the literature either in rather imprecise, general concepts or in relation to very specific domains. Cross-domain and cross-disciplinary takes on how the handling of constraints influences creative activities are rare. In t......-disciplinary research into the ambiguous role of constraints in creativity....

The roles of constraint-based and dedication-based influences on user's continued online shopping behavior.

Science.gov (United States)

Chang, Su-Chao; Chou, Chi-Min

2012-11-01

The objective of this study was to determine empirically the role of constraint-based and dedication-based influences as drivers of the intention to continue using online shopping websites. Constraint-based influences consist of two variables: trust and perceived switching costs. Dedication-based influences consist of three variables: satisfaction, perceived usefulness, and trust. The current results indicate that both constraint-based and dedication-based influences are important drivers of the intention to continue using online shopping websites. The data also shows that trust has the strongest total effect on online shoppers' intention to continue using online shopping websites. In addition, the results indicate that the antecedents of constraint-based influences, technical bonds (e.g., perceived operational competence and perceived website interactivity) and social bonds (e.g., perceived relationship investment, community building, and intimacy) have indirect positive effects on the intention to continue using online shopping websites. Based on these findings, this research suggests that online shopping websites should build constraint-based and dedication-based influences to enhance user's continued online shopping behaviors simultaneously.

Experiential Learning as a Constraint-Led Process: An Ecological Dynamics Perspective

Science.gov (United States)

Brymer, Eric; Davids, Keith

2014-01-01

In this paper we present key ideas for an ecological dynamics approach to learning that reveal the importance of learner-environment interactions to frame outdoor experiential learning. We propose that ecological dynamics provides a useful framework for understanding the interacting constraints of the learning process and for designing learning…

Fixed Costs and Hours Constraints

Science.gov (United States)

Johnson, William R.

2011-01-01

Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

Observational Constraints on Cloud Feedbacks: The Role of Active Satellite Sensors

Science.gov (United States)

Winker, David; Chepfer, Helene; Noel, Vincent; Cai, Xia

2017-11-01

Cloud profiling from active lidar and radar in the A-train satellite constellation has significantly advanced our understanding of clouds and their role in the climate system. Nevertheless, the response of clouds to a warming climate remains one of the largest uncertainties in predicting climate change and for the development of adaptions to change. Both observation of long-term changes and observational constraints on the processes responsible for those changes are necessary. We review recent progress in our understanding of the cloud feedback problem. Capabilities and advantages of active sensors for observing clouds are discussed, along with the importance of active sensors for deriving constraints on cloud feedbacks as an essential component of a global climate observing system.

Future Cosmological Constraints From Fast Radio Bursts

Science.gov (United States)

Walters, Anthony; Weltman, Amanda; Gaensler, B. M.; Ma, Yin-Zhe; Witzemann, Amadeus

2018-03-01

We consider the possible observation of fast radio bursts (FRBs) with planned future radio telescopes, and investigate how well the dispersions and redshifts of these signals might constrain cosmological parameters. We construct mock catalogs of FRB dispersion measure (DM) data and employ Markov Chain Monte Carlo analysis, with which we forecast and compare with existing constraints in the flat ΛCDM model, as well as some popular extensions that include dark energy equation of state and curvature parameters. We find that the scatter in DM observations caused by inhomogeneities in the intergalactic medium (IGM) poses a big challenge to the utility of FRBs as a cosmic probe. Only in the most optimistic case, with a high number of events and low IGM variance, do FRBs aid in improving current constraints. In particular, when FRBs are combined with CMB+BAO+SNe+H 0 data, we find the biggest improvement comes in the {{{Ω }}}{{b}}{h}2 constraint. Also, we find that the dark energy equation of state is poorly constrained, while the constraint on the curvature parameter, Ω k , shows some improvement when combined with current constraints. When FRBs are combined with future baryon acoustic oscillation (BAO) data from 21 cm Intensity Mapping, we find little improvement over the constraints from BAOs alone. However, the inclusion of FRBs introduces an additional parameter constraint, {{{Ω }}}{{b}}{h}2, which turns out to be comparable to existing constraints. This suggests that FRBs provide valuable information about the cosmological baryon density in the intermediate redshift universe, independent of high-redshift CMB data.

Faddeev-Jackiw quantization and constraints

International Nuclear Information System (INIS)

Barcelos-Neto, J.; Wotzasek, C.

1992-01-01

In a recent Letter, Faddeev and Jackiw have shown that the reduction of constrained systems into its canonical, first-order form, can bring some new insight into the research of this field. For sympletic manifolds the geometrical structure, called Dirac or generalized bracket, is obtained directly from the inverse of the nonsingular sympletic two-form matrix. In the cases of nonsympletic manifolds, this two-form is degenerated and cannot be inverted to provide the generalized brackets. This singular behavior of the sympletic matrix is indicative of the presence of constraints that have to be carefully considered to yield to consistent results. One has two possible routes to treat this problem: Dirac has taught us how to implement the constraints into the potential part (Hamiltonian) of the canonical Lagrangian, leading to the well-known Dirac brackets, which are consistent with the constraints and can be mapped into quantum commutators (modulo ordering terms). The second route, suggested by Faddeev and Jackiw, and followed in this paper, is to implement the constraints directly into the canonical part of the first order Lagrangian, using the fact that the consistence condition for the stability of the constrained manifold is linear in the time derivative. This algorithm may lead to an invertible two-form sympletic matrix from where the Dirac brackets are readily obtained. This algorithm is used in this paper to investigate some aspects of the quantization of constrained systems with first- and second-class constraints in the sympletic approach

Liquidity Constraints and Fiscal Stabilization Policy

DEFF Research Database (Denmark)

Kristoffersen, Mark Strøm

It is often claimed that the presence of liquidity constrained households enhances the need for and the effects of fi…scal stabilization policies. This paper studies this in a model of a small open economy with liquidity constrained households. The results show that the consequences of liquidity...... constraints are more complex than previously thought: The optimal stabilization policy in case of productivity shocks is independent of the liquidity constraints, and the presence of liquidity constraints tends to reduce the need for an active policy stabilizing productivity shocks....

Viral Diseases of Public Health Importance in India: Current Priorities with Special Emphasis on Prevention

Directory of Open Access Journals (Sweden)

Mageshbabu Ramamurthy

2017-10-01

Full Text Available India faces problems with both communicable and non communicable diseases. The major non communicable diseases are cancer, cardiovascular disease and diabetes mellitus. This article focuses on communicable diseases (infectious diseases especially viral infections of public health importance. The infections include bacterial, parasitic and viruses. It could be said that fungal infections by the nature of the spread are not of public health concern. The viral infections are transmitted by the respiratory route, water and food borne route, vectors and blood and blood products, sexual route and are of major concern. Efforts are aimed at early detection, prevention by use of vaccines and sentinel surveillance. For the success of public health programmes sentinel surveillance of diseases is mandatory. India has got several programme initiatives addressing the problem. The programs include IDSP, VBDCP and NACO. The approximate cumulative annual prevalence of infectious disease in India ranges from 100 to 200 million individuals affected in one year. India should aim to improve case detection by strengthening laboratory services with manpower training and nationwide quality control scheme, sentinel surveillance activity and prevention by improving the efficiency and scope of UIP. Also, creation of a single portal of infectious disease data handling hub to collect information from different sources will help avoid overlap and duplication of reporting.

Review of Minimal Flavor Constraints for Technicolor

DEFF Research Database (Denmark)

S. Fukano, Hidenori; Sannino, Francesco

2010-01-01

We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self-coupling and mas......We analyze the constraints on the the vacuum polarization of the standard model gauge bosons from a minimal set of flavor observables valid for a general class of models of dynamical electroweak symmetry breaking. We will show that the constraints have a strong impact on the self...

Relaxations of semiring constraint satisfaction problems

CSIR Research Space (South Africa)

Leenen, L

2007-03-01

Full Text Available The Semiring Constraint Satisfaction Problem (SCSP) framework is a popular approach for the representation of partial constraint satisfaction problems. In this framework preferences can be associated with tuples of values of the variable domains...

Solar system constraints on disformal gravity theories

International Nuclear Information System (INIS)

Ip, Hiu Yan; Schmidt, Fabian; Sakstein, Jeremy

2015-01-01

Disformal theories of gravity are scalar-tensor theories where the scalar couples derivatively to matter via the Jordan frame metric. These models have recently attracted interest in the cosmological context since they admit accelerating solutions. We derive the solution for a static isolated mass in generic disformal gravity theories and transform it into the parameterised post-Newtonian form. This allows us to investigate constraints placed on such theories by local tests of gravity. The tightest constraints come from preferred-frame effects due to the motion of the Solar System with respect to the evolving cosmological background field. The constraints we obtain improve upon the previous solar system constraints by two orders of magnitude, and constrain the scale of the disformal coupling for generic models to ℳ ∼> 100 eV. These constraints render all disformal effects irrelevant for cosmology

Planning a sports training program using Adaptive Particle Swarm Optimization with emphasis on physiological constraints.

Science.gov (United States)

Kumyaito, Nattapon; Yupapin, Preecha; Tamee, Kreangsak

2018-01-08

An effective training plan is an important factor in sports training to enhance athletic performance. A poorly considered training plan may result in injury to the athlete, and overtraining. Good training plans normally require expert input, which may have a cost too great for many athletes, particularly amateur athletes. The objectives of this research were to create a practical cycling training plan that substantially improves athletic performance while satisfying essential physiological constraints. Adaptive Particle Swarm Optimization using ɛ-constraint methods were used to formulate such a plan and simulate the likely performance outcomes. The physiological constraints considered in this study were monotony, chronic training load ramp rate and daily training impulse. A comparison of results from our simulations against a training plan from British Cycling, which we used as our standard, showed that our training plan outperformed the benchmark in terms of both athletic performance and satisfying all physiological constraints.

Weeds as agricultural constraint in Benin: results of a diagnostic study

NARCIS (Netherlands)

Vissoh, P.V.; Gbèhounou, G.; Ahanchedé, A.; Kuyper, T.W.; Röling, N.G.

2004-01-01

Weeds are an emerging constraint on crop production, as a result of population pressure and more intensive use of cultivated land. A diagnostic study was carried out from June through August 2002 in the five agro-ecological zones of Benin (1) to identify the relative importance of weeds among major

Observational constraints on interstellar chemistry

International Nuclear Information System (INIS)

Winnewisser, G.

1984-01-01

The author points out presently existing observational constraints in the detection of interstellar molecular species and the limits they may cast on our knowledge of interstellar chemistry. The constraints which arise from the molecular side are summarised and some technical difficulties encountered in detecting new species are discussed. Some implications for our understanding of molecular formation processes are considered. (Auth.)

Does a time constraint modify results from rating-based conjoint analysis? Case study with orange/pomegranate juice bottles.

Science.gov (United States)

Reis, Felipe; Machín, Leandro; Rosenthal, Amauri; Deliza, Rosires; Ares, Gastón

2016-12-01

People do not usually process all the available information on packages for making their food choices and rely on heuristics for making their decisions, particularly when having limited time. However, in most consumer studies encourage participants to invest a lot of time for making their choices. Therefore, imposing a time-constraint in consumer studies may increase their ecological validity. In this context, the aim of the present work was to evaluate the influence of a time-constraint on consumer evaluation of pomegranate/orange juice bottles using rating-based conjoint task. A consumer study with 100 participants was carried out, in which they had to evaluate 16 pomegranate/orange fruit juice bottles, differing in bottle design, front-of-pack nutritional information, nutrition claim and processing claim, and to rate their intention to purchase. Half of the participants evaluated the bottle images without time constraint and the other half had a time-constraint of 3s for evaluating each image. Eye-movements were recorded during the evaluation. Results showed that time-constraint when evaluating intention to purchase did not largely modify the way in which consumers visually processed bottle images. Regardless of the experimental condition (with or without time constraint), they tended to evaluate the same product characteristics and to give them the same relative importance. However, a trend towards a more superficial evaluation of the bottles that skipped complex information was observed. Regarding the influence of product characteristics on consumer intention to purchase, bottle design was the variable with the largest relative importance in both conditions, overriding the influence of nutritional or processing characteristics, which stresses the importance of graphic design in shaping consumer perception. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expressing Model Constraints Visually with VMQL

DEFF Research Database (Denmark)

Störrle, Harald

2011-01-01

) for specifying constraints on UML models. We examine VMQL's usability by controlled experiments and its expressiveness by a representative sample. We conclude that VMQL is less expressive than OCL, although expressive enough for most of the constraints in the sample. In terms of usability, however, VMQL......OCL is the de facto standard language for expressing constraints and queries on UML models. However, OCL expressions are very difficult to create, understand, and maintain, even with the sophisticated tool support now available. In this paper, we propose to use the Visual Model Query Language (VMQL...

Stochastic population dynamics under resource constraints

Energy Technology Data Exchange (ETDEWEB)

Gavane, Ajinkya S., E-mail: ajinkyagavane@gmail.com; Nigam, Rahul, E-mail: rahul.nigam@hyderabad.bits-pilani.ac.in [BITS Pilani Hyderabad Campus, Shameerpet, Hyd - 500078 (India)

2016-06-02

This paper investigates the population growth of a certain species in which every generation reproduces thrice over a period of predefined time, under certain constraints of resources needed for survival of population. We study the survival period of a species by randomizing the reproduction probabilities within a window at same predefined ages and the resources are being produced by the working force of the population at a variable rate. This randomness in the reproduction rate makes the population growth stochastic in nature and one cannot predict the exact form of evolution. Hence we study the growth by running simulations for such a population and taking an ensemble averaged over 500 to 5000 such simulations as per the need. While the population reproduces in a stochastic manner, we have implemented a constraint on the amount of resources available for the population. This is important to make the simulations more realistic. The rate of resource production then is tuned to find the rate which suits the survival of the species. We also compute the mean life time of the species corresponding to different resource production rate. Study for these outcomes in the parameter space defined by the reproduction probabilities and rate of resource production is carried out.

Thinking aloud in the presence of interruptions and time constraints

DEFF Research Database (Denmark)

Hertzum, Morten; Holmegaard, Kristin Due

2013-01-01

and time constraints, two frequent elements of real-world activities. We find that the presence of auditory, visual, audiovisual, or no interruptions interacts with thinking aloud for task solution rate, task completion time, and participants’ fixation rate. Thinking-aloud participants also spend longer......Thinking aloud is widely used for usability evaluation and its reactivity is therefore important to the quality of evaluation results. This study investigates whether thinking aloud (i.e., verbalization at levels 1 and 2) affects the behaviour of users who perform tasks that involve interruptions...... responding to interruptions than control participants. Conversely, the absence or presence of time constraints does not interact with thinking aloud, suggesting that time pressure is less likely to make thinking aloud reactive than previously assumed. Our results inform practitioners faced with the decision...

An Unrecognized Rash Progressing to Lyme Carditis: Important Features and Recommendations Regarding Lyme Disease.

Science.gov (United States)

Lee, Shawn; Singla, Montish

2016-01-01

We present a case report of 46-year-old man with no medical history, who complained of extreme fatigue, near-syncope, and palpitations. He initially presented in complete heart block. A transvenous pacemaker was placed in the emergency department, and he was started empirically on Ceftriaxone for Lyme disease. He was admitted and over the course of the next few days, his rhythm regressed to Mobitz type I first-degree atrioventricular block and then to normal sinus rhythm. This case report highlights some important features regarding Lyme carditis, a rare presentation of early disseminated Lyme disease (seen in a few weeks to months after the initial tick bite). In 25%-30% of patients, the characteristic targetoid rash may not be seen, a likely culprit of the disease not being detected early and progressing to disseminated disease. The most common cardiac complaint of Lyme disease is palpitations, occurring in 6.6% of patients, which may not accurately reflect progression into disseminated Lyme disease because it is a nonspecific finding. Conduction abnormality, occurring in 1.8% of patients, is a more specific finding of Borrelia invading cardiac tissue. Finally, this case report highlights a recommendation that patients with confirmed Lyme disease or those presenting with cardiac abnormalities or symptoms who have an atypical profile for a cardiac event should be screened with a 12-lead electrocardiogram, Lyme serology, and be considered for antibiotic therapy with the possibility of temporary pacing.

EAST kinetic equilibrium reconstruction combining with Polarimeter-Interferometer internal measurement constraints

Science.gov (United States)

Lian, H.; Liu, H. Q.; Li, K.; Zou, Z. Y.; Qian, J. P.; Wu, M. Q.; Li, G. Q.; Zeng, L.; Zang, Q.; Lv, B.; Jie, Y. X.; EAST Team

2017-12-01

Plasma equilibrium reconstruction plays an important role in the tokamak plasma research. With a high temporal and spatial resolution, the POlarimeter-INTerferometer (POINT) system on EAST has provided effective measurements for 102s H-mode operation. Based on internal Faraday rotation measurements provided by the POINT system, the equilibrium reconstruction with a more accurate core current profile constraint has been demonstrated successfully on EAST. Combining other experimental diagnostics and external magnetic fields measurement, the kinetic equilibrium has also been reconstructed on EAST. Take the pressure and edge current information from kinetic EFIT into the equilibrium reconstruction with Faraday rotation constraint, the new equilibrium reconstruction not only provides a more accurate internal current profile but also contains edge current and pressure information. One time slice result using new kinetic equilibrium reconstruction with POINT data constraints is demonstrated in this paper and the result shows there is a reversed shear of q profile and the pressure profile is also contained. The new improved equilibrium reconstruction is greatly helpful to the future theoretical analysis.

Implicit Motives and Men's Perceived Constraint in Fatherhood.

Science.gov (United States)

Ruppen, Jessica; Waldvogel, Patricia; Ehlert, Ulrike

2016-01-01

Research shows that implicit motives influence social relationships. However, little is known about their role in fatherhood and, particularly, how men experience their paternal role. Therefore, this study examined the association of implicit motives and fathers' perceived constraint due to fatherhood. Furthermore, we explored their relation to fathers' life satisfaction. Participants were fathers with biological children ( N = 276). They were asked to write picture stories, which were then coded for implicit affiliation and power motives. Perceived constraint and life satisfaction were assessed on a visual analog scale. A higher implicit need for affiliation was significantly associated with lower perceived constraint, whereas the implicit need for power had the opposite effect. Perceived constraint had a negative influence on life satisfaction. Structural equation modeling revealed significant indirect effects of implicit affiliation and power motives on life satisfaction mediated by perceived constraint. Our findings indicate that men with a higher implicit need for affiliation experience less constraint due to fatherhood, resulting in higher life satisfaction. The implicit need for power, however, results in more perceived constraint and is related to decreased life satisfaction.

Stakeholders Assessment of Constraints to Project Delivery in the Nigerian Construction Industry

Directory of Open Access Journals (Sweden)

Bruno L. Tanko

2017-01-01

Full Text Available The central goal of construction stakeholders is to successfully deliver projects to stated objective (s. However, for decades, construction projects have been plagued by perennial constraints of cost and time overruns, poor quality, and lack of sustainability. The objective of this paper is to identify and assess the constraints to construction project delivery, and to recommend solutions to enhance project performance. This paper adopted both quantitative and qualitative methods to establish the constraints in the Nigerian construction industry. A pilot survey and literature reviewed revealed a total of fifty (50 construction constraints, which were further classified into eight (8 major groups. Well-structured questionnaires were administered to construction stakeholders (client, consultant and contractor in Abuja, the federal capital city of Nigeria. Relative Importance Index (RII was used to analyze the data using Likert scale.  The results suggest that cost/time overrun related factors (inability to reduce project cost, Stakeholders interactive-related factors (inability to establish client value system, Client-related factors (Delay in interim payment and finance problem, and Labor/material-related factors (escalation of material prices and materials quality variability are the most prevalent constraints in the Nigerian construction environment.  To mitigate the effects of these challenges, it is suggested that a formal innovative approach should be used by stakeholders to address the problems of poor communication, high project cost, and delay. Clients should also take measures to provide adequate funding and should promptly honor interim certificates.

Fascioliasis: a worldwide parasitic disease of importance in travel medicine.

Science.gov (United States)

Ashrafi, Keyhan; Bargues, M Dolores; O'Neill, Sandra; Mas-Coma, Santiago

2014-01-01

Fascioliasis is a foodborne zoonotic disease caused by the two parasite species Fasciola hepatica and Fasciola gigantica. This trematodiasis has never been claimed special relevance for travellers and migrants. However, the situation has drastically changed in the last two decades, in a way that fascioliasis should today be included in the list of diseases to be enhanced in Travel Medicine. Different kind of travellers have been involved in human infection reports: business travellers, tourists, migrants, expatriated workers, military personnel, religious missionaries, and refugees. Europe is the continent where more imported cases have been reported in many countries. More cases would have been probably reported in Europe if fascioliasis would be a reportable disease. In the Americas, most of the reports concern cases diagnosed in USA. Relative few patients have been diagnosed in studies on travellers performed in Asia. In Africa, most cases were reported in Maghreb countries. Blood eosinophilia and the ingestion of watercress or any other suggestive freshwater plant in anamnesis are extremely useful in guiding towards a fascioliasis diagnosis in a developed country, although may not be so in human endemic areas of developing countries. Several suggestive clinical presentation aspects may be useful, although the clinical polymorphism may be misleading in many cases. Non-invasive techniques are helpful for the diagnosis, although images may lead to confusion. Laparoscopic visualization should assist and facilitate procurement of an accurately guided biopsy. Endoscopic retrograde cholangiopancreatography (ERCP) is the first choice in patients in the chronic phase. ERCP and sphincterotomy are used to extract parasites from the biliary tree. Fluke egg finding continues to be the gold standard and enables for burden quantification and establishing of the drug dose. Many serological and stool antigen detection tests have been developed. Immunological techniques present

On relaxing the Mangasarian-Fromovitz constraint qualification

Czech Academy of Sciences Publication Activity Database

Kruger, A.Y.; Minchenko, L.; Outrata, Jiří

2014-01-01

Roč. 18, č. 1 (2014), s. 171-189 ISSN 1385-1292 R&D Projects: GA ČR GAP402/12/1309 Institutional support: RVO:67985556 Keywords : Nonlinear programming * Regularity conditions * Constraint qualifications * Lagrange multipliers * Mangasarian–Fromovitz constraint qualification * Constant rank constraint qualification Subject RIV: BA - General Mathematics Impact factor: 0.679, year: 2014 http://library.utia.cas.cz/separaty/2014/MTR/outrata-0426110.pdf

Constraint programming for modelling and solving modal satisfiability

NARCIS (Netherlands)

Brand, S.; Gennari, R.; de Rijke, M.

2003-01-01

We explore to what extent and how efficiently constraint programmingcan be used in the context of automated reasoning for modal logics. We encode modal satisfiability problems as constraint satisfactionproblems with non-boolean domains, together with suitable constraints.Experiments show that the

Design of quadrature mirror filter bank using Lagrange multiplier method based on fractional derivative constraints

Directory of Open Access Journals (Sweden)

B. Kuldeep

2015-06-01

Full Text Available Fractional calculus has recently been identified as a very important mathematical tool in the field of signal processing. Digital filters designed by fractional derivatives give more accurate frequency response in the prescribed frequency region. Digital filters are most important part of multi-rate filter bank systems. In this paper, an improved method based on fractional derivative constraints is presented for the design of two-channel quadrature mirror filter (QMF bank. The design problem is formulated as minimization of L2 error of filter bank transfer function in passband, stopband interval and at quadrature frequency, and then Lagrange multiplier method with fractional derivative constraints is applied to solve it. The proposed method is then successfully applied for the design of two-channel QMF bank with higher order filter taps. Performance of the QMF bank design is then examined through study of various parameters such as passband error, stopband error, transition band error, peak reconstruction error (PRE, stopband attenuation (As. It is found that, the good design can be obtained with the change of number and value of fractional derivative constraint coefficients.

Cosmological constraints on Brans-Dicke theory.

Science.gov (United States)

Avilez, A; Skordis, C

2014-07-04

We report strong cosmological constraints on the Brans-Dicke (BD) theory of gravity using cosmic microwave background data from Planck. We consider two types of models. First, the initial condition of the scalar field is fixed to give the same effective gravitational strength Geff today as the one measured on Earth, GN. In this case, the BD parameter ω is constrained to ω>692 at the 99% confidence level, an order of magnitude improvement over previous constraints. In the second type, the initial condition for the scalar is a free parameter leading to a somewhat stronger constraint of ω>890, while Geff is constrained to 0.981theory and are valid for any Horndeski theory, the most general second-order scalar-tensor theory, which approximates the BD theory on cosmological scales. In this sense, our constraints place strong limits on possible modifications of gravity that might explain cosmic acceleration.

Emerging fungal diseases: the importance of the host.

Science.gov (United States)

Procop, Gary W; Roberts, Glenn D

2004-09-01

More yeasts and molds are now recognized to cause more human disease than ever before. This development is not due to a change in the virulence of these fungi, but rather to changes in the human host. These changes include immunosuppression secondary to the pandemic of HIV, the use of life-saving advances in chemotherapy and organ transplantation, and the use of corticosteroids and other immunosuppressive agents to treat a variety of diseases. Fungi that were once considered common saprophytes are now recognized as potential pathogens in these patients. This situation necessitates better communication than ever between the clinician, pathologist, and clinical mycologist to ensure the prompt and accurate determination of the cause of fungal diseases.

A Temporal Concurrent Constraint Programming Calculus

DEFF Research Database (Denmark)

Palamidessi, Catuscia; Valencia Posso, Frank Darwin

2001-01-01

The tcc model is a formalism for reactive concurrent constraint programming. In this paper we propose a model of temporal concurrent constraint programming which adds to tcc the capability of modeling asynchronous and non-deterministic timed behavior. We call this tcc extension the ntcc calculus...

Toward making the constraint hypersurface an attractor in free evolution

International Nuclear Information System (INIS)

Fiske, David R.

2004-01-01

When constructing numerical solutions to systems of evolution equations subject to a constraint, one must decide what role the constraint equations will play in the evolution system. In one popular choice, known as free evolution, a simulation is treated as a Cauchy problem, with the initial data constructed to satisfy the constraint equations. This initial data are then evolved via the evolution equations with no further enforcement of the constraint equations. The evolution, however, via the discretized evolution equations introduce constraint violating modes at the level of truncation error, and these constraint violating modes will behave in a formalism dependent way. This paper presents a generic method for incorporating the constraint equations into the evolution equations so that the off-constraint dynamics are biased toward the constraint satisfying solutions

Differential Diagnoses of Overgrowth Syndromes: The Most Important Clinical and Radiological Disease Manifestations

International Nuclear Information System (INIS)

Lacerda, L.S.; Alves, U.D.; Zanier, J.F.C.; Machado, D.C.; Camilo, G.B.; Machado, D.C.; Camilo, G.B.; Lopes, A.J.

2014-01-01

Overgrowth syndromes comprise a heterogeneous group of diseases that are characterized by excessive tissue development. Some of these syndromes may be associated with dysfunction in the receptor tyrosine kinase (RTK)/PI3K/AKT pathway, which results in an increased expression of the insulin receptor. In the current review, four overgrowth syndromes were characterized (Proteus syndrome, Klippel-Trenaunay-Weber syndrome, Made lung’s disease, and neurofibromatosis type I) and illustrated using cases from our institution. Because these syndromes have overlapping clinical manifestations and have no established genetic tests for their diagnosis, radiological methods are important contributors to the diagnosis of many of these syndromes. The correlation of genetic discoveries and molecular pathways that may contribute to the phenotypic expression is also of interest, as this may lead to potential therapeutic interventions

Emerging carbon constraints for corporate risk management

International Nuclear Information System (INIS)

Busch, Timo; Hoffmann, Volker H.

2007-01-01

While discussions about global sustainability challenges abound, the financial risks that they incur, albeit important, have received less attention. We suggest that corporate risk assessments should include sustainability-related aspects, especially with relation to the natural environment, and encompass the flux of critical materials within a company's value chain. Such a comprehensive risk assessment takes into account input- as well as output-related factors. With this paper, we focus on the flux of carbon and define carbon constraints that emerge due to the disposition of fossil fuels in the input dimension and due to direct and indirect climate change effects in the output dimension. We review the literature regarding the financial consequences of carbon constraints on the macroeconomic, sector, and company level. We conclude that: a) financial consequences seem to be asymmetrically distributed between and within sectors, b) the individual risk exposure of companies depends on the intensity of and dependency on carbon-based materials and energy, and c) financial markets have only started to incorporate these aspects in their valuations. This paper ends with recommendations on how to incorporate our results in an integrated carbon risk management framework. (author)

Judgement of Design Scheme Based on Flexible Constraint in ICAD

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

The conception of flexible constraint is proposed in the paper. The solution of flexible constraint is in special range, and maybe different in different instances of same design scheme. The paper emphasis on how to evaluate and optimize a design scheme with flexible constraints based on the satisfaction degree function defined on flexible constraints. The conception of flexible constraint is used to solve constraint conflict and design optimization in complicated constraint-based assembly design by the PFM parametrization assembly design system. An instance of gear-box design is used for verifying optimization method.

A comparison of debt and primary-deficit constraints

NARCIS (Netherlands)

Ribeiro, M.P.; Beetsma, R.; Schabert, A.

2008-01-01

This paper compares constraints on the public debt with constraints on the primary deficit. The analysis takes into account how an optimizing government reacts to the different constraints when deciding on a spending and borrowing plan. We find that the economy behaves similarly under both

Comparison of methods to identify crop productivity constraints in developing countries. A review

NARCIS (Netherlands)

Kraaijvanger, R.G.M.; Sonneveld, M.P.W.; Almekinders, C.J.M.; Veldkamp, T.

2015-01-01

Selecting a method for identifying actual crop productivity constraints is an important step for triggering innovation processes. Applied methods can be diverse and although such methods have consequences for the design of intervention strategies, documented comparisons between various methods are

Firefly Algorithm for Cardinality Constrained Mean-Variance Portfolio Optimization Problem with Entropy Diversity Constraint

Science.gov (United States)

2014-01-01

Portfolio optimization (selection) problem is an important and hard optimization problem that, with the addition of necessary realistic constraints, becomes computationally intractable. Nature-inspired metaheuristics are appropriate for solving such problems; however, literature review shows that there are very few applications of nature-inspired metaheuristics to portfolio optimization problem. This is especially true for swarm intelligence algorithms which represent the newer branch of nature-inspired algorithms. No application of any swarm intelligence metaheuristics to cardinality constrained mean-variance (CCMV) portfolio problem with entropy constraint was found in the literature. This paper introduces modified firefly algorithm (FA) for the CCMV portfolio model with entropy constraint. Firefly algorithm is one of the latest, very successful swarm intelligence algorithm; however, it exhibits some deficiencies when applied to constrained problems. To overcome lack of exploration power during early iterations, we modified the algorithm and tested it on standard portfolio benchmark data sets used in the literature. Our proposed modified firefly algorithm proved to be better than other state-of-the-art algorithms, while introduction of entropy diversity constraint further improved results. PMID:24991645

Firefly algorithm for cardinality constrained mean-variance portfolio optimization problem with entropy diversity constraint.

Science.gov (United States)

Bacanin, Nebojsa; Tuba, Milan

2014-01-01

Portfolio optimization (selection) problem is an important and hard optimization problem that, with the addition of necessary realistic constraints, becomes computationally intractable. Nature-inspired metaheuristics are appropriate for solving such problems; however, literature review shows that there are very few applications of nature-inspired metaheuristics to portfolio optimization problem. This is especially true for swarm intelligence algorithms which represent the newer branch of nature-inspired algorithms. No application of any swarm intelligence metaheuristics to cardinality constrained mean-variance (CCMV) portfolio problem with entropy constraint was found in the literature. This paper introduces modified firefly algorithm (FA) for the CCMV portfolio model with entropy constraint. Firefly algorithm is one of the latest, very successful swarm intelligence algorithm; however, it exhibits some deficiencies when applied to constrained problems. To overcome lack of exploration power during early iterations, we modified the algorithm and tested it on standard portfolio benchmark data sets used in the literature. Our proposed modified firefly algorithm proved to be better than other state-of-the-art algorithms, while introduction of entropy diversity constraint further improved results.

Integral constraints on perturbations of Robertson-Walker cosmologies

International Nuclear Information System (INIS)

Ellis, G.F.R.; Jaklitsch, M.J.

1989-01-01

Integral constraints occur in the case of spherically symmetric inhomogeneities in Robertson-Walker universes, and (according to Traschen) in the case of general perturbations of these models. It is shown that these constraints are the same in the case of spherical symmetry, and they are interpreted as 'fitting conditions', that is, as constraints on the background Robertson-Walker model rather than on the nature of inhomogeneities. These integral constraints significantly affect the interpretation of anisotropies in the cosmic microwave background radiation. 22 refs

Mathematical analysis of dynamic spread of Pine Wilt disease.

Science.gov (United States)

Dimitrijevic, D D; Bacic, J

2013-01-01

Since its detection in Portugal in 1999, the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer), a causal agent of Pine Wilt Disease, represents a threat to European forestry. Significant amount of money has been spent on its monitoring and eradication. This paper presents mathematical analysis of spread of pine wilt disease using a set of partial differential equations with space (longitude and latitude) and time as parameters of estimated spread of disease. This methodology can be used to evaluate risk of various assumed entry points of disease and make defense plans in advance. In case of an already existing outbreak, it can be used to draw optimal line of defense and plan removal of trees. Optimization constraints are economic loss of removal of susceptible trees as well as budgetary constraints of workforce cost.

Study on the unified constraint parameter for characterizing in-plane and out-of-plane constraint based on the equivalent plastic strain

International Nuclear Information System (INIS)

Yang Jie; Wang Guozhen; Xuan Fuzhen; Tu Shandong

2013-01-01

Background: Constraint can significantly alter the material's fracture toughness. Purpose: In order to increase accuracy of the structural integrity assessment. It needs to consider the effect of constraint on the fracture toughness of nuclear power materials and structures. A unified measure which can reflect both in-plane and out-of-plane constraint is needed. Methods: In this paper, the finite element numerical simulation method was used, a unified measure and characterization parameter of in-plane and out-of-plane constraint based on crack-tip equivalent plastic strain have been investigated. Results: The results show that the area surrounded by ε p isoline has a good relevance with the material's fracture toughness on different constraint conditions, so it may be a suitable parameter. Based on the area A PEEQ , a unified constraint characterization parameter √A p is defined. It was found that there exists a sole linear relation between the normalized fracture toughness J IC /J re f and √A p regardless of the in-plane, out-of-plane constraint and the selection of the p isolines. The sole J IC /J re f-√A p line exists for a certain material. For different materials, the slope of J IC /J re f-√A p reference line is different. The material whose slope is larger has a higher J IC /J re f and is more sensitive to constraint at the same magnitude of normalized unified parameter. Conclusions: The unified J IC /J re f -√A p reference line may be used to assess the safety of a cracked component with any constraint levels regardless of in-plane or out-of-plane constraint or both. (authors)

Fluid convection, constraint and causation

Science.gov (United States)

Bishop, Robert C.

2012-01-01

Complexity—nonlinear dynamics for my purposes in this essay—is rich with metaphysical and epistemological implications but is receiving sustained philosophical analysis only recently. I will explore some of the subtleties of causation and constraint in Rayleigh–Bénard convection as an example of a complex phenomenon, and extract some lessons for further philosophical reflection on top-down constraint and causation particularly with respect to causal foundationalism. PMID:23386955

Freedom and constraint analysis and optimization

NARCIS (Netherlands)

Brouwer, Dannis Michel; Boer, Steven; Aarts, Ronald G.K.M.; Meijaard, Jacob Philippus; Jonker, Jan B.

2011-01-01

Many mathematical and intuitive methods for constraint analysis of mechanisms have been proposed. In this article we compare three methods. Method one is based on Grüblers equation. Method two uses an intuitive analysis method based on opening kinematic loops and evaluating the constraints at the

Constraint theory multidimensional mathematical model management

CERN Document Server

Friedman, George J

2017-01-01

Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...

Domain general constraints on statistical learning.

Science.gov (United States)

Thiessen, Erik D

2011-01-01

All theories of language development suggest that learning is constrained. However, theories differ on whether these constraints arise from language-specific processes or have domain-general origins such as the characteristics of human perception and information processing. The current experiments explored constraints on statistical learning of patterns, such as the phonotactic patterns of an infants' native language. Infants in these experiments were presented with a visual analog of a phonotactic learning task used by J. R. Saffran and E. D. Thiessen (2003). Saffran and Thiessen found that infants' phonotactic learning was constrained such that some patterns were learned more easily than other patterns. The current results indicate that infants' learning of visual patterns shows the same constraints as infants' learning of phonotactic patterns. This is consistent with theories suggesting that constraints arise from domain-general sources and, as such, should operate over many kinds of stimuli in addition to linguistic stimuli. © 2011 The Author. Child Development © 2011 Society for Research in Child Development, Inc.

Dose constraints, what are they now?

International Nuclear Information System (INIS)

Lazo, T.

2005-01-01

The concept of a source-related dose constraint was first introduced in ICPR publication 60. The idea was to provide a number that individual exposures from a single, specific source should not exceed, and below which optimisation of protection should take place. Dose constraints were applied to occupational and public exposures from practices. In order to simplify and clarify the ICRP's recommendations, the latest draft, RPO5, presents dose constraints again, and with the same meaning as in publication 60. However, the dose constraints are now applied in all situations, not just practices. This new approach does provide simplification, in that a single concept is applied to all types of exposures (normal situations, accident situations, and existing situations). However, the approach and numerical values that are selected by regulatory authorities for the application of the concept, particularly in normal situations which are also subject to dose limits, will be crucial to the implementation of the system of radiological protection. (author)

Simulating non-holonomic constraints within the LCP-based simulation framework

DEFF Research Database (Denmark)

Ellekilde, Lars-Peter; Petersen, Henrik Gordon

2006-01-01

be incorporated directly, and derive formalism for how the non-holonomic contact constraints can be modelled as a combination of non-holonomic equality constraints and ordinary contacts constraints. For each of these three we are able to guarantee solvability, when using Lemke's algorithm. A number of examples......In this paper, we will extend the linear complementarity problem-based rigid-body simulation framework with non-holonomic constraints. We consider three different types of such, namely equality, inequality and contact constraints. We show how non-holonomic equality and inequality constraints can...... are included to demonstrate the non-holonomic constraints. Udgivelsesdato: Marts...

Energy constraints in pulsed phase control of chaos

International Nuclear Information System (INIS)

Meucci, R.; Euzzor, S.; Zambrano, S.; Pugliese, E.; Francini, F.; Arecchi, F.T.

2017-01-01

Phase control of chaos is a powerful technique but little is known about its physical constraints, relevant for real systems. As a fact, it has not been explored whether this technique can also be applied when the controlling perturbation is not harmonic. Here we apply phase control on a driven double well Duffing oscillator using periodic rectangular pulsed perturbations instead of the classical sinusoidal perturbations. Experimental measurements and numerical simulations show that this kind of perturbation is also able to stabilize the chaotic orbits for an adequate selection of the phase. Furthermore, as the duty cycle of the perturbation (that is, the fraction of the time that the periodically pulsed control is active) is increased, two separate regimes occur. In the first one, the perturbations leading to stabilization of periodic solutions are of constant energy (taken as the product of the duty cycle and the amplitude) and in the second one, a saturation phenomenon occurs, implying that increasing energy values of the perturbations are wasted. Our results unveil the versatility of the pulsed phase control scheme and the importance of energy constraints.

Energy constraints in pulsed phase control of chaos

Energy Technology Data Exchange (ETDEWEB)

Meucci, R., E-mail: riccardo.meucci@ino.it [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Euzzor, S. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Zambrano, S. [Università Vita-Salute San Raffaele, Via Olgettina 58, 20132 Milano (Italy); Pugliese, E. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira 4, 50100 Firenze (Italy); Francini, F. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Arecchi, F.T. [Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Largo E. Fermi 6, 50125 Firenze (Italy); Università di Firenze, Firenze (Italy)

2017-01-15

Phase control of chaos is a powerful technique but little is known about its physical constraints, relevant for real systems. As a fact, it has not been explored whether this technique can also be applied when the controlling perturbation is not harmonic. Here we apply phase control on a driven double well Duffing oscillator using periodic rectangular pulsed perturbations instead of the classical sinusoidal perturbations. Experimental measurements and numerical simulations show that this kind of perturbation is also able to stabilize the chaotic orbits for an adequate selection of the phase. Furthermore, as the duty cycle of the perturbation (that is, the fraction of the time that the periodically pulsed control is active) is increased, two separate regimes occur. In the first one, the perturbations leading to stabilization of periodic solutions are of constant energy (taken as the product of the duty cycle and the amplitude) and in the second one, a saturation phenomenon occurs, implying that increasing energy values of the perturbations are wasted. Our results unveil the versatility of the pulsed phase control scheme and the importance of energy constraints.

Near-Optimal Fingerprinting with Constraints

Directory of Open Access Journals (Sweden)

Gulyás Gábor György

2016-10-01

Full Text Available Several recent studies have demonstrated that people show large behavioural uniqueness. This has serious privacy implications as most individuals become increasingly re-identifiable in large datasets or can be tracked, while they are browsing the web, using only a couple of their attributes, called as their fingerprints. Often, the success of these attacks depends on explicit constraints on the number of attributes learnable about individuals, i.e., the size of their fingerprints. These constraints can be budget as well as technical constraints imposed by the data holder. For instance, Apple restricts the number of applications that can be called by another application on iOS in order to mitigate the potential privacy threats of leaking the list of installed applications on a device. In this work, we address the problem of identifying the attributes (e.g., smartphone applications that can serve as a fingerprint of users given constraints on the size of the fingerprint. We give the best fingerprinting algorithms in general, and evaluate their effectiveness on several real-world datasets. Our results show that current privacy guards limiting the number of attributes that can be queried about individuals is insufficient to mitigate their potential privacy risks in many practical cases.

[Environmental efficiency evaluation under carbon emission constraint in Western China].

Science.gov (United States)

Rong, Jian-bo; Yan, Li-jiao; Huang, Shao-rong; Zhang, Ge

2015-06-01

This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guang-xi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO2 emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency.

Coverage-based constraints for IMRT optimization

Science.gov (United States)

Mescher, H.; Ulrich, S.; Bangert, M.

2017-09-01

Radiation therapy treatment planning requires an incorporation of uncertainties in order to guarantee an adequate irradiation of the tumor volumes. In current clinical practice, uncertainties are accounted for implicitly with an expansion of the target volume according to generic margin recipes. Alternatively, it is possible to account for uncertainties by explicit minimization of objectives that describe worst-case treatment scenarios, the expectation value of the treatment or the coverage probability of the target volumes during treatment planning. In this note we show that approaches relying on objectives to induce a specific coverage of the clinical target volumes are inevitably sensitive to variation of the relative weighting of the objectives. To address this issue, we introduce coverage-based constraints for intensity-modulated radiation therapy (IMRT) treatment planning. Our implementation follows the concept of coverage-optimized planning that considers explicit error scenarios to calculate and optimize patient-specific probabilities q(\\hat{d}, \\hat{v}) of covering a specific target volume fraction \\hat{v} with a certain dose \\hat{d} . Using a constraint-based reformulation of coverage-based objectives we eliminate the trade-off between coverage and competing objectives during treatment planning. In-depth convergence tests including 324 treatment plan optimizations demonstrate the reliability of coverage-based constraints for varying levels of probability, dose and volume. General clinical applicability of coverage-based constraints is demonstrated for two cases. A sensitivity analysis regarding penalty variations within this planing study based on IMRT treatment planning using (1) coverage-based constraints, (2) coverage-based objectives, (3) probabilistic optimization, (4) robust optimization and (5) conventional margins illustrates the potential benefit of coverage-based constraints that do not require tedious adjustment of target volume objectives.

Pairwise Constraint-Guided Sparse Learning for Feature Selection.

Science.gov (United States)

Liu, Mingxia; Zhang, Daoqiang

2016-01-01

Feature selection aims to identify the most informative features for a compact and accurate data representation. As typical supervised feature selection methods, Lasso and its variants using L1-norm-based regularization terms have received much attention in recent studies, most of which use class labels as supervised information. Besides class labels, there are other types of supervised information, e.g., pairwise constraints that specify whether a pair of data samples belong to the same class (must-link constraint) or different classes (cannot-link constraint). However, most of existing L1-norm-based sparse learning methods do not take advantage of the pairwise constraints that provide us weak and more general supervised information. For addressing that problem, we propose a pairwise constraint-guided sparse (CGS) learning method for feature selection, where the must-link and the cannot-link constraints are used as discriminative regularization terms that directly concentrate on the local discriminative structure of data. Furthermore, we develop two variants of CGS, including: 1) semi-supervised CGS that utilizes labeled data, pairwise constraints, and unlabeled data and 2) ensemble CGS that uses the ensemble of pairwise constraint sets. We conduct a series of experiments on a number of data sets from University of California-Irvine machine learning repository, a gene expression data set, two real-world neuroimaging-based classification tasks, and two large-scale attribute classification tasks. Experimental results demonstrate the efficacy of our proposed methods, compared with several established feature selection methods.

OPTIMAL CONFIGURATION OF A COMMAND AND CONTROL NETWORK: BALANCING PERFORMANCE AND RECONFIGURATION CONSTRAINTS

Energy Technology Data Exchange (ETDEWEB)

L. DOWELL

1999-07-01

The optimization of the configuration of communications and control networks is important for assuring the reliability and performance of the networks. This paper presents techniques for determining the optimal configuration for such a network in the presence of communication and connectivity constraints.

Chance-Constrained Guidance With Non-Convex Constraints

Science.gov (United States)

Ono, Masahiro

2011-01-01

Missions to small bodies, such as comets or asteroids, require autonomous guidance for descent to these small bodies. Such guidance is made challenging by uncertainty in the position and velocity of the spacecraft, as well as the uncertainty in the gravitational field around the small body. In addition, the requirement to avoid collision with the asteroid represents a non-convex constraint that means finding the optimal guidance trajectory, in general, is intractable. In this innovation, a new approach is proposed for chance-constrained optimal guidance with non-convex constraints. Chance-constrained guidance takes into account uncertainty so that the probability of collision is below a specified threshold. In this approach, a new bounding method has been developed to obtain a set of decomposed chance constraints that is a sufficient condition of the original chance constraint. The decomposition of the chance constraint enables its efficient evaluation, as well as the application of the branch and bound method. Branch and bound enables non-convex problems to be solved efficiently to global optimality. Considering the problem of finite-horizon robust optimal control of dynamic systems under Gaussian-distributed stochastic uncertainty, with state and control constraints, a discrete-time, continuous-state linear dynamics model is assumed. Gaussian-distributed stochastic uncertainty is a more natural model for exogenous disturbances such as wind gusts and turbulence than the previously studied set-bounded models. However, with stochastic uncertainty, it is often impossible to guarantee that state constraints are satisfied, because there is typically a non-zero probability of having a disturbance that is large enough to push the state out of the feasible region. An effective framework to address robustness with stochastic uncertainty is optimization with chance constraints. These require that the probability of violating the state constraints (i.e., the probability of

Specifying Dynamic and Deontic Integrity Constraints

NARCIS (Netherlands)

Wieringa, Roelf J.; Meyer, John-Jules; Weigand, Hans

In the dominant view of knowledge bases (KB's), a KB is a set of facts (atomic sentences) and integrity constraints (IC's). An IC is then a sentence which must at least be consistent with the other sentences in the KB, This view obliterates the distinction between, for example, the constraint that

A mathematical formulation for interface-based modular product design with geometric and weight constraints

Science.gov (United States)

Jung-Woon Yoo, John

2016-06-01

Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.

Stability Constraints for Robust Model Predictive Control

Directory of Open Access Journals (Sweden)

Amanda G. S. Ottoni

2015-01-01

Full Text Available This paper proposes an approach for the robust stabilization of systems controlled by MPC strategies. Uncertain SISO linear systems with box-bounded parametric uncertainties are considered. The proposed approach delivers some constraints on the control inputs which impose sufficient conditions for the convergence of the system output. These stability constraints can be included in the set of constraints dealt with by existing MPC design strategies, in this way leading to the “robustification” of the MPC.

Parallel Execution of Multi Set Constraint Rewrite Rules

DEFF Research Database (Denmark)

Sulzmann, Martin; Lam, Edmund Soon Lee

2008-01-01

that the underlying constraint rewrite implementation executes rewrite steps in parallel on increasingly popular becoming multi-core architectures. We design and implement efficient algorithms which allow for the parallel execution of multi-set constraint rewrite rules. Our experiments show that we obtain some......Multi-set constraint rewriting allows for a highly parallel computational model and has been used in a multitude of application domains such as constraint solving, agent specification etc. Rewriting steps can be applied simultaneously as long as they do not interfere with each other.We wish...

Control of communicable disease; foreign--requirements for importers of nonhuman primates (NHP). Final rule.

Science.gov (United States)

2013-02-15

The Centers for Disease Control and Prevention (CDC), located within the Department of Health and Human Services (HHS), is amending regulations for the importation of live nonhuman primates (NHPs) by extending existing requirements for the importation of Macaca fascicularis (cynomolgus), Chlorocebus aethiops (African green), and Macaca mulatta (rhesus) monkeys to all NHPs with the exception of the filovirus testing requirement. Filovirus testing will only be required for Old World NHPs in quarantine that have illness consistent with filovirus infection or that die for any reason other than trauma during quarantine. HHS/CDC is also finalizing a provision to reduce the frequency at which importers of cynomolgus, African green, and rhesus monkeys are required to renew their special permits (from every 180 days to every 2 years). HHS/CDC is incorporating existing guidelines into the regulations and adding new provisions to address the following: NHPs imported as part of an animal act; NHPs imported or transferred by zoological societies; the transfer of NHPs from approved laboratories; and non-live imported NHP products. Finally, HHS/CDC is also requiring that all NHPs be imported only through ports of entry where a HHS/CDC quarantine station is located.

Serious Leisure and People with Orthopedic Impairment: Benefits and Constraints

Directory of Open Access Journals (Sweden)

Manolya AKSATAN

2017-12-01

Full Text Available There are many people around the world who have different types of disabilities. Understanding their needs is the first step of developing policies to increase their quality of life and satisfaction. Leisure is an essential need of disabled people and it plays an important role in disabled people’s lives. The purpose of this study is to gain a deep understanding on the serious leisure activities of people with orthopedic impairment, and also both benefits and constraints involved with serious leisure. Therefore, semi-structured in-depth interviews were conducted with 17 people who have orthopedic impairment. The data collected through interviews was analyzed by using a coding process. Findings of the study indicate that people with orthopedic impairment pursue many leisure activities. The research revealed that the participants were aware of significant individual and community benefits of serious leisure activities. Although the benefits of leisure for private and community life are obvious for people with orthopedic impairment, it is not always easy for them to pursue serious leisure activities. Disabled people recognize that there are many constraints involved with serious leisure. Based on the findings, these constraints are explained as psychological factors, family support, level of orthopedic impairment, community awareness and environmental factors, work and income.

Currently important animal disease management issues in sub-Saharan Africa : policy and trade issues

Directory of Open Access Journals (Sweden)

G.R. Thomson

2009-09-01

Full Text Available The present international approach to management of transboundary animal diseases (TADs is based on the assumption that most can be eradicated ; consequently, that is the usual objective adopted by international organizations concerned with animal health. However, for sub-Saharan Africa and southern Africa more particularly, eradication of most TADs is impossible for the foreseeable future for a variety of technical, financial and logistical reasons. Compounding this, the present basis for access to international markets for products derived from animals requires that the area of origin (country or zone is free from trade-influencing TADs. The ongoing development of transfrontier conservation areas (TFCAs, extending across huge areas of southern Africa, therefore presents a development conundrum because it makes creation of geographic areas free from TADs more difficult and brings development based on wildlife conservation on the one hand and that based on livestock production on the other into sharp conflict. Sub-Saharan Africa is consequently confronted by a complex problem that contributes significantly to retarded rural development which, in turn, impedes poverty alleviation. In southern Africa specifically, foot-and-mouth disease (FMD presents the greatest problem in relation to access to international markets for animal products. However, it is argued that this problem could be overcome by a combination between (1 implementation of a commodity-based approach to trade in products derived from animals and (2 amendment of the international standards for FMD specifically (i.e. the FMD chapter in the Terrestrial Animal Health Code of the World Organisation for Animal Health [OIE] so that occurrence of SAT serotype viruses in free-living African buffalo need not necessarily mean exclusion of areas where buffalo occur from international markets for animal products. This would overcome a presently intractable constraint to market access for

A novel constraint for thermodynamically designing DNA sequences.

Directory of Open Access Journals (Sweden)

Qiang Zhang

Full Text Available Biotechnological and biomolecular advances have introduced novel uses for DNA such as DNA computing, storage, and encryption. For these applications, DNA sequence design requires maximal desired (and minimal undesired hybridizations, which are the product of a single new DNA strand from 2 single DNA strands. Here, we propose a novel constraint to design DNA sequences based on thermodynamic properties. Existing constraints for DNA design are based on the Hamming distance, a constraint that does not address the thermodynamic properties of the DNA sequence. Using a unique, improved genetic algorithm, we designed DNA sequence sets which satisfy different distance constraints and employ a free energy gap based on a minimum free energy (MFE to gauge DNA sequences based on set thermodynamic properties. When compared to the best constraints of the Hamming distance, our method yielded better thermodynamic qualities. We then used our improved genetic algorithm to obtain lower-bound DNA sequence sets. Here, we discuss the effects of novel constraint parameters on the free energy gap.

Constraint programming and decision making

CERN Document Server

Kreinovich, Vladik

2014-01-01

In many application areas, it is necessary to make effective decisions under constraints. Several area-specific techniques are known for such decision problems; however, because these techniques are area-specific, it is not easy to apply each technique to other applications areas. Cross-fertilization between different application areas is one of the main objectives of the annual International Workshops on Constraint Programming and Decision Making. Those workshops, held in the US (El Paso, Texas), in Europe (Lyon, France), and in Asia (Novosibirsk, Russia), from 2008 to 2012, have attracted researchers and practitioners from all over the world. This volume presents extended versions of selected papers from those workshops. These papers deal with all stages of decision making under constraints: (1) formulating the problem of multi-criteria decision making in precise terms, (2) determining when the corresponding decision problem is algorithmically solvable; (3) finding the corresponding algorithms, and making...

Social cognition on the Internet: testing constraints on social network size.

Science.gov (United States)

Dunbar, R I M

2012-08-05

The social brain hypothesis (an explanation for the evolution of brain size in primates) predicts that humans typically cannot maintain more than 150 relationships at any one time. The constraint is partly cognitive (ultimately determined by some aspect of brain volume) and partly one of time. Friendships (but not necessarily kin relationships) are maintained by investing time in them, and failure to do so results in an inexorable deterioration in the quality of a relationship. The Internet, and in particular the rise of social networking sites (SNSs), raises the possibility that digital media might allow us to circumvent some or all of these constraints. This allows us to test the importance of these constraints in limiting human sociality. Although the recency of SNSs means that there have been relatively few studies, those that are available suggest that, in general, the ability to broadcast to many individuals at once, and the possibilities this provides in terms of continuously updating our understanding of network members' behaviour and thoughts, do not allow larger networks to be maintained. This may be because only relatively weak quality relationships can be maintained without face-to-face interaction.

Determination of minimal clinically important change in early and advanced Parkinson's disease.

Science.gov (United States)

Hauser, Robert A; Auinger, Peggy

2011-04-01

Two common primary efficacy outcome measures in Parkinson's disease (PD) are change in Unified Parkinson's Disease Rating Scale (UPDRS) scores in early PD and change in "off" time in patients with motor fluctuations. Defining the minimal clinically important change (MCIC) in these outcome measures is important to interpret the clinical relevance of changes observed in clinical trials and other situations. We analyzed data from 2 multicenter, placebo-controlled, randomized clinical trials of rasagiline; TEMPO studied 404 early PD subjects, and PRESTO studied 472 levodopa-treated subjects with motor fluctuations. An anchor-based approach using clinical global impression of improvement (CGI-I) was used to determine MCIC for UPDRS scores and daily "off" time. MCIC was defined as mean change in actively treated subjects rated minimally improved on CGI-I. Receiver operating characteristic (ROC) curves defined optimal cutoffs discriminating between changed and unchanged subjects. MCIC for improvement in total UPDRS score (parts I-III) in early PD was determined to be -3.5 points based on mean scores and -3.0 points based on ROC curves. In addition, we found an MCIC for reduction in "off" time of 1.0 hours as defined by mean reduction in "off" time in active treated subjects self-rated as minimally improved on CGI-I minus mean reduction in "off" time in placebo-treated subjects self-rated as unchanged (1.9-0.9 hours). We hypothesize that many methodological factors can influence determination of the MCIC, and a range of values is likely to emerge from multiple studies. Copyright © 2011 Movement Disorder Society.

Biological constraints do not entail cognitive closure.

Science.gov (United States)

Vlerick, Michael

2014-12-01

From the premise that our biology imposes cognitive constraints on our epistemic activities, a series of prominent authors--most notably Fodor, Chomsky and McGinn--have argued that we are cognitively closed to certain aspects and properties of the world. Cognitive constraints, they argue, entail cognitive closure. I argue that this is not the case. More precisely, I detect two unwarranted conflations at the core of arguments deriving closure from constraints. The first is a conflation of what I will refer to as 'representation' and 'object of representation'. The second confuses the cognitive scope of the assisted mind for that of the unassisted mind. Cognitive closure, I conclude, cannot be established from pointing out the (uncontroversial) existence of cognitive constraints. Copyright © 2014 Elsevier Ltd. All rights reserved.

Level-Set Topology Optimization with Aeroelastic Constraints

Science.gov (United States)

Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia

2015-01-01

Level-set topology optimization is used to design a wing considering skin buckling under static aeroelastic trim loading, as well as dynamic aeroelastic stability (flutter). The level-set function is defined over the entire 3D volume of a transport aircraft wing box. Therefore, the approach is not limited by any predefined structure and can explore novel configurations. The Sequential Linear Programming (SLP) level-set method is used to solve the constrained optimization problems. The proposed method is demonstrated using three problems with mass, linear buckling and flutter objective and/or constraints. A constraint aggregation method is used to handle multiple buckling constraints in the wing skins. A continuous flutter constraint formulation is used to handle difficulties arising from discontinuities in the design space caused by a switching of the critical flutter mode.

National Priority Setting of Clinical Practice Guidelines Development for Chronic Disease Management.

Science.gov (United States)

Jo, Heui-Sug; Kim, Dong Ik; Oh, Moo-Kyung

2015-12-01

By November 2013, a total of 125 clinical practice guidelines (CPGs) have been developed in Korea. However, despite the high burden of diseases and the clinical importance of CPGs, most chronic diseases do not have available CPGs. Merely 83 CPGs are related to chronic diseases, and only 40 guidelines had been developed in the last 5 yr. Considering the rate of the production of new evidence in medicine and the worsening burden from chronic diseases, the need for developing CPGs for more chronic diseases is becoming increasingly pressing. Since 2011, the Korean Academy of Medical Sciences and the Korea Centers for Disease Control and Prevention have been jointly developing CPGs for chronic diseases. However, priorities have to be set and resources need to be allocated within the constraint of a limited funding. This study identifies the chronic diseases that should be prioritized for the development of CPGs in Korea. Through an objective assessment by using the analytic hierarchy process and a subjective assessment with a survey of expert opinion, high priorities were placed on ischemic heart disease, cerebrovascular diseases, Alzheimer's disease and other dementias, osteoarthritis, neck pain, chronic kidney disease, and cirrhosis of the liver.

Animal diseases of public health importance.

OpenAIRE

Orriss, G. D.

1997-01-01

The Food and Agriculture Organization's (FAO) interest in emerging diseases caused by foodborne pathogens derives from its role as the leading United Nations agency with a mandate for food quality and safety matters. The Food Quality and Standards Service of FAO's Food and Nutrition Division is active in all areas related to food safety and implements the FAO/World Health Organization Food Standards Program. Its activities include providing assistance to FAO's member nations in addressing pro...

Trade-off between multiple constraints enables simultaneous formation of modules and hubs in neural systems.

Directory of Open Access Journals (Sweden)

Yuhan Chen

Full Text Available The formation of the complex network architecture of neural systems is subject to multiple structural and functional constraints. Two obvious but apparently contradictory constraints are low wiring cost and high processing efficiency, characterized by short overall wiring length and a small average number of processing steps, respectively. Growing evidence shows that neural networks are results from a trade-off between physical cost and functional value of the topology. However, the relationship between these competing constraints and complex topology is not well understood quantitatively. We explored this relationship systematically by reconstructing two known neural networks, Macaque cortical connectivity and C. elegans neuronal connections, from combinatory optimization of wiring cost and processing efficiency constraints, using a control parameter α, and comparing the reconstructed networks to the real networks. We found that in both neural systems, the reconstructed networks derived from the two constraints can reveal some important relations between the spatial layout of nodes and the topological connectivity, and match several properties of the real networks. The reconstructed and real networks had a similar modular organization in a broad range of α, resulting from spatial clustering of network nodes. Hubs emerged due to the competition of the two constraints, and their positions were close to, and partly coincided, with the real hubs in a range of α values. The degree of nodes was correlated with the density of nodes in their spatial neighborhood in both reconstructed and real networks. Generally, the rebuilt network matched a significant portion of real links, especially short-distant ones. These findings provide clear evidence to support the hypothesis of trade-off between multiple constraints on brain networks. The two constraints of wiring cost and processing efficiency, however, cannot explain all salient features in the real

How robust are inflation model and dark matter constraints from cosmological data?

International Nuclear Information System (INIS)

Hamann, J.; Hannestad, S.; Sloth, M.S.; Wong, Y.Y.Y.

2006-11-01

High-precision data from observation of the cosmic microwave background and the large scale structure of the universe provide very tight constraints on the effective parameters that describe cosmological inflation. Indeed, within a constrained class of ΛCDM models, the simple λφ 4 chaotic inflation model already appears to be ruled out by cosmological data. In this paper, we compute constraints on inflationary parameters within a more general framework that includes other physically motivated parameters such as a nonzero neutrino mass. We find that a strong degeneracy between the tensor-to-scalar ratio τ and the neutrino mass prevents λφ 4 from being excluded by present data. Reversing the argument, if λφ 4 is the correct model of inflation, it predicts a sum of neutrino masses at 0.3→0.5 eV, a range compatible with present experimental limits and within the reach of the next generation of neutrino mass measurements. We also discuss the associated constraints on the dark matter density, the dark energy equation of state, and spatial curvature, and show that the allowed regions are significantly altered. Importantly, we find an allowed range of 0.094 c h 2 <0.136 for the dark matter density, a factor of two larger than that reported in previous studies. This expanded parameter space may have implications for constraints on SUSY dark matter models. (orig.)

Developmental constraint of insect audition

Directory of Open Access Journals (Sweden)

Strauß Johannes

2006-12-01

Full Text Available Abstract Background Insect ears contain very different numbers of sensory cells, from only one sensory cell in some moths to thousands of sensory cells, e.g. in cicadas. These differences still await functional explanation and especially the large numbers in cicadas remain puzzling. Insects of the different orders have distinct developmental sequences for the generation of auditory organs. These sensory cells might have different functions depending on the developmental stages. Here we propose that constraints arising during development are also important for the design of insect ears and might influence cell numbers of the adults. Presentation of the hypothesis We propose that the functional requirements of the subadult stages determine the adult complement of sensory units in the auditory system of cicadas. The hypothetical larval sensory organ should function as a vibration receiver, representing a functional caenogenesis. Testing the hypothesis Experiments at different levels have to be designed to test the hypothesis. Firstly, the neuroanatomy of the larval sense organ should be analyzed to detail. Secondly, the function should be unraveled neurophysiologically and behaviorally. Thirdly, the persistence of the sensory cells and the rebuilding of the sensory organ to the adult should be investigated. Implications of the hypothesis Usually, the evolution of insect ears is viewed with respect to physiological and neuronal mechanisms of sound perception. This view should be extended to the development of sense organs. Functional requirements during postembryonic development may act as constraints for the evolution of adult organs, as exemplified with the auditory system of cicadas.

Linear determining equations for differential constraints

International Nuclear Information System (INIS)

Kaptsov, O V

1998-01-01

A construction of differential constraints compatible with partial differential equations is considered. Certain linear determining equations with parameters are used to find such differential constraints. They generalize the classical determining equations used in the search for admissible Lie operators. As applications of this approach equations of an ideal incompressible fluid and non-linear heat equations are discussed

Modifier constraints in alkali ultraphosphate glasses

DEFF Research Database (Denmark)

Rodrigues, B.P.; Mauro, J.C.; Yue, Yuanzheng

2014-01-01

In applying the recently introduced concept of cationic constraint strength [J. Chem. Phys. 140, 214501 (2014)] to bond constraint theory (BCT) of binary phosphate glasses in the ultraphosphate region of xR2O-(1-x)P2O5 (with x ≤ 0.5 and R = {Li, Na, Cs}), we demonstrate that a fundamental limitat...

The role of social support, family identification, and family constraints in predicting posttraumatic stress after cancer.

Science.gov (United States)

Swartzman, Samantha; Sani, Fabio; Munro, Alastair J

2017-09-01

We compared social support with other potential psychosocial predictors of posttraumatic stress after cancer. These included family identification, or a sense of belonging to and commonality with family members, and family constraints, or the extent to which family members are closed, judgmental, or unreceptive in conversations about cancer. We also tested the hypothesis that family constraints mediate the relationship between family identification and cancer-related posttraumatic stress. We used a cross-sectional design. Surveys were collected from 205 colorectal cancer survivors in Tayside, Scotland. Both family identification and family constraints were stronger independent predictors of posttraumatic stress than social support. In multivariate analyses, social support was not a significant independent predictor of posttraumatic stress. In addition, there was a significant indirect effect of family identification on posttraumatic stress through family constraints. Numerous studies demonstrate a link between social support and posttraumatic stress. However, experiences within the family may be more important in predicting posttraumatic stress after cancer. Furthermore, a sense of belonging to and commonality with the family may reduce the extent to which cancer survivors experience constraints on conversations about cancer; this may, in turn, reduce posttraumatic stress. Copyright © 2016 John Wiley & Sons, Ltd.

Implicit Motives and Men’s Perceived Constraint in Fatherhood

Science.gov (United States)

Ruppen, Jessica; Waldvogel, Patricia; Ehlert, Ulrike

2016-01-01

Research shows that implicit motives influence social relationships. However, little is known about their role in fatherhood and, particularly, how men experience their paternal role. Therefore, this study examined the association of implicit motives and fathers’ perceived constraint due to fatherhood. Furthermore, we explored their relation to fathers’ life satisfaction. Participants were fathers with biological children (N = 276). They were asked to write picture stories, which were then coded for implicit affiliation and power motives. Perceived constraint and life satisfaction were assessed on a visual analog scale. A higher implicit need for affiliation was significantly associated with lower perceived constraint, whereas the implicit need for power had the opposite effect. Perceived constraint had a negative influence on life satisfaction. Structural equation modeling revealed significant indirect effects of implicit affiliation and power motives on life satisfaction mediated by perceived constraint. Our findings indicate that men with a higher implicit need for affiliation experience less constraint due to fatherhood, resulting in higher life satisfaction. The implicit need for power, however, results in more perceived constraint and is related to decreased life satisfaction. PMID:27933023

Medical image segmentation by a constraint satisfaction neural network

International Nuclear Information System (INIS)

Chen, C.T.; Tsao, E.C.K.; Lin, W.C.

1991-01-01

This paper proposes a class of Constraint Satisfaction Neural Networks (CSNNs) for solving the problem of medical image segmentation which can be formulated as a Constraint Satisfaction Problem (CSP). A CSNN consists of a set of objects, a set of labels for each object, a collection of constraint relations linking the labels of neighboring objects, and a topological constraint describing the neighborhood relationship among various objects. Each label for a particular object indicates one possible interpretation for that object. The CSNN can be viewed as a collection of neurons that interconnect with each other. The connections and the topology of a CSNN are used to represent the constraints in a CSP. The mechanism of the neural network is to find a solution that satisfies all the constraints in order to achieve a global consistency. The final solution outlines segmented areas and simultaneously satisfies all the constraints. This technique has been applied to medical images and the results show that this CSNN method is a very promising approach for image segmentation

Implicit Motives and Men’s Perceived Constraint in Fatherhood

Directory of Open Access Journals (Sweden)

Jessica Ruppen

2016-11-01

Full Text Available Research shows that implicit motives influence social relationships. However, little is known about their role in fatherhood and, particularly, how men experience their paternal role. Therefore, this study examined the association of implicit motives and fathers’ perceived constraint due to fatherhood. Furthermore, we explored their relation to fathers’ life satisfaction. Participants were fathers with biological children (N = 276. They were asked to write picture stories, which were then coded for implicit affiliation and power motives. Perceived constraint and life satisfaction were assessed on a visual analog scale. A higher implicit need for affiliation was significantly associated with lower perceived constraint, whereas the implicit need for power had the opposite effect. Perceived constraint had a negative influence on life satisfaction. Structural equation modeling revealed significant indirect effects of implicit affiliation and power motives on life satisfaction mediated by perceived constraint. Our findings indicate that men with a higher implicit need for affiliation experience less constraint due to fatherhood, resulting in higher life satisfaction. The implicit need for power, however, results in more perceived constraint and is related to decreased life satisfaction.

Pair Production Constraints on Superluminal Neutrinos Revisited

International Nuclear Information System (INIS)

Brodsky, Stanley

2012-01-01

We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p 2 can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

Diffusion Processes Satisfying a Conservation Law Constraint

Directory of Open Access Journals (Sweden)

J. Bakosi

2014-01-01

Full Text Available We investigate coupled stochastic differential equations governing N nonnegative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires a set of fluctuating variables to be nonnegative and (if appropriately normalized sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the nonnegativity and the unit-sum conservation law constraints are satisfied as the variables evolve in time. We investigate the consequences of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.

ON Integrated Chance Constraints in ALM for Pension Funds

OpenAIRE

Youssouf A. F. Toukourou; Fran\\c{c}ois Dufresne

2015-01-01

We discuss the role of integrated chance constraints (ICC) as quantitative risk constraints in asset and liability management (ALM) for pension funds. We define two types of ICC: the one period integrated chance constraint (OICC) and the multiperiod integrated chance constraint (MICC). As their names suggest, the OICC covers only one period whereas several periods are taken into account with the MICC. A multistage stochastic linear programming model is therefore developed for this purpose and...

Liposomes for Targeted Delivery of Active Agents against Neurodegenerative Diseases (Alzheimer's Disease and Parkinson's Disease

Directory of Open Access Journals (Sweden)

Carlos Spuch

2011-01-01

Full Text Available Neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease represent a huge unmet medical need. The prevalence of both diseases is increasing, but the efficacy of treatment is still very limited due to various factors including the blood brain barrier (BBB. Drug delivery to the brain remains the major challenge for the treatment of all neurodegenerative diseases because of the numerous protective barriers surrounding the central nervous system. New therapeutic drugs that cross the BBB are critically needed for treatment of many brain diseases. One of the significant factors on neurotherapeutics is the constraint of the blood brain barrier and the drug release kinetics that cause peripheral serious side effects. Contrary to common belief, neurodegenerative and neurological diseases may be multisystemic in nature, and this presents numerous difficulties for their potential treatment. Overall, the aim of this paper is to summarize the last findings and news related to liposome technology in the treatment of neurodegenerative diseases and demonstrate the potential of this technology for the development of novel therapeutics and the possible applications of liposomes in the two most widespread neurodegenerative diseases, Alzheimer's disease and Parkinson's disease.

Constraints and Ambiguity

DEFF Research Database (Denmark)

Dove, Graham; Biskjær, Michael Mose; Lundqvist, Caroline Emilie

2017-01-01

groups of students building three models each. We studied groups building with traditional plastic bricks and also using a digital environment. The building tasks students undertake, and our subsequent analysis, are informed by the role constraints and ambiguity play in creative processes. Based...

QCD unitarity constraints on Reggeon Field Theory

Energy Technology Data Exchange (ETDEWEB)

Kovner, Alex [Physics Department, University of Connecticut,2152 Hillside Road, Storrs, CT 06269 (United States); Levin, Eugene [Departemento de Física, Universidad Técnica Federico Santa María,and Centro Científico-Tecnológico de Valparaíso,Avda. Espana 1680, Casilla 110-V, Valparaíso (Chile); Department of Particle Physics, Tel Aviv University,Tel Aviv 69978 (Israel); Lublinsky, Michael [Physics Department, Ben-Gurion University of the Negev,Beer Sheva 84105 (Israel); Physics Department, University of Connecticut,2152 Hillside Road, Storrs, CT 06269 (United States)

2016-08-04

We point out that the s-channel unitarity of QCD imposes meaningful constraints on a possible form of the QCD Reggeon Field Theory. We show that neither the BFKL nor JIMWLK nor Braun’s Hamiltonian satisfy the said constraints. In a toy, zero transverse dimensional case we construct a model that satisfies the analogous constraint and show that at infinite energy it indeed tends to a “black disk limit' as opposed to the model with triple Pomeron vertex only, routinely used as a toy model in the literature.

QCD unitarity constraints on Reggeon Field Theory

International Nuclear Information System (INIS)

Kovner, Alex; Levin, Eugene; Lublinsky, Michael

2016-01-01

We point out that the s-channel unitarity of QCD imposes meaningful constraints on a possible form of the QCD Reggeon Field Theory. We show that neither the BFKL nor JIMWLK nor Braun’s Hamiltonian satisfy the said constraints. In a toy, zero transverse dimensional case we construct a model that satisfies the analogous constraint and show that at infinite energy it indeed tends to a “black disk limit' as opposed to the model with triple Pomeron vertex only, routinely used as a toy model in the literature.

Constraint satisfaction problems CSP formalisms and techniques

CERN Document Server

Ghedira, Khaled

2013-01-01

A Constraint Satisfaction Problem (CSP) consists of a set of variables, a domain of values for each variable and a set of constraints. The objective is to assign a value for each variable such that all constraints are satisfied. CSPs continue to receive increased attention because of both their high complexity and their omnipresence in academic, industrial and even real-life problems. This is why they are the subject of intense research in both artificial intelligence and operations research. This book introduces the classic CSP and details several extensions/improvements of both formalisms a

Use of dose constraints for occupational exposure

International Nuclear Information System (INIS)

Kaijage, Tunu

2015-02-01

The use of dose constraints for occupational exposure was reviewed in this project. The role of dose constraints as used in optimization of protection of workers was described. Different issues to be considered in application of the concept and challenges associated with their implementation were also discussed. The situation where dose constraints could be misinterpreted to dose limits is also explained as the two are clearly differentiated by the International Commission of Radiological Protection (ICRP) Publication 103. Moreover, recommendations to all parties responsible for protection and safety of workers were discussed. (au)

[The importance of local and general factors in development of inflammatory periodontal diseases in children and adolescents].

Science.gov (United States)

Shishinashvili, T E; Tsagareli, Z G; Khimshiashvili, N B

2012-10-01

The aim of the study was to investigate the influence of local and general adverse risk factors and their role in the development of inflammatory periodontal diseases in children and adolescents. The study of the dental status among 618 school children, 9 to 15 years of age has been performed. The obtained results revealed an ambiguous influence of general and local risk factors on the development of inflammatory periodontal diseases. Namely, among the general risk factors the main role is given to hormonal functioning state of juvenile age (26.5%) - (arhythmia formation of hormonal activity). Among the local risk factors inducing inflammatory periodontal diseases at young age, the most significant are tooth-jaw anomalies (32.2%), especially - dental occlusion pathology, lips' bridle attachment anomalies, absence of interdental contacts, small vestibule of the mouth and so on. Poor oral hygiene, however, is also a significant factor in all age groups. Definition of the role and importance of general and local risk factors, taking into consideration patient's age, is of great importance in organization of early prevention, giving the possibility to predict disease possible development, choose most appropriate way to treat the specific situation, reduce the need of complex treatment and improve treatment outcomes.

Accuracy Constraint Determination in Fixed-Point System Design

Directory of Open Access Journals (Sweden)

Serizel R

2008-01-01

Full Text Available Most of digital signal processing applications are specified and designed with floatingpoint arithmetic but are finally implemented using fixed-point architectures. Thus, the design flow requires a floating-point to fixed-point conversion stage which optimizes the implementation cost under execution time and accuracy constraints. This accuracy constraint is linked to the application performances and the determination of this constraint is one of the key issues of the conversion process. In this paper, a method is proposed to determine the accuracy constraint from the application performance. The fixed-point system is modeled with an infinite precision version of the system and a single noise source located at the system output. Then, an iterative approach for optimizing the fixed-point specification under the application performance constraint is defined and detailed. Finally the efficiency of our approach is demonstrated by experiments on an MP3 encoder.

Theory of constraints: A state-of-art review

Directory of Open Access Journals (Sweden)

Maryam Orouji

2015-11-01

Full Text Available The theory of constraints (TOC is a management tool, which considers any manageable system as being limited in reaching more of its objectives by some constraints. According to TOC, there is always, at least, one single constraint, and TOC implements a concentrating process to detect the constraint and restructure the remaining of the organization around it. This paper presents an overview of different perspectives of TOC and its implementation in different industries such as project management, quality management, outsourcing, product mix, make-to-buy, accounting, banking and health care, etc. The results indicate that the method has been extensively implemented in different areas of accounting.

A comparison of dose-volume constraints derived using peak and longitudinal definitions of late rectal toxicity

International Nuclear Information System (INIS)

Gulliford, Sarah L.; Partridge, Mike; Sydes, Matthew R.; Andreyev, Jervoise; Dearnaley, David P.

2010-01-01

Background and purpose: Accurate reporting of complications following radiotherapy is an important part of the feedback loop to improve radiotherapy techniques. The definition of toxicity is normally regarded as the maximum or peak (P) grade of toxicity reported over the follow-up period. An alternative definition (integrated longitudinal toxicity (ILT)) is proposed which takes into account both the severity and the duration of the complication. Methods and materials: In this work, both definitions of toxicity were used to derive dose-volume constraints for six specific endpoints of late rectal toxicity from a cohort of patients who received prostate radiotherapy in the MRC RT01 trial. The dose-volume constraints were derived using ROC analysis for 30, 40, 50, 60, 65 and 70 Gy. Results: Statistically significant dose-volume constraints were not derived for all dose levels tested for each endpoint and toxicity definition. However, where both definitions produced constraints, there was generally good agreement. Variation in the derived dose-volume constraints was observed to be larger between endpoints than between the two definitions of toxicity. For one endpoint (stool frequency (LENT/SOM)) statistically significant dose-volume constraints were only derived using ILT. Conclusions: The longitudinal definition of toxicity (ILT) produced results consistent with those derived using peak toxicity and in some cases provided additional information which was not seen by analysing peak toxicity alone.

Latin hypercube sampling with inequality constraints

International Nuclear Information System (INIS)

Iooss, B.; Petelet, M.; Asserin, O.; Loredo, A.

2010-01-01

In some studies requiring predictive and CPU-time consuming numerical models, the sampling design of the model input variables has to be chosen with caution. For this purpose, Latin hypercube sampling has a long history and has shown its robustness capabilities. In this paper we propose and discuss a new algorithm to build a Latin hypercube sample (LHS) taking into account inequality constraints between the sampled variables. This technique, called constrained Latin hypercube sampling (cLHS), consists in doing permutations on an initial LHS to honor the desired monotonic constraints. The relevance of this approach is shown on a real example concerning the numerical welding simulation, where the inequality constraints are caused by the physical decreasing of some material properties in function of the temperature. (authors)

The Relationship between Leisure Constraints, Constraint Negotiation Strategies and Facilitators with Recreational Sport Activity Participation of College Students

Science.gov (United States)

Kocak, Funda

2017-01-01

The aim of this study is to determine the constraints in participating the leisure activities for college students, the strategies of negotiation regarding these constraints and the relationship between the facilitators and activity participation. The population of the study consists of currently registered students from Ankara University.…

IAEA '77: between politics and factual constraints

International Nuclear Information System (INIS)

Freytag, A.

1976-01-01

The IAEA's organization of its 20th General Conference at Rio de Janeiro clearly underlined the importance of a comprehensive international transfer of nuclear technology. Despite all efforts to keep the Agency out of general political confrontations, the Conference was tinged politically by the PLO and South Africa problems. Besides the next five year program, which was agreed upon in the light of existing factual constraints, the support and control functions of the IAEA and next year's Salzburg Fuel Cycle Conference were other main topics of discussion. The 1977 IAEA budget was approved at a level of 43.5 million, the General Fund at 6.5 million. (orig.) [de

Mission Implementation Constraints on Planetary Muon Radiography

Science.gov (United States)

Jones, Cathleen E.; Kedar, Sharon; Naudet, Charles; Webb, Frank

2011-01-01

Cost: Use heritage hardware, especially use a tested landing system to reduce cost (Phoenix or MSL EDL stage). The sky crane technology delivers higher mass to the surface and enables reaching targets at higher elevation, but at a higher mission cost. Rover vs. Stationary Lander: Rover-mounted instrument enables tomography, but the increased weight of the rover reduces the allowable payload weight. Mass is the critical design constraint for an instrument for a planetary mission. Many factors that are minor factors or do not enter into design considerations for terrestrial operation are important for a planetary application. (Landing site, diurnal temperature variation, instrument portability, shock/vibration)

Use of morphological characters to identify cassava mosaic disease ...

African Journals Online (AJOL)

Diseases are among the major constraints that prevent cassava's (Manihot esculenta L.) optimum yield. Both the improved cassava breeds and local germplasms in the International Institute of Tropical Agriculture, Ibadan expressed wide genetic variability in morphological characters and diseases resistance. The current ...

Day-Ahead Coordination of Vehicle-to-Grid Operation and Wind Power in Security Constraints Unit Commitment (SCUC)

OpenAIRE

Mohammad Javad Abdollahi; Majid Moazzami

2015-01-01

In this paper security constraints unit commitment (SCUC) in the presence of wind power resources and electrical vehicles to grid is presented. SCUC operation prepare an optimal time table for generation unit commitment in order to maximize security, minimize operation cost and satisfy the constraints of networks and units in a period of time, as one of the most important research interest in power systems. Today, the relationship between power network and energy storage systems is interested...

Extended Set Constraints and Tree Grammar Abstraction of Programs

DEFF Research Database (Denmark)

Rosendahl, Mads; Gallagher, John Patrick

2011-01-01

Set constraints are relations between sets of ground terms or trees. This paper presents two main contributions: firstly we consider an extension of the systems of set constraints to include a tuple constructor, and secondly we construct a simplified solution procedure for set constraints. We...

Evolutionary Meta-Analysis of Association Studies Reveals Ancient Constraints Affecting Disease Marker Discovery

Science.gov (United States)

Dudley, Joel T.; Chen, Rong; Sanderford, Maxwell; Butte, Atul J.; Kumar, Sudhir

2012-01-01

Genome-wide disease association studies contrast genetic variation between disease cohorts and healthy populations to discover single nucleotide polymorphisms (SNPs) and other genetic markers revealing underlying genetic architectures of human diseases. Despite scores of efforts over the past decade, many reproducible genetic variants that explain substantial proportions of the heritable risk of common human diseases remain undiscovered. We have conducted a multispecies genomic analysis of 5,831 putative human risk variants for more than 230 disease phenotypes reported in 2,021 studies. We find that the current approaches show a propensity for discovering disease-associated SNPs (dSNPs) at conserved genomic positions because the effect size (odds ratio) and allelic P value of genetic association of an SNP relates strongly to the evolutionary conservation of their genomic position. We propose a new measure for ranking SNPs that integrates evolutionary conservation scores and the P value (E-rank). Using published data from a large case-control study, we demonstrate that E-rank method prioritizes SNPs with a greater likelihood of bona fide and reproducible genetic disease associations, many of which may explain greater proportions of genetic variance. Therefore, long-term evolutionary histories of genomic positions offer key practical utility in reassessing data from existing disease association studies, and in the design and analysis of future studies aimed at revealing the genetic basis of common human diseases. PMID:22389448

Viral respiratory diseases: vaccines and antivirals.

Science.gov (United States)

Lennette, E H

1981-01-01

Acute respiratory diseases, most of which are generally attributed to viruses, account for about 6% of all deaths and for about 60% of the deaths associated with all respiratory disease. The huge cost attributable to viral respiratory infections as a result of absenteeism and the disruption of business and the burden of medical care makes control of these diseases an important objective. The viruses that infect the respiratory tract fall taxonomically into five viral families. Although immunoprophylaxis would appear to be the logical approach, the development of suitable vaccines has been confronted with numerous obstacles, including antigenic drift and shift in the influenzaviruses, the large number of antigenically distinct immunotypes among rhinoviruses, the occurrence after immunization of rare cases of a severe form of the disease following subsequent natural infection with respiratory syncytial virus, and the risk of oncogenicity of adenoviruses for man. Considerable expenditure on the development of new antiviral drugs has so far resulted in only three compounds that are at present officially approved and licensed for use in the USA. Efforts to improve the tools available for control should continue and imaginative and inventive approaches are called for. However, creativity and ingenuity must operate within the constraints imposed by economic, political, ethical, and legal considerations.

Importance of clinical examination in diagnostics of Osgood-Schlatter Disease in boys playing soccer or basketball

Directory of Open Access Journals (Sweden)

Amela Halilbasic

2012-04-01

Full Text Available Introduction: Osgood–Schlatter disease is an irritation of the patellar tendon at the tibial tubercle. Sports with jumps, running, and repeated contractions of knee extension apparatus are considered to be importantexternal risk-factors which could cause Osgood–Schlatter disease.Objectives of the study are to draw attention to the importance of clinical examination in diagnostics of Osgood–Schlatter disease in boys playing soccer or basketball.Methods: The research included data obtained from 120 boys, average age of 14 years. Examinees were split into two groups, one with young athletes which regularly have soccer or basketball trainings and thesecond one with boys who do not participating in sports. We performed anthropological measurements and clinical examinations of both knees and hips for both groups. For the statistical analysis we used pointbiserialcorrelation coefficient.Results: Based on clinical examination, Osgood–Schlatter disease was diagnosed in 51 examinees (42.5%. In “athletic group” Osgood–Schlatter disease had 31 boys or 52%, comparing with “non-athletic group” wherewe found 20 adolescents with disease (33%. Number of boys with Osgood–Schlatter disease was higher for 19% in “athletic group” comparing with “non-athletic group”. Comparing incidence rate for boys in both groups with diagnosed II and III level of Osgood–Schlatter disease we found that rate is higher in “athletic group” 2.25 times comparing with “non-athletic group”.Conclusions: Clinical examination is critical method in the process of diagnosing Osgood–Schlatter disease especially for identifying II and III level of this disease.

Origin of constraints in relativistic classical Hamiltonian dynamics

International Nuclear Information System (INIS)

Mallik, S.; Hugentobler, E.

1979-01-01

We investigate the null-plane or the front form of relativistic classical Hamiltonian dynamics as proposed by Dirac and developed by Leutwyler and Stern. For systems of two spinless particles we show that the algebra of Poincare generators is equivalent to describing dynamics in terms of two covariant constraint equations, the Poisson bracket of the two constraints being weakly zero. The latter condition is solved for certain simple forms of constraints

A New Empirical Constraint on the Prevalence of Technological Species in the Universe.

Science.gov (United States)

Frank, A; Sullivan, W T

2016-05-01

In this article, we address the cosmic frequency of technological species. Recent advances in exoplanet studies provide strong constraints on all astrophysical terms in the Drake equation. Using these and modifying the form and intent of the Drake equation, we set a firm lower bound on the probability that one or more technological species have evolved anywhere and at any time in the history of the observable Universe. We find that as long as the probability that a habitable zone planet develops a technological species is larger than ∼10(-24), humanity is not the only time technological intelligence has evolved. This constraint has important scientific and philosophical consequences. Life-Intelligence-Extraterrestrial life. Astrobiology 2016, 359-362.

Export constraints facing Lesotho-based manufacturing enterprises

Directory of Open Access Journals (Sweden)

Motšelisi C. Mokhethi

2015-07-01

Full Text Available Orientation: Exporting is preferred by many enterprises as the mode of foreign entry as it requires less commitment of organisational resources and offers flexibility of managerial actions. However, enterprises face a number of challenges when attempting to initiate exports or expand their export operations. Research purpose: This study was undertaken to determine the characteristics and composition of export barriers constraining exporting by Lesotho-based manufacturing enterprises. Motivation for the study: Lesotho is faced with low destination diversity and low diversity in export products. Research design, approach and method: Data was collected from 162 Lesotho-based manufacturing enterprises through a self-administered questionnaire. Main findings: In its findings, the study firstly identified international constraints, distribution constraints and financial constraints as factors constraining exporting. Secondly, it was determined that three exporting constraints, all internal to the enterprise and all related to one factor (namely financial constraint hampered exporting. Lastly, the ANOVA results revealed that the perceptions of export constraints differed according to the enterprise characteristics, enterprise size, ownership and type of industry. Contribution/value-add: With the majority of enterprises in this study being identified as micro-enterprises, the government of Lesotho needs to pay particular attention to addressing the export needs of these enterprises in order to enable them to participate in exporting activities − especially considering that they can play a pivotal role in the alleviation of poverty, job creation and economic rejuvenation.

Einstein constraints in the Yang-Mills form

International Nuclear Information System (INIS)

Ashtekar, A.

1987-01-01

It is pointed out that constraints of Einstein's theory play a powerful role in both classical and quantum theory because they generate motions in spacetime, rather than in an internal space. New variables are then introduced on the Einstein phase space in terms of which constraints simplify considerably. In particular, the use of these variables enables one to imbed the constraint surface of Einstein's theory into that of Yang-Mills. The imbedding suggests new lines of attack to a number of problems in classical and quantum gravity and provides new concepts and tools to investigate the microscopic structure of space-time geometry

[Inflammatory spinal diseases: axial spondyloarthritis : Central importance of imaging].

Science.gov (United States)

Baraliakos, X; Fruth, M; Kiltz, U; Braun, J

2017-03-01

The diagnosis of axial spondyloarthritis (axSpA) includes classical ankylosing spondylitis (AS) as well as earlier stages and abortive courses of the disease, in which structural alterations have not yet occurred. These are classified as non-radiographic axSpA (nr-axSpa). Inflammatory changes in the entire axial skeleton are characteristic for axSpA and can be visualized by magnetic resonance imaging (MRI), while in most patients structural alterations, such as new bone formation with syndesmophytes and ankylosis develop in the later course of the disease. These bony alterations can best be visualized by conventional radiography and by computed tomography. Certain MRI sequences are nowadays considered as the standard method for depiction of inflammatory changes in axSpA. The introduction of MRI has led to a paradigm shift for this disease because the inflammatory lesions characteristic for the disease can be visualized at an early stage using appropriate MRI sequences.

Preconditioning for partial differential equation constrained optimization with control constraints

KAUST Repository

Stoll, Martin

2011-10-18

Optimal control problems with partial differential equations play an important role in many applications. The inclusion of bound constraints for the control poses a significant additional challenge for optimization methods. In this paper, we propose preconditioners for the saddle point problems that arise when a primal-dual active set method is used. We also show for this method that the same saddle point system can be derived when the method is considered as a semismooth Newton method. In addition, the projected gradient method can be employed to solve optimization problems with simple bounds, and we discuss the efficient solution of the linear systems in question. In the case when an acceleration technique is employed for the projected gradient method, this again yields a semismooth Newton method that is equivalent to the primal-dual active set method. We also consider the Moreau-Yosida regularization method for control constraints and efficient preconditioners for this technique. Numerical results illustrate the competitiveness of these approaches. © 2011 John Wiley & Sons, Ltd.

Big Bang Nucleosynthesis and Cosmological Constraints on Neutrino Oscillation Parameters

CERN Document Server

Kirilova, Daniela P; Kirilova, Daniela; Chizhov, Mihail

2001-01-01

We present a review of cosmological nucleosynthesis (CN) with neutrino oscillations, discussing the different effects of oscillations on CN, namely: increase of the effective degrees of freedom during CN, spectrum distortion of the oscillating neutrinos, neutrino number density depletion, and growth of neutrino-antineutrino asymmetry due to active-sterile oscillations. We discuss the importance of these effects for the primordial yield of helium-4. Primordially produced He-4 value is obtained in a selfconsistent study of the nucleons and the oscillating neutrinos. The effects of spectrum distortion, depletion and neutrino-antineutrino asymmetry growth on helium-4 production are explicitly calculated. An update of the cosmological constraints on active-sterile neutrino oscillations parameters is presented, giving the values: delta m^2 sin^8 (2 theta) 0, and |delta m^2| < 8.2 x 10^{-10} eV^2 at large mixing angles for delta m^2 < 0. According to these constraints, besides the active-sterile LMA solution,...

Preconditioning for partial differential equation constrained optimization with control constraints

KAUST Repository

Stoll, Martin; Wathen, Andy

2011-01-01

Optimal control problems with partial differential equations play an important role in many applications. The inclusion of bound constraints for the control poses a significant additional challenge for optimization methods. In this paper, we propose preconditioners for the saddle point problems that arise when a primal-dual active set method is used. We also show for this method that the same saddle point system can be derived when the method is considered as a semismooth Newton method. In addition, the projected gradient method can be employed to solve optimization problems with simple bounds, and we discuss the efficient solution of the linear systems in question. In the case when an acceleration technique is employed for the projected gradient method, this again yields a semismooth Newton method that is equivalent to the primal-dual active set method. We also consider the Moreau-Yosida regularization method for control constraints and efficient preconditioners for this technique. Numerical results illustrate the competitiveness of these approaches. © 2011 John Wiley & Sons, Ltd.

Research ethics and Institutional Review Boards. The influence of moral constraints on emotion research.

Science.gov (United States)

Sontag, Michael

2012-01-01

Researchers in the twenty-first century face a set of challenges unknown to researchers a half century ago--the need to justify the moral acceptability of their research methods through formal review processes. However, the role that moral constraints play in the development and demise of scientific theories has largely gone unappreciated. The rise of Institutional Review Boards (IRB) in the 1960s compounded the impact of moral constraints on scientific research and on the theories that develop out of such highly monitored research. To demonstrate the effects of moral constraints on scientific theory and research, this paper offers a history and analysis of the interaction between evolving moral standards and twentieth century emotion theory. Recommendations regarding IRB reform are also reviewed. The paper concludes by arguing that, while appropriate IRB reform is important, it cannot eliminate the need for careful reflection on the broader forces that shape scientific practice and understanding.

Evaluating Direct Manipulation Operations for Constraint-Based Layout

OpenAIRE

Zeidler , Clemens; Lutteroth , Christof; Stuerzlinger , Wolfgang; Weber , Gerald

2013-01-01

Part 11: Interface Layout and Data Entry; International audience; Layout managers are used to control the placement of widgets in graphical user interfaces (GUIs). Constraint-based layout managers are more powerful than other ones. However, they are also more complex and their layouts are prone to problems that usually require direct editing of constraints. Today, designers commonly use GUI builders to specify GUIs. The complexities of traditional approaches to constraint-based layouts pose c...

On the possible role of robustness in the evolution of infectious diseases

Science.gov (United States)

Ogbunugafor, C. Brandon; Pease, James B.; Turner, Paul E.

2010-06-01

Robustness describes the capacity for a biological system to remain canalized despite perturbation. Genetic robustness affords maintenance of phenotype despite mutational input, necessarily involving the role of epistasis. Environmental robustness is phenotypic constancy in the face of environmental variation, where epistasis may be uninvolved. Here we discuss genetic and environmental robustness, from the standpoint of infectious disease evolution, and suggest that robustness may be a unifying principle for understanding how different disease agents evolve. We focus especially on viruses with RNA genomes due to their importance in the evolution of emerging diseases and as model systems to test robustness theory. We present new data on adaptive constraints for a model RNA virus challenged to evolve in response to UV radiation. We also draw attention to other infectious disease systems where robustness theory may prove useful for bridging evolutionary biology and biomedicine, especially the evolution of antibiotic resistance in bacteria, immune evasion by influenza, and malaria parasite infections.

Optimal Portfolio Choice with Wash Sale Constraints

DEFF Research Database (Denmark)

Astrup Jensen, Bjarne; Marekwica, Marcel

2011-01-01

We analytically solve the portfolio choice problem in the presence of wash sale constraints in a two-period model with one risky asset. Our results show that wash sale constraints can heavily affect portfolio choice of investors with unrealized losses. The trading behavior of such investors...

Executive summary of imported infectious diseases after returning from foreign travel: Consensus document of the Spanish Society for Infectious Diseases and Clinical Microbiology (SEIMC).

Science.gov (United States)

Pérez-Arellano, José Luis; Górgolas-Hernández-Mora, Miguel; Salvador, Fernando; Carranza-Rodríguez, Cristina; Ramírez-Olivencia, Germán; Martín-Echeverría, Esteban; Rodríguez-Guardado, Azucena; Norman, Francesca; Velasco-Tirado, Virginia; Zubero-Sulibarría, Zuriñe; Rojo-Marcos, Gerardo; Muñoz-Gutierrez, José; Ramos-Rincón, José Manuel; Sánchez-Seco-Fariñas, M Paz; Velasco-Arribas, María; Belhassen-García, Moncef; Lago-Nuñez, Mar; Cañas García-Otero, Elías; López-Vélez, Rogelio

2018-03-01

In a global world, knowledge of imported infectious diseases is essential in daily practice, both for the microbiologist-parasitologist and the clinician who diagnoses and treats infectious diseases in returned travelers. Tropical and subtropical countries where there is a greater risk of contracting an infectious disease are among the most frequently visited tourist destinations. The SEIMC considers it appropriate to produce a consensus document that will be useful to primary care physicians as well as specialists in internal medicine, infectious diseases and tropical medicine who help treat travelers returning from tropical and sub-tropical areas with infections. Preventive aspects of infectious diseases and infections imported by immigrants are explicitly excluded here, since they have been dealt with in other SEIMC documents. Various types of professionals (clinicians, microbiologists, and parasitologists) have helped produce this consensus document by evaluating the available evidence-based data in order to propose a series of key facts about individual aspects of the topic. The first section of the document is a summary of some of the general aspects concerning the general assessment of travelers who return home with potential infections. The main second section contains the key facts (causative agents, diagnostic procedures and therapeutic measures) associated with the major infectious syndromes affecting returned travelers [gastrointestinal syndrome (acute or persistent diarrhea); febrile syndrome with no obvious source of infection; localized cutaneous lesions; and respiratory infections]. Finally, the characteristics of special traveler subtypes, such as pregnant women and immunocompromised travelers, are described. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Study of low energy thermal constraints for a copper-plated niobium structure carried out by thermal projection

International Nuclear Information System (INIS)

Gassot, H.; Durante, M.; Thiebault, A.; Vernay, E.

1999-06-01

In the framework of T.T.F. (Tesla Test Facility), the international collaboration on research and development of superconducting cavities, a study of a new method of manufacturing cavities was launched, which consists in deposing a metal (copper) or an alloy by thermal projection on niobium cavities in order to stiffen them. Analytical and numerical calculations showed that when cooled this bi-material cavities behave very differently in comparison with classical pure niobium cavities and strong thermal constraints do occur in niobium as well as in copper. These strong constraints may have important consequences upon the functioning of superconducting cavities. In addition these constraints may induce in time cracks in materials and interfaces. In this paper an experiment for measuring constraints at the temperature of cavity operation, i.e., at the liquid helium temperature, is proposed in order to compare the measured constraints with the calculated constraints. The sample studied has a cylindrical shape, rather representative for the geometrical shape of cavities, but easier to handle than a prototype cavity. The experimental approach consists in carrying out two deformation measurements. The first one, is done on single material sample (niobium and copper) to establish the laws of compensation of the constraint gauges as a function of temperature. The other measurement establishes the global deformations of a bi-metallic tube (Nb-Cu) when the interior surface (niobium) and the external surface (porous copper) of the tube are cooled. From these deformation data the thermal constraints of the bi-metallic tube at low temperature have been derived. The implementation of the entire setup of the methods of measuring the constraints at low temperature constitutes a new development in the field of superconducting cavities. The experiments have also indicated certain further developments which should be achieved if the plastic deformations induced by the freezing regime

Optimal capital stock and financing constraints

OpenAIRE

Saltari, Enrico; Giuseppe, Travaglini

2011-01-01

In this paper we show that financing constraints affect the optimal level of capital stock even when the financing constraint is ineffective. This happens when the firm rationally anticipates that access to external financing resources may be rationed in the future. We will show that with these expectations, the optimal investment policy is to invest less in any given period, thereby lowering the desired optimal capital stock in the long run.

Isocurvature constraints on portal couplings

Energy Technology Data Exchange (ETDEWEB)

Kainulainen, Kimmo; Nurmi, Sami; Vaskonen, Ville [Department of Physics, University of Jyväskylä, P.O.Box 35 (YFL), FI-40014 University of Jyväskylä (Finland); Tenkanen, Tommi; Tuominen, Kimmo, E-mail: kimmo.kainulainen@jyu.fi, E-mail: sami.t.nurmi@jyu.fi, E-mail: tommi.tenkanen@helsinki.fi, E-mail: kimmo.i.tuominen@helsinki.fi, E-mail: ville.vaskonen@jyu.fi [Department of Physics, University of Helsinki P.O. Box 64, FI-00014, Helsinki (Finland)

2016-06-01

We consider portal models which are ultraweakly coupled with the Standard Model, and confront them with observational constraints on dark matter abundance and isocurvature perturbations. We assume the hidden sector to contain a real singlet scalar s and a sterile neutrino ψ coupled to s via a pseudoscalar Yukawa term. During inflation, a primordial condensate consisting of the singlet scalar s is generated, and its contribution to the isocurvature perturbations is imprinted onto the dark matter abundance. We compute the total dark matter abundance including the contributions from condensate decay and nonthermal production from the Standard Model sector. We then use the Planck limit on isocurvature perturbations to derive a novel constraint connecting dark matter mass and the singlet self coupling with the scale of inflation: m {sub DM}/GeV ∼< 0.2λ{sub s}{sup 3/8} ( H {sub *}/10{sup 11} GeV){sup −3/2}. This constraint is relevant in most portal models ultraweakly coupled with the Standard Model and containing light singlet scalar fields.

Hemispheric symmetry of the Earth's Energy Balance as a fundamental constraint on the Earth's climate

Science.gov (United States)

Stephens, G. L.; Webster, P. J.; OBrien, D. M.

2013-12-01

We currently lack a quantitative understanding of how the Earth's energy balance and the poleward energy transport adjust to different forcings that determine climate change. Currently, there are no constraints that guide this understanding. We will demonstrate that the Earth's energy balance exhibits a remarkable symmetry about the equator, and that this symmetry is a necessary condition of a steady state climate. Our analysis points to clouds as the principal agent that highly regulates this symmetry and sets the steady state. The existence of this thermodynamic steady-state constraint on climate and the symmetry required to sustain it leads to important inferences about the synchronous nature of climate changes between hemispheres, offering for example insights on mechanisms that can sustain global ice ages forced by asymmetric hemispheric solar radiation variations or how climate may respond to increases in greenhouse gas concentration. Further inferences regarding cloud effects on climate can also be deduced without resorting to the complex and intricate processes of cloud formation, whose representation continues to challenge the climate modeling community. The constraint suggests cloud feedbacks must be negative buffering the system against change. We will show that this constraint doesn't exist in the current CMIP5 model experiments and the lack of such a constraint suggests there is insufficient buffering in models in response to external forcings

Network Design with Node Degree Balance Constraints

DEFF Research Database (Denmark)

Pedersen, Michael Berliner; Crainic, Teodor Gabriel

This presentation discusses an extension to the network design model where there in addition to the flow conservation constraints also are constraints that require design conservation. This means that the number of arcs entering and leaving a node must be the same. As will be shown the model has ...

Constraint solving for direct manipulation of features

NARCIS (Netherlands)

Lourenco, D.; Oliveira, P.; Noort, A.; Bidarra, R.

2006-01-01

In current commercial feature modeling systems, support for direct manipulation of features is not commonly available. This is partly due to the strong reliance of such systems on constraints, but also to the lack of speed of current constraint solvers. In this paper, an approach to the optimization

South Asian people and heart disease: an assessment of the importance of socioeconomic position.

Science.gov (United States)

Nazroo, J Y

2001-01-01

Higher rates of mortality from ischemic heart disease among South Asian people are well established and appear to be unrelated to socioeconomic position. However, traditional indicators of socioeconomic position may be inadequate when making comparisons across ethnic groups. This study investigates these issues in a British morbidity survey. The Fourth National Survey was a British cross-sectional study conducted from 1993 to 1994. The study used a national representative community sample, consisting of 2867 white respondents, 2001 Indian respondents, and 1776 Pakistani and Bangladeshi respondents. Data on occupational class and standard of living were used to examine the contribution of socioeconomic factors to differences in rates of reported severe chest pain and diagnosed heart disease. White and Indian respondents had similar rates of reported indicators of heart disease, while Pakistani and Bangladeshi respondents had rates that were considerably higher. There was a clear socioeconomic gradient in reported heart disease for each ethnic group, with those who were poorer having higher rates. Controlling for occupational class made little difference to the greater risk of heart disease found in the Pakistani and Bangladeshi group; however, controlling for a more sensitive indicator of socioeconomic position-standard of living-greatly reduced their disproportionate risk. The findings suggest that South Asian people do not share a uniformly greater risk of heart disease. The more economically advantaged South Asian group, Indians, had rates that are similar to those found among white people, while the poorest groups, Pakistanis and Bangladeshis, had rates that are considerably higher. Socioeconomic position predicted risk in each ethnic group and made a key contribution to the higher risk found for Pakistani and Bangladeshi individuals. Other studies may have failed to identify the important contribution of socioeconomic position because the indicators used were

Constraint processing in our extensible language for cooperative imaging system

Science.gov (United States)

Aoki, Minoru; Murao, Yo; Enomoto, Hajime

1996-02-01

The extensible WELL (Window-based elaboration language) has been developed using the concept of common platform, where both client and server can communicate with each other with support from a communication manager. This extensible language is based on an object oriented design by introducing constraint processing. Any kind of services including imaging in the extensible language is controlled by the constraints. Interactive functions between client and server are extended by introducing agent functions including a request-respond relation. Necessary service integrations are satisfied with some cooperative processes using constraints. Constraints are treated similarly to data, because the system should have flexibilities in the execution of many kinds of services. The similar control process is defined by using intentional logic. There are two kinds of constraints, temporal and modal constraints. Rendering the constraints, the predicate format as the relation between attribute values can be a warrant for entities' validity as data. As an imaging example, a processing procedure of interaction between multiple objects is shown as an image application for the extensible system. This paper describes how the procedure proceeds in the system, and that how the constraints work for generating moving pictures.

Risk activities and pre-travel health seeking practices of notified cases of imported infectious diseases in Australia.

Science.gov (United States)

Paudel, Prakash; Raina, C; Zwar, Nicholas; Seale, Holly; Worth, Heather; Sheikh, Mohamud; Heywood, Anita E

2017-09-01

Travellers are at risk of acquiring infectious diseases during travel, with risks differing by destination, travel and traveller characteristics. A pre-travel health consultation may minimize this risk. However, uptake of pre-travel health advice remains low. We investigated pre-travel health preparations and disease-specific risk behaviours among notified cases of selected travel-associated infectious diseases imported into Australia. Prospective enhanced surveillance of notified cases of typhoid, paratyphoid, measles, hepatitis A, hepatitis E, malaria and chikungunya was conducted in two Australian states between February 2013 and January 2014. Details of pre-travel health preparation and disease-specific risk behaviours were collected. Among 180 cases associated with international travel, 28% were travellers and 22% were frequent travellers, having travelled ≥5 times in the past 5 years. 25% had sought pre-travel advice from a healthcare provider, and 16% reported a pre-travel vaccine. Seeking pre-travel health advice did not differ by immigrant status ( P  = 0.22) or by reason for travel ( P  = 0.13) but was more commonly sought by first time travellers ( P  = 0.03). Travellers visiting friends and relatives were more likely to report at-risk activities of brushing teeth with tap water ( P  food ( P  = 0.03) during travel compared to other travellers. Pre-travel health advice seeking practices and vaccine uptake was suboptimal among cases of notified disease. The results of this study highlight the need for a better understanding of barriers to pre-travel health seeking, particularly among high risk travellers, to reduce the importation of infectious diseases into Australia. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Monitoring emerging diseases of fish and shellfish using electronic sources.

Science.gov (United States)

Thrush, M A; Dunn, P L; Peeler, E J

2012-10-01

New and emerging fish and shellfish diseases represent an important constraint to the growth and sustainability of many aquaculture sectors and have also caused substantial economic and environmental impacts in wild stocks. This paper details the results of 8 years of a monitoring programme for emerging aquatic animal diseases reported around the world. The objectives were to track global occurrences and, more specifically, to identify and provide advanced warning of disease threats that may affect wild and farmed fish stocks in the UK. A range of electronic information sources, including Internet newsletters, alerting services and news agency releases, was systematically searched for reports of new diseases, new presentations of known pathogens and known diseases occurring in new geographic locations or new host species. A database was established to log the details of key findings, and 250 emerging disease events in 52 countries were recorded during the period of study. These included 14 new diseases and a further 16 known diseases in new species. Viruses and parasites accounted for the majority of reports (55% and 24%, respectively), and known diseases occurring in new locations were the most important emerging disease category (in which viruses were dominant). Emerging diseases were reported disproportionally in salmonid species (33%), in farmed populations (62%) and in Europe and North America (80%). The lack of reports from some regions with significant aquaculture or fishery production may indicate that emerging diseases are not being recognized in these areas owing to insufficient surveillance or testing or that these events are being under-reported. The results are discussed in relation to processes underpinning disease emergence in the aquatic environment. © 2011 Crown Copyright. Reproduced with the permission of the Controller of Her Majesty’s Stationery Office and Centre for Environment Fisheries & Aquaculture Science.

Constraints in distortion-invariant target recognition system simulation

Science.gov (United States)

Iftekharuddin, Khan M.; Razzaque, Md A.

2000-11-01

Automatic target recognition (ATR) is a mature but active research area. In an earlier paper, we proposed a novel ATR approach for recognition of targets varying in fine details, rotation, and translation using a Learning Vector Quantization (LVQ) Neural Network (NN). The proposed approach performed segmentation of multiple objects and the identification of the objects using LVQNN. In this current paper, we extend the previous approach for recognition of targets varying in rotation, translation, scale, and combination of all three distortions. We obtain the analytical results of the system level design to show that the approach performs well with some constraints. The first constraint determines the size of the input images and input filters. The second constraint shows the limits on amount of rotation, translation, and scale of input objects. We present the simulation verification of the constraints using DARPA's Moving and Stationary Target Recognition (MSTAR) images with different depression and pose angles. The simulation results using MSTAR images verify the analytical constraints of the system level design.

Brain evolution and development: adaptation, allometry and constraint

Science.gov (United States)

Barton, Robert A.

2016-01-01

Phenotypic traits are products of two processes: evolution and development. But how do these processes combine to produce integrated phenotypes? Comparative studies identify consistent patterns of covariation, or allometries, between brain and body size, and between brain components, indicating the presence of significant constraints limiting independent evolution of separate parts. These constraints are poorly understood, but in principle could be either developmental or functional. The developmental constraints hypothesis suggests that individual components (brain and body size, or individual brain components) tend to evolve together because natural selection operates on relatively simple developmental mechanisms that affect the growth of all parts in a concerted manner. The functional constraints hypothesis suggests that correlated change reflects the action of selection on distributed functional systems connecting the different sub-components, predicting more complex patterns of mosaic change at the level of the functional systems and more complex genetic and developmental mechanisms. These hypotheses are not mutually exclusive but make different predictions. We review recent genetic and neurodevelopmental evidence, concluding that functional rather than developmental constraints are the main cause of the observed patterns. PMID:27629025

Sustainability constraints on UK bioenergy development

International Nuclear Information System (INIS)

Thornley, Patricia; Upham, Paul; Tomei, Julia

2009-01-01

Use of bioenergy as a renewable resource is increasing in many parts of the world and can generate significant environmental, economic and social benefits if managed with due regard to sustainability constraints. This work reviews the environmental, social and economic constraints on key feedstocks for UK heat, power and transport fuel. Key sustainability constraints include greenhouse gas savings achieved for different fuels, land availability, air quality impacts and facility siting. Applying those constraints, we estimate that existing technologies would facilitate a sustainability constrained level of medium-term bioenergy/biofuel supply to the UK of 4.9% of total energy demand, broken down into 4.3% of heat demands, 4.3% of electricity, and 5.8% of transport fuel. This suggests that attempts to increase the supply above these levels could have counterproductive sustainability impacts in the absence of compensating technology developments or identification of additional resources. The barriers that currently prevent this level of supply being achieved have been analysed and classified. This suggests that the biggest policy impacts would be in stimulating the market for heat demand in rural areas, supporting feedstock prices in a manner that incentivised efficient use/maximum greenhouse gas savings and targeting investment capital that improves yield and reduces land-take.

Serious Leisure and People with Orthopedic Impairment: Benefits and Constraints

OpenAIRE

Manolya AKSATAN; Zehra Gökçe SEL

2017-01-01

There are many people around the world who have different types of disabilities. Understanding their needs is the first step of developing policies to increase their quality of life and satisfaction. Leisure is an essential need of disabled people and it plays an important role in disabled people’s lives. The purpose of this study is to gain a deep understanding on the serious leisure activities of people with orthopedic impairment, and also both benefits and constraints ...

Nonlinear Model Predictive Control with Constraint Satisfactions for a Quadcopter

Science.gov (United States)

Wang, Ye; Ramirez-Jaime, Andres; Xu, Feng; Puig, Vicenç

2017-01-01

This paper presents a nonlinear model predictive control (NMPC) strategy combined with constraint satisfactions for a quadcopter. The full dynamics of the quadcopter describing the attitude and position are nonlinear, which are quite sensitive to changes of inputs and disturbances. By means of constraint satisfactions, partial nonlinearities and modeling errors of the control-oriented model of full dynamics can be transformed into the inequality constraints. Subsequently, the quadcopter can be controlled by an NMPC controller with the updated constraints generated by constraint satisfactions. Finally, the simulation results applied to a quadcopter simulator are provided to show the effectiveness of the proposed strategy.

Lorentz violation. Motivation and new constraints

Energy Technology Data Exchange (ETDEWEB)

Liberati, S. [Scuola Internazionale Superiore di Studi Avanzati SISSA, Trieste (Italy); Istituto Nazionale di Fisica Nucleare INFN, Sezione di Trieste (Italy); Maccione, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2009-09-15

We review the main theoretical motivations and observational constraints on Planck scale sup-pressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework of Effective Field Theory, describing several possible ways of including Lorentz violation therein and discussing their theoretical viability. We review the main low energy effects that are expected in this framework. We discuss the current observational constraints on such a framework, focusing on those achievable through high-energy astrophysics observations. In this context we present a summary of the most recent and strongest constraints on QED with Lorentz violating non-renormalizable operators. Finally, we discuss the present status of the field and its future perspectives. (orig.)

Lorentz violation. Motivation and new constraints

International Nuclear Information System (INIS)

Liberati, S.; Maccione, L.

2009-09-01

We review the main theoretical motivations and observational constraints on Planck scale sup-pressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework of Effective Field Theory, describing several possible ways of including Lorentz violation therein and discussing their theoretical viability. We review the main low energy effects that are expected in this framework. We discuss the current observational constraints on such a framework, focusing on those achievable through high-energy astrophysics observations. In this context we present a summary of the most recent and strongest constraints on QED with Lorentz violating non-renormalizable operators. Finally, we discuss the present status of the field and its future perspectives. (orig.)

Millennium development goals: Examining Kenya constraints in achieving the eight goals

Directory of Open Access Journals (Sweden)

Wambua Leonard Munyao

2013-06-01

Full Text Available This paper examines Kenya’s performance in achieving the famous millennium development goals. The paper provides the government and other stakeholders with proper understanding of the constraints of achieving the millennium development goals as well as reflecting the phase and the passion of the country in achieving this important development goal. The paper further seeks to stress the importance of this goal in reducing poverty in the country. The paper has cited some key factors undermining achieving of the millennium development goals in Kenya. Major recommendations that can contribute towards achieving of the millennium development goals have also been made.

Mapping the developmental constraints on working memory span performance.

Science.gov (United States)

Bayliss, Donna M; Jarrold, Christopher; Baddeley, Alan D; Gunn, Deborah M; Leigh, Eleanor

2005-07-01

This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related variance in complex span. Results showed that developmental improvements in complex span were driven by 2 age-related but separable factors: 1 associated with general speed of processing and 1 associated with storage ability. In addition, there was an age-related contribution shared between working memory, processing speed, and storage ability that was important for higher level cognition. These results pose a challenge for models of complex span performance that emphasize the importance of processing speed alone.

Imports, exports, and Alberta's transmission system impact on price fluctuation

International Nuclear Information System (INIS)

Johnson, K.

2002-01-01

The roles, responsibilities and objectives of ESBI, a private for-profit company, appointed by the Alberta Government to be the Independent Transmission Administrator in the province, is sketched, prior to a discussion of price volatility in electricity, Alberta interconnections, intertie issues, the economic theory and the reality impact on prices. Given that imports and exports constitute a relatively small proportion of total generation or load in Alberta, price volatility is considered to have been only minimally affected by imports/exports. In contrast, transmission constraints, i.e. the limits on physical capacity of the existing transmission system to accommodate all desired transactions, have significant impact on imports/exports. Factors underlying constraints and price volatility such as uncertainty of generation dispatch, leading to reduced interest to invest, which in turn leads to scarce capacity for imports/exports, and the actions required to reduce uncertainty and address other issues such as congestion management, tariff design and the creation of regional transmission organizations, are also discussed to provide further clarification of the issues. It is suggested that these and other related issues need to be resolved to provide the clarity around transmission access and the tools required to manage price fluctuations

Renal function trajectory is more important than chronic kidney disease stage for managing patients with chronic kidney disease.

Science.gov (United States)

Rosansky, Steven J

2012-01-01

Management of patients with chronic kidney disease (CKD) emphasizes a current level of function as calculated from the modification of diet in renal disease glomerulofiltration rate equations (eGFR) and proteinuria for staging of CKD. Change in a patient's eGFR over time (renal function trajectory) is an additional and potentially more important consideration in deciding which patients will progress to the point where they will require renal replacement therapy (RRT). Many patients with CKD 3-5 have stable renal function for years. Proteinuria/albuminuria is a primary determinant of renal trajectory which may be slowed by medications that decrease proteinuria and/or aggressively lower blood pressure. A renal trajectory of >3 ml/min/1.73 m(2)/year may relate to a need for closer renal follow-up and increased morbidity and mortality. Additional CKD population-based studies need to examine the relationship of renal trajectory to: baseline renal function; acute kidney injury episodes; age, race, sex and primary etiologies of renal disease; blood pressure control and therapies; dietary protein intake; blood glucose control in diabetics and the competitive risk of death versus the requirement for renal replacement therapy. In the elderly CKD 4 population with significant comorbidities and slow decline in renal function, the likelihood of death prior to the need for RRT should be considered before placing AV access for dialysis. Prediction models of renal progression must account for the competitive risk of death as well as stable or improved renal function to be clinically useful. Copyright © 2012 S. Karger AG, Basel.

Cognitive constraints on high school students' representations of real environmental problems

Science.gov (United States)

Barnes, Ervin Kenneth

One class of juniors and seniors was studied through one semester in the investigation of how students think about, learn from, and solve real environmental problems. The intention was to listen to student voices while researching the features of their representations of these problems, the beliefs they held (tenets), the cognitive processes they employed, and the principles of science, ecology, problem solving, and ethics they held as tenets. The focus was upon two self-selected groups as they perceived, engaged, analyzed, and proposed solutions for problems. Analysis of the student representations involved interpretation of the features to include both the perspective tenets and the envisioning processes. These processes included the intentive and attentive constraints as tenet acquisition and volitive and agential constraints as tenet affirmation. The perspective tenets included a variety of conceptual (basic science, ecological, ethical, and problem-solving) constraints as well as ontological, epistemological, and other cultural (role, status, power, and community) constraints. The perspective tenets were interpreted thematically including the ways populations of people cause and care about environmental problems, the magnitude of environmental problems and the science involved, the expectations and limitations students perceive for themselves, and the importance of community awareness and cooperation to addressing these problems. Some of these tenets were interpreted to be principles in that they were rules that were accepted by some people as true. The perspective tenets, along with the envisioning processes, were perceived to be the constraints that determined the environmental problems and limited the solution possibilities. The students thought about environmental problems in mature and principled ways using a repertoire of cognitive processes. They learned from them as they acquired and affirmed tenets. They solved them through personal choices and

Pension fund's illiquid assets allocation under liquidity and capital constraints

OpenAIRE

Broeders, Dirk; Jansen, Kristy; Werker, Bas

2017-01-01

This paper empirically assesses the impact of liquidity and capital constraints on the allocation of defined benefit pension funds to illiquid assets. Liquidity constraints result from short-term pension payments and collateral requirements on derivatives. Capital constraints follow from the requirement to retain sufficient capital to absorb unexpected losses. Liability duration and hedging affect the allocation to illiquid assets through both these constraints. First, we find a hump-shaped i...

A note on migration with borrowing constraints.

Science.gov (United States)

Ghatak, S; Levine, P

1994-12-01

"This note examines an important conflict between the theory and evidence on migration in LDCs. While the Harris-Todaro class of models explain the phenomenon of migration mainly by expected income differential between the economically advanced and the backward regions, the actual evidence in some cases suggests that migration could actually rise following a rise in income in backward areas. We resolve this puzzle by analysing migration in the context of the existence of imperfect credit markets in LDCs. We show that under certain plausible conditions, the rate of migration from the rural to the urban areas may actually rise when rural wages rise, as they ease the constraints on borrowing by potential migrants." excerpt

Distribution system constraints and their impact on distributed generation: final report

Energy Technology Data Exchange (ETDEWEB)

Thornycroft, J.; Caisley, A.; Russell, T.; Willis, S.; Youssef, R.; Bawden, R.; Holden, G.; Williams, J.

2004-05-01

This report examines constraints due to the connection of distributed generators to the distribution network focusing on small generators with the aim of developing technical and economic models to examine the relationship between the initial investment and the ensuing cost of the constraints under different scenarios. Constraints are defined as limitations to operation of connected generators, and the types of constraints, and the allocation of reinforcement and constraint costs are considered. Details are given of the modeling of sections of urban, rural and semi-rural network at Faversham, and the current constraints on this network are described.

Understanding the leisure constraints of Hispanic-Americans in Northern Virginia: an exploratory analysis of constraints, socioeconomic status and acculturation

Science.gov (United States)

Edward F, II Byrne; Ellen B. Drogin Rodgers

2003-01-01

The purpose of this study is to investigate the constraints to use of outdoor recreation resources and participation in leisure activities among Hispanic restaurant workers in Northern Virginia; specifically, the relationship of socioeconomic status and acculturation to leisure constraints. The dramatic rate of increase of Hispanic-Americans, the group's low...

[Alzheimer's disease, the importance of the choice of words].

Science.gov (United States)

Stefanuto, Muriel; Canovas, Stéphane; Khaddar, Marie; Sanchez, Stéphane; Denormandie, Philippe

The terms 'dementia' and 'demented' are frequently used to refer to people with neurodegenerative diseases, such as Alzheimer's disease. Based on the cross-analysis of some observational data (historical, linguistic, legal and medical), it is possible to highlight the risks and the issues related to the terminological choices for patients and health professionals. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Self-Imposed Creativity Constraints

DEFF Research Database (Denmark)

Biskjaer, Michael Mose

2013-01-01

Abstract This dissertation epitomizes three years of research guided by the research question: how can we conceptualize creative self-binding as a resource in art and design processes? Concretely, the dissertation seeks to offer insight into the puzzling observation that highly skilled creative...... practitioners sometimes freely and intentionally impose rigid rules, peculiar principles, and other kinds of creative obstructions on themselves as a means to spur momentum in the process and reach a distinctly original outcome. To investigate this the dissertation is composed of four papers (Part II) framed...... of analysis. Informed by the insight that constraints both enable and restrain creative agency, the dissertation’s main contention is that creative self- binding may profitably be conceptualized as the exercise of self-imposed creativity constraints. Thus, the dissertation marks an analytical move from vague...

Distance Constraint Satisfaction Problems

Science.gov (United States)

Bodirsky, Manuel; Dalmau, Victor; Martin, Barnaby; Pinsker, Michael

We study the complexity of constraint satisfaction problems for templates Γ that are first-order definable in ({ Z}; {suc}), the integers with the successor relation. Assuming a widely believed conjecture from finite domain constraint satisfaction (we require the tractability conjecture by Bulatov, Jeavons and Krokhin in the special case of transitive finite templates), we provide a full classification for the case that Γ is locally finite (i.e., the Gaifman graph of Γ has finite degree). We show that one of the following is true: The structure Γ is homomorphically equivalent to a structure with a certain majority polymorphism (which we call modular median) and CSP(Γ) can be solved in polynomial time, or Γ is homomorphically equivalent to a finite transitive structure, or CSP(Γ) is NP-complete.

A hierarchical procedure for calculation of risk importance measures

International Nuclear Information System (INIS)

Poern, K.; Dinsmore, S.C.

1987-01-01

Starting with a general importance definition based on conditional probabilities, a hierarchical process for calculating risk importance measures from a PSA's numerical results is developed. By the appropriate choice of events in the general definition, measures such as the risk achievement worth and the risk reduction worth can be calculated without requantifying the PSA's models. Required approximations are clearly defined and the subsequent constraints on the applicability of the process discussed. (orig.)

Canonical and D-transformations in Theories with Constraints

OpenAIRE

Gitman, Dmitri M.

1995-01-01

A class class of transformations in a super phase space (we call them D-transformations) is described, which play in theories with second-class constraints the role of ordinary canonical transformations in theories without constraints.

Constraints of chromoelectric dipole moments to natural SUSY type sfermion spectrum

Science.gov (United States)

Maekawa, Nobuhiro; Muramatsu, Yu; Shigekami, Yoshihiro

2017-06-01

We investigate the lower bounds of sfermion masses from the constraints of chromoelectric dipole moments (CEDMs) in the natural SUSY-type sfermion mass spectrum, in which stop mass mt ˜ is much smaller than the other sfermion masses m0. The natural SUSY-type sfermion mass spectrum has been studied since the supersymmetric (SUSY) flavor-changing neutral currents (FCNC) are suppressed because of large sfermion masses of the first two generations, and the weak scale is stabilized because of the light stop. However, this type of sfermion mass spectrum is severely constrained by CEDM, because the light stop contributions to the up quark CEDM are not decoupled in the limit m0→∞ , while the down quark CEDM is decoupled in the limit. It is important that the constraints are severe even if SUSY-breaking parameters (and Higgsino mass) are taken to be real because complex diagonalizing matrices of Yukawa matrices, which are from complex Yukawa couplings, generate nonvanishing C P phases in off-diagonal elements of sfermion mass matrices. We calculate the CEDM of up and down quarks numerically in the minimal SUSY standard model, and give the lower bounds for stop mass and the other sfermion masses. We show that the lower bound of stop mass becomes 7 TeV to satisfy the CEDM constraints from Hg EDM. The result is not acceptable if the weak scale stability is considered seriously. We show that if the up-type Yukawa couplings are taken to be real at the grand unification scale, the CEDM constraints are satisfied even if mt ˜˜1 TeV .

Magnetic Pair Creation Attenuation Altitude Constraints in Gamma-Ray Pulsars

Science.gov (United States)

Baring, Matthew; Story, Sarah

The Fermi gamma-ray pulsar database now exceeds 150 sources and has defined an important part of Fermi's science legacy, providing rich information for the interpretation of young energetic pulsars and old millisecond pulsars. Among the well established population characteristics is the common occurrence of exponential turnovers in the 1-10 GeV range. These turnovers are too gradual to arise from magnetic pair creation in the strong magnetic fields of pulsar inner magnetospheres, so their energy can be used to provide lower bounds to the typical altitude of GeV band emission. We explore such constraints due to single-photon pair creation transparency at and below the turnover energy. Our updated computations span both domains when general relativistic influences are important and locales where flat spacetime photon propagation is modified by rotational aberration effects. The altitude bounds, typically in the range of 2-5 stellar radii, provide key information on the emission altitude in radio quiet pulsars that do not possess double-peaked pulse profiles. However, the exceptional case of the Crab pulsar provides an altitude bound of around 20% of the light cylinder radius if pair transparency persists out to 350 GeV, the maximum energy detected by MAGIC. This is an impressive new physics-based constraint on the Crab's gamma-ray emission locale.

Exploring the Impact of Early Decisions in Variable Ordering for Constraint Satisfaction Problems

Directory of Open Access Journals (Sweden)

José Carlos Ortiz-Bayliss

2018-01-01

Full Text Available When solving constraint satisfaction problems (CSPs, it is a common practice to rely on heuristics to decide which variable should be instantiated at each stage of the search. But, this ordering influences the search cost. Even so, and to the best of our knowledge, no earlier work has dealt with how first variable orderings affect the overall cost. In this paper, we explore the cost of finding high-quality orderings of variables within constraint satisfaction problems. We also study differences among the orderings produced by some commonly used heuristics and the way bad first decisions affect the search cost. One of the most important findings of this work confirms the paramount importance of first decisions. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. We propose a simple method to improve early decisions of heuristics. By using it, performance of heuristics increases.

Exploring the Impact of Early Decisions in Variable Ordering for Constraint Satisfaction Problems.

Science.gov (United States)

Ortiz-Bayliss, José Carlos; Amaya, Ivan; Conant-Pablos, Santiago Enrique; Terashima-Marín, Hugo

2018-01-01

When solving constraint satisfaction problems (CSPs), it is a common practice to rely on heuristics to decide which variable should be instantiated at each stage of the search. But, this ordering influences the search cost. Even so, and to the best of our knowledge, no earlier work has dealt with how first variable orderings affect the overall cost. In this paper, we explore the cost of finding high-quality orderings of variables within constraint satisfaction problems. We also study differences among the orderings produced by some commonly used heuristics and the way bad first decisions affect the search cost. One of the most important findings of this work confirms the paramount importance of first decisions. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. Another one is the evidence that many of the existing variable ordering heuristics fail to appropriately select the first variable to instantiate. We propose a simple method to improve early decisions of heuristics. By using it, performance of heuristics increases.

The Issue of Unit Constraints and the Non-Confiscatory Electricity Market

DEFF Research Database (Denmark)

Haji Bashi, Mazaher; Rahmati, Iman; Bak, Claus Leth

2017-01-01

Security constraint unit commitment is devised to drive the generation unit schedule in a deregulated environment. Generation bids, transmission system constraints and generation unit constraints are thoroughly considered in this optimization problem. It is acceptable that the transmission system...... normal condition constraints may affect the economic opportunities of the generation companies in the electricity market. Transmission system limitations are the inherent limits of the market environment but this is not true for the generation unit constraints. It means that the generation unit...... constraint of a certain player should not affect the economic opportunities of the rivals. If this happen, generation units can claim to the electricity market regulatory board. In this paper the effect of generation unit constraint on the market outcome is discussed. A fair mechanism is introduced in which...

Pension fund's illiquid assets allocation under liquidity and capital constraints

NARCIS (Netherlands)

Broeders, Dirk; Jansen, Kristy; Werker, Bas

2017-01-01

This paper empirically assesses the impact of liquidity and capital constraints on the allocation of defined benefit pension funds to illiquid assets. Liquidity constraints result from short-term pension payments and collateral requirements on derivatives. Capital constraints follow from the

Effective constraint algebras with structure functions

International Nuclear Information System (INIS)

Bojowald, Martin; Brahma, Suddhasattwa

2016-01-01

This article presents the result that fluctuations and higher moments of a state, by themselves, do not imply quantum corrections in structure functions of constrained systems. Moment corrections are isolated from other types of quantum effects, such as factor-ordering choices and regularization, by introducing a new condition with two parts: (i) having a direct (or faithful) quantization of the classical structure functions, (ii) free of factor-ordering ambiguities. In particular, it is assumed that the classical constraints can be quantized in an anomaly free way, so that properties of the resulting constraint algebras can be derived. If the two-part condition is not satisfied, effective constraints can still be evaluated, but quantum effects may be stronger. Consequences for canonical quantum gravity, whose structure functions encode space–time structure, are discussed. In particular, deformed algebras found in models of loop quantum gravity provide reliable information even in the Planck regime. (paper)

WMAP constraints on the Cardassian model

International Nuclear Information System (INIS)

Sen, A.A.; Sen, S.

2003-01-01

We investigate the constraints on the Cardassian model using the recent results from the Wilkinson microwave anisotropy probe for the locations of the peaks of the cosmic microwave background (CMB) anisotropy spectrum. We find that the model is consistent with the recent observational data for a certain range of the model parameter n and the cosmological parameters. We find that the Cardassian model is favored compared to the ΛCDM model for a higher spectral index (n s ≅1) together with a lower value of the Hubble parameter h (h≤0.71). But for smaller values of n s , both ΛCDM and Cardassian models are equally favored. Also, irrespective of supernova constraints, CMB data alone predict the current acceleration of the Universe in this model. We have also studied the constraint on σ 8 , the rms density fluctuations at the 8h -1 Mpc scale

New constraint of clustering for AMD and its application to the study of the 2α-12C structure of 20Ne

International Nuclear Information System (INIS)

Taniguchi, Yasutaka; Horiuchi, Hisashi; Kimura, Masaaki

2004-01-01

A new constraint of clustering for the AMD calculation is proposed. This constraint yield a significant improvement in the investigation of the cluster structure using AMD, which sometimes meets with difficulty in producing certain specific cluster configuration. The usefulness of this constraint is verified by applying it to the study of the K π = 0 3 + band of 20 Ne, which has been conjectured to have 2α- 12 C structure. This band is not easy to construct with AMD. We show that the constraint in the AMD + GCM calculation is effective for the purpose of obtaining the K π 0 3 + band, which contains the 2α- 12 C structure as an important component. (author)

A combined constraint handling framework: an empirical study

DEFF Research Database (Denmark)

Si, Chengyong; Hu, Junjie; Lan, Tian

2017-01-01

This paper presents a new combined constraint handling framework (CCHF) for solving constrained optimization problems (COPs). The framework combines promising aspects of different constraint handling techniques (CHTs) in different situations with consideration of problem characteristics. In order...

Inflammatory pathways of importance for management of inflammatory bowel disease.

Science.gov (United States)

Pedersen, Jannie; Coskun, Mehmet; Soendergaard, Christoffer; Salem, Mohammad; Nielsen, Ole Haagen

2014-01-07

Inflammatory bowel disease (IBD) is a group of chronic disorders of the gastrointestinal tract comprising Crohn's disease (CD) and ulcerative colitis (UC). Their etiologies are unknown, but they are characterised by an imbalanced production of pro-inflammatory mediators, e.g., tumor necrosis factor (TNF)-α, as well as increased recruitment of leukocytes to the site of inflammation. Advantages in understanding the role of the inflammatory pathways in IBD and an inadequate response to conventional therapy in a large portion of patients, has over the last two decades lead to new therapies which includes the TNF inhibitors (TNFi), designed to target and neutralise the effect of TNF-α. TNFi have shown to be efficient in treating moderate to severe CD and UC. However, convenient alternative therapeutics targeting other immune pathways are needed for patients with IBD refractory to conventional therapy including TNFi. Indeed, several therapeutics are currently under development, and have shown success in clinical trials. These include antibodies targeting and neutralising interleukin-12/23, small pharmacologic Janus kinase inhibitors designed to block intracellular signaling of several pro-inflammatory cytokines, antibodies targeting integrins, and small anti-adhesion molecules that block adhesion between leukocytes and the intestinal vascular endothelium, reducing their infiltration into the inflamed mucosa. In this review we have elucidated the major signaling pathways of clinical importance for IBD therapy and highlighted the new promising therapies available. As stated in this paper several new treatment options are under development for the treatment of CD and UC, however, no drug fits all patients. Hence, optimisations of treatment regimens are warranted for the benefit of the patients either through biomarker establishment or other rationales to maximise the effect of the broad range of mode-of-actions of the present and future drugs in IBD.

Design with Nonlinear Constraints

KAUST Repository

Tang, Chengcheng

2015-01-01

. The first application is the design of meshes under both geometric and static constraints, including self-supporting polyhedral meshes that are not height fields. Then, with a formulation bridging mesh based and spline based representations, the application

Nucleon Edm from Atomic Systems and Constraints on Supersymmetry Parameters

OpenAIRE

Oshima, Sachiko; Nihei, Takeshi; Fujita, Takehisa

2005-01-01

The nucleon EDM is shown to be directly related to the EDM of atomic systems. From the observed EDM values of the atomic Hg system, the neutron EDM can be extracted, which gives a very stringent constraint on the supersymmetry parameters. It is also shown that the measurement of Nitrogen and Thallium atomic systems should provide important information on the flavor dependence of the quark EDM. We perform numerical analyses on the EDM of neutron, proton and electron in the minimal supersymmetr...

A constraint-based bottom-up counterpart to definite clause grammars

DEFF Research Database (Denmark)

Christiansen, Henning

2004-01-01

A new grammar formalism, CHR Grammars (CHRG), is proposed that provides a constraint-solving approach to language analysis, built on top of the programming language of Constraint Handling Rules in the same way as Definite Clause Grammars (DCG) on Prolog. CHRG works bottom-up and adds the following......, integrity constraints, operators a la assumption grammars, and to incorporate other constraint solvers. (iv)~Context-sensitive rules that apply for disambiguation, coordination in natural language and tagger-like rules....

Some technical constraints on possible Tokamak machines from next generation to reactor size

International Nuclear Information System (INIS)

Knobloch, A.

1975-11-01

A simplified consistent scaling of possible Tokamak reactors is set up in the power range of 0.1 - 10 GW. The influence of some important parameters on the scaling is shown and the role of some technical constraints is discussed. The scaling is evaluated for the two cases of a circular and a strongly elongated plasma section. (orig.) [de

OPTIMAL CONFIGURATION OF A COMMAND AND CONTROL NETWORK: BALANCING PERFORMANCE AND RECONFIGURATION CONSTRAINTS

Energy Technology Data Exchange (ETDEWEB)

L. DOWELL

1999-08-01

The optimization of the configuration of communications and control networks is important for assuring the reliability and performance of the networks. This paper presents techniques for determining the optimal configuration for such a network in the presence of communication and connectivity constraints. reconfiguration to restore connectivity to a data-fusion network following the failure of a network component.

Towards livestock disease diagnosis and control in the 21st century. Proceedings of an international symposium

International Nuclear Information System (INIS)

1998-01-01

Livestock diseases remain a key constraint to livestock production in developing countries. Diseases like rinderpest, foot-and-mouth disease, brucellosis, trypanosomosis, tick borne diseases such as anaplasmosis, heartwater and East Coast fever, contagious bovine pleuropneumonia and Newcastle disease have caused great economic losses in various parts of the world. The control, and ultimate eradication where possible, of these and other diseases is important for the economies of many nations. It is for this reason that both the IAEA and the FAO have put great emphasis on the control and eradication of livestock diseases. The success of any disease control or eradication programme relies heavily on the robustness and efficacy of tile diagnosis, surveillance or seromonitoring method or methods being used. Nuclear based and related techniques such as enzyme linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) have played and continue to play a vital role in this regard. The aim of this symposium is to review existing and emerging techniques used in disease diagnosis and control and to carefully put them in context for use in developing countries in the future

Financial constraint and R&D investment: evidence from CIS

OpenAIRE

Tiwari, A.K.; Mohnen, P.; Palm, F.C.; Schim van der Loeff, S.

2007-01-01

Using direct information on financial constraints from questionnaires, rather than the commonly used balance sheet information, this paper presents evidence that, controlling for traditional factors as size, market share, cooperative arrangement, and expected profitability, financial constraints affect a firm's decision of how much to invest in R&D activities. Apart from these constraints, other hampering factors as market uncertainty and institutional bottlenecks, regulations and organizatio...

Late radiation-induced heart disease after radiotherapy. Clinical importance, radiobiological mechanisms and strategies of prevention

International Nuclear Information System (INIS)

Andratschke, Nicolaus; Maurer, Jean; Molls, Michael; Trott, Klaus-Ruediger

2011-01-01

The clinical importance of radiation-induced heart disease, in particular in post-operative radiotherapy of breast cancer patients, has been recognised only recently. There is general agreement, that a co-ordinated research effort would be needed to explore all the potential strategies of how to reduce the late risk of radiation-induced heart disease in radiotherapy. This approach would be based, on one hand, on a comprehensive understanding of the radiobiological mechanisms of radiation-induced heart disease after radiotherapy which would require large-scale long-term animal experiments with high precision local heart irradiation. On the other hand - in close co-operation with mechanistic in vivo research studies - clinical studies in patients need to determine the influence of dose distribution in the heart on the risk of radiation-induced heart disease. The aim of these clinical studies would be to identify the critical structures within the organ which need to be spared and their radiation sensitivity as well as a potential volume and dose effect. The results of the mechanistic studies might also provide concepts of how to modify the gradual progression of radiation damage in the heart by drugs or biological molecules. The results of the studies in patients would need to also incorporate detailed dosimetric and imaging studies in order to develop early indicators of impending radiation-induced heart disease which would be a pre-condition to develop sound criteria for treatment plan optimisation.

Universal constraints on axions from inflation

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Ricardo Z.; Sloth, Martin S. [CP-Origins, Center for Cosmology and Particle Physics Phenomenology,University of Southern Denmark, Campusvej 55, 5230 Odense M (Denmark)

2014-12-19

We consider the presence of an axion like particle, σ, with a generic CP violating axial coupling of the form (α σ/f)FF-tilde, where F{sub μν} is the gauge field strength of a generic abelian U(1) gauge group, not necessarily associated with the standard electromagnetism, and f is the decay constant of the axion. It has previously been demonstrated that if the axion is identified with the inflaton, such an interaction can lead to measurable cosmological signatures (non-Gaussian modifications of the curvature perturbation spectrum) depending on the parameter ξ=α σ-dot /(fH). In the present paper we will show that the generation of curvature perturbation at horizon crossing due to the axial coupling has a universal form and remains unmodified in terms of the ξ parameter even if the axion, σ, is not identified with the inflaton. As a consequence, it does not appear to be possible to generate CMB tensor perturbations through this mechanism, larger than the vacuum ones, without violating the observational constraints unless we combine this mechanism with a curvaton or if the σ field becomes heavy and decays during inflation. Even in this last case there are non-trivial constraints coming from the slow-roll evolution of the curvature perturbation on super horizon scales which should be taken into account. We also comment on implications for inflationary models where axions play an important role as, for example, models of natural inflation where more than one axion are included and models where the curvaton is an axion.

Ideal heat transfer conditions for tubular solar receivers with different design constraints

Science.gov (United States)

Kim, Jin-Soo; Potter, Daniel; Gardner, Wilson; Too, Yen Chean Soo; Padilla, Ricardo Vasquez

2017-06-01

The optimum heat transfer condition for a tubular type solar receiver was investigated for various receiver pipe size, heat transfer fluid, and design requirement and constraint(s). Heat transfer of a single plain receiver pipe exposed to concentrated solar energy was modelled along the flow path of the heat transfer fluid. Three different working fluids, molten salt, sodium, and supercritical carbon dioxide (sCO2) were considered in the case studies with different design conditions. The optimized ideal heat transfer condition was identified through fast iterative heat transfer calculations solving for all relevant radiation, conduction and convection heat transfers throughout the entire discretized tubular receiver. The ideal condition giving the best performance was obtained by finding the highest acceptable solar energy flux optimally distributed to meet different constraint(s), such as maximum allowable material temperature of receiver, maximum allowable film temperature of heat transfer fluid, and maximum allowable stress of receiver pipe material. The level of fluid side turbulence (represented by pressure drop in this study) was also optimized to give the highest net power production. As the outcome of the study gives information on the most ideal heat transfer condition, it can be used as a useful guideline for optimal design of a real receiver and solar field in a combined manner. The ideal heat transfer condition is especially important for high temperature tubular receivers (e.g. for supplying heat to high efficiency Brayton cycle turbines) where the system design and performance is tightly constrained by the receiver pipe material strength.

Overview of the use of dose constraints in occupational exposures

International Nuclear Information System (INIS)

Bonny, A.

2013-04-01

An overview of the use of dose constraints in occupational exposures has been carried out in this project. This was done by reviewing and analyzing some of the operational issues/challenges associated with their implementation and providing suggestions regarding operational objectives and uses of dose constraints.The role of dose constraints in the process of optimisation of radiation protection was described, and explanations provided where necessary in order to avoid the possible situations where dose constraints are misinterpreted or used as a stringent limit. Finally, the identification of potential issues that need to be considered in the implementation and setting of dose constraints for the purposes of occupational radiation protection were discussed. (author)

Mobility and Position Error Analysis of a Complex Planar Mechanism with Redundant Constraints

Science.gov (United States)

Sun, Qipeng; Li, Gangyan

2018-03-01

Nowadays mechanisms with redundant constraints have been created and attracted much attention for their merits. The mechanism of the redundant constraints in a mechanical system is analyzed in this paper. A analysis method of Planar Linkage with a repetitive structure is proposed to get the number and type of constraints. According to the difference of applications and constraint characteristics, the redundant constraints are divided into the theoretical planar redundant constraints and the space-planar redundant constraints. And the calculation formula for the number of redundant constraints and type of judging method are carried out. And a complex mechanism with redundant constraints is analyzed of the influence about redundant constraints on mechanical performance. With the combination of theoretical derivation and simulation research, a mechanism analysis method is put forward about the position error of complex mechanism with redundant constraints. It points out the direction on how to eliminate or reduce the influence of redundant constraints.

The Importance of Non-neuronal Cell Types in hiPSC-Based Disease Modeling and Drug Screening

Directory of Open Access Journals (Sweden)

David M. Gonzalez

2017-12-01

Full Text Available Current applications of human induced pluripotent stem cell (hiPSC technologies in patient-specific models of neurodegenerative and neuropsychiatric disorders tend to focus on neuronal phenotypes. Here, we review recent efforts toward advancing hiPSCs toward non-neuronal cell types of the central nervous system (CNS and highlight their potential use for the development of more complex in vitro models of neurodevelopment and disease. We present evidence from previous works in both rodents and humans of the importance of these cell types (oligodendrocytes, microglia, astrocytes in neurological disease and highlight new hiPSC-based models that have sought to explore these relationships in vitro. Lastly, we summarize efforts toward conducting high-throughput screening experiments with hiPSCs and propose methods by which new screening platforms could be designed to better capture complex relationships between neural cell populations in health and disease.

Constrained dynamical systems: separation of constraints into first and second classes

International Nuclear Information System (INIS)

Chitaya, N.P.; Gogilidze, S.A.; Surovtsev, Yu.S.

1996-01-01

In the Dirac approach to the generalized Hamiltonian formalism, dynamical systems with first- and second-class constraints are investigated. The classification and separation of constraints into the first- and second-class ones are presented with the help of passing to an equivalent canonical set of constraints. The general structure of second-class constraints is clarified. 14 refs

Constraints and spandrels of interareal connectomes

Science.gov (United States)

Rubinov, Mikail

2016-12-01

Interareal connectomes are whole-brain wiring diagrams of white-matter pathways. Recent studies have identified modules, hubs, module hierarchies and rich clubs as structural hallmarks of these wiring diagrams. An influential current theory postulates that connectome modules are adequately explained by evolutionary pressures for wiring economy, but that the other hallmarks are not explained by such pressures and are therefore less trivial. Here, we use constraint network models to test these postulates in current gold-standard vertebrate and invertebrate interareal-connectome reconstructions. We show that empirical wiring-cost constraints inadequately explain connectome module organization, and that simultaneous module and hub constraints induce the structural byproducts of hierarchies and rich clubs. These byproducts, known as spandrels in evolutionary biology, include the structural substrate of the default-mode network. Our results imply that currently standard connectome characterizations are based on circular analyses or double dipping, and we emphasize an integrative approach to future connectome analyses for avoiding such pitfalls.

Constraints on grand unified superstring theories

International Nuclear Information System (INIS)

Ellis, J.; Lopez, J.L.; Nanopoulos, D.V.; Houston Advanced Research Center

1990-01-01

We evaluate some constraints on the construction of grand unified superstring theories (GUSTs) using higher level Kac-Moody algebras on the world-sheet. In the most general formulation of the heterotic string in four dimensions, an analysis of the basic GUST model-building constraints, including a realistic hidden gauge group, reveals that there are no E 6 models and any SO(10) models can only exist at level-5. Also, any such SU(5) models can exist only for levels 4≤k≤19. These SO(10) and SU(5) models risk having many large, massless, phenomenologically troublesome representations. We also show that with a suitable hidden sector gauge group, it is possible to avoid free light fractionally charged particles, which are endemic to string derived models. We list all such groups and their representations for the flipped SU(5)xU(1) model. We conclude that a sufficiently binding hidden sector gauge group becomes a basic model-building constraint. (orig.)

Water Constraints in an Electric Sector Capacity Expansion Model

Energy Technology Data Exchange (ETDEWEB)

Macknick, Jordan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Newmark, Robin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Martinez, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sullivan, Patrick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tidwell, Vince [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-07-17

This analysis provides a description of the first U.S. national electricity capacity expansion model to incorporate water resource availability and costs as a constraint for the future development of the electricity sector. The Regional Energy Deployment System (ReEDS) model was modified to incorporate water resource availability constraints and costs in each of its 134 Balancing Area (BA) regions along with differences in costs and efficiencies of cooling systems. Water resource availability and cost data are from recently completed research at Sandia National Laboratories (Tidwell et al. 2013b). Scenarios analyzed include a business-as-usual 3 This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. scenario without water constraints as well as four scenarios that include water constraints and allow for different cooling systems and types of water resources to be utilized. This analysis provides insight into where water resource constraints could affect the choice, configuration, or location of new electricity technologies.

The influence of end constraints on smooth pipe bends

International Nuclear Information System (INIS)

Thomson, G.; Spence, J.

1981-01-01

With present trends in the power industries towards higher operating temperatures and pressures, problems associated with the design and safety assessment of pipework systems have become increasingly complex. Within such systems, the importance of smooth pipe bends is well established. The work which will be presented will attempt to clarify the situation and unify the results. An analytical solution of the problem of a linear elastic smooth pipe bend with end constraints under in-plane bending will be presented. The analysis will deal with constraints in the form of flanged tangents of any length. The analysis employs the theorem of minimum total potential energy with suitable kinematically admissible displacements in the form of Fourier series. The integrations and minimisation were performed numerically, thereby permitting the removal of several of the assumptions made by previous authors. Typical results for flexibilities will be given along with comparisons with other works. The differences in some earlier theory are clarified and other more recent work using different solution techniques is substantiated. The bend behaviour is shown to be strongly influenced by the pipe bend parameter, the bend angle, the tangent pipe length and the bend/cross-sectional radius ratio. (orig./GL)

Rigorous constraints on the matrix elements of the energy–momentum tensor

Directory of Open Access Journals (Sweden)

Peter Lowdon

2017-11-01

Full Text Available The structure of the matrix elements of the energy–momentum tensor play an important role in determining the properties of the form factors A(q2, B(q2 and C(q2 which appear in the Lorentz covariant decomposition of the matrix elements. In this paper we apply a rigorous frame-independent distributional-matching approach to the matrix elements of the Poincaré generators in order to derive constraints on these form factors as q→0. In contrast to the literature, we explicitly demonstrate that the vanishing of the anomalous gravitomagnetic moment B(0 and the condition A(0=1 are independent of one another, and that these constraints are not related to the specific properties or conservation of the individual Poincaré generators themselves, but are in fact a consequence of the physical on-shell requirement of the states in the matrix elements and the manner in which these states transform under Poincaré transformations.

Formation control of marine craft using constraint functions

DEFF Research Database (Denmark)

Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.

This article presents a method for formation control of marine surface vessels inspired by Lagrangian mechanics. The desired formation configuration is given as a set of constraint functions. The functions are treated analytically and by using feedback from the imposed constraint functions, const...

Osmotic virial coefficients for model protein and colloidal solutions: Importance of ensemble constraints in the analysis of light scattering data

Science.gov (United States)

Siderius, Daniel W.; Krekelberg, William P.; Roberts, Christopher J.; Shen, Vincent K.

2012-05-01

Protein-protein interactions in solution may be quantified by the osmotic second virial coefficient (OSVC), which can be measured by various experimental techniques including light scattering. Analysis of Rayleigh light scattering measurements from such experiments requires identification of a scattering volume and the thermodynamic constraints imposed on that volume, i.e., the statistical mechanical ensemble in which light scattering occurs. Depending on the set of constraints imposed on the scattering volume, one can obtain either an apparent OSVC, A2,app, or the true thermodynamic OSVC, {B_{22}^{osm}}, that is rigorously defined in solution theory [M. A. Blanco, E. Sahin, Y. Li, and C. J. Roberts, J. Chem. Phys. 134, 225103 (2011), 10.1063/1.3596726]. However, it is unclear to what extent A2,app and {B_{22}^{osm}} differ, which may have implications on the physical interpretation of OSVC measurements from light scattering experiments. In this paper, we use the multicomponent hard-sphere model and a well-known equation of state to directly compare A2,app and {B_{22}^{osm}}. Our results from the hard-sphere equation of state indicate that A2,app underestimates {B_{22}^{osm}}, but in a systematic manner that may be explained using fundamental thermodynamic expressions for the two OSVCs. The difference between A2,app and {B_{22}^{osm}} may be quantitatively significant, but may also be obscured in experimental application by statistical uncertainty or non-steric interactions. Consequently, the two OSVCs that arise in the analysis of light scattering measurements do formally differ, but in a manner that may not be detectable in actual application.

Climate change adaptation: Uncovering constraints to the use of adaptation strategies among food crop farmers in South-west, Nigeria using principal component analysis (PCA

Directory of Open Access Journals (Sweden)

Moradeyo Adebanjo Otitoju

2016-12-01

Full Text Available This study focused on the constraints to the use of climate variability/change adaptation strategies in South-west Nigeria. Multistage random technique was employed to select the location and the respondents. Descriptive statistics and principal component analysis (PCA were the analytical tools engaged in this study. The constraints to climate variability and change examined before did not use PCA but generalized factor analysis. Hence, there is need to examine these constraints extensively using PCA. Uncovering the constraints to the use of climate variability/change adaptation strategies among crop framers is important to give a realistic direction in the development of farmer-inclusive climate policies in Nigeria. The PCA result showed that the principal constraints that the farmers faced in climate change adaptation were public, institutional and labour constraint; land, neighbourhood norms and religious beliefs constraint; high cost of inputs, technological and information constraint; farm distance, access to climate information, off-farm job and credit constraint; and poor agricultural programmes and service delivery constraint. These findings pointed out the need for both the government and non-government organizations to intensify efforts on institutional, technological and farmers’ friendly land tenure and information systems as effective measures to guide inclusive climate change adaptation policies and development in South-west Nigeria.

Resources, constraints and capabilities

NARCIS (Netherlands)

Dhondt, S.; Oeij, P.R.A.; Schröder, A.

2018-01-01

Human and financial resources as well as organisational capabilities are needed to overcome the manifold constraints social innovators are facing. To unlock the potential of social innovation for the whole society new (social) innovation friendly environments and new governance structures

Mathematical programs with complementarity constraints in traffic and telecommunications networks.

Science.gov (United States)

Ralph, Daniel

2008-06-13

Given a suitably parametrized family of equilibrium models and a higher level criterion by which to measure an equilibrium state, mathematical programs with equilibrium constraints (MPECs) provide a framework for improving or optimizing the equilibrium state. An example is toll design in traffic networks, which attempts to reduce total travel time by choosing which arcs to toll and what toll levels to impose. Here, a Wardrop equilibrium describes the traffic response to each toll design. Communication networks also have a deep literature on equilibrium flows that suggest some MPECs. We focus on mathematical programs with complementarity constraints (MPCCs), a subclass of MPECs for which the lower level equilibrium system can be formulated as a complementarity problem and therefore, importantly, as a nonlinear program (NLP). Although MPECs and MPCCs are typically non-convex, which is a consequence of the upper level objective clashing with the users' objectives in the lower level equilibrium program, the last decade of research has paved the way for finding local solutions of MPCCs via standard NLP techniques.

Effects of Contingency versus Constraints on the Body-Mass Scaling of Metabolic Rate

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Douglas S. Glazier

2018-01-01

Full Text Available I illustrate the effects of both contingency and constraints on the body-mass scaling of metabolic rate by analyzing the significantly different influences of ambient temperature (Ta on metabolic scaling in ectothermic versus endothermic animals. Interspecific comparisons show that increasing Ta results in decreasing metabolic scaling slopes in ectotherms, but increasing slopes in endotherms, a pattern uniquely predicted by the metabolic-level boundaries hypothesis, as amended to include effects of the scaling of thermal conductance in endotherms outside their thermoneutral zone. No other published theoretical model explicitly predicts this striking variation in metabolic scaling, which I explain in terms of contingent effects of Ta and thermoregulatory strategy in the context of physical and geometric constraints related to the scaling of surface area, volume, and heat flow across surfaces. My analysis shows that theoretical models focused on an ideal 3/4-power law, as explained by a single universally applicable mechanism, are clearly inadequate for explaining the diversity and environmental sensitivity of metabolic scaling. An important challenge is to develop a theory of metabolic scaling that recognizes the contingent effects of multiple mechanisms that are modulated by several extrinsic and intrinsic factors within specified constraints.

An efficient method for minimizing a convex separable logarithmic function subject to a convex inequality constraint or linear equality constraint

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available We consider the problem of minimizing a convex separable logarithmic function over a region defined by a convex inequality constraint or linear equality constraint, and two-sided bounds on the variables (box constraints. Such problems are interesting from both theoretical and practical point of view because they arise in some mathematical programming problems as well as in various practical problems such as problems of production planning and scheduling, allocation of resources, decision making, facility location problems, and so forth. Polynomial algorithms are proposed for solving problems of this form and their convergence is proved. Some examples and results of numerical experiments are also presented.

Constraints on reusability of learning objects

DEFF Research Database (Denmark)

May, Michael; Hussmann, Peter Munkebo; Jensen, Anne Skov

2010-01-01

It is the aim of this paper to discuss some didactic constraints on the use and reuse of digital modular learning objects. Engineering education is used as the specific context of use with examples from courses in introductory electronics and mathematics. Digital multimedia and modular learning....... Constraints on reuse arise from the nature of conceptual understanding in higher education and the functionality of learning objects within present technologies. We will need didactic as well as technical perspectives on learning objects in designing for understanding....

Fast and Easy 3D Reconstruction with the Help of Geometric Constraints and Genetic Algorithms

Science.gov (United States)

Annich, Afafe; El Abderrahmani, Abdellatif; Satori, Khalid

2017-09-01

The purpose of the work presented in this paper is to describe new method of 3D reconstruction from one or more uncalibrated images. This method is based on two important concepts: geometric constraints and genetic algorithms (GAs). At first, we are going to discuss the combination between bundle adjustment and GAs that we have proposed in order to improve 3D reconstruction efficiency and success. We used GAs in order to improve fitness quality of initial values that are used in the optimization problem. It will increase surely convergence rate. Extracted geometric constraints are used first to obtain an estimated value of focal length that helps us in the initialization step. Matching homologous points and constraints is used to estimate the 3D model. In fact, our new method gives us a lot of advantages: reducing the estimated parameter number in optimization step, decreasing used image number, winning time and stabilizing good quality of 3D results. At the end, without any prior information about our 3D scene, we obtain an accurate calibration of the cameras, and a realistic 3D model that strictly respects the geometric constraints defined before in an easy way. Various data and examples will be used to highlight the efficiency and competitiveness of our present approach.

Selective constraints in experimentally defined primate regulatory regions.

Directory of Open Access Journals (Sweden)

Daniel J Gaffney

2008-08-01

Full Text Available Changes in gene regulation may be important in evolution. However, the evolutionary properties of regulatory mutations are currently poorly understood. This is partly the result of an incomplete annotation of functional regulatory DNA in many species. For example, transcription factor binding sites (TFBSs, a major component of eukaryotic regulatory architecture, are typically short, degenerate, and therefore difficult to differentiate from randomly occurring, nonfunctional sequences. Furthermore, although sites such as TFBSs can be computationally predicted using evolutionary conservation as a criterion, estimates of the true level of selective constraint (defined as the fraction of strongly deleterious mutations occurring at a locus in regulatory regions will, by definition, be upwardly biased in datasets that are a priori evolutionarily conserved. Here we investigate the fitness effects of regulatory mutations using two complementary datasets of human TFBSs that are likely to be relatively free of ascertainment bias with respect to evolutionary conservation but, importantly, are supported by experimental data. The first is a collection of almost >2,100 human TFBSs drawn from the literature in the TRANSFAC database, and the second is derived from several recent high-throughput chromatin immunoprecipitation coupled with genomic microarray (ChIP-chip analyses. We also define a set of putative cis-regulatory modules (pCRMs by spatially clustering multiple TFBSs that regulate the same gene. We find that a relatively high proportion ( approximately 37% of mutations at TFBSs are strongly deleterious, similar to that at a 2-fold degenerate protein-coding site. However, constraint is significantly reduced in human and chimpanzee pCRMS and ChIP-chip sequences, relative to macaques. We estimate that the fraction of regulatory mutations that have been driven to fixation by positive selection in humans is not significantly different from zero. We also find

submitter Emerging importance of chemokine receptor CXCR3 and its ligands in cardiovascular diseases

CERN Document Server

Altara, R; Brandao, R D; Zeidan, A; Booz, G W; Zouein, F A

2016-01-01

The CXC chemokines, CXCL4, -9, -10, -11, CXCL4L1, and the CC chemokine CCL21, activate CXC chemokine receptor 3 (CXCR3), a cell-surface G protein-coupled receptor expressed mainly by Th1 cells, cytotoxic T (Tc) cells and NK cells that have a key role in immunity and inflammation. However, CXCR3 is also expressed by vascular smooth muscle and endothelial cells, and appears to be important in controlling physiological vascular function. In the last decade, evidence from pre-clinical and clinical studies has revealed the participation of CXCR3 and its ligands in multiple cardiovascular diseases (CVDs) of different aetiologies including atherosclerosis, hypertension, cardiac hypertrophy and heart failure, as well as in heart transplant rejection and transplant coronary artery disease (CAD). CXCR3 ligands have also proven to be valid biomarkers for the development of heart failure and left ventricular dysfunction, suggesting an underlining pathophysiological relation between levels of these chemokines and the deve...

RNA Interference: A Promising Tool in the Control of Important Vector Born Diseases Zika, Dengue Fever, and Malaria

Directory of Open Access Journals (Sweden)

Jalil Nejati

2017-05-01

Full Text Available Background and Objectives: RNA interference is a process, in which a molecule of double-stranded RNA prevents the expression of a particular gene and leads to its silencing. Application of this technology in the control of disease-carrying insects is rising in agriculture and medical sciences. Also, its application in control of insect-borne diseases could be considered as a new, important, and effective approach. In this article, it was attempted to study the mechanisms of RNA interference, routs of its delivery to insects, as well as its application in genetic control of disease vector insects. Methods: In this study, 71 indexed articles in databases, such as Pubmed, SID, Scopus, Science direct, and Google scholar, were used. Results: dsRNA could be delivered to insect body through three routes of oral, injection, and Impregnation. The mechanism of dsRNA entrance into the cells has considerable effect on the success and applicability of this technique. Identification of host-parasite relationship in the insect body is one of the important applications of RNAi in medical entomology. Conclusion: Although, there is a considerable number of researches on RNAi in the agricultural pests field, studies on insect vectors of human diseases have been mostly in-vivo. However, application of RNAi is suggested as a new, safe and applicable approach, alone or along with other methods. Certainly, further researches in this field can pave the way for enforcement measures in the control of disease vectors, especially Zika, dengue fever, and malaria in the not so distant future.

Important complications of chronic kidney disease

African Journals Online (AJOL)

A raised parathyroid hormone level (secondary hyperparathyroidism) is also a major risk factor for cardiovascular .... Evaluation of the iron deficit and correct iron supply is important ... growth factor 23 which, in turn, inhibits the hydroxylation of.

Practical constraints on fuel management a utility perspective

International Nuclear Information System (INIS)

Grier, C.A.

1986-01-01

The practical and potential constraints of performing fuel management at a large utility are reviewed. Based on approximately six years of experience in performing fuel management the constraints due to commercial, technical, utility system, design methods, and personnel and computer resources are discussed in detail

Applying the theory of constraints in health care: Part 1--The philosophy.

Science.gov (United States)

Breen, Anne M; Burton-Houle, Tracey; Aron, David C

2002-01-01

The imperative to improve both technical and service quality while simultaneously reducing costs is quite clear. The Theory of Constraints (TOC) is an emerging philosophy that rests on two assumptions: (1) systems thinking and (2) if a constraint "is anything that limits a system from achieving higher performance versus its goal," then every system must have at least one (and at most no more than a few) constraints or limiting factors. A constraint is neither good nor bad in itself. Rather, it just is. In fact, recognition of the existence of constraints represents an excellent opportunity for improvement because it allows one to focus ones efforts in the most productive area--identifying and managing the constraints. This is accomplished by using the five focusing steps of TOC: (1) identify the system's constraint; (2) decide how to exploit it; (3) subordinate/synchronize everything else to the above decisions; (4) elevate the system's constraint; and (5) if the constraint has shifted in the above steps, go back to step 1. Do not allow inertia to become the system's constraint. TOC also refers to a series of tools termed "thinking processes" and the sequence in which they are used.

A methodology for controlling motion and constraint forces in holonomically constrained systems

International Nuclear Information System (INIS)

Sapio, Vincent De; Srinivasa, Narayan

2015-01-01

Holonomic constraints are ubiquitous in multibody systems. We present an approach to effectively address the control of holonomically constrained systems using a novel decomposition of task, constraint, and posture space. In addition to providing a natural approach for motion control in the presence of constraints, this scheme also allows for concurrent specification of desired constraint forces, given sufficient actuation. It does this by exposing both motion coordinates and constraint forces within the control formalism, allowing for substantial flexibility in control synthesis. Implementations are presented based on a partitioning of the constraint forces into controlled and uncontrolled subsets, as well as a specification of implicit conditions on the constraint forces. A number of examples demonstrate the practical efficacy of the approach. Finally, a system-level methodology for constraint management during robot interactions with the environment is presented

A methodology for controlling motion and constraint forces in holonomically constrained systems

Energy Technology Data Exchange (ETDEWEB)

Sapio, Vincent De, E-mail: vdesapio@hrl.com; Srinivasa, Narayan, E-mail: nsrinivasa@hrl.com [HRL Laboratories, LLC, Information and Systems Sciences Laboratory (United States)

2015-02-15

Holonomic constraints are ubiquitous in multibody systems. We present an approach to effectively address the control of holonomically constrained systems using a novel decomposition of task, constraint, and posture space. In addition to providing a natural approach for motion control in the presence of constraints, this scheme also allows for concurrent specification of desired constraint forces, given sufficient actuation. It does this by exposing both motion coordinates and constraint forces within the control formalism, allowing for substantial flexibility in control synthesis. Implementations are presented based on a partitioning of the constraint forces into controlled and uncontrolled subsets, as well as a specification of implicit conditions on the constraint forces. A number of examples demonstrate the practical efficacy of the approach. Finally, a system-level methodology for constraint management during robot interactions with the environment is presented.

Constraints to Hamari sheep farming under range conditions in Darfur and Kordofan Regions of Western Sudan.

Science.gov (United States)

Tirab, Ahmed Berima; Chimonyo, Michael

2016-08-01

The study was conducted to identify the major production constraints of Hamari sheep in Darfur and Kordofan Regions of Western Sudan. A structured questionnaire was administered to 128 farmers in Darfur and Kordofan. Feed shortages, prevalence of diseases and parasites, and predation were more severe in Darfur than Kordofan (P Darfur Region (P Darfur region ranked diseases, parasites and predation higher than those practising semi-nomadic and sedentary system in Kordofan region (P Darfur Region than those practising semi-nomadic system in Kordofan Region (P < 0.05). It can be concluded that the severity of challenges facing Hamari sheep producers vary with flock size, region and production system used.

Importance of hypoglycemia on the risk of Alzheimer’s disease in elderly subjects with diabetes mellitus

Directory of Open Access Journals (Sweden)

Muratli S

2015-11-01

Full Text Available Sevilay Muratli,1 Fatih Tufan,2 Ozlem Soyluk,2 Gulistan Bahat,1 M Akif Karan11Division of Geriatrics, Department of Internal Medicine, 2Department of Gerontology, Faculty of Medical Sciences, Istanbul University, Istanbul, TurkeyWe read the article on the study of "Link between type 2 diabetes and Alzheimer’s disease: from epidemiology to mechanism and treatment" by Li et al.1 The review is very detailed and rational, considering the link between diabetes and Alzheimer’s disease and giving a new outlook as type 3 diabetes. It provides important information about the effects of the hyperglycemic complications of diabetes and treatment of dementia.View original paper by Li et al

Quantum centipedes with strong global constraint

Science.gov (United States)

Grange, Pascal

2017-06-01

A centipede made of N quantum walkers on a one-dimensional lattice is considered. The distance between two consecutive legs is either one or two lattice spacings, and a global constraint is imposed: the maximal distance between the first and last leg is N  +  1. This is the strongest global constraint compatible with walking. For an initial value of the wave function corresponding to a localized configuration at the origin, the probability law of the first leg of the centipede can be expressed in closed form in terms of Bessel functions. The dispersion relation and the group velocities are worked out exactly. Their maximal group velocity goes to zero when N goes to infinity, which is in contrast with the behaviour of group velocities of quantum centipedes without global constraint, which were recently shown by Krapivsky, Luck and Mallick to give rise to ballistic spreading of extremal wave-front at non-zero velocity in the large-N limit. The corresponding Hamiltonians are implemented numerically, based on a block structure of the space of configurations corresponding to compositions of the integer N. The growth of the maximal group velocity when the strong constraint is gradually relaxed is explored, and observed to be linear in the density of gaps allowed in the configurations. Heuristic arguments are presented to infer that the large-N limit of the globally constrained model can yield finite group velocities provided the allowed number of gaps is a finite fraction of N.

Precision medicine and drug development in Alzheimer's disease: The importance of sexual dimorphism and patient stratification.

Science.gov (United States)

Hampel, Harald; Vergallo, Andrea; Giorgi, Filippo Sean; Kim, Seung Hyun; Depypere, Herman; Graziani, Manuela; Saidi, Amira; Nisticò, Robert; Lista, Simone

2018-06-12

Neurodegenerative diseases (ND) are among the leading causes of disability and mortality. Considerable sex differences exist in the occurrence of the various manifestations leading to cognitive decline. Alzheimer's disease (AD) exhibits substantial sexual dimorphisms and disproportionately affects women. Women have a higher life expectancy compared to men and, consequently, have more lifespan to develop AD. The emerging precision medicine and pharmacology concepts - taking into account the individual genetic and biological variability relevant for disease risk, prevention, detection, diagnosis, and treatment - are expected to substantially enhance our knowledge and management of AD. Stratifying the affected individuals by sex and gender is an important basic step towards personalization of scientific research, drug development, and care. We hypothesize that sex and gender differences, extending from genetic to psychosocial domains, are highly relevant for the understanding of AD pathophysiology, and for the conceptualization of basic/translational research and for clinical therapy trial design. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of constraints and mastery on mental and physical health: Conceptual and methodological considerations.

Science.gov (United States)

Infurna, Frank J; Mayer, Axel

2015-06-01

Perceived control and health are closely interrelated in adulthood and old age. However, less is known regarding the differential implications of 2 facets of perceived control, constraints and mastery, for mental and physical health. Furthermore, a limitation of previous research testing the pathways linking perceived control to mental and physical health is that mediation was tested with cross-sectional designs and not in a longitudinal mediation design that accounts for temporal ordering and prior confounds. Using data from the Health and Retirement Study (HRS; n = 7,612, M age = 68, SD = 10.66; 59% women) we examined the effect of constraints and mastery on 4-year changes in mental and physical health and whether physical activity mediated such effects in a longitudinal mediation design. Using confirmatory factor analysis, we modeled the 2-factor structure of perceived control that consisted of constraints and mastery. In our longitudinal mediation model, where we accounted for possible confounders (e.g., age, gender, education, neuroticism, conscientiousness, memory, and health conditions), constraints showed a stronger total effect on mental and physical health, than mastery, such that more constraints were associated with 4-year declines in mental and physical health. Physical activity did not mediate the effect of constraints and mastery on mental and physical health (indirect effect). To demonstrate the importance of a longitudinal mediation model that accounts for confounders, we also estimated the mediated effect using 2 models commonly used in the literature: cross-sectional mediation model and longitudinal mediation model without accounting for confounders. These mediation models indicated a spurious indirect effect that cannot be causally interpreted. Our results showcase that constraints and mastery have differential implications for mental and physical health, as well as how a longitudinal mediation design can illustrate (or not) pathways in

Multi-scale image segmentation method with visual saliency constraints and its application

Science.gov (United States)

Chen, Yan; Yu, Jie; Sun, Kaimin

2018-03-01

Object-based image analysis method has many advantages over pixel-based methods, so it is one of the current research hotspots. It is very important to get the image objects by multi-scale image segmentation in order to carry out object-based image analysis. The current popular image segmentation methods mainly share the bottom-up segmentation principle, which is simple to realize and the object boundaries obtained are accurate. However, the macro statistical characteristics of the image areas are difficult to be taken into account, and fragmented segmentation (or over-segmentation) results are difficult to avoid. In addition, when it comes to information extraction, target recognition and other applications, image targets are not equally important, i.e., some specific targets or target groups with particular features worth more attention than the others. To avoid the problem of over-segmentation and highlight the targets of interest, this paper proposes a multi-scale image segmentation method with visually saliency graph constraints. Visual saliency theory and the typical feature extraction method are adopted to obtain the visual saliency information, especially the macroscopic information to be analyzed. The visual saliency information is used as a distribution map of homogeneity weight, where each pixel is given a weight. This weight acts as one of the merging constraints in the multi- scale image segmentation. As a result, pixels that macroscopically belong to the same object but are locally different can be more likely assigned to one same object. In addition, due to the constraint of visual saliency model, the constraint ability over local-macroscopic characteristics can be well controlled during the segmentation process based on different objects. These controls will improve the completeness of visually saliency areas in the segmentation results while diluting the controlling effect for non- saliency background areas. Experiments show that this method works

A Constraint Model for Constrained Hidden Markov Models

DEFF Research Database (Denmark)

Christiansen, Henning; Have, Christian Theil; Lassen, Ole Torp

2009-01-01

A Hidden Markov Model (HMM) is a common statistical model which is widely used for analysis of biological sequence data and other sequential phenomena. In the present paper we extend HMMs with constraints and show how the familiar Viterbi algorithm can be generalized, based on constraint solving ...

ANALYSIS OF CONSTRAINTS IN RESOURCE USE EFFICIENCY IN ...

African Journals Online (AJOL)

ANALYSIS OF CONSTRAINTS IN RESOURCE USE EFFICIENCY IN MULTIPLE CROPPING SYSTEM BY SMALL-HOLDER FARMERS IN EBONYI STATE OF ... high cost of modern inputs, lack of adequate finance and lack of collaterals among others served as major constraints, which constituted29%, 36%, 33% and 22% ...

Balancing healthy meals and busy lives: associations between work, school, and family responsibilities and perceived time constraints among young adults.

Science.gov (United States)

Pelletier, Jennifer E; Laska, Melissa N

2012-01-01

To characterize associations between perceived time constraints for healthy eating and work, school, and family responsibilities among young adults. Cross-sectional survey. A large, Midwestern metropolitan region. A diverse sample of community college (n = 598) and public university (n = 603) students. Time constraints in general, as well as those specific to meal preparation/structure, and perceptions of a healthy life balance. Chi-square tests and multivariate logistic regression (α = .005). Women, 4-year students, and students with lower socioeconomic status perceived more time constraints (P balance (P ≤ .003). Having a heavy course load and working longer hours were important predictors of time constraints among men (P life balance despite multiple time demands. Interventions focused on improved time management strategies and nutrition-related messaging to achieve healthy diets on a low time budget may be more successful if tailored to the factors that contribute to time constraints separately among men and women. Copyright © 2012 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

The Importance of Haematological and Biochemical Findings in Patients with West Nile Virus Neuroinvasive Disease

Directory of Open Access Journals (Sweden)

Urošević Aleksandar

2016-10-01

Full Text Available Background: West Nile virus neuroinvasive disease (WNND occurs in less than 1% of infected people. Leukocytosis with lymphocytopenia, mild anaemia, thrombocytopenia, elevated liver and muscle enzymes and hyponatremia are occasionally present in patients with WNND. Cerebrospinal fluid (CSF findings resemble other viral neuroinfections. The purpose of this study is to present some of the most important laboratory findings of our patients with WNND and to evaluate their correlation with fatal outcome.

Spin glasses and nonlinear constraints in portfolio optimization

International Nuclear Information System (INIS)

Andrecut, M.

2014-01-01

We discuss the portfolio optimization problem with the obligatory deposits constraint. Recently it has been shown that as a consequence of this nonlinear constraint, the solution consists of an exponentially large number of optimal portfolios, completely different from each other, and extremely sensitive to any changes in the input parameters of the problem, making the concept of rational decision making questionable. Here we reformulate the problem using a quadratic obligatory deposits constraint, and we show that from the physics point of view, finding an optimal portfolio amounts to calculating the mean-field magnetizations of a random Ising model with the constraint of a constant magnetization norm. We show that the model reduces to an eigenproblem, with 2N solutions, where N is the number of assets defining the portfolio. Also, in order to illustrate our results, we present a detailed numerical example of a portfolio of several risky common stocks traded on the Nasdaq Market.

Spin glasses and nonlinear constraints in portfolio optimization

Energy Technology Data Exchange (ETDEWEB)

Andrecut, M., E-mail: mircea.andrecut@gmail.com

2014-01-17

We discuss the portfolio optimization problem with the obligatory deposits constraint. Recently it has been shown that as a consequence of this nonlinear constraint, the solution consists of an exponentially large number of optimal portfolios, completely different from each other, and extremely sensitive to any changes in the input parameters of the problem, making the concept of rational decision making questionable. Here we reformulate the problem using a quadratic obligatory deposits constraint, and we show that from the physics point of view, finding an optimal portfolio amounts to calculating the mean-field magnetizations of a random Ising model with the constraint of a constant magnetization norm. We show that the model reduces to an eigenproblem, with 2N solutions, where N is the number of assets defining the portfolio. Also, in order to illustrate our results, we present a detailed numerical example of a portfolio of several risky common stocks traded on the Nasdaq Market.

Model quality assessment using distance constraints from alignments

DEFF Research Database (Denmark)

Paluszewski, Martin; Karplus, Kevin

2008-01-01

that model which is closest to the true structure. In this article, we present a new approach for addressing the MQA problem. It is based on distance constraints extracted from alignments to templates of known structure, and is implemented in the Undertaker program for protein structure prediction. One novel...... feature is that we extract noncontact constraints as well as contact constraints. We describe how the distance constraint extraction is done and we show how they can be used to address the MQA problem. We have compared our method on CASP7 targets and the results show that our method is at least comparable...... with the best MQA methods that were assessed at CASP7. We also propose a new evaluation measure, Kendall's tau, that is more interpretable than conventional measures used for evaluating MQA methods (Pearson's r and Spearman's rho). We show clear examples where Kendall's tau agrees much more with our intuition...

Analysis of Space Tourism Constraints

Science.gov (United States)

Bonnal, Christophe

2002-01-01

Space tourism appears today as a new Eldorado in a relatively near future. Private operators are already proposing services for leisure trips in Low Earth Orbit, and some happy few even tested them. But are these exceptional events really marking the dawn of a new space age ? The constraints associated to the space tourism are severe : - the economical balance of space tourism is tricky; development costs of large manned - the technical definition of such large vehicles is challenging, mainly when considering - the physiological aptitude of passengers will have a major impact on the mission - the orbital environment will also lead to mission constraints on aspects such as radiation, However, these constraints never appear as show-stoppers and have to be dealt with pragmatically: - what are the recommendations one can make for future research in the field of space - which typical roadmap shall one consider to develop realistically this new market ? - what are the synergies with the conventional missions and with the existing infrastructure, - how can a phased development start soon ? The paper proposes hints aiming at improving the credibility of Space Tourism and describes the orientations to follow in order to solve the major hurdles found in such an exciting development.

Tumour burden in early stage Hodgkin's disease: the single most important prognostic factor for outcome after radiotherapy

DEFF Research Database (Denmark)

Specht, L; Nordentoft, A M; Cold, Søren

1987-01-01

One hundred and forty-two patients with Hodgkin's disease PS I or II were treated with total or subtotal nodal irradiation as part of a prospective randomized trial in the Danish National Hodgkin Study during the period 1971-83. They were followed till death or--at the time of this analysis......--from 15 to 146 months after initiation of therapy. The initial tumour burden of each patient was assessed, combining tumour size of each involved region and number of regions involved. Tumour burden thus assessed proved to be the single most important prognostic factor with regard to disease free survival...

Managing Constraint Generators in Retail Design Processes

DEFF Research Database (Denmark)

Münster, Mia Borch; Haug, Anders

case studies of fashion store design projects, the present paper addresses this gap. The and six case studies of fashion store design projects, the present paper sheds light on the types of constraints generated by the relevant constraint generators. The paper shows that in the cases studied......Retail design concepts are complex designs meeting functional and aesthetic demands. During a design process a retail designer has to consider various constraint generators such as stakeholder interests, physical limitations and restrictions. Obviously the architectural site, legislators...... and landlords need to be considered as well as the interest of the client and brand owner. Furthermore the users need to be taken into account in order to develop an interesting and functional shopping and working environments. Finally, suppliers and competitors may influence the design with regard...

Reconciling Scientific Aspirations and Engineering Constraints for a Lunar Mission via Hyperdimensional Interpolation

Science.gov (United States)

Weisbin, Charles R.; Clark, Pamela; Elfes, Alberto; Smith, Jeffrey H.; Mrozinski, Joseph; Adumitroaie, Virgil; Hua, Hook; Shelton, Kacie; Lincoln, William; Silberg, Robert

2010-01-01

technology-improvement investments would be likely to produce the largest or most important return. However, the number of variations that need to be considered for such analysis quickly balloons to an unwieldy size. If three variations are considered for each of six constraints-a very modest example-there are a total of 243 variations to consider. If it takes 40 minutes to compute each variation, as it does with HURON, our automated optimization system, then it would take 162 hours or nearly 7 days of round-the-clock computing to calculate the results. Adding further constraints or variations exponentially increases the amount of time that is needed.

Assessing opportunities and constraints for biofuel development in sub-Saharan Africa

CSIR Research Space (South Africa)

Von Maltitz, Graham P

2011-01-01

Full Text Available , the development of sustainability principles, criteria and indicators for biofuel development, and constraints to imports in the EU, have been some key responses to reduce unsustainable practices (Harrison et al. 2010a, Vis et al. 2008). �ough the adoption... FSC Forest Stewardship Council GAIA Movement Trust Living Earth Green World Action GAP Good Agricultural Practices GHG Greenhouse gas GIZ Gesellscha� f?r Internationale Zusammenarbeit Ha Hectare HCV High Conservation Value HDI Human Development...

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

Exact penalty results for mathematical programs with vanishing constraints

Czech Academy of Sciences Publication Activity Database

Hoheisel, T.; Kanzow, Ch.; Outrata, Jiří

2010-01-01

Roč. 72, č. 5 (2010), s. 2514-2526 ISSN 0362-546X R&D Projects: GA AV ČR IAA100750802 Institutional research plan: CEZ:AV0Z10750506 Keywords : Mathematical programs with vanishing constraints * Mathematical programs with equilibrium constraints * Exact penalization * Calmness * Subdifferential calculus * Limiting normal cone Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/outrata-exact penalty results for mathematical programs with vanishing constraints.pdf

Hematologically important mutations: X-linked chronic granulomatous disease (third update)

NARCIS (Netherlands)

Roos, Dirk; Kuhns, Douglas B.; Maddalena, Anne; Roesler, Joachim; Lopez, Juan Alvaro; Ariga, Tadashi; Avcin, Tadej; de Boer, Martin; Bustamante, Jacinta; Condino-Neto, Antonio; Di Matteo, Gigliola; He, Jianxin; Hill, Harry R.; Holland, Steven M.; Kannengiesser, Caroline; Köker, M. Yavuz; Kondratenko, Irina; van Leeuwen, Karin; Malech, Harry L.; Marodi, László; Nunoi, Hiroyuki; Stasia, Marie-José; Ventura, Anna Maria; Witwer, Carl T.; Wolach, Baruch; Gallin, John I.

2010-01-01

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide is used to kill phagocytosed micro-organisms in neutrophils, eosinophils, monocytes

Social Constraints on Animate Vision

National Research Council Canada - National Science Library

Breazeal, Cynthia; Edsinger, Aaron; Fitzpatrick, Paul; Scassellati, Brian

2000-01-01

.... In humanoid robotic systems, or in any animate vision system that interacts with people, social dynamics provide additional levels of constraint and provide additional opportunities for processing economy...

Interpersonal violence: an important risk factor for disease and injury in South Africa

Directory of Open Access Journals (Sweden)

Abrahams Naeemah

2010-12-01

Full Text Available Abstract Background Burden of disease estimates for South Africa have highlighted the particularly high rates of injuries related to interpersonal violence compared with other regions of the world, but these figures tell only part of the story. In addition to direct physical injury, violence survivors are at an increased risk of a wide range of psychological and behavioral problems. This study aimed to comprehensively quantify the excess disease burden attributable to exposure to interpersonal violence as a risk factor for disease and injury in South Africa. Methods The World Health Organization framework of interpersonal violence was adapted. Physical injury mortality and disability were categorically attributed to interpersonal violence. In addition, exposure to child sexual abuse and intimate partner violence, subcategories of interpersonal violence, were treated as risk factors for disease and injury using counterfactual estimation and comparative risk assessment methods. Adjustments were made to account for the combined exposure state of having experienced both child sexual abuse and intimate partner violence. Results Of the 17 risk factors included in the South African Comparative Risk Assessment study, interpersonal violence was the second leading cause of healthy years of life lost, after unsafe sex, accounting for 1.7 million disability-adjusted life years (DALYs or 10.5% of all DALYs (95% uncertainty interval: 8.5%-12.5% in 2000. In women, intimate partner violence accounted for 50% and child sexual abuse for 32% of the total attributable DALYs. Conclusions The implications of our findings are that estimates that include only the direct injury burden seriously underrepresent the full health impact of interpersonal violence. Violence is an important direct and indirect cause of health loss and should be recognized as a priority health problem as well as a human rights and social issue. This study highlights the difficulties in measuring

Interpersonal violence: an important risk factor for disease and injury in South Africa.

Science.gov (United States)

Norman, Rosana; Schneider, Michelle; Bradshaw, Debbie; Jewkes, Rachel; Abrahams, Naeemah; Matzopoulos, Richard; Vos, Theo

2010-12-01

Burden of disease estimates for South Africa have highlighted the particularly high rates of injuries related to interpersonal violence compared with other regions of the world, but these figures tell only part of the story. In addition to direct physical injury, violence survivors are at an increased risk of a wide range of psychological and behavioral problems. This study aimed to comprehensively quantify the excess disease burden attributable to exposure to interpersonal violence as a risk factor for disease and injury in South Africa. The World Health Organization framework of interpersonal violence was adapted. Physical injury mortality and disability were categorically attributed to interpersonal violence. In addition, exposure to child sexual abuse and intimate partner violence, subcategories of interpersonal violence, were treated as risk factors for disease and injury using counterfactual estimation and comparative risk assessment methods. Adjustments were made to account for the combined exposure state of having experienced both child sexual abuse and intimate partner violence. Of the 17 risk factors included in the South African Comparative Risk Assessment study, interpersonal violence was the second leading cause of healthy years of life lost, after unsafe sex, accounting for 1.7 million disability-adjusted life years (DALYs) or 10.5% of all DALYs (95% uncertainty interval: 8.5%-12.5%) in 2000. In women, intimate partner violence accounted for 50% and child sexual abuse for 32% of the total attributable DALYs. The implications of our findings are that estimates that include only the direct injury burden seriously underrepresent the full health impact of interpersonal violence. Violence is an important direct and indirect cause of health loss and should be recognized as a priority health problem as well as a human rights and social issue. This study highlights the difficulties in measuring the disease burden from interpersonal violence as a risk factor

Ecosystems emerging. 5: Constraints

Czech Academy of Sciences Publication Activity Database

Patten, B. C.; Straškraba, Milan; Jorgensen, S. E.

2011-01-01

Roč. 222, č. 16 (2011), s. 2945-2972 ISSN 0304-3800 Institutional research plan: CEZ:AV0Z50070508 Keywords : constraint * epistemic * ontic Subject RIV: EH - Ecology, Behaviour Impact factor: 2.326, year: 2011 http://www.sciencedirect.com/science/article/pii/S0304380011002274

The importance of behavioural and pyschological symptoms in Alzheimer's disease.