Nuclear DNA content and base composition in 28 taxa of Musa.

Science.gov (United States)

Kamaté, K; Brown, S; Durand, P; Bureau, J M; De Nay, D; Trinh, T H

2001-08-01

The nuclear DNA content of 28 taxa of Musa was assessed by flow cytometry, using line PxPC6 of Petunia hybrida as an internal standard. The 2C DNA value of Musa balbisiana (BB genome) was 1.16 pg, whereas Musa acuminata (AA genome) had an average 2C DNA value of 1.27 pg, with a difference of 11% between its subspecies. The two haploid (IC) genomes, A and B, comprising most of the edible bananas, are therefore of similar size, 0.63 pg (610 million bp) and 0.58 pg (560 million bp), respectively. The genome of diploid Musa is thus threefold that of Arabidopsis thaliana. The genome sizes in a set of triploid Musa cultivars or clones were quite different, with 2C DNA values ranging from 1.61 to 2.23 pg. Likewise, the genome sizes of tetraploid cultivars ranged from 1.94 to 2.37 pg (2C). Apparently, tetraploids (for instance, accession I.C.2) can have a genome size that falls within the range of triploid genome sizes, and vice versa (as in the case of accession Simili Radjah). The 2C values estimated for organs such as leaf, leaf sheath, rhizome, and flower were consistent, whereas root material gave atypical results, owing to browning. The genomic base composition of these Musa taxa had a median value of 40.8% GC (SD = 0.43%).

Contrasting spatial patterns and ecological attributes of soil bacterial and archaeal taxa across a landscape.

Science.gov (United States)

Constancias, Florentin; Saby, Nicolas P A; Terrat, Sébastien; Dequiedt, Samuel; Horrigue, Wallid; Nowak, Virginie; Guillemin, Jean-Philippe; Biju-Duval, Luc; Chemidlin Prévost-Bouré, Nicolas; Ranjard, Lionel

2015-06-01

Even though recent studies have clarified the influence and hierarchy of environmental filters on bacterial community structure, those constraining bacterial populations variations remain unclear. In consequence, our ability to understand to ecological attributes of soil bacteria and to predict microbial community response to environmental stress is therefore limited. Here, we characterized the bacterial community composition and the various bacterial taxonomic groups constituting the community across an agricultural landscape of 12 km(2) , by using a 215 × 215 m systematic grid representing 278 sites to precisely decipher their spatial distribution and drivers at this scale. The bacterial and Archaeal community composition was characterized by applying 16S rRNA gene pyrosequencing directly to soil DNA from samples. Geostatistics tools were used to reveal the heterogeneous distribution of bacterial composition at this scale. Soil physical parameters and land management explained a significant amount of variation, suggesting that environmental selection is the major process shaping bacterial composition. All taxa systematically displayed also a heterogeneous and particular distribution patterns. Different relative influences of soil characteristics, land use and space were observed, depending on the taxa, implying that selection and spatial processes might be differentially but not exclusively involved for each bacterial phylum. Soil pH was a major factor determining the distribution of most of the bacterial taxa and especially the most important factor explaining the spatial patterns of α-Proteobacteria and Planctomycetes. Soil texture, organic carbon content and quality were more specific to a few number of taxa (e.g., β-Proteobacteria and Chlorobi). Land management also influenced the distribution of bacterial taxa across the landscape and revealed different type of response to cropping intensity (positive, negative, neutral or hump-backed relationships

Host-specificity among abundant and rare taxa in the sponge microbiome.

Science.gov (United States)

Reveillaud, Julie; Maignien, Loïs; Murat Eren, A; Huber, Julie A; Apprill, Amy; Sogin, Mitchell L; Vanreusel, Ann

2014-06-01

Microbial communities have a key role in the physiology of the sponge host, and it is therefore essential to understand the stability and specificity of sponge-symbiont associations. Host-specific bacterial associations spanning large geographic distance are widely acknowledged in sponges. However, the full spectrum of specificity remains unclear. In particular, it is not known whether closely related sponges host similar or very different microbiota over wide bathymetric and geographic gradients, and whether specific associations extend to the rare members of the sponge microbiome. Using the ultra-deep Illumina sequencing technology, we conducted a comparison of sponge bacterial communities in seven closely related Hexadella species with a well-resolved host phylogeny, as well as of a distantly related sponge Mycale. These samples spanned unprecedentedly large bathymetric (15-960 m) gradients and varying European locations. In addition, this study included a bacterial community analysis of the local background seawater for both Mycale and the widespread deep-sea taxa Hexadella cf. dedritifera. We observed a striking diversity of microbes associated with the sponges, spanning 47 bacterial phyla. The data did not reveal any Hexadella microbiota co-speciation pattern, but confirmed sponge-specific and species-specific host-bacteria associations, even within extremely low abundant taxa. Oligotyping analysis also revealed differential enrichment preferences of closely related Nitrospira members in closely related sponges species. Overall, these results demonstrate highly diverse, remarkably specific and stable sponge-bacteria associations that extend to members of the rare biosphere at a very fine phylogenetic scale, over significant geographic and bathymetric gradients.

Scaling-up HIV responses with key populations in West Africa.

Science.gov (United States)

Wheeler, Tisha; Wolf, R Cameron; Kapesa, Laurent; Cheng Surdo, Alison; Dallabetta, Gina

2015-03-01

Despite decades of HIV responses in pockets of West and Central Africa (WCA), the HIV response with key populations remains an understudied area. Recently, there has been a proliferation of studies highlighting epidemiologic and behavioral data that challenge attitudes of complacency among donors and country governments uncomfortable in addressing key populations. The articles in this series highlight new studies that provide a better understanding of the epidemiologic and structural burden facing key populations in the WCA region and how to improve responses through more effective targeting. Key populations face pervasive structural barriers including institutional and sexual violence and an intersection of stigma, criminalization, and marginalization as sexual minorities. Despite decades of smaller interventions that have shown the importance of integrated services for key populations, there remains incongruent provision of outreach or testing or family planning pointing to sustained risk. There remains an incongruent resource provision for key populations where they shoulder the burden of HIV and their access to services alone could turn around HIV epidemics within the region. These proximal and distal determinants must be addressed in regional efforts, led by the community, and resourced for scale, targeting those most at risk for the acquisition and transmission of HIV. This special issue builds the knowledge base for the region focusing on interventions that remove barriers to service access including treatment uptake for those living with HIV. Better analysis and use of data for strategic planning are shown to lead to more effective targeting of prevention, care, and HIV treatment programs with key populations. These articles further demonstrate the immediate need for comprehensive action to address HIV among key populations throughout the WCA region.

Mammal taxa constituting potential coevolved reservoirs of filoviruses

DEFF Research Database (Denmark)

Peterson, A.Townsend; Papes, Monica; Carroll, Darin S.

2007-01-01

-term coevolved reservoir of the filoviruses based on a coarse, regional classification of occurrences; here, we greatly refine the geographic data set for the mammalian taxa based on rich occurrence data sets and range interpolations from ecological niche models for each species involved. This improved detail...

Organisationally relevant variables and Keyes's Mental Health Continuum Scale: An exploratory study

Directory of Open Access Journals (Sweden)

Deo J.W. Strümpfer

2009-09-01

Full Text Available In an exploratory study on a sample of convenience (n = 165, 11 self-report variables with presumed organisational  relevance were  related,  as  predictors,  to  the  three  subscores  and  summed  score of  the Keyes  (2005a, 2005b; 2007 Mental Health Continuum  scale  (long  form. Keyes's  scale was administered five to seven days after the first set of scales. The predictor scores were reduced to three factorial scores, labelled positive orientation, negative orientation and positive striving. When classified thus, the predictor variables showed significant and meaningful relationships with some or all of the Keyes subscores and the total score, although few reached medium effect sizes.

Information filtering via a scaling-based function.

Science.gov (United States)

Qiu, Tian; Zhang, Zi-Ke; Chen, Guang

2013-01-01

Finding a universal description of the algorithm optimization is one of the key challenges in personalized recommendation. In this article, for the first time, we introduce a scaling-based algorithm (SCL) independent of recommendation list length based on a hybrid algorithm of heat conduction and mass diffusion, by finding out the scaling function for the tunable parameter and object average degree. The optimal value of the tunable parameter can be abstracted from the scaling function, which is heterogeneous for the individual object. Experimental results obtained from three real datasets, Netflix, MovieLens and RYM, show that the SCL is highly accurate in recommendation. More importantly, compared with a number of excellent algorithms, including the mass diffusion method, the original hybrid method, and even an improved version of the hybrid method, the SCL algorithm remarkably promotes the personalized recommendation in three other aspects: solving the accuracy-diversity dilemma, presenting a high novelty, and solving the key challenge of cold start problem.

Information filtering via a scaling-based function.

Directory of Open Access Journals (Sweden)

Tian Qiu

Full Text Available Finding a universal description of the algorithm optimization is one of the key challenges in personalized recommendation. In this article, for the first time, we introduce a scaling-based algorithm (SCL independent of recommendation list length based on a hybrid algorithm of heat conduction and mass diffusion, by finding out the scaling function for the tunable parameter and object average degree. The optimal value of the tunable parameter can be abstracted from the scaling function, which is heterogeneous for the individual object. Experimental results obtained from three real datasets, Netflix, MovieLens and RYM, show that the SCL is highly accurate in recommendation. More importantly, compared with a number of excellent algorithms, including the mass diffusion method, the original hybrid method, and even an improved version of the hybrid method, the SCL algorithm remarkably promotes the personalized recommendation in three other aspects: solving the accuracy-diversity dilemma, presenting a high novelty, and solving the key challenge of cold start problem.

Multilevel regularized regression for simultaneous taxa selection and network construction with metagenomic count data.

Science.gov (United States)

Liu, Zhenqiu; Sun, Fengzhu; Braun, Jonathan; McGovern, Dermot P B; Piantadosi, Steven

2015-04-01

Identifying disease associated taxa and constructing networks for bacteria interactions are two important tasks usually studied separately. In reality, differentiation of disease associated taxa and correlation among taxa may affect each other. One genus can be differentiated because it is highly correlated with another highly differentiated one. In addition, network structures may vary under different clinical conditions. Permutation tests are commonly used to detect differences between networks in distinct phenotypes, and they are time-consuming. In this manuscript, we propose a multilevel regularized regression method to simultaneously identify taxa and construct networks. We also extend the framework to allow construction of a common network and differentiated network together. An efficient algorithm with dual formulation is developed to deal with the large-scale n ≪ m problem with a large number of taxa (m) and a small number of samples (n) efficiently. The proposed method is regularized with a general Lp (p ∈ [0, 2]) penalty and models the effects of taxa abundance differentiation and correlation jointly. We demonstrate that it can identify both true and biologically significant genera and network structures. Software MLRR in MATLAB is available at http://biostatistics.csmc.edu/mlrr/. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diversity among Cynodon accessions and taxa based on DNA amplification fingerprinting.

Science.gov (United States)

Assefa, S; Taliaferro, C M; Anderson, M P; de los Reyes, B G; Edwards, R M

1999-06-01

The genus Cynodon (Gramineae), comprised of 9 species, is geographically widely distributed and genetically diverse. Information on the amounts of molecular genetic variation among and within Cynodon taxa is needed to enhance understanding of phylogenetic relations and facilitate germplasm management and breeding improvement efforts. Genetic relatedness among 62 Cynodon accessions, representing eight species, was assessed using DNA amplification fingerprinting (DAF). Ten 8-mer oligonucleotides were used to amplify specific Cynodon genomic sequences. The DNA amplification products of individual accessions were scored for presence (1) or absence (0) of bands. Similarity matrices were developed and the accessions were grouped by cluster (UPGMA) and principal coordinate analysis. Analyses were conducted within ploidy level (2x = 18 and 4x = 36) and over ploidy levels. Each primer revealed polymorphic loci among accessions within species. Of 539 loci (bands) scored, 496 (92%) were polymorphic. Cynodon arcuatus was clearly separated from other species by numerous monomorphic bands. The strongest species similarities were between C. aethiopicus and C. arcuatus, C. transvaalensis and C. plectostachyus, and C. incompletus and C. nlemfuensis. Intraspecific variation was least for C. aethiopicus, C. arcuatus, and C. transvaalensis, and greatest for C. dactylon. Accessions of like taxonomic classification were generally clustered, except the cosmopolitan C. dactylon var. dactylon and C. dactylon var. afganicus. Within taxa, accessions differing in chromosome number clustered in all instances indicating the 2x and 4x forms to be closely related. Little, if any, relationship was found between relatedness as indicated by the DAF profiles and previous estimates of hybridization potential between the different taxa.

Simple Web-based interactive key development software (WEBiKEY) and an example key for Kuruna (Poaceae: Bambusoideae).

Science.gov (United States)

Attigala, Lakshmi; De Silva, Nuwan I; Clark, Lynn G

2016-04-01

Programs that are user-friendly and freely available for developing Web-based interactive keys are scarce and most of the well-structured applications are relatively expensive. WEBiKEY was developed to enable researchers to easily develop their own Web-based interactive keys with fewer resources. A Web-based multiaccess identification tool (WEBiKEY) was developed that uses freely available Microsoft ASP.NET technologies and an SQL Server database for Windows-based hosting environments. WEBiKEY was tested for its usability with a sample data set, the temperate woody bamboo genus Kuruna (Poaceae). WEBiKEY is freely available to the public and can be used to develop Web-based interactive keys for any group of species. The interactive key we developed for Kuruna using WEBiKEY enables users to visually inspect characteristics of Kuruna and identify an unknown specimen as one of seven possible species in the genus.

Integrative taxonomy for continental-scale terrestrial insect observations.

Directory of Open Access Journals (Sweden)

Cara M Gibson

Full Text Available Although 21(st century ecology uses unprecedented technology at the largest spatio-temporal scales in history, the data remain reliant on sound taxonomic practices that derive from 18(th century science. The importance of accurate species identifications has been assessed repeatedly and in instances where inappropriate assignments have been made there have been costly consequences. The National Ecological Observatory Network (NEON will use a standardized system based upon an integrative taxonomic foundation to conduct observations of the focal terrestrial insect taxa, ground beetles and mosquitoes, at the continental scale for a 30 year monitoring program. The use of molecular data for continental-scale, multi-decadal research conducted by a geographically widely distributed set of researchers has not been evaluated until this point. The current paper addresses the development of a reference library for verifying species identifications at NEON and the key ways in which this resource will enhance a variety of user communities.

Integrative Taxonomy for Continental-Scale Terrestrial Insect Observations

Science.gov (United States)

Gibson, Cara M.; Kao, Rebecca H.; Blevins, Kali K.; Travers, Patrick D.

2012-01-01

Although 21st century ecology uses unprecedented technology at the largest spatio-temporal scales in history, the data remain reliant on sound taxonomic practices that derive from 18th century science. The importance of accurate species identifications has been assessed repeatedly and in instances where inappropriate assignments have been made there have been costly consequences. The National Ecological Observatory Network (NEON) will use a standardized system based upon an integrative taxonomic foundation to conduct observations of the focal terrestrial insect taxa, ground beetles and mosquitoes, at the continental scale for a 30 year monitoring program. The use of molecular data for continental-scale, multi-decadal research conducted by a geographically widely distributed set of researchers has not been evaluated until this point. The current paper addresses the development of a reference library for verifying species identifications at NEON and the key ways in which this resource will enhance a variety of user communities. PMID:22666362

Contributions towards a monograph of Phoma (Coelomycetes) — I. 2. Section Phoma: Additional taxa with very small conidia and taxa with conidia up to 7 µm long

OpenAIRE

Gruyter, de, J.; Noordeloos, M.E.; Boerema, G.H.

1993-01-01

Twenty-seven taxa in section Phoma with conidia not exceeding 7 µm in length are keyed out and described on account of their characteristics in vitro. Four new species are introduced: Phoma aurea de Gruyter, Noordel. & Boerema, Phoma crystallifer de Gruyter, Noordel. & Boerema, Phoma flavescens de Gruyter, Noordel. & Boerema and Phoma subherbarum de Gruyter, Noordel. & Boerema. As new names are proposed Phoma chenopodiicola de Gruyter, Noordel. & Boerema, Phoma pereupyrena de Gruyter, Noordel...

In vitro propagation of endangered Dianthus taxa

Directory of Open Access Journals (Sweden)

Marković Marija

2015-01-01

Full Text Available The review of recent researches regarding the in vitro culture of 30 endangered Dianthus taxa is presented in this paper. Various in vitro protocols developed for selected rare and threatened Dianthus taxa are analysed in order to provide a useful synthesis of the data obtained with the main principles, techniques and recommendations for futher research and practice. The recapitulated data presented in this review can be used as a tool for the micropropagation of other endangered Dianthus taxa, enabling their propagation and obtaining a sufficient amount of plants for reintroduction. In addition, the obtained results represent the basis for ex situ conservation of the investigated taxa, especially for medium-term and long-term conservation (cryopreservation. [Projekat Ministarstva nauke Republike Srbije, br. 43007

A theoretical framework for whole-plant carbon assimilation efficiency based on metabolic scaling theory: a test case using Picea seedlings.

Science.gov (United States)

Wang, Zhiqiang; Ji, Mingfei; Deng, Jianming; Milne, Richard I; Ran, Jinzhi; Zhang, Qiang; Fan, Zhexuan; Zhang, Xiaowei; Li, Jiangtao; Huang, Heng; Cheng, Dongliang; Niklas, Karl J

2015-06-01

Simultaneous and accurate measurements of whole-plant instantaneous carbon-use efficiency (ICUE) and annual total carbon-use efficiency (TCUE) are difficult to make, especially for trees. One usually estimates ICUE based on the net photosynthetic rate or the assumed proportional relationship between growth efficiency and ICUE. However, thus far, protocols for easily estimating annual TCUE remain problematic. Here, we present a theoretical framework (based on the metabolic scaling theory) to predict whole-plant annual TCUE by directly measuring instantaneous net photosynthetic and respiratory rates. This framework makes four predictions, which were evaluated empirically using seedlings of nine Picea taxa: (i) the flux rates of CO(2) and energy will scale isometrically as a function of plant size, (ii) whole-plant net and gross photosynthetic rates and the net primary productivity will scale isometrically with respect to total leaf mass, (iii) these scaling relationships will be independent of ambient temperature and humidity fluctuations (as measured within an experimental chamber) regardless of the instantaneous net photosynthetic rate or dark respiratory rate, or overall growth rate and (iv) TCUE will scale isometrically with respect to instantaneous efficiency of carbon use (i.e., the latter can be used to predict the former) across diverse species. These predictions were experimentally verified. We also found that the ranking of the nine taxa based on net photosynthetic rates differed from ranking based on either ICUE or TCUE. In addition, the absolute values of ICUE and TCUE significantly differed among the nine taxa, with both ICUE and temperature-corrected ICUE being highest for Picea abies and lowest for Picea schrenkiana. Nevertheless, the data are consistent with the predictions of our general theoretical framework, which can be used to access annual carbon-use efficiency of different species at the level of an individual plant based on simple, direct

About the scientific names of paraphyletic taxa

OpenAIRE

TIMM, Tarmo

2012-01-01

The 'naturality' of monophyletic taxa in comparison with that of paraphyletic ones is discussed, with examples from Clitellata. Regular scientific names for paraphyletic taxa are inevitable in a workable biological classification.

Determinantes Macroeconômicos da Estrutura a Termo da Taxa de Juros

OpenAIRE

Reis, Yuri Azevedo Pinto dos

2014-01-01

Este trabalho propõe a implementação de um modelo de três fatores em que os movimentos da Estrutura a Termo da Taxa de Juros são determinados por variáveis macroeconômicas observáveis. Desenvolvi o estudo com base na metodologia elaborada por Huse (2007), que propôs um novo modelo baseado nos estudos de Nelson e Siegel (1987) e Diebold e Li (2006). Os fatores utilizados foram: taxa de câmbio em reais por dólar, expectativa da taxa de inflação para daqui a doze meses, spread do Credit Default ...

Key Distribution and Changing Key Cryptosystem Based on Phase Retrieval Algorithm and RSA Public-Key Algorithm

Directory of Open Access Journals (Sweden)

Tieyu Zhao

2015-01-01

Full Text Available The optical image encryption has attracted more and more researchers’ attention, and the various encryption schemes have been proposed. In existing optical cryptosystem, the phase functions or images are usually used as the encryption keys, and it is difficult that the traditional public-key algorithm (such as RSA, ECC, etc. is used to complete large numerical key transfer. In this paper, we propose a key distribution scheme based on the phase retrieval algorithm and the RSA public-key algorithm, which solves the problem for the key distribution in optical image encryption system. Furthermore, we also propose a novel image encryption system based on the key distribution principle. In the system, the different keys can be used in every encryption process, which greatly improves the security of the system.

Identification of the key ecological factors influencing vegetation degradation in semi-arid agro-pastoral ecotone considering spatial scales

Science.gov (United States)

Peng, Yu; Wang, Qinghui; Fan, Min

2017-11-01

When assessing re-vegetation project performance and optimizing land management, identification of the key ecological factors inducing vegetation degradation has crucial implications. Rainfall, temperature, elevation, slope, aspect, land use type, and human disturbance are ecological factors affecting the status of vegetation index. However, at different spatial scales, the key factors may vary. Using Helin County, Inner-Mongolia, China as the study site and combining remote sensing image interpretation, field surveying, and mathematical methods, this study assesses key ecological factors affecting vegetation degradation under different spatial scales in a semi-arid agro-pastoral ecotone. It indicates that the key factors are different at various spatial scales. Elevation, rainfall, and temperature are identified as crucial for all spatial extents. Elevation, rainfall and human disturbance are key factors for small-scale quadrats of 300 m × 300 m and 600 m × 600 m, temperature and land use type are key factors for a medium-scale quadrat of 1 km × 1 km, and rainfall, temperature, and land use are key factors for large-scale quadrats of 2 km × 2 km and 5 km × 5 km. For this region, human disturbance is not the key factor for vegetation degradation across spatial scales. It is necessary to consider spatial scale for the identification of key factors determining vegetation characteristics. The eco-restoration programs at various spatial scales should identify key influencing factors according their scales so as to take effective measurements. The new understanding obtained in this study may help to explore the forces which driving vegetation degradation in the degraded regions in the world.

Retroelement insertional polymorphisms, diversity and phylogeography within diploid, D-genome Aegilops tauschii (Triticeae, Poaceae) sub-taxa in Iran.

Science.gov (United States)

Saeidi, Hojjatollah; Rahiminejad, Mohammad Reza; Heslop-Harrison, J S

2008-04-01

The diploid goat grass Aegilops tauschii (2n = 2x = 14) is native to the Middle East and is the D-genome donor to hexaploid bread wheat. The aim of this study was to measure the diversity of different subspecies and varieties of wild Ae. tauschii collected across the major areas where it grows in Iran and to examine patterns of diversity related to the taxa and geography. Inter-retroelement amplified polymorphism (IRAP) markers were used to analyse the biodiversity of DNA from 57 accessions of Ae. tauschii from northern and central Iran, and two hexaploid wheats. Key Results Eight IRAP primer combinations amplified a total of 171 distinct DNA fragments between 180 and 3200 bp long from the accessions, of which 169 were polymorphic. On average, about eight fragments were amplified with each primer combination, with more bands being amplified from accessions from the north-west of the country than from other accessions. The IRAP markers showed high levels of genetic diversity. Analysis of all accessions together did not allow the allocation of individuals to taxa based on morphology, but showed a tendency to put accessions from the north-west apart from others regions. It is speculated that this could be due to different activity of retroelements in the different regions. Within the two taxa with most accessions, there was a range of IRAP genotypes that could be correlated closely with geographical origin. This supports suggestions that the centre of origin of the species is towards the south-east of the Caspian Sea. IRAP is an appropriate marker system to evaluate genetic diversity and evolutionary relationships within the taxa, but it is too variable to define the taxa themselves, where more slowly evolving morphological, DNA sequence or chromosomal makers may be more appropriate.

Multiple stressor effects on marine infauna: responses of estuarine taxa and functional traits to sedimentation, nutrient and metal loading

KAUST Repository

Ellis, Joanne

2017-09-14

Sedimentation, nutrients and metal loading to coastal environments are increasing, associated with urbanization and global warming, hence there is a growing need to predict ecological responses to such change. Using a regression technique we predicted how maximum abundance of 20 macrobenthic taxa and 22 functional traits separately and interactively responded to these key stressors. The abundance of most taxa declined in response to sedimentation and metal loading while a unimodal response was often associated with nutrient loading. Optimum abundances for both taxa and traits occurred at relatively low stressor levels, highlighting the vulnerability of estuaries to increasing stressor loads. Individual taxa were more susceptible to stress than traits, suggesting that functional traits may be less sensitive for detecting changes in ecosystem health. Multiplicative effects were more common than additive interactions. The observed sensitivity of most taxa to increasing sedimentation and metal loading and the documented interaction effects between multiple stressors have important implications for understanding and managing the ecological consequences of eutrophication, sedimentation and contaminants on coastal ecosystems.

Fossil preservation and the stratigraphic ranges of taxa

Science.gov (United States)

Foote, M.; Raup, D. M.

1996-01-01

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy. Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased.(3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of

Habitat structure and body size distributions: Cross-ecosystem comparison for taxa with determinate and indeterminate growth

Science.gov (United States)

Nash, Kirsty L.; Allen, Craig R.; Barichievy, Chris; Nystrom, Magnus; Sundstrom, Shana M.; Graham, Nicholas A.J.

2014-01-01

Habitat structure across multiple spatial and temporal scales has been proposed as a key driver of body size distributions for associated communities. Thus, understanding the relationship between habitat and body size is fundamental to developing predictions regarding the influence of habitat change on animal communities. Much of the work assessing the relationship between habitat structure and body size distributions has focused on terrestrial taxa with determinate growth, and has primarily analysed discontinuities (gaps) in the distribution of species mean sizes (species size relationships or SSRs). The suitability of this approach for taxa with indeterminate growth has yet to be determined. We provide a cross-ecosystem comparison of bird (determinate growth) and fish (indeterminate growth) body mass distributions using four independent data sets. We evaluate three size distribution indices: SSRs, species size–density relationships (SSDRs) and individual size–density relationships (ISDRs), and two types of analysis: looking for either discontinuities or abundance patterns and multi-modality in the distributions. To assess the respective suitability of these three indices and two analytical approaches for understanding habitat–size relationships in different ecosystems, we compare their ability to differentiate bird or fish communities found within contrasting habitat conditions. All three indices of body size distribution are useful for examining the relationship between cross-scale patterns of habitat structure and size for species with determinate growth, such as birds. In contrast, for species with indeterminate growth such as fish, the relationship between habitat structure and body size may be masked when using mean summary metrics, and thus individual-level data (ISDRs) are more useful. Furthermore, ISDRs, which have traditionally been used to study aquatic systems, present a potentially useful common currency for comparing body size distributions

Keystone taxa as drivers of microbiome structure and functioning.

Science.gov (United States)

Banerjee, Samiran; Schlaeppi, Klaus; van der Heijden, Marcel G A

2018-05-22

Microorganisms have a pivotal role in the functioning of ecosystems. Recent studies have shown that microbial communities harbour keystone taxa, which drive community composition and function irrespective of their abundance. In this Opinion article, we propose a definition of keystone taxa in microbial ecology and summarize over 200 microbial keystone taxa that have been identified in soil, plant and marine ecosystems, as well as in the human microbiome. We explore the importance of keystone taxa and keystone guilds for microbiome structure and functioning and discuss the factors that determine their distribution and activities.

Quantum election scheme based on anonymous quantum key distribution

International Nuclear Information System (INIS)

Zhou Rui-Rui; Yang Li

2012-01-01

An unconditionally secure authority-certified anonymous quantum key distribution scheme using conjugate coding is presented, based on which we construct a quantum election scheme without the help of an entanglement state. We show that this election scheme ensures the completeness, soundness, privacy, eligibility, unreusability, fairness, and verifiability of a large-scale election in which the administrator and counter are semi-honest. This election scheme can work even if there exist loss and errors in quantum channels. In addition, any irregularity in this scheme is sensible. (general)

Maximum parsimony on subsets of taxa.

Science.gov (United States)

Fischer, Mareike; Thatte, Bhalchandra D

2009-09-21

In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

Phylogenetic conservatism of thermal traits explains dispersal limitation and genomic differentiation of Streptomyces sister-taxa.

Science.gov (United States)

Choudoir, Mallory J; Buckley, Daniel H

2018-06-07

The latitudinal diversity gradient is a pattern of biogeography observed broadly in plants and animals but largely undocumented in terrestrial microbial systems. Although patterns of microbial biogeography across broad taxonomic scales have been described in a range of contexts, the mechanisms that generate biogeographic patterns between closely related taxa remain incompletely characterized. Adaptive processes are a major driver of microbial biogeography, but there is less understanding of how microbial biogeography and diversification are shaped by dispersal limitation and drift. We recently described a latitudinal diversity gradient of species richness and intraspecific genetic diversity in Streptomyces by using a geographically explicit culture collection. Within this geographically explicit culture collection, we have identified Streptomyces sister-taxa whose geographic distribution is delimited by latitude. These sister-taxa differ in geographic distribution, genomic diversity, and ecological traits despite having nearly identical SSU rRNA gene sequences. Comparative genomic analysis reveals genomic differentiation of these sister-taxa consistent with restricted gene flow across latitude. Furthermore, we show phylogenetic conservatism of thermal traits between the sister-taxa suggesting that thermal trait adaptation limits dispersal and gene flow across climate regimes as defined by latitude. Such phylogenetic conservatism of thermal traits is commonly associated with latitudinal diversity gradients for plants and animals. These data provide further support for the hypothesis that the Streptomyces latitudinal diversity gradient was formed as a result of historical demographic processes defined by dispersal limitation and driven by paleoclimate dynamics.

Automatic selection of reference taxa for protein-protein interaction prediction with phylogenetic profiling

DEFF Research Database (Denmark)

Simonsen, Martin; Maetschke, S.R.; Ragan, M.A.

2012-01-01

Motivation: Phylogenetic profiling methods can achieve good accuracy in predicting protein–protein interactions, especially in prokaryotes. Recent studies have shown that the choice of reference taxa (RT) is critical for accurate prediction, but with more than 2500 fully sequenced taxa publicly......: We present three novel methods for automating the selection of RT, using machine learning based on known protein–protein interaction networks. One of these methods in particular, Tree-Based Search, yields greatly improved prediction accuracies. We further show that different methods for constituting...... phylogenetic profiles often require very different RT sets to support high prediction accuracy....

The HST Key Project on the Extragalactic Distance Scale

Science.gov (United States)

Freedman, W. L.

1994-12-01

One of the major unresolved problems in observational cosmology is the determination of the Hubble Constant, (H_0). The Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale aims to provide a measure of H_0 to an accuracy of 10%. Historically the route to H_0 has been plagued by systematic errors; hence there is no quick and easy route to a believeable value of H_0. Achieving plausible error limits of 10% requires careful attention to eliminating potential sources of systematic error. The strategy adopted by the Key Project team is threefold: First, to discover Cepheids in spiral galaxies located in the field and in small groups that are suitable for the calibration of several independent secondary methods. Second, to make direct Cepheid measurements of 3 spiral galaxies in the Virgo cluster and 2 members of the Fornax cluster. Third, to provide a check on the the Cepheid distance scale via independent distance estimates to nearby galaxies, and in addition, to undertake an empirical test of the sensitivity of the zero point of the Cepheid PL relation to heavy-element abundances. First results from the HST Key Project will be presented. We have now determined Cepheid distances to 4 galaxies using the HST: these are the nearby galaxies M81 and M101, the edge-on galaxy NGC 925, and the face-on spiral galaxy M100 in the Virgo cluster. Recently we have measured a Cepheid distance for M100 of 17 +/- 2 Mpc, which yields a value of H_0 = 80 +/- 17 km/sec/Mpc. This work was carried out in collaboration with the other members of the HST Key Project team, R. Kennicutt, J. Mould, F. Bresolin, S. Faber, L. Ferrarese, H. Ford, J. Graham, J. Gunn, M. Han, P. Harding, J. Hoessel, R. Hill, J. Huchra, S. Hughes, G. Illingworth, D. Kelson, B. Madore, R. Phelps, A. Saha, N. Silbermann, P. Stetson, and A. Turner.

Climate Controls AM Fungal Distributions from Global to Local Scales

Science.gov (United States)

Kivlin, S. N.; Hawkes, C.; Muscarella, R.; Treseder, K. K.; Kazenel, M.; Lynn, J.; Rudgers, J.

2016-12-01

Arbuscular mycorrhizal (AM) fungi have key functions in terrestrial biogeochemical processes; thus, determining the relative importance of climate, edaphic factors, and plant community composition on their geographic distributions can improve predictions of their sensitivity to global change. Local adaptation by AM fungi to plant hosts, soil nutrients, and climate suggests that all of these factors may control fungal geographic distributions, but their relative importance is unknown. We created species distribution models for 142 AM fungal taxa at the global scale with data from GenBank. We compared climate variables (BioClim and soil moisture), edaphic variables (phosphorus, carbon, pH, and clay content), and plant variables using model selection on models with (1) all variables, (2) climatic variables only (including soil moisture) and (3) resource-related variables only (all other soil parameters and NPP) using the MaxEnt algorithm evaluated with ENMEval. We also evaluated whether drivers of AM fungal distributions were phylogenetically conserved. To test whether global correlates of AM fungal distributions were reflected at local scales, we then surveyed AM fungi in nine plant hosts along three elevation gradients in the Upper Gunnison Basin, Colorado, USA. At the global scale, the distributions of 55% of AM fungal taxa were affected by both climate and soil resources, whereas 16% were only affected by climate and 29% were only affected by soil resources. Even for AM fungi that were affected by both climate and resources, the effects of climatic variables nearly always outweighed those of resources. Soil moisture and isothermality were the main climatic and NPP and soil carbon the main resource related factors influencing AM fungal distributions. Distributions of closely related AM fungal taxa were similarly affected by climate, but not by resources. Local scale surveys of AM fungi across elevations confirmed that climate was a key driver of AM fungal

FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION

Directory of Open Access Journals (Sweden)

B. Lakshmi

2010-09-01

Full Text Available In this paper, a novel encryption scheme with time based key technique on an FPGA is presented. Time based key technique ensures right key to be entered at right time and hence, vulnerability of encryption through brute force attack is eliminated. Presently available encryption systems, suffer from Brute force attack and in such a case, the time taken for breaking a code depends on the system used for cryptanalysis. The proposed scheme provides an effective method in which the time is taken as the second dimension of the key so that the same system can defend against brute force attack more vigorously. In the proposed scheme, the key is rotated continuously and four bits are drawn from the key with their concatenated value representing the delay the system has to wait. This forms the time based key concept. Also the key based function selection from a pool of functions enhances the confusion and diffusion to defend against linear and differential attacks while the time factor inclusion makes the brute force attack nearly impossible. In the proposed scheme, the key scheduler is implemented on FPGA that generates the right key at right time intervals which is then connected to a NIOS – II processor (a virtual microcontroller which is brought out from Altera FPGA that communicates with the keys to the personal computer through JTAG (Joint Test Action Group communication and the computer is used to perform encryption (or decryption. In this case the FPGA serves as hardware key (dongle for data encryption (or decryption.

Benefits to poorly studied taxa of conservation of bird and mammal diversity on islands.

Science.gov (United States)

Aslan, Clare; Holmes, Nick; Tershy, Bernie; Spatz, Dena; Croll, Donald A

2015-02-01

Protected area delineation and conservation action are urgently needed on marine islands, but the potential biodiversity benefits of these activities can be difficult to assess due to lack of species diversity information for lesser known taxa. We used linear mixed effects modeling and simple spatial analyses to investigate whether conservation activities based on the diversity of well-known insular taxa (birds and mammals) are likely to also capture the diversity of lesser known taxa (reptiles, amphibians, vascular land plants, ants, land snails, butterflies, and tenebrionid beetles). We assembled total, threatened, and endemic diversity data for both well-known and lesser known taxa and combined these with physical island biogeography characteristics for 1190 islands from 109 archipelagos. Among physical island biogeography factors, island area was the best indicator of diversity of both well-known and little-known taxa. Among taxonomic factors, total mammal species richness was the best indicator of total diversity of lesser known taxa, and the combination of threatened mammal and threatened bird diversity was the best indicator of lesser known endemic richness. The results of other intertaxon diversity comparisons were highly variable, however. Based on our results, we suggest that protecting islands above a certain minimum threshold area may be the most efficient use of conservation resources. For example, using our island database, if the threshold were set at 10 km(2) and the smallest 10% of islands greater than this threshold were protected, 119 islands would be protected. The islands would range in size from 10 to 29 km(2) and would include 268 lesser known species endemic to a single island, along with 11 bird and mammal species endemic to a single island. Our results suggest that for islands of equivalent size, prioritization based on total or threatened bird and mammal diversity may also capture opportunities to protect lesser known species endemic to

Differential growth responses of soil bacterial taxa to carbon substrates of varying chemical recalcitrance

Energy Technology Data Exchange (ETDEWEB)

Goldfarb, K.C.; Karaoz, U.; Hanson, C.A.; Santee, C.A.; Bradford, M.A.; Treseder, K.K.; Wallenstein, M.D.; Brodie, E.L.

2011-04-18

Soils are immensely diverse microbial habitats with thousands of co-existing bacterial, archaeal, and fungal species. Across broad spatial scales, factors such as pH and soil moisture appear to determine the diversity and structure of soil bacterial communities. Within any one site however, bacterial taxon diversity is high and factors maintaining this diversity are poorly resolved. Candidate factors include organic substrate availability and chemical recalcitrance, and given that they appear to structure bacterial communities at the phylum level, we examine whether these factors might structure bacterial communities at finer levels of taxonomic resolution. Analyzing 16S rRNA gene composition of nucleotide analog-labeled DNA by PhyloChip microarrays, we compare relative growth rates on organic substrates of increasing chemical recalcitrance of >2,200 bacterial taxa across 43 divisions/phyla. Taxa that increase in relative abundance with labile organic substrates (i.e., glycine, sucrose) are numerous (>500), phylogenetically clustered, and occur predominantly in two phyla (Proteobacteria and Actinobacteria) including orders Actinomycetales, Enterobacteriales, Burkholderiales, Rhodocyclales, Alteromonadales, and Pseudomonadales. Taxa increasing in relative abundance with more chemically recalcitrant substrates (i.e., cellulose, lignin, or tannin-protein) are fewer (168) but more phylogenetically dispersed, occurring across eight phyla and including Clostridiales, Sphingomonadalaes, Desulfovibrionales. Just over 6% of detected taxa, including many Burkholderiales increase in relative abundance with both labile and chemically recalcitrant substrates. Estimates of median rRNA copy number per genome of responding taxa demonstrate that these patterns are broadly consistent with bacterial growth strategies. Taken together, these data suggest that changes in availability of intrinsically labile substrates may result in predictable shifts in soil bacterial composition.

Agri-Environmental Resource Management by Large-Scale Collective Action: Determining KEY Success Factors

Science.gov (United States)

Uetake, Tetsuya

2015-01-01

Purpose: Large-scale collective action is necessary when managing agricultural natural resources such as biodiversity and water quality. This paper determines the key factors to the success of such action. Design/Methodology/Approach: This paper analyses four large-scale collective actions used to manage agri-environmental resources in Canada and…

The "most wanted" taxa from the human microbiome for whole genome sequencing.

Directory of Open Access Journals (Sweden)

Anthony A Fodor

Full Text Available The goal of the Human Microbiome Project (HMP is to generate a comprehensive catalog of human-associated microorganisms including reference genomes representing the most common species. Toward this goal, the HMP has characterized the microbial communities at 18 body habitats in a cohort of over 200 healthy volunteers using 16S rRNA gene (16S sequencing and has generated nearly 1,000 reference genomes from human-associated microorganisms. To determine how well current reference genome collections capture the diversity observed among the healthy microbiome and to guide isolation and future sequencing of microbiome members, we compared the HMP's 16S data sets to several reference 16S collections to create a 'most wanted' list of taxa for sequencing. Our analysis revealed that the diversity of commonly occurring taxa within the HMP cohort microbiome is relatively modest, few novel taxa are represented by these OTUs and many common taxa among HMP volunteers recur across different populations of healthy humans. Taken together, these results suggest that it should be possible to perform whole-genome sequencing on a large fraction of the human microbiome, including the 'most wanted', and that these sequences should serve to support microbiome studies across multiple cohorts. Also, in stark contrast to other taxa, the 'most wanted' organisms are poorly represented among culture collections suggesting that novel culture- and single-cell-based methods will be required to isolate these organisms for sequencing.

SDG and qualitative trend based model multiple scale validation

Science.gov (United States)

Gao, Dong; Xu, Xin; Yin, Jianjin; Zhang, Hongyu; Zhang, Beike

2017-09-01

Verification, Validation and Accreditation (VV&A) is key technology of simulation and modelling. For the traditional model validation methods, the completeness is weak; it is carried out in one scale; it depends on human experience. The SDG (Signed Directed Graph) and qualitative trend based multiple scale validation is proposed. First the SDG model is built and qualitative trends are added to the model. And then complete testing scenarios are produced by positive inference. The multiple scale validation is carried out by comparing the testing scenarios with outputs of simulation model in different scales. Finally, the effectiveness is proved by carrying out validation for a reactor model.

Uma estimação Econométrica da taxa de câmbio do Chile

Directory of Open Access Journals (Sweden)

Diogo Del Fiori

2011-05-01

Full Text Available O objetivo deste trabalho é modelar a taxa de câmbio do Chile, tendo por base dois modelos aplicados para a estimação da taxa de câmbio do Peru. O objetivo deste trabalho é averiguar qual dentre esses dois modelos aplicados para o caso do Peru é o mais adequado para o caso chileno, aplicando-se o critério de Akaike e o teste de Wald. Foi estimada uma relação de longo prazo (cointegração entre as variáveis do modelo. Assim, foi encontrada uma relação de longo prazo entre a taxa de câmbio e a taxa de juros e o risco-país para o caso chileno.

Indicator taxa revisited: useful for conservation planning?

DEFF Research Database (Denmark)

Larsen, Frank Wugt; Bladt, Jesper; Rahbek, Carsten

2009-01-01

Aim:  Indicators for biodiversity are needed to facilitate the identification of complementary reserve networks for biodiversity conservation. One widely adopted approach is to use indicator taxa, i.e. a single taxon such as birds or butterflies, despite the ongoing debate regarding their usefuln......Aim:  Indicators for biodiversity are needed to facilitate the identification of complementary reserve networks for biodiversity conservation. One widely adopted approach is to use indicator taxa, i.e. a single taxon such as birds or butterflies, despite the ongoing debate regarding...

Does better taxon sampling help? A new phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha) based on 50 new taxa and the same old mitochondrial and nuclear markers.

Science.gov (United States)

Zhao, Lei; Annie, Ang Shi Hui; Amrita, Srivathsan; Yi, Su Kathy Feng; Rudolf, Meier

2013-10-01

We here present a phylogenetic hypothesis for Sepsidae (Diptera: Cyclorrhapha), a group of schizophoran flies with ca. 320 described species that is widely used in sexual selection research. The hypothesis is based on five nuclear and five mitochondrial markers totaling 8813 bp for ca. 30% of the diversity (105 sepsid taxa) and - depending on analysis - six or nine outgroup species. Maximum parsimony (MP), maximum likelihood (ML), and Bayesian inferences (BI) yield overall congruent, well-resolved, and supported trees that are largely unaffected by three different ways to partition the data in BI and ML analyses. However, there are also five areas of uncertainty that affect suprageneric relationships where different analyses yield alternate topologies and MP and ML trees have significant conflict according to Shimodaira-Hasegawa tests. Two of these were already affected by conflict in a previous analysis that was based on the same genes and a subset of 69 species. The remaining three involve newly added taxa or genera whose relationships were previously resolved with low support. We thus find that the denser taxon sample in the present analysis does not reduce the topological conflict that had been identified previously. The present study nevertheless presents a significant contribution to the understanding of sepsid relationships in that 50 additional taxa from 18 genera are added to the Tree-of-Life of Sepsidae and that the placement of most taxa is well supported and robust to different tree reconstruction techniques. Copyright © 2013 Elsevier Inc. All rights reserved.

Key Questions in Marine Megafauna Movement Ecology.

Science.gov (United States)

Hays, Graeme C; Ferreira, Luciana C; Sequeira, Ana M M; Meekan, Mark G; Duarte, Carlos M; Bailey, Helen; Bailleul, Fred; Bowen, W Don; Caley, M Julian; Costa, Daniel P; Eguíluz, Victor M; Fossette, Sabrina; Friedlaender, Ari S; Gales, Nick; Gleiss, Adrian C; Gunn, John; Harcourt, Rob; Hazen, Elliott L; Heithaus, Michael R; Heupel, Michelle; Holland, Kim; Horning, Markus; Jonsen, Ian; Kooyman, Gerald L; Lowe, Christopher G; Madsen, Peter T; Marsh, Helene; Phillips, Richard A; Righton, David; Ropert-Coudert, Yan; Sato, Katsufumi; Shaffer, Scott A; Simpfendorfer, Colin A; Sims, David W; Skomal, Gregory; Takahashi, Akinori; Trathan, Philip N; Wikelski, Martin; Womble, Jamie N; Thums, Michele

2016-06-01

It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vegetation stability and the habitat associations of the endemic taxa of the Olympic Peninsula, Washington, USA

Directory of Open Access Journals (Sweden)

Daniel G. Gavin

2015-07-01

Full Text Available Explanations for areas of endemism often involve relative climatic stability, or low climate velocity, over time scales ranging from the Pleistocene to the late Cenozoic. Given that many narrowly endemic taxa in forested landscapes display discrete habitat associations, habitat stability should be similarly important for endemic persistence. Furthermore, while past climate variability is exceedingly difficult to quantify on millennial time scales, past distributions of habitats may be robustly inferred from paleoecological records. The Olympic Peninsula, Washington, supports a biota with several insular features including 29 endemic plant and animal taxa. Here I present the geographic distribution and habitat of the endemic taxa, and then examine the vegetation stability of the past 14,300 years from five pollen records associated with discrete vegetation zones on the peninsula. I show that 11 endemics have distributions centered on dry alpine scree and rock in the northeastern quadrant of the peninsula, and nine occur in shaded riparian forests in the southwest. Vegetation turnover during the post-glacial period was smallest in these areas. However, another long pollen record from the western peninsula reveals existence of shrub tundra and greatly reduced forest cover, indicating southward displacement of shaded riparian habitats by perhaps as much as 100 km. Although this study supports an association of post-glacial vegetation stability with endemism, records spanning the glacial maximum indicate widespread tundra during long periods of the late Pleistocene and therefore suggest southern displacement of forest-associated endemics. While some of the alpine scree-associated endemics may have persisted in situ, many others likely arrived via a variety of dispersal trajectories. These histories include dispersal from southern refugia towards ocean barriers preventing further northward dispersal, contraction from more widespread distributions, and

A Key Pre-Distribution Scheme Based on µ-PBIBD for Enhancing Resilience in Wireless Sensor Networks.

Science.gov (United States)

Yuan, Qi; Ma, Chunguang; Yu, Haitao; Bian, Xuefen

2018-05-12

Many key pre-distribution (KPD) schemes based on combinatorial design were proposed for secure communication of wireless sensor networks (WSNs). Due to complexity of constructing the combinatorial design, it is infeasible to generate key rings using the corresponding combinatorial design in large scale deployment of WSNs. In this paper, we present a definition of new combinatorial design, termed “µ-partially balanced incomplete block design (µ-PBIBD)”, which is a refinement of partially balanced incomplete block design (PBIBD), and then describe a 2-D construction of µ-PBIBD which is mapped to KPD in WSNs. Our approach is of simple construction which provides a strong key connectivity and a poor network resilience. To improve the network resilience of KPD based on 2-D µ-PBIBD, we propose a KPD scheme based on 3-D Ex-µ-PBIBD which is a construction of µ-PBIBD from 2-D space to 3-D space. Ex-µ-PBIBD KPD scheme improves network scalability and resilience while has better key connectivity. Theoretical analysis and comparison with the related schemes show that key pre-distribution scheme based on Ex-µ-PBIBD provides high network resilience and better key scalability, while it achieves a trade-off between network resilience and network connectivity.

Aligning conservation goals: are patterns of species richness and endemism concordant at regional scales?

Directory of Open Access Journals (Sweden)

Ricketts, T. H.

2001-01-01

Full Text Available Biodiversity conservation strategies commonly target areas of high species richness and/or high endemism. However, the correlation between richness and endemism at scales relevant to conservation is unclear; these two common goals of conservation plans may therefore be in conflict. Here the spatial concordance between richness and endemism is tested using five taxa in North America: butterflies, birds, mammals, amphibians, and reptiles. This concordance is also tested using overall indices of richness and endemism (incorporating all five taxa. For all taxa except birds, richness and endemism were significantly correlated, with amphibians, reptiles, and the overall indices showing the highest correlations (rs = 0.527-0.676. However, 'priority sets' of ecoregions (i.e., the top 10% of ecoregions based on richness generally overlapped poorly with those based on endemism (< 50% overlap for all but reptiles. These results offer only limited support for the idea that richness and endemism are correlated at broad scales and indicate that land managers will need to balance these dual, and often conflicting, goals of biodiversity conservation.

Image encryption using fingerprint as key based on phase retrieval algorithm and public key cryptography

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2015-09-01

In this paper, a novel image encryption system with fingerprint used as a secret key is proposed based on the phase retrieval algorithm and RSA public key algorithm. In the system, the encryption keys include the fingerprint and the public key of RSA algorithm, while the decryption keys are the fingerprint and the private key of RSA algorithm. If the users share the fingerprint, then the system will meet the basic agreement of asymmetric cryptography. The system is also applicable for the information authentication. The fingerprint as secret key is used in both the encryption and decryption processes so that the receiver can identify the authenticity of the ciphertext by using the fingerprint in decryption process. Finally, the simulation results show the validity of the encryption scheme and the high robustness against attacks based on the phase retrieval technique.

Diversity and dynamics of dominant and rare bacterial taxa in replicate sequencing batch reactors operated under different solids retention time

KAUST Repository

Bagchi, Samik; Garcia Tellez, Berenice; Rao, Hari Ananda; Lamendella, Regina; Saikaly, Pascal

2014-01-01

In this study, 16S rRNA gene pyrosequencing was applied in order to provide a better insight on the diversity and dynamics of total, dominant, and rare bacterial taxa in replicate lab-scale sequencing batch reactors (SBRs) operated at different

Key processes at the stand to landscape scale

International Nuclear Information System (INIS)

Perry, D.A.

1991-01-01

The smooth transition from one mature community type to another during climate change depends on the rate of climate change, the speed of migration, and the stability of extant communities as they become increasingly maladapted to local climates. The expected increase in natural disturbances will probably be the most important factor influencing forests over the next century, and has the potential to convert many forests to early successional, perhaps weedy vegetation. Protecting key structures and processes at both the stand and landscape scale will be critically important to easing the transition from one mature forest type to another and preventing site capture by weeds. Two general steps are necessary at the landscape scale: maintain migration corridors, and promote landscape patterns that dampen, rather than magnify, the spread of disturbances. At the stand level, it will be important to protect photosynthetic capacity and soil fertility. Steps to accomplish these goals include: protection of habitats required by natural enemies of forest pests; maintenance or restoration of natural biological diversity; maintenance or restoration of individual tree vigor through practices such as aggressive thinning; and moving from clearcutting to shelterwoods and/or group selections, thereby keeping some cover of mature green trees on sites at all times. 28 refs

Ripple scalings in geothermal facilities, a key to understand the scaling process

Science.gov (United States)

Köhl, Bernhard; Grundy, James; Baumann, Thomas

2017-04-01

Scalings are a widespread problem among geothermal plants which exploit the Malm Aquifer in the Bavarian Molasse Zone. They effect the technical and economic efficiency of geothermal plants. The majority of the scalings observed at geothermal facilities exploring the Malm aquifer in the Bavarian Molasse Basin are carbonates. They are formed due to a disruption of the lime-carbonic-acid equilibrium during production caused by degassing of CO2. These scalings are found in the production pipes, at the pumps and at filters and can nicely be described using existing hydrogeochemical models. This study proposes a second mechanism for the formation of scalings in ground-level facilities. We investigated scalings which accumulated at the inlet to the heat exchanger. Interestingly, the scalings were recovered after the ground level facilities had been cleaned. The scalings showed distinct ripple structures, which is likely a result of solid particle deposition. From the ripple features the the flow conditions during their formation were calculated based on empirical equations (Soulsby, 2012). The calculations suggest that the deposits were formed during maintenance works. Thin section images of the sediments indicate a two-step process: deposition of sediment grains, followed by stabilization with a calcite layer. The latter likely occured during maintenance. To prevent this type of scalings blocking the heat exchangers, the maintenance procedure has to be revised. References: Soulsby, R. L.; Whitehouse, R. J. S.; Marten, K. V.: Prediction of time-evolving sand ripples in shelf seas. Continental Shelf Research 2012, 38, 47-62

Multi-scale Drivers of Variations in Atmospheric Evaporative Demand Based on Observations and Physically-based Modeling

Science.gov (United States)

Peng, L.; Sheffield, J.; Li, D.

2015-12-01

Evapotranspiration (ET) is a key link between the availability of water resources and climate change and climate variability. Variability of ET has important environmental and socioeconomic implications for managing hydrological hazards, food and energy production. Although there have been many observational and modeling studies of ET, how ET has varied and the drivers of the variations at different temporal scales remain elusive. Much of the uncertainty comes from the atmospheric evaporative demand (AED), which is the combined effect of radiative and aerodynamic controls. The inconsistencies among modeled AED estimates and the limited observational data may originate from multiple sources including the limited time span and uncertainties in the data. To fully investigate and untangle the intertwined drivers of AED, we present a spectrum analysis to identify key controls of AED across multiple temporal scales. We use long-term records of observed pan evaporation for 1961-2006 from 317 weather stations across China and physically-based model estimates of potential evapotranspiration (PET). The model estimates are based on surface meteorology and radiation derived from reanalysis, satellite retrievals and station data. Our analyses show that temperature plays a dominant role in regulating variability of AED at the inter-annual scale. At the monthly and seasonal scales, the primary control of AED shifts from radiation in humid regions to humidity in dry regions. Unlike many studies focusing on the spatial pattern of ET drivers based on a traditional supply and demand framework, this study underlines the importance of temporal scales when discussing controls of ET variations.

A brief review of revocable ID-based public key cryptosystem

Directory of Open Access Journals (Sweden)

Tsu-Yang Wu

2016-03-01

Full Text Available The design of ID-based cryptography has received much attention from researchers. However, how to revoke the misbehaviour/compromised user in ID-based public key cryptosystem becomes an important research issue. Recently, Tseng and Tsai proposed a novel public key cryptosystem called revocable ID-based public key cryptosystem (RIBE to solve the revocation problem. Later on, numerous research papers based on the Tseng-Tsai key RIBE were proposed. In this paper, we brief review Tseng and Tsai's RIBE. We hope this review can help the readers to understand the Tseng and Tsai's revocable ID-based public key cryptosystem.

Revisions and key to the Vernonieae (Compositae) of Thailand

Science.gov (United States)

Bunwong, Sukhonthip; Chantaranothai, Pranom; Keeley, Sterling C.

2014-01-01

Abstract Seventeen genera and 48 species, in five subtribes, are recognized in Thailand. These include 15 endemic taxa, half of which are in the largest genus, Acilepis, with others in the genera Camchaya, Koyamasia, and Okia. A new monotypic genus, Pulicarioidea, is established with P. annamica, the new name for the species formerly known as Vernonia pulicarioides. New combinations are also made for Acilepis kerrii, Cyanthillium montanum, Koyamasia curtisii and Okia pseudobirmanica. Forty-six characters including habit, leaf, flower, achene and pollen morphology were analyzed using UPGMA. Five clusters of taxa were identified. Keys to genera, species and varieties, descriptions, vernacular names, ecological data and illustrations are provided. PMID:24843297

Sea snakes in Australian waters (Serpentes: subfamilies Hydrophiinae and Laticaudinae)—a review with an updated identification key

DEFF Research Database (Denmark)

Redsted Rasmussen, Arne; Sanders, Kate Laura; Guinea, Michael L

2014-01-01

Sea snakes (Elapidae, subfamilies Hydrophiinae and Laticaudinae) reach high species richness in the South China Sea and in the Australian region; however, most countries in the two regions still lack up-to-date checklists and identification tools for these snakes. We present an updated reviewed...... checklist and a new complete identification key to sea snakes in Australian waters. The identification key includes 29 species documented and 4 possibly occurring taxa and is based mostly on easy-to-use external characters. We find no evidence for breeding populations of Laticauda in Australian waters...

Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa?

Science.gov (United States)

Berger, Elisabeth; Haase, Peter; Schäfer, Ralf B; Sundermann, Andrea

2018-04-01

Monitoring of macroinvertebrate communities is frequently used to define the ecological health status of rivers. Ideally, biomonitoring should also give an indication on the major stressors acting on the macroinvertebrate communities supporting the selection of appropriate management measures. However, most indices are affected by more than one stressor. Biological traits (e.g. size, generation time, reproduction) could potentially lead to more stressor-specific indices. However, such an approach has rarely been tested. In this study we classify 324 macroinvertebrate taxa as vulnerable (decreasing abundances) or tolerant (increasing abundances) along 21 environmental gradients (i.e. nutrients, major ions, oxygen and micropollutants) from 422 monitoring sites in Germany using Threshold Indicator Taxa Analysis (TITAN). Subsequently, we investigate which biological traits and taxonomic groups are associated with taxa classified as vulnerable or tolerant with regard to specific gradients. The response of most taxa towards different gradients was similar and especially high for correlated gradients. Traits associated with vulnerable taxa across most gradients included: larval aquatic life stages, isolated cemented eggs, reproductive cycle per year macrophytes, microphytes, silt or mud and a body size >2-4cm. Our results question whether stressor-specific indices based on macroinvertebrate assemblages can be achieved using single traits, because we observed that similar taxa responded to different gradients and also similar traits were associated with vulnerable and tolerant taxa across a variety of water quality gradients. Future studies should examine whether combinations of traits focusing on specific taxonomic groups achieve higher stressor specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

A conformação estrutural da taxa de juros

OpenAIRE

Reinert, José Nilson

2010-01-01

Trata da conformação da taxa de juros no longo prazo. Aborda o tema dentro da teoria marxista e apresenta o volume de reservas formadas ao longo dos ciclos econômicos como determinante principal da taxa de juros. Analisa dados da economia norte-americana, visando ilustrar as hopóteses apresentadas.

Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers

Science.gov (United States)

Garzón-Martínez, Gina A.; Osorio-Guarín, Jaime A.; Delgadillo-Durán, Paola; Mayorga, Franklin; Enciso-Rodríguez, Felix E.; Landsman, David

2015-01-01

The genus Physalis is common in the Americas and includes several economically important species, among them Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNPs) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation FST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies. PMID:26550601

Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers.

Science.gov (United States)

Garzón-Martínez, Gina A; Osorio-Guarín, Jaime A; Delgadillo-Durán, Paola; Mayorga, Franklin; Enciso-Rodríguez, Felix E; Landsman, David; Mariño-Ramírez, Leonardo; Barrero, Luz Stella

2015-12-01

The genus Physalis is common in the Americas and includes several economically important species, among them Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNPs) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation F ST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies.

A secure key agreement protocol based on chaotic maps

International Nuclear Information System (INIS)

Wang Xing-Yuan; Luan Da-Peng

2013-01-01

To guarantee the security of communication in the public channel, many key agreement protocols have been proposed. Recently, Gong et al. proposed a key agreement protocol based on chaotic maps with password sharing. In this paper, Gong et al.'s protocol is analyzed, and we find that this protocol exhibits key management issues and potential security problems. Furthermore, the paper presents a new key agreement protocol based on enhanced Chebyshev polynomials to overcome these problems. Through our analysis, our key agreement protocol not only provides mutual authentication and the ability to resist a variety of common attacks, but also solve the problems of key management and security issues existing in Gong et al.'s protocol

Progressive Amalgamation of Building Clusters for Map Generalization Based on Scaling Subgroups

Directory of Open Access Journals (Sweden)

Xianjin He

2018-03-01

Full Text Available Map generalization utilizes transformation operations to derive smaller-scale maps from larger-scale maps, and is a key procedure for the modelling and understanding of geographic space. Studies to date have largely applied a fixed tolerance to aggregate clustered buildings into a single object, resulting in the loss of details that meet cartographic constraints and may be of importance for users. This study aims to develop a method that amalgamates clustered buildings gradually without significant modification of geometry, while preserving the map details as much as possible under cartographic constraints. The amalgamation process consists of three key steps. First, individual buildings are grouped into distinct clusters by using the graph-based spatial clustering application with random forest (GSCARF method. Second, building clusters are decomposed into scaling subgroups according to homogeneity with regard to the mean distance of subgroups. Thus, hierarchies of building clusters can be derived based on scaling subgroups. Finally, an amalgamation operation is progressively performed from the bottom-level subgroups to the top-level subgroups using the maximum distance of each subgroup as the amalgamating tolerance instead of using a fixed tolerance. As a consequence of this step, generalized intermediate scaling results are available, which can form the multi-scale representation of buildings. The experimental results show that the proposed method can generate amalgams with correct details, statistical area balance and orthogonal shape while satisfying cartographic constraints (e.g., minimum distance and minimum area.

Previdência e Taxa de Juros no Brasil

Directory of Open Access Journals (Sweden)

Brian Bolarinwa Ogundairo

Full Text Available O presente trabalho relaciona a alta taxa de juros real brasileira com o elevado gasto em previdência sob um regime de repartição. Para tanto, utilizamos uma versão padrão do modelo de gerações sobrepostas, com um regime de previdência misto (isto é, parte capitalização e parte repartição. O modelo é calibrado para a economia brasileira no período 2000-2014. Considera-se um estado estacionário inicial de modo a reproduzir a taxa de juros real média nesse período, sob um regime totalmente do tipo repartição. Simula-se então uma mudança para replicar os gastos em previdência do Chile, um país com um sistema majoritariamente do tipo capitalização. Em nossa especificação preferida, o modelo prevê uma queda de 1 ponto percentual na taxa de juros real (ao ano de longo prazo. Isso corresponde a 18% do diferencial médio de juros entre Brasil e Chile no período 2000-2014.

PERENNIAL HELIANTHUS TAXA IN TÂRGU-MURES CITY AND ITS SURROUNDINGS

Directory of Open Access Journals (Sweden)

FILEP RITA

2010-12-01

Full Text Available Although in the neighbouring countries several perennial Helianthus taxa have been recorded in the last decade, in Romania only three have been identified so far. The literature and herbaria data of Târgu-Mures date back to the end of the XIXth century, and only refer to H. × multiflorus and H. tuberosus. The aim of this study was to identify the perennial Helianthus taxa in this region and to prepare their current distribution map. The survey was conducted in Târgu Mures city and the neighbouring villages: Livezeni, Sântana de Mures, Sâncraiu de Mures, Sângeorgiu de Mures, and Corunca. Four taxa were identified: H. pauciflorus Nutt., H. × laetiflorus Pers., H. tuberosus L. s.str., and Helianthus tuberosus L. s.l. The first two taxa are cultivated as ornamental plants, H. tuberosus s. str. is cultivated in a few farms, whereas H. tuberosus s. l. is an invasive species that spreads along the rivers.

Verificação do poder preditivo do spread entre as taxas de juros de longo e curto prazos na variação das taxas de curto prazo no Brasil

OpenAIRE

Silva, Arlete da

2006-01-01

A Hipótese das Expectativas (HE) é testada na Estrutura a Termo das Taxas de Juros brasileira (ETTJ) no sentido de se verificar se a inclinação da curva de juros, representada pelo spread entre as taxas de juros de longo e curto prazos, pode explicar as variações das taxas de juros de curto prazo no Brasil. Foram utilizadas séries com médias mensais das taxas de juros de um, três e seis meses, de janeiro de 1995 a janeiro de 2006, empregando metodologia baseada em regressões individuais. Os r...

Password-based authenticated key exchange scheme using smart card

Science.gov (United States)

Liu, Hui; Zhong, Shaojun

2013-03-01

A protocol that allows any two entities to negotiate a shared session key is commonly called a key exchange protocol. If the protocol provides a function to authenticate each other, we call the protocol authenticated key exchange protocol (AKE). Password authentication key exchange (PAKE) is the AKE protocol in which the two entities share a humanmemorable password. Most of current PAKE relies on the existence of a public key infrastructure, which sometime is impossible for a certain environments such as low computational device due to the computation overhead. In this paper, we propose password-based authenticated key exchange using smart card. Compared to previous PAKE, our protocol is more efficient because our protocol is based on ECC. Thereby, the proposed protocol can be well applied to low computation device.

Optimal attacks on qubit-based Quantum Key Recycling

Science.gov (United States)

Leermakers, Daan; Škorić, Boris

2018-03-01

Quantum Key Recycling (QKR) is a quantum cryptographic primitive that allows one to reuse keys in an unconditionally secure way. By removing the need to repeatedly generate new keys, it improves communication efficiency. Škorić and de Vries recently proposed a QKR scheme based on 8-state encoding (four bases). It does not require quantum computers for encryption/decryption but only single-qubit operations. We provide a missing ingredient in the security analysis of this scheme in the case of noisy channels: accurate upper bounds on the required amount of privacy amplification. We determine optimal attacks against the message and against the key, for 8-state encoding as well as 4-state and 6-state conjugate coding. We provide results in terms of min-entropy loss as well as accessible (Shannon) information. We show that the Shannon entropy analysis for 8-state encoding reduces to the analysis of quantum key distribution, whereas 4-state and 6-state suffer from additional leaks that make them less effective. From the optimal attacks we compute the required amount of privacy amplification and hence the achievable communication rate (useful information per qubit) of qubit-based QKR. Overall, 8-state encoding yields the highest communication rates.

Illustrated Plant Identification Keys: An Interactive Tool to Learn Botany

Science.gov (United States)

Silva, Helena; Pinho, Rosa; Lopes, Lisia; Nogueira, Antonio J. A.; Silveira, Paulo

2011-01-01

An Interactive Dichotomous Key (IDK) for 390 "taxa" of vascular plants from the Ria de Aveiro, available on a website, was developed to help teach botany to school and universitary students. This multimedia tool includes several links to Descriptive and Illustrated Glossaries. Questionnaires answered by high-school and undergraduate students about…

Previsão da taxa de juros utilizando o modelo de Vasicek

OpenAIRE

Schoof, Hagen

2011-01-01

Este trabalho estuda a previsão da taxa de juros com foco em uma estratégia de investimento. Inicialmente é feita a parametrização da taxa de juros com o modelo de Vasicek para posterior aplicação do modelo autorregressivo tanto na taxa de juros quanto nos parâmetros do Vasicek. O instrumento financeiro escolhido para verificar a eficácia da metodologia proposta foi o constant matutity swap aplicado em alguns vértices. Os resultados variaram significativamente para os diferentes horizontes de...

Spatial structure of a natural mixed topodeme of subalpine Sorbus taxa

Directory of Open Access Journals (Sweden)

Dušan Gömöry

2011-01-01

Full Text Available Spatial distribution and genetic variation of a population of Sorbus chamaemespilus (L. Crantz and putative hybrids between S. chamaemespilus, S. aria and S. aucuparia growing in the nature reserve Skalnä Alpa (central Slovakia were studied. The analysis of spatial patterns using Ripley's K-function revealed a significant clustering of the adults of both S. chamaemespilus and hybrid taxa at distances up to ~15 m and a strong affinity between both taxonomical groups, indicating similar ecological requirements. Bivariate point-pattern analysis considering cardinal direction showed that juvenile individuals of S. chamaemespilus are clustered around the adults up to the distance of ~2 m, whereas in hybrid taxa with larger and more dense crowns, juveniles are clustered at distances more than ~3 m from the adults. The analysis of genetic variation in a subset of adult shrubs using 4 nuclear microsatellite loci revealed that unlike expected, there was no variation in S. chamaemespilus but several genotypes were found in the group of hybrid taxa. Implications for the reproduction system and conservation of the investigated taxa are discussed.

Zulma Ageitos de Castellanos: Publications and status of described taxa.

Science.gov (United States)

Signorelli, Javier H; Urteaga, Diego; Teso, Valeria

2015-10-28

Zulma Ageitos de Castellanos was an Argentinian malacologist working in the "Facultad de Ciencias Naturales y Museo" at La Plata University where she taught invertebrate zoology between 1947 and 1990. Her scientific publications are listed in chronological order. Described genus-group and species-group taxa are listed. Information about the type locality and type material, and taxonomic remarks are also provided. Finally, type material of all described taxa was requested and, when located, illustrated.

Finite-key analysis for quantum key distribution with weak coherent pulses based on Bernoulli sampling

Science.gov (United States)

Kawakami, Shun; Sasaki, Toshihiko; Koashi, Masato

2017-07-01

An essential step in quantum key distribution is the estimation of parameters related to the leaked amount of information, which is usually done by sampling of the communication data. When the data size is finite, the final key rate depends on how the estimation process handles statistical fluctuations. Many of the present security analyses are based on the method with simple random sampling, where hypergeometric distribution or its known bounds are used for the estimation. Here we propose a concise method based on Bernoulli sampling, which is related to binomial distribution. Our method is suitable for the Bennett-Brassard 1984 (BB84) protocol with weak coherent pulses [C. H. Bennett and G. Brassard, Proceedings of the IEEE Conference on Computers, Systems and Signal Processing (IEEE, New York, 1984), Vol. 175], reducing the number of estimated parameters to achieve a higher key generation rate compared to the method with simple random sampling. We also apply the method to prove the security of the differential-quadrature-phase-shift (DQPS) protocol in the finite-key regime. The result indicates that the advantage of the DQPS protocol over the phase-encoding BB84 protocol in terms of the key rate, which was previously confirmed in the asymptotic regime, persists in the finite-key regime.

An Empirical Study on the Moderate Scale of Food-production-based Family Farm in Guangxi

Institute of Scientific and Technical Information of China (English)

Yaogui WU

2016-01-01

The moderate scale family farm is the future agricultural business entity in China,and the scale of family farm is a key factor affecting its development.With Guigang City in Guangxi as a point for the study,from the perspective of maximizing income of rural households,this paper uses production function model to calculate the moderate scale of food-production-based family farm at 5.7 ha,and makes policy recommendations.

Multi-biometrics based cryptographic key regeneration scheme

OpenAIRE

Kanade , Sanjay Ganesh; Petrovska-Delacrétaz , Dijana; Dorizzi , Bernadette

2009-01-01

International audience; Biometrics lack revocability and privacy while cryptography cannot detect the user's identity. By obtaining cryptographic keys using biometrics, one can achieve the properties such as revocability, assurance about user's identity, and privacy. In this paper, we propose a multi-biometric based cryptographic key regeneration scheme. Since left and right irises of a person are uncorrelated, we treat them as two independent biometrics and combine in our system. We propose ...

How many taxa can be recognized within the complex Tillandsia capillaris (Bromeliaceae, Tillandsioideae? Analysis of the available classifications using a multivariate approach

Directory of Open Access Journals (Sweden)

Lucía Castello

2013-05-01

Full Text Available Tillandsia capillaris Ruiz & Pav., which belongs to the subgenus Diaphoranthema is distributed in Ecuador, Peru, Bolivia, northern and central Argentina, and Chile, and includes forms that are difficult to circumscribe, thus considered to form a complex. The entities of this complex are predominantly small-sized epiphytes, adapted to xeric environments. The most widely used classification defines 5 forms for this complex based on few morphological reproductive traits: T. capillaris Ruiz & Pav. f. capillaris, T. capillaris f. incana (Mez L.B. Sm., T. capillaris f. cordobensis (Hieron. L.B. Sm., T. capillaris f. hieronymi (Mez L.B. Sm. and T. capillaris f. virescens (Ruiz & Pav. L.B. Sm. In this study, 35 floral and vegetative characters were analyzed with a multivariate approach in order to assess and discuss different proposals for classification of the T. capillaris complex, which presents morphotypes that co-occur in central and northern Argentina. To accomplish this, data of quantitative and categorical morphological characters of flowers and leaves were collected from herbarium specimens and field collections and were analyzed with statistical multivariate techniques. The results suggest that the last classification for the complex seems more comprehensive and three taxa were delimited: T. capillaris (=T. capillaris f. incana-hieronymi, T. virescens s. str. (=T. capillaris f. cordobensis and T. virescens s. l. (=T. capillaris f. virescens. While T. capillaris and T. virescens s. str. co-occur, T. virescens s. l. is restricted to altitudes above 2000 m in Argentina. Characters previously used for taxa delimitation showed continuous variation and therefore were not useful. New diagnostic characters are proposed and a key is provided for delimiting these three taxa within the complex.

How many taxa can be recognized within the complex Tillandsia capillaris (Bromeliaceae, Tillandsioideae)? Analysis of the available classifications using a multivariate approach.

Science.gov (United States)

Castello, Lucía V; Galetto, Leonardo

2013-01-01

Tillandsia capillaris Ruiz & Pav., which belongs to the subgenus Diaphoranthema is distributed in Ecuador, Peru, Bolivia, northern and central Argentina, and Chile, and includes forms that are difficult to circumscribe, thus considered to form a complex. The entities of this complex are predominantly small-sized epiphytes, adapted to xeric environments. The most widely used classification defines 5 forms for this complex based on few morphological reproductive traits: Tillandsia capillaris Ruiz & Pav. f. capillaris, Tillandsia capillaris f. incana (Mez) L.B. Sm., Tillandsia capillaris f. cordobensis (Hieron.) L.B. Sm., Tillandsia capillaris f. hieronymi (Mez) L.B. Sm. and Tillandsia capillaris f. virescens (Ruiz & Pav.) L.B. Sm. In this study, 35 floral and vegetative characters were analyzed with a multivariate approach in order to assess and discuss different proposals for classification of the Tillandsia capillaris complex, which presents morphotypes that co-occur in central and northern Argentina. To accomplish this, data of quantitative and categorical morphological characters of flowers and leaves were collected from herbarium specimens and field collections and were analyzed with statistical multivariate techniques. The results suggest that the last classification for the complex seems more comprehensive and three taxa were delimited: Tillandsia capillaris (=Tillandsia capillaris f. incana-hieronymi), Tillandsia virescens s. str. (=Tillandsia capillaris f. cordobensis) and Tillandsia virescens s. l. (=Tillandsia capillaris f. virescens). While Tillandsia capillaris and Tillandsia virescens s. str. co-occur, Tillandsia virescens s. l. is restricted to altitudes above 2000 m in Argentina. Characters previously used for taxa delimitation showed continuous variation and therefore were not useful. New diagnostic characters are proposed and a key is provided for delimiting these three taxa within the complex.

A Key to the Pupal Exuviae of the Midges (Diptera: Chironomidae) of Everglades National Park, Florida

Science.gov (United States)

Jacobsen, Richard E.

2008-01-01

A key has been developed for identifying the pupal exuviae of 132 taxa of chironomid midges collected in Everglades National Park, as well as 18 additional species from freshwater habitats adjacent to the Park. Descriptions and illustrations are based upon voucher specimens from extensive collections of chironomid pupal exuviae for faunal surveys and biomonitoring research conducted in ENP and surrounding freshwater areas from 1998 to 2007. The key includes taxonomic comments for confirming identifications, as well as brief summaries of the distribution and ecology of each species in southern Florida waters. Information is also provided on the morphology of chironomid pupal exuviae, recommended references for identifying pupal exuviae, techniques for making slides, and methods to confirm proper identification.

High congruence of isotope sewage signals in multiple marine taxa

International Nuclear Information System (INIS)

Connolly, Rod M.; Gorman, Daniel; Hindell, Jeremy S.; Kildea, Timothy N.; Schlacher, Thomas A.

2013-01-01

Highlights: • Sewage inputs are routinely mapped with stable isotopes ( 15 N) in organisms. • We tested whether choice of species influences spatial 15 N distributions. • Spatial gradients were consistent between algae, seagrasses, crabs, and fish. • A match of sewage-N signals in multiple marine taxa has not been reported before. • Spatially-coupled transfers in the food web produce the congruence of N imprints. -- Abstract: Assessments of sewage pollution routinely employ stable nitrogen isotope analysis (δ 15 N) in biota, but multiple taxa are rarely used. This single species focus leads to underreporting of whether derived spatial N patterns are consistent. Here we test the question of ‘reproducibility’, incorporating ‘taxonomic replication’ in the measurement of δ 15 N gradients in algae, seagrasses, crabs and fish with distance from a sewage outfall on the Adelaide coast (southern Australia). Isotopic sewage signals were equally strong in all taxa and declined at the same rate. This congruence amongst taxa has not been reported previously. It implies that sewage-N propagates to fish via a tight spatial coupling between production and consumption processes, resulting from limited animal movement that closely preserves the spatial pollution imprint. In situations such as this where consumers mirror pollution signals of primary producers, analyses of higher trophic levels will capture a broader ambit of ecological effects

Taxa de juros e default em mercados de empréstimos colateralizados

Directory of Open Access Journals (Sweden)

Sergio Ricardo Faustino Batista

2011-12-01

Full Text Available Este artigo investiga como variações nas taxas de juros afetam a probabilidade de default (PD em um modelo de equilíbrio geral com mercados incompletos e exigência de colateral. Teoricamente, a PD possui relação positiva com taxa de juro real do empréstimo e negativa com a taxa de juro real da economia. Empiricamente, essas relações são confirmadas por meio da estimação do modelo de risco proporcional de Cox para uma grande amostra de empréstimos colateralizados. Dentre as variáveis de controle, há características do indivíduo, do contrato e da economia como um todo. Intuitivamente, uma taxa de juro real básica mais baixa implica menor retorno das operações de tesouraria, levando os bancos a ampliarem suas carteiras de crédito, emprestando para indivíduos mais arriscados.

Quantum key distribution using card, base station and trusted authority

Energy Technology Data Exchange (ETDEWEB)

Nordholt, Jane E.; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T.; Dallmann, Nicholas

2017-06-14

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trust authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

Quantum key distribution using card, base station and trusted authority

Science.gov (United States)

Nordholt, Jane Elizabeth; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T; Dallman, Nicholas

2015-04-07

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trusted authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

Differences in root uptake of radiocaesium by 30 plant taxa

Energy Technology Data Exchange (ETDEWEB)

Broadley, M R; Willey, N J [University of the West of England, Bristol (United Kingdom). Faculty of Applied Sciences

1998-12-31

The concentration of Cs was measured in the shoots of 30 taxa of plants after exposing the roots for 6 h to 0.1 {mu}g radiolabelled Cs g{sup -1} soil. There were maximum differences between Chenopodium quinoa and Koeleria macrantha of 20-fold in Cs concentration and 100-fold in total Cs accumulated. There was a weak relationship between Rb(K) and Cs concentration across the 30 taxa, but a strong relationship within the Gramineae and Chenopodiaceae. Taxa in the Chenopodiaceae discriminated approximately nine times less between Rb and Cs during uptake than did those in the Gramineae. The lowest Cs concentrations occurred in slow growing Gramineae and the highest in fast growing Chenopodiaceae. If radiocaesium uptake by the Chenopodiaceae during chronic exposures shows similar patterns to those reported here after acute exposure, then the food contamination implications and the potential for phytoremediation of radiocaesium contaminated soils using plants in this family may be worth investigating. (author).

Differences in root uptake of radiocaesium by 30 plant taxa

International Nuclear Information System (INIS)

Broadley, M.R.; Willey, N.J.

1997-01-01

The concentration of Cs was measured in the shoots of 30 taxa of plants after exposing the roots for 6 h to 0.1 μg radiolabelled Cs g -1 soil. There were maximum differences between Chenopodium quinoa and Koeleria macrantha of 20-fold in Cs concentration and 100-fold in total Cs accumulated. There was a weak relationship between Rb(K) and Cs concentration across the 30 taxa, but a strong relationship within the Gramineae and Chenopodiaceae. Taxa in the Chenopodiaceae discriminated approximately nine times less between Rb and Cs during uptake than did those in the Gramineae. The lowest Cs concentrations occurred in slow growing Gramineae and the highest in fast growing Chenopodiaceae. If radiocaesium uptake by the Chenopodiaceae during chronic exposures shows similar patterns to those reported here after acute exposure, then the food contamination implications and the potential for phytoremediation of radiocaesium contaminated soils using plants in this family may be worth investigating. (author)

Differences in root uptake of radiocaesium by 30 plant taxa

Energy Technology Data Exchange (ETDEWEB)

Broadley, M.R.; Willey, N.J. [University of the West of England, Bristol (United Kingdom). Faculty of Applied Sciences

1997-12-31

The concentration of Cs was measured in the shoots of 30 taxa of plants after exposing the roots for 6 h to 0.1 {mu}g radiolabelled Cs g{sup -1} soil. There were maximum differences between Chenopodium quinoa and Koeleria macrantha of 20-fold in Cs concentration and 100-fold in total Cs accumulated. There was a weak relationship between Rb(K) and Cs concentration across the 30 taxa, but a strong relationship within the Gramineae and Chenopodiaceae. Taxa in the Chenopodiaceae discriminated approximately nine times less between Rb and Cs during uptake than did those in the Gramineae. The lowest Cs concentrations occurred in slow growing Gramineae and the highest in fast growing Chenopodiaceae. If radiocaesium uptake by the Chenopodiaceae during chronic exposures shows similar patterns to those reported here after acute exposure, then the food contamination implications and the potential for phytoremediation of radiocaesium contaminated soils using plants in this family may be worth investigating. (author).

A Computer-Based Visual Analog Scale,

Science.gov (United States)

1992-06-01

34 keys on the computer keyboard or other input device. The initial position of the arrow is always in the center of the scale to prevent biasing the...3 REFERENCES 1. Gift, A.G., "Visual Analogue Scales: Measurement of Subjective Phenomena." Nursing Research, Vol. 38, pp. 286-288, 1989. 2. Ltmdberg...3. Menkes, D.B., Howard, R.C., Spears, G.F., and Cairns, E.R., "Salivary THC Following Cannabis Smoking Correlates With Subjective Intoxication and

Ambiguous taxa: Effects on the characterization and interpretation of invertebrate assemblages

Science.gov (United States)

Cuffney, T.F.; Bilger, Michael D.; Haigler, A.M.

2007-01-01

Damaged and immature specimens often result in macroinvertebrate data that contain ambiguous parent-child pairs (i.e., abundances associated with multiple related levels of the taxonomic hierarchy such as Baetis pluto and the associated ambiguous parent Baetis sp.). The choice of method used to resolve ambiguous parent-child pairs may have a very large effect on the characterization of invertebrate assemblages and the interpretation of responses to environmental change because very large proportions of taxa richness (73-78%) and abundance (79-91%) can be associated with ambiguous parents. To address this issue, we examined 16 variations of 4 basic methods for resolving ambiguous taxa: RPKC (remove parent, keep child), MCWP (merge child with parent), RPMC (remove parent or merge child with parent depending on their abundances), and DPAC (distribute parents among children). The choice of method strongly affected assemblage structure, assemblage characteristics (e.g., metrics), and the ability to detect responses along environmental (urbanization) gradients. All methods except MCWP produced acceptable results when used consistently within a study. However, the assemblage characteristics (e.g., values of assemblage metrics) differed widely depending on the method used, and data should not be combined unless the methods used to resolve ambiguous taxa are well documented and are known to be comparable. The suitability of the methods was evaluated and compared on the basis of 13 criteria that considered conservation of taxa richness and abundance, consistency among samples, methods, and studies, and effects on the interpretation of the data. Methods RPMC and DPAC had the highest suitability scores regardless of whether ambiguous taxa were resolved for each sample separately or for a group of samples. Method MCWP gave consistently poor results. Methods MCWP and DPAC approximate the use of family-level identifications and operational taxonomic units (OTU), respectively. Our

Constructing large scale SCI-based processing systems by switch elements

International Nuclear Information System (INIS)

Wu, B.; Kristiansen, E.; Skaali, B.; Bogaerts, A.; Divia, R.; Mueller, H.

1993-05-01

The goal of this paper is to study some of the design criteria for the switch elements to form the interconnection of large scale SCI-based processing systems. The approved IEEE standard 1596 makes it possible to couple up to 64K nodes together. In order to connect thousands of nodes to construct large scale SCI-based processing systems, one has to interconnect these nodes by switch elements to form different topologies. A summary of the requirements and key points of interconnection networks and switches is presented. Two models of the SCI switch elements are proposed. The authors investigate several examples of systems constructed for 4-switches with simulations and the results are analyzed. Some issues and enhancements are discussed to provide the ideas behind the switch design that can improve performance and reduce latency. 29 refs., 11 figs., 3 tabs

Chaotic maps-based password-authenticated key agreement using smart cards

Science.gov (United States)

Guo, Cheng; Chang, Chin-Chen

2013-06-01

Password-based authenticated key agreement using smart cards has been widely and intensively researched. Inspired by the semi-group property of Chebyshev maps and key agreement protocols based on chaotic maps, we proposed a novel chaotic maps-based password-authenticated key agreement protocol with smart cards. In our protocol, we avoid modular exponential computing or scalar multiplication on elliptic curve used in traditional authenticated key agreement protocols using smart cards. Our analysis shows that our protocol has comprehensive characteristics and can withstand attacks, including the insider attack, replay attack, and others, satisfying essential security requirements. Performance analysis shows that our protocol can refrain from consuming modular exponential computing and scalar multiplication on an elliptic curve. The computational cost of our protocol compared with related protocols is acceptable.

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

Science.gov (United States)

Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

2015-01-01

The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa

Science.gov (United States)

Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

2015-01-01

The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

Directory of Open Access Journals (Sweden)

Julian Martin Corbelli

Full Text Available The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD, functional (FBD and phylogenetic (PBD facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants from two contrasting biomes (subtropical forest and grassland and land uses (tree plantations and cropfields in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland, and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

BARI+: a biometric based distributed key management approach for wireless body area networks.

Science.gov (United States)

Muhammad, Khaliq-ur-Rahman Raazi Syed; Lee, Heejo; Lee, Sungyoung; Lee, Young-Koo

2010-01-01

Wireless body area networks (WBAN) consist of resource constrained sensing devices just like other wireless sensor networks (WSN). However, they differ from WSN in topology, scale and security requirements. Due to these differences, key management schemes designed for WSN are inefficient and unnecessarily complex when applied to WBAN. Considering the key management issue, WBAN are also different from WPAN because WBAN can use random biometric measurements as keys. We highlight the differences between WSN and WBAN and propose an efficient key management scheme, which makes use of biometrics and is specifically designed for WBAN domain.

Reach-scale stream restoration in agricultural streams of southern Minnesota alters structural and functional responses of macroinvertebrates

Science.gov (United States)

Dolph, Christine L.; Eggert, Susan L.; Magner, Joe; Ferrington, Leonard C.; Vondracek, Bruce C.

2015-01-01

Recent studies suggest that stream restoration at the reach scale may not increase stream biodiversity, raising concerns about the utility of this conservation practice. We examined whether reach-scale restoration in disturbed agricultural streams was associated with changes in macroinvertebrate community structure (total macroinvertebrate taxon richness, total macroinvertebrate density, Ephemeroptera, Plecoptera, Trichoptera [EPT] taxon richness, % abundance of EPT taxa) or secondary production (macroinvertebrate biomass over time). We collected macroinvertebrate samples over the course of 1 y from restored and unrestored reaches of 3 streams in southern Minnesota and used generalized least-square (GLS) models to assess whether measures of community structure were related to reach type, stream site, or sampling month. After accounting for effects of stream site and time, we found no significant difference in total taxon richness or % abundance of EPT taxa between restored and unrestored reaches. However, the number of EPT taxa and macroinvertebrate density were significantly higher in restored than in unrestored reaches. We compared secondary production estimates among study reaches based on 95th-percentile confidence intervals generated via bootstrapping. In each study stream, secondary production was significantly (2–3×) higher in the restored than in the unrestored reach. Higher productivity in the restored reaches was largely a result of the disproportionate success of a few dominant, tolerant taxa. Our findings suggest that reach-scale restoration may have ecological effects that are not detected by measures of total taxon richness alone.

Valor econômico: relevância da taxa de criação de valor.

Directory of Open Access Journals (Sweden)

Roseli da Silva

2002-12-01

Full Text Available O objetivo desse estudo é debater em favor de uma taxa de criação de valor como a variável mais relevante para a avaliação de investimentos, considerando aquela taxa como uma variável fundamental para a equalização das taxas de lucro no sistema capitalista. A taxa de criação de valor é o resultado da diferença entre a taxa de retorno sobre o capital investido e o custo médio ponderado de capital, isto é, o spread na metodologia do valor econômico adicionado, como mostramos nesse artigo.

Biogeography of key mesozooplankton species in the North Atlantic, by manual counting methods, and egg production of Calanus finmarchicus

DEFF Research Database (Denmark)

Melle, W.; Runge, J. A.; Head, E.

2014-01-01

Here we present a new, pan-Atlantic compilation of data on key mesozooplankton species, including the possibly most important copepod, Calanus finmarchicus. Distributional data of ten representative zooplankton taxa, from recent (2000–2009) Continuous Plankton Recorder data, are presented, along...... with basin-scale data of the phytoplankton colour index. Then we present a compilation of data on C. finmarchicus including observations of abundance, demography, egg production and female size with accompanying data on temperature and chlorophyll. This is a contribution by Canadian, European and US...... scientists and their institutions. http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393....

Leaf structural adaptations of two Limonium miller (Plumbaginales, Plumbaginaceae taxa

Directory of Open Access Journals (Sweden)

Zorić Lana N.

2013-01-01

Full Text Available Limonium gmelinii (Willd. O. Kuntze 1891 subsp. hungaricum (Klokov Soó is Pannonian endemic subspecies that inhabits continental halobiomes, while Limonium anfractum (Salmon Salmon 1924 is one of the indicators of halophyte vegetation of marine rocks and its distribution is restricted to the southern parts of Mediterranean Sea coast. In this work, micromorphological and anatomical characters of leaves of these two Limonium taxa were analyzed, in order to examine their adaptations to specific environmental conditions on saline habitats. The results showed that both taxa exhibited strong xeromorphic adaptations that reflected in flat cell walls of epidermal cells, thick cuticle, high palisade/spongy tissue ratio, high index of palisade cells, the presence of sclereid idioblasts in leaf mesophyll and mechanical tissue by phloem and xylem. Both taxa are crynohalophytes and have salt glands on adaxial and abaxial epidermis for excretion of surplus salt. Relatively high dimensions of mesophyll cells, absence of non-glandular hairs and unprotected stomata slightly increased above the level of epidermal cells, are also adaptations to increased salinity. [Projekat Ministarstva nauke Republike Srbije, br. 173002

Melanosome evolution indicates a key physiological shift within feathered dinosaurs.

Science.gov (United States)

Li, Quanguo; Clarke, Julia A; Gao, Ke-Qin; Zhou, Chang-Fu; Meng, Qingjin; Li, Daliang; D'Alba, Liliana; Shawkey, Matthew D

2014-03-20

Inference of colour patterning in extinct dinosaurs has been based on the relationship between the morphology of melanin-containing organelles (melanosomes) and colour in extant bird feathers. When this relationship evolved relative to the origin of feathers and other novel integumentary structures, such as hair and filamentous body covering in extinct archosaurs, has not been evaluated. Here we sample melanosomes from the integument of 181 extant amniote taxa and 13 lizard, turtle, dinosaur and pterosaur fossils from the Upper-Jurassic and Lower-Cretaceous of China. We find that in the lineage leading to birds, the observed increase in the diversity of melanosome morphologies appears abruptly, near the origin of pinnate feathers in maniraptoran dinosaurs. Similarly, mammals show an increased diversity of melanosome form compared to all ectothermic amniotes. In these two clades, mammals and maniraptoran dinosaurs including birds, melanosome form and colour are linked and colour reconstruction may be possible. By contrast, melanosomes in lizard, turtle and crocodilian skin, as well as the archosaurian filamentous body coverings (dinosaur 'protofeathers' and pterosaur 'pycnofibres'), show a limited diversity of form that is uncorrelated with colour in extant taxa. These patterns may be explained by convergent changes in the key melanocortin system of mammals and birds, which is known to affect pleiotropically both melanin-based colouration and energetic processes such as metabolic rate in vertebrates, and may therefore support a significant physiological shift in maniraptoran dinosaurs.

Agaricus section Xanthodermatei: a phylogenetic reconstruction with commentary on taxa.

Science.gov (United States)

Kerrigan, Richard W; Callac, Philippe; Guinberteau, Jacques; Challen, Michael P; Parra, Luis A

2005-01-01

Agaricus section Xanthodermatei comprises a group of species allied to A. xanthodermus and generally characterized by basidiomata having phenolic odors, transiently yellowing discolorations in some parts of the basidiome, Schaeffer's reaction negative, and mild to substantial toxicity. The section has a global distribution, while most included species have distributions restricted to regions of single continents. Using specimens and cultures from Europe, North America, and Hawaii, we analyzed DNA sequences from the ITS1+2 region of the nuclear rDNA to identify and characterize phylogenetically distinct entities and to construct a hypothesis of relationships, both among members of the section and with representative taxa from other sections of the genus. 61 sequences from affiliated taxa, plus 20 from six (or seven) other sections of Agaricus, and one Micropsalliota sequence, were evaluated under distance, maximum parsimony and maximum likelihood methods. We recognized 21 discrete entities in Xanthodermatei, including 14 established species and 7 new ones, three of which are described elsewhere. Four species from California, New Mexico, and France deserve further study before they are described. Type studies of American taxa are particularly emphasized, and a lectotype is designated for A. californicus. Section Xanthodermatei formed a single clade in most analyses, indicating that the traditional sectional characters noted above are good unifying characters that appear to have arisen only once within Agaricus. Deep divisions within the sequence-derived structure of the section could be interpreted as subsections in Xanthodermatei; however, various considerations led us to refrain from proposing new supraspecific taxa. The nearest neighbors of section Xanthodermatei are putatively in section Duploannulati.

Belowground carabid beetle diversity in the western Palaearctic – effects of history and climate on range-restricted taxa (Coleoptera, Carabidae

Directory of Open Access Journals (Sweden)

Andreas Schuldt

2011-05-01

Full Text Available Broad-scale patterns of subterranean diversity are a fascinating but neglected part of biodiversity research. Carabid beetles adapted to belowground habitats form a particularly species-rich part of the subterranean fauna. We studied large-scale diversity patterns of these belowground carabids across the western Palaearctic and evaluated potential impacts of historical and contemporary environmental conditions on the distribution of these taxa, using available species richness and environmental data at country level. Regression modelling and variation partitioning showed a strong relationship between species richness and range in elevation. Potential effects of climatic variables, mainly those related to ambient energy input, were much weaker. We discuss the implications of this combination of effects, which suggests, concordant with the absence of subterranean carabids in northern and highest richness in southern Europe, a strong prevailing influence of historical processes on current richness distributions of these taxa. Previous studies did not provide clear indications for such an influence. In contrast to more mobile and widespread carabid beetles, dispersal limitation due to high adaptation of belowground carabids to subterranean habitats has probably hindered their re-colonization of former permafrost and glaciated regions. Hotspots of highest belowground diversity are located in regions with an assumed long-term stability of environmental conditions, correlating with patterns of other dispersal-limited taxa such as many endemic plants. Our study provides important new information in the discussion of potential determinants of the distinct geographic patterns of belowground diversity. Moreover, it contributes to a better understanding of range size related differences previously found in the distribution of diversity and environmental dependencies of widespread and range-restricted species within the highly diverse carabid beetles.

Selection of morphological features of pollen grains for chosen tree taxa

Directory of Open Access Journals (Sweden)

Agnieszka Kubik-Komar

2018-05-01

Full Text Available The basis of aerobiological studies is to monitor airborne pollen concentrations and pollen season timing. This task is performed by appropriately trained staff and is difficult and time consuming. The goal of this research is to select morphological characteristics of grains that are the most discriminative for distinguishing between birch, hazel and alder taxa and are easy to determine automatically from microscope images. This selection is based on the split attributes of the J4.8 classification trees built for different subsets of features. Determining the discriminative features by this method, we provide specific rules for distinguishing between individual taxa, at the same time obtaining a high percentage of correct classification. The most discriminative among the 13 morphological characteristics studied are the following: number of pores, maximum axis, minimum axis, axes difference, maximum oncus width, and number of lateral pores. The classification result of the tree based on this subset is better than the one built on the whole feature set and it is almost 94%. Therefore, selection of attributes before tree building is recommended. The classification results for the features easiest to obtain from the image, i.e. maximum axis, minimum axis, axes difference, and number of lateral pores, are only 2.09 pp lower than those obtained for the complete set, but 3.23 pp lower than the results obtained for the selected most discriminating attributes only.

Catalog of taxa introduced by Luitfried Salvini-Plawen (1939-2014).

Science.gov (United States)

Affenzeller, Susanne; Steiner, Gerhard

2017-10-17

Luitfried Salvini-Plawen was one of the most distinguished researchers for molluscan phylogenetic systematics of the last decades. In his publications he described a total of 193 species: 134 Solenogastres, 34 Caudofoveata, 14 interstitial Gastropoda, one polyplacophoran and the remaining comprising Cnidaria, Priapulida, Kamptozoa, and Echinodermata. In addition, he introduced 47 genus-group names and 54 names for family-level and higher taxa. This catalog comprises lists of all taxon names published by Luitfried Salvini-Plawen. The catalog entries contain taxonomic information, original citations, type localities and type collections. It aims to facilitate further research on these and related taxa.

BARI+: A Biometric Based Distributed Key Management Approach for Wireless Body Area Networks

Directory of Open Access Journals (Sweden)

Syed Muhammad Khaliq-ur-Rahman Raazi

2010-04-01

Full Text Available Wireless body area networks (WBAN consist of resource constrained sensing devices just like other wireless sensor networks (WSN. However, they differ from WSN in topology, scale and security requirements. Due to these differences, key management schemes designed for WSN are inefficient and unnecessarily complex when applied to WBAN. Considering the key management issue, WBAN are also different from WPAN because WBAN can use random biometric measurements as keys. We highlight the differences between WSN and WBAN and propose an efficient key management scheme, which makes use of biometrics and is specifically designed for WBAN domain.

Enabling Large-Scale IoT-Based Services through Elastic Publish/Subscribe.

Science.gov (United States)

Vavassori, Sergio; Soriano, Javier; Fernández, Rafael

2017-09-19

In this paper, we report an algorithm that is designed to leverage the cloud as infrastructure to support Internet of Things (IoT) by elastically scaling in/out so that IoT-based service users never stop receiving sensors' data. This algorithm is able to provide an uninterrupted service to end users even during the scaling operation since its internal state repartitioning is transparent for publishers or subscribers; its scaling operation is time-bounded and depends only on the dimension of the state partitions to be transmitted to the different nodes. We describe its implementation in E-SilboPS, an elastic content-based publish/subscribe (CBPS) system specifically designed to support context-aware sensing and communication in IoT-based services. E-SilboPS is a key internal asset of the FIWARE IoT services enablement platform, which offers an architecture of components specifically designed to capture data from, or act upon, IoT devices as easily as reading/changing the value of attributes linked to context entities. In addition, we discuss the quantitative measurements used to evaluate the scale-out process, as well as the results of this evaluation. This new feature rounds out the context-aware content-based features of E-SilboPS by providing, for example, the necessary middleware for constructing dashboards and monitoring panels that are capable of dynamically changing queries and continuously handling data in IoT-based services.

Pyrosequencing detects human and animal pathogenic taxa in the grapevine endosphere.

Science.gov (United States)

Yousaf, Sohail; Bulgari, Daniela; Bergna, Alessandro; Pancher, Michael; Quaglino, Fabio; Casati, Paola; Campisano, Andrea

2014-01-01

Generally, plants are not considered as hosts for human and animal pathogens (HAP). The recent produce-associated outbreaks of food-borne diseases have drawn attention toward significant deficiencies in our understanding of the ecology of HAP, and their potential for interkingdom transfer. To examine the association of microorganisms classified as HAP with plants, we surveyed the presence and distribution of HAP bacterial taxa (henceforth HAPT, for brevity's sake) in the endosphere of grapevine (Vitis vinifera L.) both in the plant stems and leaves. An enrichment protocol was used on leaves to detect taxa with very low abundance in undisturbed tissues. We used pyrosequencing and phylogenetic analyses of the 16S rDNA gene. We identified several HAPT, and focused on four genera (Propionibacterium, Staphylococcus, Clostridium, and Burkholderia). The majority of the bacterial sequences in the genus Propionibacterium, from grapevine leaf and stem, were identified as P. acnes. Clostridia were detected in leaves and stems, but their number was much higher in leaves after enrichment. HAPT were indentified both in leaves and wood of grapevines. This depicts the ability of these taxa to be internalized within plant tissues and maintain their population levels in a variety of environments. Our analysis highlighted the presence of HAPT in the grapevine endosphere and unexpected occurrence of these bacterial taxa in this atypical environment.

Ecological patterns, diversity and core taxa of microbial communities in groundwater-fed rapid gravity filters

DEFF Research Database (Denmark)

Gülay, Arda; Musovic, Sanin; Albrechtsen, Hans-Jørgen

2016-01-01

Here, we document microbial communities in rapid gravity filtration units, specifically serial rapid sand filters (RSFs), termed prefilters (PFs) and after- filters (AFs), fed with anoxic groundwaters low in organic carbon to prepare potable waters. A comprehensive 16S rRNA-based amplicon...... sequencing survey revealed a core RSF microbiome comprising few bacterial taxa (29–30 genera) dominated by Nitrospirae, Proteobacteria and Acidobacteria, with a strikingly high abundance (75–87±18%) across five examined waterworks in Denmark. Lineages within the Nitrospira genus consistently comprised...... the second most and most abundant fraction in PFs (27±23%) and AFs (45.2±23%), respectively, and were far more abundant than typical proteobacterial ammonium-oxidizing bacteria, suggesting a physiology beyond nitrite oxidation for Nitrospira. Within the core taxa, sequences closely related to types...

Relaciones polen-vegetación de algunos taxa de la estepa patagónica (Argentina Pollen-vegetation relationships of some taxa from the Patagonian steppe (Argentina

Directory of Open Access Journals (Sweden)

LIDIA S. BURRY

2001-06-01

Full Text Available La aplicación de un análisis de regresión lineal simple a datos de lluvia de polen y de vegetación, en una zona de la Patagonia (Provincia de Chubut, Argentina permitió relacionar cuantitativamente los porcentajes de lluvia polínica y de cobertura de la vegetación para los taxa Poaceae, Papilionoideae, tipo Senecio y Mulinum spinosum. Se obtuvo un buen ajuste de las rectas de regresión para cada uno de los taxa considerados, con coeficientes de correlación r de Pearson altos para M. spinosum (0,82 y tipo Senecio (0,81 y coeficientes algo menores en el caso de Poaceae (0,66 y Papilionoideae (0,61. Estas regresiones permitieron inferir la presencia o ausencia de polen regional y el valor predictivo de la presencia de polen en ausencia de la vegetación que lo produce. Al respecto, la lluvia de polen estudiada incluye el aporte regional (excepto Papilionoideae aun cuando M. spinosum tiene una baja contribución. Esta sobrerrepresentación es atribuible al transporte de larga distancia, a través de los vientos que provienen del oeste. Estas relaciones cuantitativas nos permitirán extrapolar cambios vegetacionales pasados en estos taxa a partir de espectros de polen fósil para el área de estudioThe use of simple linear regression to data of pollen rain and vegetation cover in Patagonia (Province of Chubut, Argentina allowed us to develop quantitative relationships between modern pollen rain perecentages and vegetation cover for the taxa Poaceae, Papilionoideae, Senecio type, and Mulinum spinosum. The analysis revealed a good fit of data to regression lines for all taxa, with high Pearson r coefficient values in the case of M. spinosum (0.82 and Senecio type (0.81, and somewhat lower values in the case of Poaceae (0.66 and Papilionoideae (0.61. These regressions allowed us to infer the presence or absence of regional pollen and predict the quantity of pollen in the absence of the vegetation producing it. In this regard, the studied pollen

Optical image encryption using password key based on phase retrieval algorithm

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2016-04-01

A novel optical image encryption system is proposed using password key based on phase retrieval algorithm (PRA). In the encryption process, a shared image is taken as a symmetric key and the plaintext is encoded into the phase-only mask based on the iterative PRA. The linear relationship between the plaintext and ciphertext is broken using the password key, which can resist the known plaintext attack. The symmetric key and the retrieved phase are imported into the input plane and Fourier plane of 4f system during the decryption, respectively, so as to obtain the plaintext on the CCD. Finally, we analyse the key space of the password key, and the results show that the proposed scheme can resist a brute force attack due to the flexibility of the password key.

Influence of anglers' specializations on catch, harvest, and bycatch of targeted taxa

Science.gov (United States)

Pope, Kevin L.; Chizinski, Christopher J.; Wiley, Christopher L.; Martin, Dustin R.

2016-01-01

Fishery managers often use catch per unit effort (CPUE) of a given taxon derived from a group of anglers, those that sought said taxon, to evaluate fishery objectives because managers assume CPUE for this group of anglers is most sensitive to changes in fish taxon density. Further, likelihood of harvest may differ for sought and non-sought taxa if taxon sought is a defining characteristic of anglers’ attitude toward harvest. We predicted that taxon-specific catch across parties and reservoirs would be influenced by targeted taxon after controlling for number of anglers in a party and time spent fishing (combine to quantify fishing effort of party); we also predicted similar trends for taxon-specific harvest. We used creel-survey data collected from anglers that varied in taxon targeted, from generalists (targeting “anything” [no primary target taxa, but rather targeting all fishes]) to target specialists (e.g., anglers targeting largemouth bass Micropterus salmoides) in 19 Nebraska reservoirs during 2009–2011 to test our predictions. Taxon-specific catch and harvest were, in general, positively related to fishing effort. More importantly, we observed differences of catch and harvest among anglers grouped by taxon targeted for each of the eight taxa assessed. Anglers targeting a specific taxon had the greatest catch for that taxon and anglers targeting anything typically had the second highest catch for that taxon. In addition, anglers tended to catch more of closely related taxa and of taxa commonly targeted with similar fishing techniques. We encourage managers to consider taxon-specific objectives of target and non-target catch and harvest.

Roles of epi-anecic taxa of earthworms in the organic matter recycling

Science.gov (United States)

Hoeffner, Kevin; Monard, Cécile; Santonja, Mathieu; Pérès, Guénola; Cluzeau, Daniel

2017-04-01

Given their impact on soil functioning and their interactions with soil organisms, earthworms contribute to the recycling of organic matter and participate significantly in the numerous ecosystem services provided by soils. Most studies on the role of earthworms in organic matter recycling were conducted at the level of the four functional groups (epigeic, epi-anecic, anecic strict and endogeic), but their effects at taxa level remain largely unknown. Still, within a functional group, anatomic and physiologic earthworm taxa traits are different, which should impact organic matter recycling. This study aims at determining, under controlled conditions, epi-anecic taxa differences in (i) leaf litter mass loss, (ii) assimilation and (iii) impact on microorganisms communities implied in organic matter degradation. In seperate microcosms, we chose 4 epi anecic taxa (Lumbricus rubellus, Lumbricus festivus, Lumbricus centralis and Lumbricus terrestris). Each taxon was exposed separately to leaves of three different plants (Holcus lanatus, Lolium perenne and Corylus avellana). In the same microcosm, leaves of each plant was both placed on the surface and buried 10cm deep. The experiment lasted 10 days for half of the samples and 20 days for the second half. Microorganisms communities were analysed using TRFLP in each earthworm taxon burrow walls at 20 days. We observed differences between epi-anecic taxa depending on species of plant and the duration of the experiment. Results are discussed taking into account physical and chemical properties of these 3 trophic resources (e.g. C/N ratio, phenolic compounds, percentage of lignin and cellulose...).

Virtual-optical information security system based on public key infrastructure

Science.gov (United States)

Peng, Xiang; Zhang, Peng; Cai, Lilong; Niu, Hanben

2005-01-01

A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.

LBTool: A stochastic toolkit for leave-based key updates

DEFF Research Database (Denmark)

Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

2012-01-01

Quantitative techniques have been successfully employed in verification of information and communication systems. However, the use of such techniques are still rare in the area of security. In this paper, we present a toolkit that implements transient analysis on a key update method for wireless...... sensor networks. The analysis aims to find out the probability of a network key being compromised at a specific time point, which result in fluctuations over time for a specific key update method called Leave-based key update. For such a problem, the use of current tools is limited in many ways...

Critical Taxonomic Appraisal of Some Taxa of Pedicularis from Indian Himalayas Belonging to Section Siphonanthae

Directory of Open Access Journals (Sweden)

Arti Garg

2009-06-01

Full Text Available The existing confusion on the taxonomic status of five taxa of Pedicularis viz. P. punctata Decne, P. siphonantha D. Don, P. hookeriana Wall. ex Benth., P. megalantha D. Don and P. hoffmeisteri Kl. ex Kl. & Garcke is resolved on the basis of critical morphological study. These taxa belong to section Siphonanthae, subgenus Longirostres. Pennell’s view of segregating these taxa into distinct species is defended and upheld.

Specialized specialists and the narrow niche fallacy: a tale of scale-feeding fishes.

Science.gov (United States)

Kolmann, Matthew A; Huie, Jonathan M; Evans, Kory; Summers, Adam P

2018-01-01

Although rare within the context of 30 000 species of extant fishes, scale-feeding as an ecological strategy has evolved repeatedly across the teleost tree of life. Scale-feeding (lepidophagous) fishes are diverse in terms of their ecology, behaviour, and specialized morphologies for grazing on scales and mucus of sympatric species. Despite this diversity, the underlying ontogenetic changes in functional and biomechanical properties of associated feeding morphologies in lepidophagous fishes are less understood. We examined the ontogeny of feeding mechanics in two evolutionary lineages of scale-feeding fishes: Roeboides , a characin, and Catoprion , a piranha. We compare these two scale-feeding taxa with their nearest, non-lepidophagous taxa to identify traits held in common among scale-feeding fishes. We use a combination of micro-computed tomography scanning and iodine staining to measure biomechanical predictors of feeding behaviour such as tooth shape, jaw lever mechanics and jaw musculature. We recover a stark contrast between the feeding morphology of scale-feeding and non-scale-feeding taxa, with lepidophagous fishes displaying some paedomorphic characters through to adulthood. Few traits are shared between lepidophagous characins and piranhas, except for their highly-modified, stout dentition. Given such variability in development, morphology and behaviour, ecological diversity within lepidophagous fishes has been underestimated.

Renormalization group invariance and optimal QCD renormalization scale-setting: a key issues review

Science.gov (United States)

Wu, Xing-Gang; Ma, Yang; Wang, Sheng-Quan; Fu, Hai-Bing; Ma, Hong-Hao; Brodsky, Stanley J.; Mojaza, Matin

2015-12-01

A valid prediction for a physical observable from quantum field theory should be independent of the choice of renormalization scheme—this is the primary requirement of renormalization group invariance (RGI). Satisfying scheme invariance is a challenging problem for perturbative QCD (pQCD), since a truncated perturbation series does not automatically satisfy the requirements of the renormalization group. In a previous review, we provided a general introduction to the various scale setting approaches suggested in the literature. As a step forward, in the present review, we present a discussion in depth of two well-established scale-setting methods based on RGI. One is the ‘principle of maximum conformality’ (PMC) in which the terms associated with the β-function are absorbed into the scale of the running coupling at each perturbative order; its predictions are scheme and scale independent at every finite order. The other approach is the ‘principle of minimum sensitivity’ (PMS), which is based on local RGI; the PMS approach determines the optimal renormalization scale by requiring the slope of the approximant of an observable to vanish. In this paper, we present a detailed comparison of the PMC and PMS procedures by analyzing two physical observables R e+e- and Γ(H\\to b\\bar{b}) up to four-loop order in pQCD. At the four-loop level, the PMC and PMS predictions for both observables agree within small errors with those of conventional scale setting assuming a physically-motivated scale, and each prediction shows small scale dependences. However, the convergence of the pQCD series at high orders, behaves quite differently: the PMC displays the best pQCD convergence since it eliminates divergent renormalon terms; in contrast, the convergence of the PMS prediction is questionable, often even worse than the conventional prediction based on an arbitrary guess for the renormalization scale. PMC predictions also have the property that any residual dependence on

Chaotic Image Encryption Based on Running-Key Related to Plaintext

Directory of Open Access Journals (Sweden)

Cao Guanghui

2014-01-01

Full Text Available In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

Chaotic image encryption based on running-key related to plaintext.

Science.gov (United States)

Guanghui, Cao; Kai, Hu; Yizhi, Zhang; Jun, Zhou; Xing, Zhang

2014-01-01

In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.

Comparative epidermal anatomical studies in six taxa of genus Nephrolepis Swart in Nigeria

Directory of Open Access Journals (Sweden)

A. A. Fajuke

2018-04-01

Full Text Available Anatomical studies in six taxa of genus Nephrolepis; N. biserrata, N. cordifolia, N. exaltata (i & (ii, N. biserrata var. furcans and N. undulata were carried out with a view to identify anatomic characters of taxonomic values. Both qualitative and quantitative anatomical studies were carried out. Quantitative data were subjected to descriptive statistical analysis. Anatomical characters studied include venation patterns, trichome types, presence and absence of stomata and values of the stomatal index which are valuable in delimiting the species. The overall results showed overlaps in the quantitative anatomical attributes of the Nephrolepis taxa studied suggesting that they belong to the same genus. Qualitative anatomical attributes that separated the genus into distinct taxa are the presence of simple multicellular glandular trichomes in N. biserrata and simple multicellular non-glandular trichomes in N. exaltata (i and N. exalta (ii while N. biserrata var. furcans and N. undulata have simple unicellular non-glandular trichomes and absence of trichome in N. cordifolia. Presence of anisocytic, diacytic or anomocytic stomata were of diagnostic important in the six taxa.

Security of public key encryption technique based on multiple chaotic systems

International Nuclear Information System (INIS)

Wang Kai; Pei Wenjiang; Zou Liuhua; Cheung Yiuming; He Zhenya

2006-01-01

Recently, a new public key encryption technique based on multiple chaotic systems has been proposed [B. Ranjan, Phys. Rev. Lett. 95 (2005) 098702]. This scheme employs m-chaotic systems and a set of linear functions for key exchange over an insecure channel. Security of the proposed algorithm grows as (NP) m , where N, P are the size of the key and the computational complexity of the linear functions respectively. In this Letter, the fundamental weakness of the cryptosystem is pointed out and a successful attack is described. Given the public keys and the initial vector, one can calculate the secret key based on Parseval's theorem. Both theoretical and experimental results show that the attacker can access to the secret key without difficulty. The lack of security discourages the use of such algorithm for practical applications

The Endemic Plant Taxa of the Köprülü Kanyon National Park and Its Surroundings (Antalya-Isparta

Directory of Open Access Journals (Sweden)

Hasan ÖZÇELİK

2014-07-01

Full Text Available This study has been conducted in 2003-2004 in order to identify the endemic plants of the Köprülü Kanyon National Park (Antalya-Isparta and its surroundings. A total of 230 endemic taxa belonging to 29 families were determined in the national park and its surroundings. There are 229 taxa belonging to Angiospermae subdivision and 1 taxon belonging to Gymnospermae subdivision in these collected and identified endemic taxa from the research area. There is no endemic taxon in the Bryophyta and Pteridophyta divisions of the park. 218 of the 229 taxa belonging to the Angiospermae subdivision are in the Magnoliopsida (Dicotyledoneae class and other 11 are in the Liliopsida (Monocotyledoneae class. 18 taxa of the vascular plants are specific to the research area. 44 of endemic taxa are included in the endangered category. The number of priority conservation requiring taxa is 21. Endemic taxon number is almost 25% of total flora of the area. The top five families with the highest number of taxa in the study area are Lamiaceae (38, Caryophyllaceae (37, Asteraceae (26, Scrophulariaceae (20, Fabaceae (16 (Table 2. The 10 largest genera with the highest number of taxa are as follows: Silene (15, Astragalus (9, Sideritis (8, Verbascum (7, Centaurea (7, Stachys (6, Helichrysum (6, Alkanna (6, Veronica (5 and Minuartia (5. The distributions according to the phytogeographical regions of the endemic plants identified from the area is as follows: 59.565% Mediterranean elements (137 taxa, 23.478% Irano-Turanian elements (54 taxa, 0.304% Euro-Siberian elements (7 taxa and 13.913% with unknown phytogeographical region (32 taxa. The distributions of these taxa according to the conservation status is as follows: CR (Critically Endangered: 3, EN (Endangered: 22, VU (Vulnerable: 34, LR (Low Risk: 164, (cd (Conservation Dependent: 29, (lc (Least Concern: 106, (nt (Near Threatened: 29. In this study, menacing factors on the flora and vegetation of the area and

Three-dimensional geometric morphometric analysis of talar morphology in extant gorilla taxa from highland and lowland habitats.

Science.gov (United States)

Knigge, Ryan P; Tocheri, Matthew W; Orr, Caley M; Mcnulty, Kieran P

2015-01-01

Western gorillas (Gorilla gorilla) are known to climb significantly more often than eastern gorillas (Gorilla beringei), a behavioral distinction attributable to major differences in their respective habitats (i.e., highland vs. lowland). Genetic evidence suggests that the lineages leading to these taxa began diverging from one another between approximately 1 and 3 million years ago. Thus, gorillas offer a special opportunity to examine the degree to which morphology of recently diverged taxa may be "fine-tuned" to differing ecological requirements. Using three-dimensional (3D) geometric morphometrics, we compared talar morphology in a sample of 87 specimens including western (lowland), mountain (highland), and grauer gorillas (lowland and highland populations). Talar shape was captured with a series of landmarks and semilandmarks superimposed by generalized Procrustes analysis. A between-group principal components analysis of overall talar shape separates gorillas by ecological habitat and by taxon. An analysis of only the trochlea and lateral malleolar facet identifies subtle variations in trochlear shape between western lowland and lowland grauer gorillas, potentially indicative of convergent evolution of arboreal adaptations in the talus. Lastly, talar shape scales differently with centroid size for highland and lowland gorillas, suggesting that ankle morphology may track body-size mediated variation in arboreal behaviors differently depending on ecological setting. Several of the observed shape differences are linked biomechanically to the facilitation of climbing in lowland gorillas and to stability and load-bearing on terrestrial substrates in the highland taxa, providing an important comparative model for studying morphological variation in groups known only from fossils (e.g., early hominins). © 2014 Wiley Periodicals, Inc.

Signcryption-Based Key Management for MANETs Applications in Mobile Commerce

Institute of Scientific and Technical Information of China (English)

LI Jingfeng; ZHU Yuefei; ZHANG Yajuan; PAN Heng

2006-01-01

Mobile commerce uses wireless device and wireless link to result in the transfer of values in exchange of information, services or goods. Wireless mobile ad hoc networks (MANETs) will bring a revolution to the business model of mobile commerce if such networks are used as the underlying network technology for mobile commerce. Mobile commerce will remain in a niche market until the security issue is properly addressed. Hence, security is also very important for MANET applications in mobile commerce. Robust key management is one of the most crucial technologies for security of MANETs. In this paper, a new solution for key management is proposed using identity-based (ID-based) signcryption and threshold secret sharing. It enables flexible and efficient key management while respecting the constraints of MANETs. In our solution, each mobile host uses its globally unique identity as its public key. It greatly decreases the computation and storage costs of mobile hosts, as well as communication cost for system key management.

Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle.

Science.gov (United States)

Ferrari, Renata; Marzinelli, Ezequiel M; Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F; Byrne, Maria; Malcolm, Hamish A; Williams, Stefan B; Steinberg, Peter D

2018-01-01

Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate 'no-take' and 'general-use' (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5-10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical analyses and

Estimation of taxa included in the first volume of the Red Data Book of the Republic of Mordovia (Russia using the IUCN Red List Categories and Criteria

Directory of Open Access Journals (Sweden)

Anatoliy A. Khapugin

2017-05-01

Full Text Available The paper presents an estimation of taxa included in the first volume of the Red Data Book of the Republic of Mordovia using the IUCN Red List Categories and Criteria. Each taxon is provided by a category and all criteria appropriate for it within the region. The paper contains the estimation results of 177 taxa of vascular plants, mosses and algae from the first volume Red Data Book of the Republic of Mordovia (second edition. Of these, 137 are Threatened: 73 taxa are Critically Endangered (category CR, 41 taxa Endangered (category EN, 23 are Vulnerable (category VU, 31 taxa are Near Threatened (category NT. Nine taxa are in the category Data Deficient (DD, due to a lack of sufficient factual material needed for the evaluation. Another 59 taxa of the Red Data Book of the Republic of Mordovia (35 macromycetes and 24 lichens were not evaluated in the present study, also due to the lack of sufficient data needed for an evaluation. Therefore, these taxa are temporarily in the category Not Evaluated (NE. But they could be assigned to one of the threatened categories when evaluated in the future, according to the Guidelines for Application of IUCN Red List Criteria. This paper is considered as a base for establishing the Red List of plant taxa of the Republic of Mordovia in the future.

Phylogeny of palaeotropic Derris-like taxa (Fabaceae) based on chloroplast and nuclear DNA sequences shows reorganization of (infra)generic classifications is needed.

Science.gov (United States)

Sirichamorn, Yotsawate; Adema, Frits A C B; Gravendeel, Barbara; van Welzen, Peter C

2012-11-01

Palaeotropic Derris-like taxa (family Fabaceae, tribe Millettieae) comprise 6-9 genera. They are well known as important sources of rotenone toxin, which are used as organic insecticide and fish poison. However, their phylogenetic relationships and classification are still problematic due to insufficient sampling and high morphological variability. Fifty species of palaeotropic Derris-like taxa were sampled, which is more than in former studies. Three chloroplast genes (trnK-matK, trnL-F IGS, and psbA-trnH IGS) and nuclear ribosomal ITS /5.8S were analyzed using parsimony and Bayesian methods. Parsimony and Bayesian analyses of individual and combined markers show more or less similar tree topologies (only varying in terminal branches). The old-world monophyletic genera Aganope, Brachypterum, and Leptoderris are distinct from Derris s.s., and their generic status is here confirmed. Aganope may be classified into two or three subgeneric taxa. Paraderris has to be included in Derris s.s. to form a monophyletic group. The genera Philenoptera, Deguelia, and Lonchocarpus are monophyletic and distinct from each other and clearly separate from Derris s.s. Morphologically highly similar species of Derris s.s. are shown to be unrelated. Our study shows that previous infrageneric classifications of Derris are incorrect. Paraderris elliptica may contain several cryptic lineages that need further investigation. The concept of the genus Derris s.s. should be reorganized with a new generic circumscription by including Paraderris but excluding Brachypterum. Synapomorphic morphological features will be examined in future studies, and the status of the newly defined Derris and its closely related taxa will be formalized.

Mapas de taxas epidemiológicas: uma abordagem Bayesiana

Directory of Open Access Journals (Sweden)

Assunção Renato Martins

1998-01-01

Full Text Available Neste artigo, apresentamos métodos estatísticos desenvolvidos recentemente para a análise de mapas de taxas de morbidade quando as unidades geográficas possuem pequenas populações de risco. Eles adotam a abordagem Bayesiana e utilizam métodos computacionais intensivos para estimação do risco de cada área. O objetivo dos métodos é separar a variabilidade das taxas devida às diferenças entre as regiões do risco subjacente daquela devida à pura flutuação aleatória. As estimativas de risco possuem um erro quadrático médio total menor que as estimativas usuais. Aplicamos esses novos métodos para estimar o risco de mortalidade infantil nos municípios de Minas Gerais em 1994.

One Step Quantum Key Distribution Based on EPR Entanglement.

Science.gov (United States)

Li, Jian; Li, Na; Li, Lei-Lei; Wang, Tao

2016-06-30

A novel quantum key distribution protocol is presented, based on entanglement and dense coding and allowing asymptotically secure key distribution. Considering the storage time limit of quantum bits, a grouping quantum key distribution protocol is proposed, which overcomes the vulnerability of first protocol and improves the maneuverability. Moreover, a security analysis is given and a simple type of eavesdropper's attack would introduce at least an error rate of 46.875%. Compared with the "Ping-pong" protocol involving two steps, the proposed protocol does not need to store the qubit and only involves one step.

Improved chaotic maps-based password-authenticated key agreement using smart cards

Science.gov (United States)

Lin, Han-Yu

2015-02-01

Elaborating on the security of password-based authenticated key agreement, in this paper, the author cryptanalyzes a chaotic maps-based password-authenticated key agreement proposed by Guo and Chang recently. Specifically, their protocol could not achieve strong user anonymity due to a fixed parameter and a malicious adversary is able to derive the shared session key by manipulating the property of Chebyshev chaotic maps. Additionally, the author also presents an improved scheme to eliminate the above weaknesses and still maintain the efficiency.

How acoustic signals scale with individual body size: common trends across diverse taxa

OpenAIRE

Rafael L. Rodríguez; Marcelo Araya-Salas; David A. Gray; Michael S. Reichert; Laurel B. Symes; Matthew R. Wilkins; Rebecca J. Safran; Gerlinde Höbel

2015-01-01

We use allometric analysis to explore how acoustic signals scale on individual body size and to test hypotheses about the factors shaping relationships between signals and body size. Across case studies spanning birds, crickets, tree crickets, and tree frogs, we find that most signal traits had low coefficients of variation, shallow allometric scalings, and little dispersion around the allometric function. We relate variation in these measures to the shape of mate preferences and the level of...

Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time.

Science.gov (United States)

O'Connor, Anne; Wills, Matthew A

2016-09-01

The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence-however measured-also varied throughout the Phanerozoic, reflecting

A distributional and cytological survey of the presently recognized taxa of Hibiscus section Furcaria (Malvaceae.

Directory of Open Access Journals (Sweden)

F. Douglas Wilson

2006-01-01

Full Text Available Hibiscus section Furcaria is a natural group of plants that presently includes 109 recognized taxa. Taxa are found in subsaharan Africa, India, southeastern Asia, Malesia, Australia, islands of the Pacific basin, the Caribbean, North, Central, and South America. The basic chromosome number is x = 18. In nature, ploidy levels range from diploid to decaploid. The taxa exhibit a remarkable amount of genome diversity. At least 13 genomes have been identified, some distributed widely and others with more restricted distributions. No modern taxonomic monograph ofHibiscus section Furcaria exists, but a number of regional studies have appeared that are essentially global in extent. Also, a number of studies of chromosome numbers and genome relationships have been published. The present paper includes a census of all the presently accepted taxa, the geographical distribution of each taxon, and chromosome numbers and genome designations of the 49 taxa for which the information is available. Important mechanisms of speciation include genome divergence at the diploid level, followed by hybridization and allopolyploidy, significant species radiation at the tetraploid and hexaploid levels, and the development of even higher levels of allopolyploids.

Hierarchical multi-taxa models inform riparian vs. hydrologic restoration of urban streams in a permeable landscape.

Science.gov (United States)

Gwinn, Daniel C; Middleton, Jen A; Beesley, Leah; Close, Paul; Quinton, Belinda; Storer, Tim; Davies, Peter M

2018-03-01

The degradation of streams caused by urbanization tends to follow predictable patterns; however, there is a growing appreciation for heterogeneity in stream response to urbanization due to the local geoclimatic context. Furthermore, there is building evidence that streams in mildly sloped, permeable landscapes respond uncharacteristically to urban stress calling for a more nuanced approach to restoration. We evaluated the relative influence of local-scale riparian characteristics and catchment-scale imperviousness on the macroinvertebrate assemblages of streams in the flat, permeable urban landscape of Perth, Western Australia. Using a hierarchical multi-taxa model, we predicted the outcomes of stylized stream restoration strategies to increase the riparian integrity at the local scale or decrease the influences of imperviousness at the catchment scale. In the urban streams of Perth, we show that local-scale riparian restoration can influence the structure of macroinvertebrate assemblages to a greater degree than managing the influences of catchment-scale imperviousness. We also observed an interaction between the effect of riparian integrity and imperviousness such that the effect of increased riparian integrity was enhanced at lower levels of catchment imperviousness. This study represents one of few conducted in flat, permeable landscapes and the first aimed at informing urban stream restoration in Perth, adding to the growing appreciation for heterogeneity of the Urban Stream Syndrome and its importance for urban stream restoration. © 2017 by the Ecological Society of America.

Combining phylogenomics and fossils in higher-level squamate reptile phylogeny: molecular data change the placement of fossil taxa.

Science.gov (United States)

Wiens, John J; Kuczynski, Caitlin A; Townsend, Ted; Reeder, Tod W; Mulcahy, Daniel G; Sites, Jack W

2010-12-01

Molecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa. We find several intriguing results. First, some fossil taxa undergo major changes in their phylogenetic position when molecular data are added. Second, most fossil taxa are placed with strong support in the expected clades by the combined data Bayesian analyses, despite each having >98% missing cells and despite recent suggestions that extensive missing data are problematic for Bayesian phylogenetics. Third, morphological data can change the placement of living taxa in combined analyses, even when there is an overwhelming majority of molecular characters. Finally, we find strong but apparently misleading signal in the morphological data, seemingly associated with a burrowing lifestyle in snakes, amphisbaenians, and dibamids. Overall, our results suggest promise for an integrated and comprehensive Tree of Life by combining molecular and morphological data for living and fossil taxa.

Increase in physical activities in kindergarten children with cerebral palsy by employing MaKey-MaKey-based task systems.

Science.gov (United States)

Lin, Chien-Yu; Chang, Yu-Ming

2014-09-01

In this study, we employed Flash- and Scratch-based multimedia by using a MaKey-MaKey-based task system to increase the motivation level of children with cerebral palsy to perform physical activities. MaKey MaKey is a circuit board that converts physical touch to a digital signal, which is interpreted by a computer as a keyboard message. In this study, we used conductive materials to control this interaction. This study followed single-case design using ABAB models in which A indicated the baseline and B indicated the intervention. The experiment period comprised 1 month and a half. The experimental results demonstrated that in the case of two kindergarten children with cerebral palsy, their scores were considerably increased during the intervention phrases. The developmental applications of the results are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Higher-dimensional orbital-angular-momentum-based quantum key distribution with mutually unbiased bases

CSIR Research Space (South Africa)

Mafu, M

2013-09-01

Full Text Available We present an experimental study of higher-dimensional quantum key distribution protocols based on mutually unbiased bases, implemented by means of photons carrying orbital angular momentum. We perform (d + 1) mutually unbiased measurements in a...

A taxa de câmbio no centro da teoria do desenvolvimento

Directory of Open Access Journals (Sweden)

Luiz Carlos Bresser-Pereira

2012-08-01

Full Text Available Este artigo apresenta as principais ideias da macroeconomia estruturalista do desenvolvimento - a teoria por trás de novo-desenvolvimentismo. Seu foco é a taxa de câmbio que é pela primeira vez colocada no centro da economia do desenvolvimento. A teoria econômica geralmente vê a taxa de câmbio como um problema de curto prazo a ser discutido na macroeconomia. A macroeconomia estruturalista do desenvolvimento mostra que há, nos países em desenvolvimento, a tendência à sobreapreciação cíclica da taxa de câmbio causada pela falta de neutralização da doença holandesa e por entradas de capital excessivas. Em consequência, considera a taxa de câmbio cronicamente sobreapreciada e, por isso, um grande obstáculo ao crescimento econômico. No processo de desenvolvimento, a taxa de câmbio tem a função de um interruptor de luz que conecta ou desconecta as empresas nacionais que utilizam a tecnologia no estado da arte mundial dos mercados mundiais.This paper presents the main ideas of structuralist development macroeconomics - the theory behind new developmentalism. Its focus is on the exchange rate that is positioned for the first time in the core of development economics. Economic theory usually views the exchange rate as a short term problem to be discussed in open macroeconomics. Structuralist development macroeconomics argues that there is in developing countries a tendency to the cyclical overvaluation of the exchange rate caused by the lack of neutralization of the Dutch disease and by excessive capital inflows. In consequence it views the exchange rate as chronically overvalued, and, for that reason, a major obstacle to economic growth. In the development process, the exchange rate has the role of light switch that connects or disconnects the national business enterprises utilizing technology in the world state of the art from world markets.

Quantum deterministic key distribution protocols based on the authenticated entanglement channel

International Nuclear Information System (INIS)

Zhou Nanrun; Wang Lijun; Ding Jie; Gong Lihua

2010-01-01

Based on the quantum entanglement channel, two secure quantum deterministic key distribution (QDKD) protocols are proposed. Unlike quantum random key distribution (QRKD) protocols, the proposed QDKD protocols can distribute the deterministic key securely, which is of significant importance in the field of key management. The security of the proposed QDKD protocols is analyzed in detail using information theory. It is shown that the proposed QDKD protocols can safely and effectively hand over the deterministic key to the specific receiver and their physical implementation is feasible with current technology.

Quantum deterministic key distribution protocols based on the authenticated entanglement channel

Energy Technology Data Exchange (ETDEWEB)

Zhou Nanrun; Wang Lijun; Ding Jie; Gong Lihua [Department of Electronic Information Engineering, Nanchang University, Nanchang 330031 (China)], E-mail: znr21@163.com, E-mail: znr21@hotmail.com

2010-04-15

Based on the quantum entanglement channel, two secure quantum deterministic key distribution (QDKD) protocols are proposed. Unlike quantum random key distribution (QRKD) protocols, the proposed QDKD protocols can distribute the deterministic key securely, which is of significant importance in the field of key management. The security of the proposed QDKD protocols is analyzed in detail using information theory. It is shown that the proposed QDKD protocols can safely and effectively hand over the deterministic key to the specific receiver and their physical implementation is feasible with current technology.

A Public-key based Information Management Model for Mobile Agents

OpenAIRE

Rodriguez, Diego; Sobrado, Igor

2000-01-01

Mobile code based computing requires development of protection schemes that allow digital signature and encryption of data collected by the agents in untrusted hosts. These algorithms could not rely on carrying encryption keys if these keys could be stolen or used to counterfeit data by hostile hosts and agents. As a consequence, both information and keys must be protected in a way that only authorized hosts, that is the host that provides information and the server that has sent the mobile a...

Bit-Oriented Quantum Public-Key Cryptosystem Based on Bell States

Science.gov (United States)

Wu, WanQing; Cai, QingYu; Zhang, HuanGuo; Liang, XiaoYan

2018-06-01

Quantum public key encryption system provides information confidentiality using quantum mechanics. This paper presents a quantum public key cryptosystem ( Q P K C) based on the Bell states. By H o l e v o' s theorem, the presented scheme provides the security of the secret key using one-wayness during the QPKC. While the QPKC scheme is information theoretic security under chosen plaintext attack ( C P A). Finally some important features of presented QPKC scheme can be compared with other QPKC scheme.

Two-Dimensional Key Table-Based Group Key Distribution in Advanced Metering Infrastructure

Directory of Open Access Journals (Sweden)

Woong Go

2014-01-01

Full Text Available A smart grid provides two-way communication by using the information and communication technology. In order to establish two-way communication, the advanced metering infrastructure (AMI is used in the smart grid as the core infrastructure. This infrastructure consists of smart meters, data collection units, maintenance data management systems, and so on. However, potential security problems of the AMI increase owing to the application of the public network. This is because the transmitted information is electricity consumption data for charging. Thus, in order to establish a secure connection to transmit electricity consumption data, encryption is necessary, for which key distribution is required. Further, a group key is more efficient than a pairwise key in the hierarchical structure of the AMI. Therefore, we propose a group key distribution scheme using a two-dimensional key table through the analysis result of the sensor network group key distribution scheme. The proposed scheme has three phases: group key predistribution, selection of group key generation element, and generation of group key.

Key to Plecoptera nymphs from the Brazilian Amazon (Insecta).

Science.gov (United States)

Ribeiro, José Moacir Ferreira; Gorayeb, Inocêncio DE Sousa

2016-12-19

Nymphs of 22 species of Plecoptera from the Brazilian Amazon are keyed and illustrated to enhance their usefulness as water quality indicator taxa. Four described species of Anacroneuria, two species of Macrogynoplax, and two species of Enderleina have been associated with adults: Anacroneuria marlieri, A. manauensis, A. minuta, A. singularis, M. delicata, M. pulchra, E. froehlichi, and E. flinti. Nymphs of 14 additional morphospecies not yet associated with adults are included. Characters of the head, pronotum, mesonotum, and metanotum are used to distinguish late instar nymphs.

Information security system based on virtual-optics imaging methodology and public key infrastructure

Science.gov (United States)

Peng, Xiang; Zhang, Peng; Cai, Lilong

In this paper, we present a virtual-optical based information security system model with the aid of public-key-infrastructure (PKI) techniques. The proposed model employs a hybrid architecture in which our previously published encryption algorithm based on virtual-optics imaging methodology (VOIM) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). For an asymmetric system, given an encryption key, it is computationally infeasible to determine the decryption key and vice versa. The whole information security model is run under the framework of PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOIM security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network.

Uptake and accumulation of arsenic by 11 Pteris taxa from southern China

Energy Technology Data Exchange (ETDEWEB)

Wang, H.B. [State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); School of Environmental Sciences and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Wong, M.H. [Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR (China); Lan, C.Y. [State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Baker, A.J.M. [School of Botany, University of Melbourne, Parkville VIC 3010 (Australia); Qin, Y.R. [State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Shu, W.S. [State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Chen, G.Z. [School of Environmental Science and Engineering, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Ye, Z.H. [State Key Laboratory for Bio-control and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China)]. E-mail: lsdyzhh@zsu.edu.cn

2007-01-15

A field survey was conducted at a deserted arsenic (As) mine in Guangxi Province, China to explore new potential As hyperaccumulators. In addition, young plants of 11 Pteris taxa were grown in glasshouse conditions for 12 weeks on As-amended soils with 0, 50 and 200 mg As kg{sup -1}. Results of the field survey showed that the fern Pteris fauriei accumulated over 1000 mg As kg{sup -1} in its fronds. Of the 11 Pteris taxa, Pteris aspericaulis, Pteris cretica var. nervosa, P. fauriei, Pteris multifida, P. multifida f. serrulata, and Pteris oshimensis were all found to hyperaccumulate As in addition to P. cretica 'Albo-Lineata' and Pteris vittata (already reported as As hyperaccumulators). However, Pteris ensiformis, Pteris semipinnata and Pteris setuloso-costulata showed no evidence of As hyperaccumulation. Results also revealed a constitutive property of As hyperaccumulation in different populations of P. cretica var. nervosa, P. multifida, P. oshimensis and P. vittata. - Eight Pteris taxa show the ability to hyperaccumulate As under glasshouse conditions.

Information verification cryptosystem using one-time keys based on double random phase encoding and public-key cryptography

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2016-08-01

A novel image encryption system based on double random phase encoding (DRPE) and RSA public-key algorithm is proposed. The main characteristic of the system is that each encryption process produces a new decryption key (even for the same plaintext), thus the encryption system conforms to the feature of the one-time pad (OTP) cryptography. The other characteristic of the system is the use of fingerprint key. Only with the rightful authorization will the true decryption be obtained, otherwise the decryption will result in noisy images. So the proposed system can be used to determine whether the ciphertext is falsified by attackers. In addition, the system conforms to the basic agreement of asymmetric cryptosystem (ACS) due to the combination with the RSA public-key algorithm. The simulation results show that the encryption scheme has high robustness against the existing attacks.

Simple security proof of quantum key distribution based on complementarity

International Nuclear Information System (INIS)

Koashi, M

2009-01-01

We present an approach to the unconditional security of quantum key distribution protocols based on a complementarity argument. The approach is applicable to, but not limited to, every case that has been treated via the argument by Shor and Preskill based on entanglement distillation, with a benefit of decoupling of the error correction from the privacy amplification. It can also treat cases with uncharacterized apparatuses. We derive a secure key rate for the Bennett-Brassard-1984 protocol with an arbitrary source characterized only by a single parameter representing the basis dependence.

Psychometric analysis of two new scales: the evidence-based practice nursing leadership and work environment scales.

Science.gov (United States)

Pryse, Yvette; McDaniel, Anna; Schafer, John

2014-08-01

Those in nursing have been charged with practicing to the full extent of their education and training by the Institute of Medicine. Therefore, evidence-based practice (EBP) has never been more important to nursing than in the current healthcare environment. Frequently the burden of EBP is the responsibility of the bedside practitioner, but has been found to be a process that requires leadership and organizational support. A key underlying component of a strong EBP environment includes effective communications and collaboration among staff and nursing leadership. Developing measurement tools that examine the milieu and nursing leadership in which the staff nurse practices is an important component of understanding the factors that support or hinder EBP. The aim of this study is to report on the development and analysis of two new scales designed to explore leadership and organizational support for EBP. The EBP Nursing Leadership Scale (10 items) examines the staff nurses perception of support provided by the nurse manager for EBP, and the EBP Work Environment Scale (8 items) examines organizational support for EBP. Staff nurses who worked at least .5 FTE in direct patient care, from two inner city hospitals (n = 422) completed the scales. The scales were evaluated for internal consistency reliability with the Cronbach alpha technique, content validity using a panel of experts, and construct validity by The content validity index computed from expert rankings was .78 to 1.0 with an average of.96. Cronbach's alpha was .96 (n = 422) for the EBP Nursing Leadership Scale and .86 (n = 422) for the EBP Work Environment Scale. Factor analysis confirmed that each scale measured a unidimensional construct (p organizational influences on EBP. © 2014 Sigma Theta Tau International.

An efficient three-party password-based key agreement protocol using extended chaotic maps

International Nuclear Information System (INIS)

Shu Jian

2015-01-01

Three-party password-based key agreement protocols allow two users to authenticate each other via a public channel and establish a session key with the aid of a trusted server. Recently, Farash et al. [Farash M S, Attari M A 2014 “An efficient and provably secure three-party password-based authenticated key exchange protocol based on Chebyshev chaotic maps”, Nonlinear Dynamics 77(7): 399–411] proposed a three-party key agreement protocol by using the extended chaotic maps. They claimed that their protocol could achieve strong security. In the present paper, we analyze Farash et al.’s protocol and point out that this protocol is vulnerable to off-line password guessing attack and suffers communication burden. To handle the issue, we propose an efficient three-party password-based key agreement protocol using extended chaotic maps, which uses neither symmetric cryptosystems nor the server’s public key. Compared with the relevant schemes, our protocol provides better performance in terms of computation and communication. Therefore, it is suitable for practical applications. (paper)

Chaotic map based key agreement with/out clock synchronization

International Nuclear Information System (INIS)

Han, S.; Chang, E.

2009-01-01

In order to address Bergamo et al.'s attack, Xiao et al. proposed a key agreement protocol using chaotic maps. Han then presented three attacks on Xiao et al.'s protocol. To enhance the security of key agreement based on chaotic maps, Chang et al. proposed a new key agreement using passphrase, which works in clock synchronization environment. However, their protocol still has some issues: one is its passphrase is not easy to remember and much longer than password; the second one is it cannot resist guessing attack if the constructed passphrase is easy to remember and also has already existed in some rational dictionaries; the third one is it cannot work without clock synchronization. In this paper, we will present two different key agreement protocols, which can resist guessing attack. The first one works in clock synchronization environment. The second one can work without clock synchronization. They both use authenticated password for secure communications. The protocols are secure against replaying attacks and a shared session key can be established.

Using real-time PCR and Bayesian analysis to distinguish susceptible tubificid taxa important in the transmission of Myxobolus cerebralis, the cause of salmonid whirling disease.

Science.gov (United States)

Fytilis, Nikolaos; Rizzo, Donna M; Lamb, Ryan D; Kerans, Billie L; Stevens, Lori

2013-05-01

Aquatic oligochaetes have long been appreciated for their value in assessing habitat quality because they are ubiquitous sediment-dwelling filter feeders. Many oligochaete taxa are also important in the transmission of fish diseases. Distinguishing resistant and susceptible taxa is important for managing fish disease, yet challenging in practice. Tubifex tubifex (Oligochaeta: Tubificidae) is the definitive host for the complex life-cycle parasite, Myxobolus cerebralis, the causative agent of salmonid whirling disease. We developed two hydrolysis probe-based qualitative real-time PCR (qPCR) multiplex assays that distinguish among tubificid taxa collected from the Madison River, Montana, USA. The first assay distinguishes T. tubifex from Rhyacodrilus spp.; while the second classifies T. tubifex identified by the first assay into two genetic lineages (I and III). Specificity and sensitivity were optimized for each assay; the two assays showed specificity of 94.3% and 98.6% for the target oligochaetes, respectively. DNA sequencing verified the results. The development of these assays allowed us to more fully describe tubificid community composition (the taxa and their abundance at a site) and estimate the relative abundances of host taxa. To relate tubificid relative abundance to fish disease risk, we determined M. cerebralis infection prevalence in samples identified as T. tubifex using similar molecular techniques. Given prior information (i.e., morphological identification of sexually mature worms), Bayesian analysis inferred that the first qPCR assay improved taxonomic identification. Bayesian inference of the relative abundance of T. tubifex, combined with infection assay results, identified sites with a high prevalence of infected T. tubifex. To our knowledge, this study represents both the first assessment of oligochaete community composition using a qPCR assay based on fluorescent probes and the first use of Bayesian analysis to fully characterize the dominant

Comportamento e informação na estrutura a termo das taxas de juros do Brasil

OpenAIRE

Novy, Luiz Gustavo Guimarães

2010-01-01

O comportamento da curva que relaciona o rendimento dos títulos de desconto negociados no sistema financeiro nacional e o seu prazo de vencimento, ou seja, da estrutura a termo das taxas de juros, é minusciosamenteestudado através da análise de componentes. principais. Através de duas equações de regressão busca-se discutir as ·informações implícitas nas taxas de juros a termo sobre as taxas de juros e prêmios esperados para o futuro.

Some extinct plant taxa on the territory of Novi Sad and their vulnerability status in Vojvodina and Serbia

Directory of Open Access Journals (Sweden)

Đakić Žarko S.

2012-01-01

Full Text Available Natural habitats on the territory of Novi Sad are almost fully destroyed today, as well as their characteristic plant taxa. The reason for disappearance of natural habitats is the development of suburban communities, which is an irreversible process. Plant taxa, specific for wet, salty, and sandy ecosystems grew on those habitats twenty years ago and earlier. This paper presents the overview of 9 taxa (Suaeda maritima subsp. maritima, Androsace elongata subsp. elongata, Cirsium boujartii subsp. boujartii, Aster sedifolius subsp. canus, Blackstonia perfoliata subsp. serotina, Plantago maritima subsp. maritima, Salvia nutans, Allium angulosum, and Typha schuttleworthii. These taxa presented integral parts of autochthonous flora of Novi Sad. Since some of these taxa were found in the field 21 years ago and some even 93 years ago, they are extinct from the flora of Novi Sad.

A dinâmica da taxa de lucro, da taxa de juros e do grau de utilização da capacidade produtiva em um modelo pós-keynesiano

Directory of Open Access Journals (Sweden)

Luciano Dias de Carvalho

2007-12-01

Full Text Available O objetivo do presente artigo é analisar, por meio de simulação computacional, as trajetórias dinâmicas da taxa de acumulação de capital, da taxa de lucro, da taxa de juros e do grau de utilização da capacidade diante de mudanças exógenas do ritmo do progresso tecnológico e da propensão a poupar dos capitalistas. A simulação foi realizada a partir de um modelo macrodinâmico pós-keynesiano que leva em consideração a interação entre o lado real e monetário da economia. Dentre outros resultados, as simulações mostraram que: (i a taxa de lucro é significativamente elástica com relação a um choque tecnológico positivo, ao passo que a taxa de juros e o grau de utilização da capacidade são pouco sensíveis a esse tipo de choque; e (ii a confirmação do paradoxo da frugalidade, segundo o qual o aumento da propensão a poupar dos capitalistas acaba por reduzir o nível da poupança agregada, a taxa de lucro e o grau de utilização da capacidade.The objective of this paper is to analyze the dynamic path of the profit rate, the interest rate, the rate of capital accumulation and the degree of utilization of the productive capacity - face exogenous changes of the intensity of technological progress and the propensity to save of capitalists within a Post-Keynesian macroeconomic dynamic model that join the real and monetary side of the economy. The computational simulation allowed investigating the degree of proximity of the model to the dynamics of a real economy. The simulation showed, amongst other results, that: (i the profit rate is significantly elastic with regard to the rate of technological progress, while the interests rate and the degree of utilization of the capacity are little sensible to this variable; and (ii the confirmation of the paradox of the thrift, according to which an increase of the propensity to save of the capitalists reduces the level of the aggregate saving.

Incongruent genetic connectivity patterns for VME indicator taxa: implications for the management of New Zealand's vulnerable marine ecosystems

Science.gov (United States)

Clark, M. R.; Gardner, J.; Holland, L.; Zeng, C.; Hamilton, J. S.; Rowden, A. A.

2016-02-01

In the New Zealand region vulnerable marine ecosystems (VMEs) are at risk from commercial fishing activity and future seabed mining. Understanding connectivity among VMEs is important for the design of effective spatial management strategies, i.e. a network of protected areas. To date however, genetic connectivity in the New Zealand region has rarely been documented. As part of a project developing habitat suitability models and spatial management options for VMEs we used DNA sequence data and microsatellite genotyping to assess genetic connectivity for a range of VME indicator taxa, including the coral Desmophyllum dianthus, and the sponges Poecilastra laminaris and Penares palmatoclada. Overall, patterns of connectivity were inconsistent amonst taxa. Nonetheless, genetic data from each taxon were relevant to inform management at a variety of spatial scales. D. dianthus populations in the Kermadec volcanic arc and the Louisville Seamount Chain were indistinguishable, highlighting the importance of considering source-sink dynamics between populations beyond the EEZ in conservation planning. Poecilastra laminaris populations showed significant divergence across the Chatham Rise, in contrast to P. palmatoclada, which had a uniform haplotypic distribution. However, both sponge species exhibited the highest genetic diversity on the Chatham Rise, suggesting that this area is a genetic hotspot. The spatial heterogeneity of genetic patterns of structure suggest that inclusion of several taxa is necessary to facilitate understanding of regional connectivity patterns, variation in which may be attributed to alternate life history strategies, local hydrodynamic regimes, or in some cases, suboptimal sample sizes. Our findings provide important information for use by environmental managers, including summary maps of genetic diversity and barriers to gene flow, which will be used in spatial management decision-support tools.

Diverse, rare microbial taxa responded to the Deepwater Horizon deep-sea hydrocarbon plume.

Science.gov (United States)

Kleindienst, Sara; Grim, Sharon; Sogin, Mitchell; Bracco, Annalisa; Crespo-Medina, Melitza; Joye, Samantha B

2016-02-01

The Deepwater Horizon (DWH) oil well blowout generated an enormous plume of dispersed hydrocarbons that substantially altered the Gulf of Mexico's deep-sea microbial community. A significant enrichment of distinct microbial populations was observed, yet, little is known about the abundance and richness of specific microbial ecotypes involved in gas, oil and dispersant biodegradation in the wake of oil spills. Here, we document a previously unrecognized diversity of closely related taxa affiliating with Cycloclasticus, Colwellia and Oceanospirillaceae and describe their spatio-temporal distribution in the Gulf's deepwater, in close proximity to the discharge site and at increasing distance from it, before, during and after the discharge. A highly sensitive, computational method (oligotyping) applied to a data set generated from 454-tag pyrosequencing of bacterial 16S ribosomal RNA gene V4-V6 regions, enabled the detection of population dynamics at the sub-operational taxonomic unit level (0.2% sequence similarity). The biogeochemical signature of the deep-sea samples was assessed via total cell counts, concentrations of short-chain alkanes (C1-C5), nutrients, (colored) dissolved organic and inorganic carbon, as well as methane oxidation rates. Statistical analysis elucidated environmental factors that shaped ecologically relevant dynamics of oligotypes, which likely represent distinct ecotypes. Major hydrocarbon degraders, adapted to the slow-diffusive natural hydrocarbon seepage in the Gulf of Mexico, appeared unable to cope with the conditions encountered during the DWH spill or were outcompeted. In contrast, diverse, rare taxa increased rapidly in abundance, underscoring the importance of specialized sub-populations and potential ecotypes during massive deep-sea oil discharges and perhaps other large-scale perturbations.

TAXA DE CRESCIMENTO DO ALMEIRÃO SUBMETIDO AO DÉFICIT DE ÁGUA NO SOLO

Directory of Open Access Journals (Sweden)

Rogério Rangel Rodrigues

2017-01-01

Full Text Available Objetivou-se com esse trabalho avaliar a influencia do déficit hídrico sobre o desenvolvimento do almeirão (Cichorium intybus L. cultivar folha amarela. Foi elaborado um experimento em casa de vegetação no Centro de Ciências Agrárias e Engenharias da Universidade Federal do Espírito Santo, em Alegre, ES. O experimento constitui-se de quatro tratamentos, sendo 80, 60, 40 e 20% da água disponível no solo, com quatro repetições, em um delineamento inteiramente casualizado. A época de avaliação foi aos 35 dias após início dos tratamentos. As variáveis avaliadas foram: taxa de biomassa fresca e seca da parte aérea, taxa do sistema radicular fresco e seco e taxa da área foliar. Os resultados demonstraram que os maiores valores, em taxa de crescimento, das variáveis avaliadas foram obtidos quando se utilizou até 80% da água disponível, diferindo significativamente dos demais tratamentos.

Conceptual framework for holistic dialysis management based on key performance indicators.

Science.gov (United States)

Liu, Hu-Chen; Itoh, Kenji

2013-10-01

This paper develops a theoretical framework of holistic hospital management based on performance indicators that can be applied to dialysis hospitals, clinics or departments in Japan. Selection of a key indicator set and its validity tests were performed primarily by a questionnaire survey to dialysis experts as well as their statements obtained through interviews. The expert questionnaire asked respondents to rate the degree of "usefulness" for each of 66 indicators on a three-point scale (19 responses collected). Applying the theoretical framework, we selected a minimum set of key performance indicators for dialysis management that can be used in the Japanese context. The indicator set comprised 27 indicators and items that will be collected through three surveys: patient satisfaction, employee satisfaction, and safety culture. The indicators were confirmed by expert judgment from viewpoints of face, content and construct validity as well as their usefulness. This paper established a theoretical framework of performance measurement for holistic dialysis management from primary healthcare stakeholders' perspectives. In this framework, performance indicators were largely divided into healthcare outcomes and performance shaping factors. Indicators of the former type may be applied for the detection of operational problems or weaknesses in a dialysis hospital, clinic or department, while latent causes of each problem can be more effectively addressed by the latter type of indicators in terms of process, structure and culture/climate within the organization. © 2013 The Authors. Therapeutic Apheresis and Dialysis © 2013 International Society for Apheresis.

Graduate Curriculum for Biological Information Specialists: A Key to Integration of Scale in Biology

Directory of Open Access Journals (Sweden)

Carole L. Palmer

2007-12-01

Full Text Available Scientific data problems do not stand in isolation. They are part of a larger set of challenges associated with the escalation of scientific information and changes in scholarly communication in the digital environment. Biologists in particular are generating enormous sets of data at a high rate, and new discoveries in the biological sciences will increasingly depend on the integration of data across multiple scales. This work will require new kinds of information expertise in key areas. To build this professional capacity we have developed two complementary educational programs: a Biological Information Specialist (BIS masters degree and a concentration in Data Curation (DC. We believe that BISs will be central in the development of cyberinfrastructure and information services needed to facilitate interdisciplinary and multi-scale science. Here we present three sample cases from our current research projects to illustrate areas in which we expect information specialists to make important contributions to biological research practice.

Mining key elements for severe convection prediction based on CNN

Science.gov (United States)

Liu, Ming; Pan, Ning; Zhang, Changan; Sha, Hongzhou; Zhang, Bolei; Liu, Liang; Zhang, Meng

2017-04-01

Severe convective weather is a kind of weather disasters accompanied by heavy rainfall, gust wind, hail, etc. Along with recent developments on remote sensing and numerical modeling, there are high-volume and long-term observational and modeling data accumulated to capture massive severe convective events over particular areas and time periods. With those high-volume and high-variety weather data, most of the existing studies and methods carry out the dynamical laws, cause analysis, potential rule study, and prediction enhancement by utilizing the governing equations from fluid dynamics and thermodynamics. In this study, a key-element mining method is proposed for severe convection prediction based on convolution neural network (CNN). It aims to identify the key areas and key elements from huge amounts of historical weather data including conventional measurements, weather radar, satellite, so as numerical modeling and/or reanalysis data. Under this manner, the machine-learning based method could help the human forecasters on their decision-making on operational weather forecasts on severe convective weathers by extracting key information from the real-time and historical weather big data. In this paper, it first utilizes computer vision technology to complete the data preprocessing work of the meteorological variables. Then, it utilizes the information such as radar map and expert knowledge to annotate all images automatically. And finally, by using CNN model, it cloud analyze and evaluate each weather elements (e.g., particular variables, patterns, features, etc.), and identify key areas of those critical weather elements, then help forecasters quickly screen out the key elements from huge amounts of observation data by current weather conditions. Based on the rich weather measurement and model data (up to 10 years) over Fujian province in China, where the severe convective weathers are very active during the summer months, experimental tests are conducted with

A KPI-based process monitoring and fault detection framework for large-scale processes.

Science.gov (United States)

Zhang, Kai; Shardt, Yuri A W; Chen, Zhiwen; Yang, Xu; Ding, Steven X; Peng, Kaixiang

2017-05-01

Large-scale processes, consisting of multiple interconnected subprocesses, are commonly encountered in industrial systems, whose performance needs to be determined. A common approach to this problem is to use a key performance indicator (KPI)-based approach. However, the different KPI-based approaches are not developed with a coherent and consistent framework. Thus, this paper proposes a framework for KPI-based process monitoring and fault detection (PM-FD) for large-scale industrial processes, which considers the static and dynamic relationships between process and KPI variables. For the static case, a least squares-based approach is developed that provides an explicit link with least-squares regression, which gives better performance than partial least squares. For the dynamic case, using the kernel representation of each subprocess, an instrument variable is used to reduce the dynamic case to the static case. This framework is applied to the TE benchmark process and the hot strip mill rolling process. The results show that the proposed method can detect faults better than previous methods. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Quantitative evaluation of sperm in men, based on an interval scale

Directory of Open Access Journals (Sweden)

V. V. Danilov

2014-11-01

Full Text Available Modern methods of estimation spermogram are quite difficult and highly subjective. Were analyzed spermogram 215 men aged 20 to 46 years (mean age 29,7 ± 2,4 years. The analysis spermogram were selected 5 out of 21 key indicators of ejaculate that affect fertility: the total number, motility, viability, morphology of sperm, ejaculate volume. Based on these data the interval scale, which allows to quantify the sperm. Obtained as a result of an integral index is a reflection of pathological semen analysis based on deviations from the “ideal norm”, that allows to evaluate different sperm, and to evaluate the effectiveness of treatment, as with the use of conservative methods, and various options for surgical intervention.

Cryptanalysis on a parallel keyed hash function based on chaotic maps

International Nuclear Information System (INIS)

Guo Wei; Wang Xiaoming; He Dake; Cao Yang

2009-01-01

This Letter analyzes the security of a novel parallel keyed hash function based on chaotic maps, proposed by Xiao et al. to improve the efficiency in parallel computing environment. We show how to devise forgery attacks on Xiao's scheme with differential cryptanalysis and give the experiment results of two kinds of forgery attacks firstly. Furthermore, we discuss the problem of weak keys in the scheme and demonstrate how to utilize weak keys to construct collision.

DNA based random key generation and management for OTP encryption.

Science.gov (United States)

Zhang, Yunpeng; Liu, Xin; Sun, Manhui

2017-09-01

One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.

Key performance indicators in hospital based on balanced scorecard model

Directory of Open Access Journals (Sweden)

Hamed Rahimi

2017-01-01

Full Text Available Introduction: Performance measurement is receiving increasing verification all over the world. Nowadays in a lot of organizations, irrespective of their type or size, performance evaluation is the main concern and a key issue for top administrators. The purpose of this study is to organize suitable key performance indicators (KPIs for hospitals’ performance evaluation based on the balanced scorecard (BSC. Method: This is a mixed method study. In order to identify the hospital’s performance indicators (HPI, first related literature was reviewed and then the experts’ panel and Delphi method were used. In this study, two rounds were needed for the desired level of consensus. The experts rated the importance of the indicators, on a five-point Likert scale. In the consensus calculation, the consensus percentage was calculated by classifying the values 1-3 as not important (0 and 4-5 to (1 as important. Simple additive weighting technique was used to rank the indicators and select hospital’s KPIs. The data were analyzed by Excel 2010 software. Results: About 218 indicators were obtained from a review of selected literature. Through internal expert panel, 77 indicators were selected. Finally, 22 were selected for KPIs of hospitals. Ten indicators were selected in internal process perspective and 5, 4, and 3 indicators in finance, learning and growth, and customer, respectively. Conclusion: This model can be a useful tool for evaluating and comparing the performance of hospitals. However, this model is flexible and can be adjusted according to differences in the target hospitals. This study can be beneficial for hospital administrators and it can help them to change their perspective about performance evaluation.

Restingomyces, a new sequestrate genus from the Brazilian Atlantic rainforest that is phylogenetically related to early-diverging taxa in Trappeaceae (Phallales).

Science.gov (United States)

Sulzbacher, Marcelo A; Grebenc, Tine; Cabral, Tiara S; Giachini, Admir J; Goto, Bruno T; Smith, Matthew E; Baseia, Iuri G

2016-09-01

Restingomyces reticulatus gen. et sp. nov. is a recently discovered false truffle species from Atlantic "restinga" rainforest in northeastern Brazil. Molecular and morphological characters separate this new sequestrate species from other described taxa in the order Phallales (Phallomycetidae, Basidiomycota). In our phylogenetic analysis based on nuc 28S rDNA and atp6, R. reticulatus forms a sister clade to Trappea darkeri and Phallobata alba, with the three taxa forming the earliest diverging lineage within Phallales. Morphological and molecular data warrant the recognition of the new genus and species, described here, and we also amend the taxonomic description for the family Trappeaceae. © 2016 by The Mycological Society of America.

An Attribute Involved Public Key Cryptosystem Based on P-Sylow Subgroups and Randomization

Directory of Open Access Journals (Sweden)

Sumalatha GUNNALA

2018-04-01

Full Text Available The Asymmetric Key Cryptosystem (AKC or Public Key Encryption (PKE is a mechanism used to encrypt the messages by using public key and decrypt the enciphered messages by using private key. Of late, the Attribute-Based Encryption (ABE is an expansion of asymmetric key encryption scheme that allows users to encrypt and decrypt the plaintext messages using the key based on the user’s credentials, called attributes, like social security number, PAN (Permanent Account Number, email ids or Aadhar number etc. Most of the existing ABE schemes rely on the multiple attributes from which the access control policies are derived. These policies define the users’ private keys, required for the decryption process and access to the confidential information. In this paper, we proposed a new attribute based asymmetric cryptosystem that uses the features of both the schemes: PKE and ABE. Here, we used a value of an attribute, personal to the user, for the encryption and the decryption process. This scheme assures that the receiver will only be able to access the secret data if recipient is shared with the valid attribute value. The asymmetric nature is this scheme is based on the concept of p-sylow sub-group assumption. In addition, the randomization factor is used in the encipherment process to strengthen the cipher further. The development of this cryptosystem is an embodiment where the merits of randomized asymmetric encryption technique and the attribute based encryption are integrated to achieve the authentication on top of confidentiality to secure the information transmission over the public networks.

An Authenticated Key Agreement Scheme Based on Cyclic Automorphism Subgroups of Random Orders

Directory of Open Access Journals (Sweden)

Yang Jun

2017-01-01

Full Text Available Group-based cryptography is viewed as a modern cryptographic candidate solution to blocking quantum computer attacks, and key exchange protocols on the Internet are one of the primitives to ensure the security of communication. In 2016 Habeeb et al proposed a “textbook” key exchange protocol based on the semidirect product of two groups, which is insecure for use in real-world applications. In this paper, after discarding the unnecessary disguising notion of semidirect product in the protocol, we establish a simplified yet enhanced authenticated key agreement scheme based on cyclic automorphism subgroups of random orders by making hybrid use of certificates and symmetric-key encryption as challenge-and-responses in the public-key setting. Its passive security is formally analyzed, which is relative to the cryptographic hardness assumption of a computational number-theoretic problem. Cryptanalysis of this scheme shows that it is secure against the intruder-in-the-middle attack even in the worst case of compromising the signatures, and provides explicit key confirmation to both parties.

COMMUNITY SCALE STREAM TAXA SENSITIVITIES TO DIFFERENT COMPOSITIONS OF EXCESS TOTAL DISSOLVED SOLIDS

Science.gov (United States)

Model stream chronic dosing studies (42 d) were conducted with three total dissolved solids (TDS) recipes. The recipes differed in composition of major ions. Community scale emergence was compared with single-species responses conducted simultaneously using the whole effluent tox...

Diversity of kelp holdfast-associated fauna in an Arctic fjord - inconsistent responses to glacial mineral sedimentation across different taxa

Science.gov (United States)

Ronowicz, Marta; Kukliński, Piotr; Włodarska-Kowalczuk, Maria

2018-05-01

Kelp forests are complex underwater habitats that support diverse assemblages of animals ranging from sessile filter feeding invertebrates to fishes and marine mammals. In this study, the diversity of invertebrate fauna associated with kelp holdfasts was surveyed in a high Arctic glacial fjord (76 N, Hornsund, Svalbard). The effects of algal host identity (three kelp species: Laminaria digitata, Saccharina latissima and Alaria esculenta), depth (5 and 10 m) and glacier-derived disturbance (three sites with varying levels of mineral sedimentation) on faunal species richness and composition were studied based on 239 collected algal holdfasts. The species pool was mostly made up by three taxa: colonial Bryozoa and Hydrozoa, and Polychaeta. While the all-taxa species richness did not differ between depths, algal hosts and sites, the patterns varied when the two colonial sessile filter-feeding taxa were analysed alone (Hydrozoa and Bryozoa). The Hydrozoa sample species richness and average taxonomic distinctness were the highest at undisturbed sites, whereas Bryozoa species richness was higher in sediment-impacted localities, indicating relative insensitivity of this phylum to the increased level of mineral suspension in the water column. The average taxonomic distinctness of Bryozoa did not vary between sites. The species composition of kelp-associated fauna varied between sites and depths for the whole community and the most dominant taxa (Bryozoa, Hydrozoa). The high load of inorganic suspension and sedimentation did not cause pauperization of kelp holdfast-associated fauna but instead triggered the changes in species composition and shifts between dominant taxonomic groups.

prepare_taxa_charts.py: A Python program to automate generation of publication ready taxonomic pie chart images from QIIME.

Science.gov (United States)

Lakhujani, Vijay; Badapanda, Chandan

2017-06-01

QIIME (Quantitative Insights Into Microbial Ecology) is one of the most popular open-source bioinformatics suite for performing metagenome, 16S rRNA amplicon and Internal Transcribed Spacer (ITS) data analysis. Although, it is very comprehensive and powerful tool, it lacks a method to provide publication ready taxonomic pie charts. The script plot_taxa_summary . py bundled with QIIME generate a html file and a folder containing taxonomic pie chart and legend as separate images. The images have randomly generated alphanumeric names. Therefore, it is difficult to associate the pie chart with the legend and the corresponding sample identifier. Even if the option to have the legend within the html file is selected while executing plot_taxa_summary . py , it is very tedious to crop a complete image (having both the pie chart and the legend) due to unequal image sizes. It requires a lot of time to manually prepare the pie charts for multiple samples for publication purpose. Moreover, there are chances of error while identifying the pie chart and legend pair due to random alphanumeric names of the images. To bypass all these bottlenecks and make this process efficient, we have developed a python based program, prepare_taxa_charts . py , to automate the renaming, cropping and merging of taxonomic pie chart and corresponding legend image into a single, good quality publication ready image. This program not only augments the functionality of plot_taxa_summary . py but is also very fast in terms of CPU time and user friendly.

Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

Science.gov (United States)

Queiroz, Joel A.; Quirino, Zelma G. M.; Machado, Isabel C.

2015-01-01

Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat–hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h−1) than in I. aff. marcellia (0.57 visits h−1), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h−1 and I. aff. marcellia: 0.64 visits h−1). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat–hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

Non-linear dose response of a few plant taxa to acute gamma radiation

International Nuclear Information System (INIS)

George, J.T.; Patel, B.B.; Pius, J.; Narula, B.; Shankhadarwar, S.; Rane, V.A.; Venu-Babu, P.; Eapen, S.; Singhal, R.K.

2014-01-01

Micronuclei induction serves as an essential biomarker of radiation stress in a living system, and the simplicity of its detection technique has made it a widely used indicator of radiation damage. The present study was conducted to reveal the cytological dose-response of a few plant taxa, viz., Allium cepa var. aggregatum Linn., Allium sativum Linn., Chlorophytum comosum (Thunb.) Jacques and Eichhornia crassipes (Mart.) Solms, to low LET gamma radiation with special emphasis on the pattern of micronuclei induced across low and high dose regimes. A tri-phasic non-linear dose-response pattern was observed in the four taxa studied, characterized by a low dose linear segment, a plateau and a high dose linear segment. Despite a similar response trend, the critical doses where the phase transitions occurred varied amongst the plant taxa, giving an indication to their relative radiosensitivities. E. crassipes and A. sativum, with their lower critical doses for slope modifications of phase transitions, were concluded as being more radiosensitive as compared to C. comosum and A. cepa, which had relatively higher critical doses. (author)

Differences in diet and activity pattern between two groups of Alouatta palliata associated with the availability of big trees and fruit of top food taxa.

Science.gov (United States)

Dunn, Jacob C; Cristóbal-Azkarate, Jurgi; Veà, Joaquím J

2009-08-01

The threat that forest fragmentation and habitat loss presents for several Alouatta taxa requires us to determine the key elements that may promote the persistence of howler monkeys in forest fragments and to evaluate how changes in the availability of these elements may affect their future conservation prospects. In this study we analyzed the relationship between the availability of both big trees of top food taxa (BTTFT) (diameter at breast height>60) and fruit of top food taxa (FrTFT) in the home ranges of two groups of Alouatta palliata mexicana occupying different forest fragments in Los Tuxtlas, Mexico, and their diet and activity pattern. Both study groups preferred big trees for feeding and the group with lower availability of BTTFT in their home range fed from more, smaller food sources. Furthermore, both study groups also increased the number of food sources when their consumption of fruit decreased, and the group with lower availability of FrTFT in their home range fed from more food sources. The increase in the number of food sources used under such conditions, in turn, set up a process of higher foraging effort and lower rest. In summary, our results support other studies that suggest that the availability of big trees and fruit may be two important elements influencing the persistence of howler monkeys in forest fragments.

Key exchange using biometric identity based encryption for sharing encrypted data in cloud environment

Science.gov (United States)

Hassan, Waleed K.; Al-Assam, Hisham

2017-05-01

The main problem associated with using symmetric/ asymmetric keys is how to securely store and exchange the keys between the parties over open networks particularly in the open environment such as cloud computing. Public Key Infrastructure (PKI) have been providing a practical solution for session key exchange for loads of web services. The key limitation of PKI solution is not only the need for a trusted third partly (e.g. certificate authority) but also the absent link between data owner and the encryption keys. The latter is arguably more important where accessing data needs to be linked with identify of the owner. Currently available key exchange protocols depend on using trusted couriers or secure channels, which can be subject to man-in-the-middle attack and various other attacks. This paper proposes a new protocol for Key Exchange using Biometric Identity Based Encryption (KE-BIBE) that enables parties to securely exchange cryptographic keys even an adversary is monitoring the communication channel between the parties. The proposed protocol combines biometrics with IBE in order to provide a secure way to access symmetric keys based on the identity of the users in unsecure environment. In the KE-BIOBE protocol, the message is first encrypted by the data owner using a traditional symmetric key before migrating it to a cloud storage. The symmetric key is then encrypted using public biometrics of the users selected by data owner to decrypt the message based on Fuzzy Identity-Based Encryption. Only the selected users will be able to decrypt the message by providing a fresh sample of their biometric data. The paper argues that the proposed solution eliminates the needs for a key distribution centre in traditional cryptography. It will also give data owner the power of finegrained sharing of encrypted data by control who can access their data.

Why and how might genetic and phylogenetic diversity be reflected in the identification of key biodiversity areas?

Science.gov (United States)

Brooks, T M; Cuttelod, A; Faith, D P; Garcia-Moreno, J; Langhammer, P; Pérez-Espona, S

2015-02-19

'Key biodiversity areas' are defined as sites contributing significantly to the global persistence of biodiversity. The identification of these sites builds from existing approaches based on measures of species and ecosystem diversity and process. Here, we therefore build from the work of Sgró et al. (2011 Evol. Appl. 4, 326-337. (doi:10.1111/j.1752-4571.2010.00157.x)) to extend a framework for how components of genetic diversity might be considered in the identification of key biodiversity areas. We make three recommendations to inform the ongoing process of consolidating a key biodiversity areas standard: (i) thresholds for the threatened species criterion currently consider a site's share of a threatened species' population; expand these to include the proportion of the species' genetic diversity unique to a site; (ii) expand criterion for 'threatened species' to consider 'threatened taxa' and (iii) expand the centre of endemism criterion to identify as key biodiversity areas those sites holding a threshold proportion of the compositional or phylogenetic diversity of species (within a taxonomic group) whose restricted ranges collectively define a centre of endemism. We also recommend consideration of occurrence of EDGE species (i.e. threatened phylogenetic diversity) in key biodiversity areas to prioritize species-specific conservation actions among sites.

Cryptanalysis of the public key encryption based on multiple chaotic systems

International Nuclear Information System (INIS)

Zhang Linhua

2008-01-01

Recently, Ranjan proposed a novel public key encryption technique based on multiple chaotic systems [Phys Lett 2005;95]. Unfortunately, Wang soon gave a successful attack on its special case based on Parseval's theorem [Wang K, Pei W, Zhou L, et al. Security of public key encryption technique based on multiple chaotic system. Phys Lett A, in press]. In this letter, we give an improved example which can avoid the attack and point out that Wang cannot find the essential drawback of the technique. However, further experimental result shows Ruanjan's encryption technique is inefficient, and detailed theoretic analysis shows that the complexity to break the cryptosystem is overestimated

Key to higher taxa of South American weevils based on adult characters (Coleoptera, Curculionoidea Clave de taxones superiores de gorgojos sudamericanos basada en caracteres de los adultos (Coleoptera, Curculionoidea

Directory of Open Access Journals (Sweden)

ADRIANA E. MARVALDI

2005-03-01

Full Text Available The weevils (Coleoptera: Curculionoidea from South America are currently classified in the following families and subfamilies: Nemonychidae (Rhinorhynchinae, Anthribidae (Anthribinae, Belidae (Belinae and Oxycoryninae, Attelabidae (Attelabinae and Rhynchitinae, Brentidae (Apioninae and Brentinae, Caridae (Carinae and Curculionidae (Erirhininae, Dryophthorinae, Entiminae, Aterpinae, Gonipterinae, Rhythirrininae, Thecesterninae, Eugnominae, Hyperinae, Curculioninae, Cryptorhynchinae, Mesoptiliinae (= Magdalidinae, Molytinae, Baridinae, Lixinae, Conoderinae (= Zygopinae, Cossoninae, Scolytinae and Platypodinae. In the present contribution we bring a dichotomous key for the identification of seven families and 28 subfamilies of Curculionoidea from South America, and for 21 tribes of the highly heterogeneous subfamilies Curculioninae and Molytinae. These tribes are Curculionini Anthonomini, Ceutorhynchini, Derelomini, Otidocephalini, Erodiscini, Camarotini, Piazorhinini, Prionobrachiini, Smicronychini, Rhamphini and Tychiini, within Curculioninae; and Hylobiini, Pissodini, Conotrachelini, Cleogonini, Sternechini, Pacholenini, Cholini, Petalochilini and Amalactini, within Molytinae. Most of them have been classified as subfamilies in traditional schemes. The key is mainly based on external morphological characters, but also includes data on genitalia, mouth parts and other biological features. Definitions and illustrations of diagnostic characters used in the key are providedLos gorgojos (Coleoptera: Curculionoidea de América del Sur se clasifican actualmente en las siguientes familias y subfamilias: Nemonychidae (Rhinorhynchinae, Anthribidae (Anthribinae, Belidae (Belinae y Oxycoryninae, Attelabidae (Attelabinae y Rhynchitinae, Brentidae (Apioninae y Brentinae, Caridae (Carinae y Curculionidae (Erirhininae, Dryophthorinae, Entiminae, Aterpinae, Gonipterinae, Rhythirrininae, Thecesterninae, Eugnominae, Hyperinae, Curculioninae, Cryptorhynchinae

Privacy authentication using key attribute-based encryption in mobile cloud computing

Science.gov (United States)

Mohan Kumar, M.; Vijayan, R.

2017-11-01

Mobile Cloud Computing is becoming more popular in nowadays were users of smartphones are getting increased. So, the security level of cloud computing as to be increased. Privacy Authentication using key-attribute based encryption helps the users for business development were the data sharing with the organization using the cloud in a secured manner. In Privacy Authentication the sender of data will have permission to add their receivers to whom the data access provided for others the access denied. In sender application, the user can choose the file which is to be sent to receivers and then that data will be encrypted using Key-attribute based encryption using AES algorithm. In which cipher created, and that stored in Amazon Cloud along with key value and the receiver list.

Scaling analysis in bepu licensing of LWR

International Nuclear Information System (INIS)

D'auria, Francesco; Lanfredini, Marco; Muellner, Nikolaus

2012-01-01

'Scaling' plays an important role for safety analyses in the licensing of water cooled nuclear power reactors. Accident analyses, a sub set of safety analyses, is mostly based on nuclear reactor system thermal hydraulics, and therefore based on an adequate experimental data base, and in recent licensing applications, on best estimate computer code calculations. In the field of nuclear reactor technology, only a small set of the needed experiments can be executed at a nuclear power plant; the major part of experiments, either because of economics or because of safety concerns, has to be executed at reduced scale facilities. How to address the scaling issue has been the subject of numerous investigations in the past few decades (a lot of work has been performed in the 80thies and 90thies of the last century), and is still the focus of many scientific studies. The present paper proposes a 'roadmap' to scaling. Key elements are the 'scaling-pyramid', related 'scaling bridges' and a logical path across scaling achievements (which constitute the 'scaling puzzle'). The objective is addressing the scaling issue when demonstrating the applicability of the system codes, the 'key-to-scaling', in the licensing process of a nuclear power plant. The proposed 'road map to scaling' aims at solving the 'scaling puzzle', by introducing a unified approach to the problem.

Fast algorithms for computing phylogenetic divergence time.

Science.gov (United States)

Crosby, Ralph W; Williams, Tiffani L

2017-12-06

The inference of species divergence time is a key step in most phylogenetic studies. Methods have been available for the last ten years to perform the inference, but the performance of the methods does not yet scale well to studies with hundreds of taxa and thousands of DNA base pairs. For example a study of 349 primate taxa was estimated to require over 9 months of processing time. In this work, we present a new algorithm, AncestralAge, that significantly improves the performance of the divergence time process. As part of AncestralAge, we demonstrate a new method for the computation of phylogenetic likelihood and our experiments show a 90% improvement in likelihood computation time on the aforementioned dataset of 349 primates taxa with over 60,000 DNA base pairs. Additionally, we show that our new method for the computation of the Bayesian prior on node ages reduces the running time for this computation on the 349 taxa dataset by 99%. Through the use of these new algorithms we open up the ability to perform divergence time inference on large phylogenetic studies.

Computation of a Suburban Night Train Timetable Based on Key Performance Indicators

DEFF Research Database (Denmark)

Schittenhelm, Bernd; Landex, Alex

2010-01-01

Timetable evaluation can be based on a set of key performance indicators. This article presents six essential key performance indicators: Fixed interval service frequency, direct connections, transfer waiting time, use of dedicated rolling stock, dedicated train personnel, dedicated tracks...

A REGION-BASED MULTI-SCALE APPROACH FOR OBJECT-BASED IMAGE ANALYSIS

Directory of Open Access Journals (Sweden)

T. Kavzoglu

2016-06-01

Full Text Available Within the last two decades, object-based image analysis (OBIA considering objects (i.e. groups of pixels instead of pixels has gained popularity and attracted increasing interest. The most important stage of the OBIA is image segmentation that groups spectrally similar adjacent pixels considering not only the spectral features but also spatial and textural features. Although there are several parameters (scale, shape, compactness and band weights to be set by the analyst, scale parameter stands out the most important parameter in segmentation process. Estimating optimal scale parameter is crucially important to increase the classification accuracy that depends on image resolution, image object size and characteristics of the study area. In this study, two scale-selection strategies were implemented in the image segmentation process using pan-sharped Qickbird-2 image. The first strategy estimates optimal scale parameters for the eight sub-regions. For this purpose, the local variance/rate of change (LV-RoC graphs produced by the ESP-2 tool were analysed to determine fine, moderate and coarse scales for each region. In the second strategy, the image was segmented using the three candidate scale values (fine, moderate, coarse determined from the LV-RoC graph calculated for whole image. The nearest neighbour classifier was applied in all segmentation experiments and equal number of pixels was randomly selected to calculate accuracy metrics (overall accuracy and kappa coefficient. Comparison of region-based and image-based segmentation was carried out on the classified images and found that region-based multi-scale OBIA produced significantly more accurate results than image-based single-scale OBIA. The difference in classification accuracy reached to 10% in terms of overall accuracy.

RANS based CFD methodology for a real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jae-Ho, E-mail: jhjeong@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of); Song, Min-Seop [Department of Nuclear Engineering, Seoul National University, 559 Gwanak-ro, Gwanak-gu, Seoul (Korea, Republic of); Lee, Kwi-Lim [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of)

2017-03-15

Highlights: • This paper presents a suitable way for a practical RANS based CFD methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR. • A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI function in a general-purpose commercial CFD code, CFX. • The RANS based CFD methodology is implemented with high resolution scheme and SST turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC and JNC. Furthermore, the RANS based CFD methodology can be successfully extended to the real scale 217-pin wire-wrapped fuel bundles of KAERI PGSFR. • Three-dimensional thermal-hydraulic characteristics have been also investigated briefly. - Abstract: This paper presents a suitable way for a practical RANS (Reynolds Averaged Navier-Stokes simulation) based CFD (Computational Fluid Dynamics) methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI (Korea Atomic Energy Research Institute) PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor). The main purpose of the current study is to support license issue for the KAERI PGSFR core safety and to elucidate thermal-hydraulic characteristics in a 217-pin wire-wrapped fuel assembly of KAERI PGSFR. A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI (General Grid Interface) function in a general-purpose commercial CFD code, CFX. The innovative grid generation method with GGI function can achieve to simulate a real wire shape with minimizing cell skewness. The RANS based CFD methodology is implemented with high resolution scheme in convection term and SST (Shear Stress Transport) turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC (Power reactor and Nuclear fuel

Evidence of Taxa-, Clone-, and Kin-discrimination in Protists: Ecological and Evolutionary Implications.

Science.gov (United States)

Espinosa, Avelina; Paz-Y-Miño-C, Guillermo

2014-11-01

Unicellular eukaryotes, or protists, are among the most ancient organisms on Earth. Protists belong to multiple taxonomic groups; they are widely distributed geographically and in all environments. Their ability to discriminate among con- and heterospecifics has been documented during the past decade. Here we discuss exemplar cases of taxa-, clone-, and possible kin-discrimination in five major lineages: Mycetozoa ( Dictyostelium , Polysphondylium ), Dikarya ( Saccharomyces ), Ciliophora ( Tetrahymena ), Apicomplexa ( Plasmodium ) and Archamoebae ( Entamoeba ). We summarize the proposed genetic mechanisms involved in discrimination-mediated aggregation (self versus different), including the csA , FLO and trg (formerly lag ) genes, and the Proliferation Activation Factors (PAFs), which facilitate clustering in some protistan taxa. We caution about the experimental challenges intrinsic to studying recognition in protists, and highlight the opportunities for exploring the ecology and evolution of complex forms of cell-cell communication, including social behavior, in a polyphyletic, still superficially understood group of organisms. Because unicellular eukaryotes are the evolutionary precursors of multicellular life, we infer that their mechanisms of taxa-, clone-, and possible kin-discrimination gave origin to the complex diversification and sophistication of traits associated with species and kin recognition in plants, fungi, invertebrates and vertebrates.

Use of AFLP and RAPD molecular genetic markers and cytogenetic analysis to explore relationships among taxa of the Patagonian Bromus setifolius complex

Directory of Open Access Journals (Sweden)

Ana M. García

2009-01-01

Full Text Available Bromus setifolius var. pictus (Hook Skottsb., B. setifolius var. setifolius Presl. and B. setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70 and B. setifolius var. setifolius (2n = 28 and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.

Simple group password-based authenticated key agreements for the integrated EPR information system.

Science.gov (United States)

Lee, Tian-Fu; Chang, I-Pin; Wang, Ching-Cheng

2013-04-01

The security and privacy are important issues for electronic patient records (EPRs). The goal of EPRs is sharing the patients' medical histories such as the diagnosis records, reports and diagnosis image files among hospitals by the Internet. So the security issue for the integrated EPR information system is essential. That is, to ensure the information during transmission through by the Internet is secure and private. The group password-based authenticated key agreement (GPAKE) allows a group of users like doctors, nurses and patients to establish a common session key by using password authentication. Then the group of users can securely communicate by using this session key. Many approaches about GAPKE employ the public key infrastructure (PKI) in order to have higher security. However, it not only increases users' overheads and requires keeping an extra equipment for storing long-term secret keys, but also requires maintaining the public key system. This investigation presents a simple group password-based authenticated key agreement (SGPAKE) protocol for the integrated EPR information system. The proposed SGPAKE protocol does not require using the server or users' public keys. Each user only remembers his weak password shared with a trusted server, and then can obtain a common session key. Then all users can securely communicate by using this session key. The proposed SGPAKE protocol not only provides users with convince, but also has higher security.

Evidence-based adaptation and scale-up of a mobile phone health information service.

Science.gov (United States)

L'Engle, Kelly; Plourde, Kate F; Zan, Trinity

2017-01-01

The research base recommending the use of mobile phone interventions for health improvement is growing at a rapid pace. The use of mobile phones to deliver health behavior change and maintenance interventions in particular is gaining a robust evidence base across geographies, populations, and health topics. However, research on best practices for successfully scaling mHealth interventions is not keeping pace, despite the availability of frameworks for adapting and scaling health programs. m4RH-Mobile for Reproductive Health-is an SMS, or text message-based, health information service that began in two countries and over a period of 7 years has been adapted and scaled to new population groups and new countries. Success can be attributed to following key principles for scaling up health programs, including continuous stakeholder engagement; ongoing monitoring, evaluation, and research including extensive content and usability testing with the target audience; strategic dissemination of results; and use of marketing and sustainability principles for social initiatives. This article investigates how these factors contributed to vertical, horizontal, and global scale-up of the m4RH program. Vertical scale of m4RH is demonstrated in Tanzania, where the early engagement of stakeholders including the Ministry of Health catalyzed expansion of m4RH content and national-level program reach. Ongoing data collection has provided real-time data for decision-making, information about the user base, and peer-reviewed publications, yielding government endorsement and partner hand-off for sustainability of the m4RH platform. Horizontal scale-up and adaptation of m4RH has occurred through expansion to new populations in Rwanda, Uganda, and Tanzania, where best practices for design and implementation of mHealth programs were followed to ensure the platform meets the needs of target populations. m4RH also has been modified and packaged for global scale-up through licensing and toolkit

Daylight operation of a free space, entanglement-based quantum key distribution system

Energy Technology Data Exchange (ETDEWEB)

Peloso, Matthew P; Gerhardt, Ilja; Ho, Caleb; Lamas-Linares, AntIa; Kurtsiefer, Christian [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)], E-mail: christian.kurtsiefer@gmail.com

2009-04-15

Many quantum key distribution (QKD) implementations using a free space transmission path are restricted to operation at night time in order to distinguish the signal photons used for a secure key establishment from the background light. Here, we present a lean entanglement-based QKD system overcoming that limitation. By implementing spectral, spatial and temporal filtering techniques, we establish a secure key continuously over several days under varying light and weather conditions.

Estrutura a termo da taxa de juros e imunização: novas perspectivas na gestão do risco de taxa de juros em fundo de pensão

OpenAIRE

Machado,Sérgio Jurandyr; Motta,Luis Felipe Jacques da

2007-01-01

O termo imunização denota a construção de uma carteira de títulos de forma a torná-la imune a variações nas taxas de juros. No caso dos fundos de pensão, o objetivo da imunização é distribuir os recebimentos intermediários e finais dos ativos de acordo com a previsão para o fluxo de pagamentos dos benefícios. Nesse sentido, o artigo busca comparar o desempenho de duas alternativas de imunização ao método tradicional que restringe o gerenciamento do risco de taxa de juros à compatibilização da...

Scaling analysis in bepu licensing of LWR

Energy Technology Data Exchange (ETDEWEB)

D' auria, Francesco; Lanfredini, Marco; Muellner, Nikolaus [University of Pisa, Pisa (Italy)

2012-08-15

'Scaling' plays an important role for safety analyses in the licensing of water cooled nuclear power reactors. Accident analyses, a sub set of safety analyses, is mostly based on nuclear reactor system thermal hydraulics, and therefore based on an adequate experimental data base, and in recent licensing applications, on best estimate computer code calculations. In the field of nuclear reactor technology, only a small set of the needed experiments can be executed at a nuclear power plant; the major part of experiments, either because of economics or because of safety concerns, has to be executed at reduced scale facilities. How to address the scaling issue has been the subject of numerous investigations in the past few decades (a lot of work has been performed in the 80thies and 90thies of the last century), and is still the focus of many scientific studies. The present paper proposes a 'roadmap' to scaling. Key elements are the 'scaling-pyramid', related 'scaling bridges' and a logical path across scaling achievements (which constitute the 'scaling puzzle'). The objective is addressing the scaling issue when demonstrating the applicability of the system codes, the 'key-to-scaling', in the licensing process of a nuclear power plant. The proposed 'road map to scaling' aims at solving the 'scaling puzzle', by introducing a unified approach to the problem.

Domestic biogas diffusion in Rwanda - Key learning for scale up

International Nuclear Information System (INIS)

2016-03-01

The NGO Veterinaires Sans Frontieres Belgium (VSF-B) supports local populations to improve livestock keeping and other related aspects such as natural resources management and micro-loans. In 2013, ENEA conducted a study to assess the opportunity for VSF-B to include domestic biogas energy within its scope of activities in Rwanda. In 2014, VSF-B launched the EVE project to install 100 bio-digesters and provide capacity building to smallholder farmers in Southern Rwanda within 3 years. The project is strongly integrated to the local context, partnering with a local federation of farmers, IMBARAGA, to implement the project, and leveraging the Rwandan National Domestic Biogas Program (NDBP). In mid-2015, ENEA conducted a new study to provide VSF-B with an intermediate evaluation of the project, a preliminary assessment of its impacts as well as recommendations to scale-up. VSF-B / IMBARAGA's activity on biogas within the EVE project is successful thanks to an efficient approach combining sensitisation and financial and technical support. By September 2015, half of the target of the pilot phase had been reached - 50 biogas systems were installed or under construction - and the remaining half was likely to be reached by the end of the project. This is the result of an efficient approach for domestic biogas distribution set up by VSF-B / IMBARAGA. Intensive work of sensitisation of farmers combined with an adapted financial support scheme (additional subsidies and guarantee funds for credit) and with technical support and monitoring of farmers are the three pillars on which VSF-B / IMBARAGA's success is based. End-users are highly satisfied of biogas systems and use, thanks to the robustness of the technology and the various outcomes delivered. Although the initial levers for biogas adoption by farmers were fuel savings and convenience to cook, other outcomes appears to be as meaningful to them once they start using the system: increased convenience to boil water or milk

Análise do impacto das taxas de juros no desempenho financeiro dos bancos brasileiros

Directory of Open Access Journals (Sweden)

Marcus Vinicius Moreira Zittei

2016-05-01

Full Text Available A rentabilidade dos bancos é geralmente considerada um fator relevante para garantir a solidez do sistema financeiro, reduzindo os riscos associados aos eventos de insolvência nesse setor. No Brasil, há discussões quanto aos lucros das instituições financeiras que atuam no país, centradas no argumento de que tais lucros seriam supostamente muito elevados, onerando demasiadamente o setor produtivo. As instituições bancárias incorporaram processos como forma de adequação ao mercado. Um desses processos é a taxa de juros que representa a remuneração adicional ao capital emprestado, de forma que mantenha a valorização econômica da moeda, com inferência direta pela variação do tempo na atividade de crédito. Este estudo busca analisar o impacto das taxas de juros no desempenho financeiro dos bancos brasileiros. Os dados extraídos compreenderam os períodos de 2009 a 2012 de nove instituições bancárias, que representam 64% dos maiores bancos. Para a coleta dos dados, foi utilizado o sistema de informações cadastrais e contábeis do Banco Central do Brasil e o sistema de informações sobre operações bancárias do Banco Central do Brasil. Os resultados, apurados com o uso da metodologia de dados em regressão linear múltipla e testes não paramétricos demonstram, inicialmente, que a taxa de juros tem forte relação com o lucro líquido de todas as instituições, na medida em que tem uma oscilação na taxa juros, e, consequentemente, terá no lucro. Assim, foram obtidas evidências de que as taxas de juros implicam rentabilidade no setor bancário nacional.

Properties of small-scale interfacial turbulence from a novel thermography based approach

Science.gov (United States)

Schnieders, Jana; Garbe, Christoph

2013-04-01

Oceans cover nearly two thirds of the earth's surface and exchange processes between the Atmosphere and the Ocean are of fundamental environmental importance. At the air-sea interface, complex interaction processes take place on a multitude of scales. Turbulence plays a key role in the coupling of momentum, heat and mass transfer [2]. Here we use high resolution infrared imagery to visualize near surface aqueous turbulence. Thermographic data is analized from a range of laboratory facilities and experimental conditions with wind speeds ranging from 1ms-1 to 7ms-1 and various surface conditions. The surface heat pattern is formed by distinct structures on two scales - small-scale short lived structures termed fish scales and larger scale cold streaks that are consistent with the footprints of Langmuir Circulations. There are two key characteristics of the observed surface heat patterns: (1) The surface heat patterns show characteristic features of scales. (2) The structure of these patterns change with increasing wind stress and surface conditions. We present a new image processing based approach to the analysis of the spacing of cold streaks based on a machine learning approach [4, 1] to classify the thermal footprints of near surface turbulence. Our random forest classifier is based on classical features in image processing such as gray value gradients and edge detecting features. The result is a pixel-wise classification of the surface heat pattern with a subsequent analysis of the streak spacing. This approach has been presented in [3] and can be applied to a wide range of experimental data. In spite of entirely different boundary conditions, the spacing of turbulent cells near the air-water interface seems to match the expected turbulent cell size for flow near a no-slip wall. The analysis of the spacing of cold streaks shows consistent behavior in a range of laboratory facilities when expressed as a function of water sided friction velocity, u*. The scales

Improved regional-scale Brazilian cropping systems' mapping based on a semi-automatic object-based clustering approach

Science.gov (United States)

Bellón, Beatriz; Bégué, Agnès; Lo Seen, Danny; Lebourgeois, Valentine; Evangelista, Balbino Antônio; Simões, Margareth; Demonte Ferraz, Rodrigo Peçanha

2018-06-01

Cropping systems' maps at fine scale over large areas provide key information for further agricultural production and environmental impact assessments, and thus represent a valuable tool for effective land-use planning. There is, therefore, a growing interest in mapping cropping systems in an operational manner over large areas, and remote sensing approaches based on vegetation index time series analysis have proven to be an efficient tool. However, supervised pixel-based approaches are commonly adopted, requiring resource consuming field campaigns to gather training data. In this paper, we present a new object-based unsupervised classification approach tested on an annual MODIS 16-day composite Normalized Difference Vegetation Index time series and a Landsat 8 mosaic of the State of Tocantins, Brazil, for the 2014-2015 growing season. Two variants of the approach are compared: an hyperclustering approach, and a landscape-clustering approach involving a previous stratification of the study area into landscape units on which the clustering is then performed. The main cropping systems of Tocantins, characterized by the crop types and cropping patterns, were efficiently mapped with the landscape-clustering approach. Results show that stratification prior to clustering significantly improves the classification accuracies for underrepresented and sparsely distributed cropping systems. This study illustrates the potential of unsupervised classification for large area cropping systems' mapping and contributes to the development of generic tools for supporting large-scale agricultural monitoring across regions.

User-based key frame detection in social web video

OpenAIRE

Chorianopoulos, Konstantinos

2012-01-01

Video search results and suggested videos on web sites are represented with a video thumbnail, which is manually selected by the video up-loader among three randomly generated ones (e.g., YouTube). In contrast, we present a grounded user-based approach for automatically detecting interesting key-frames within a video through aggregated users' replay interactions with the video player. Previous research has focused on content-based systems that have the benefit of analyzing a video without use...

Stego Keys Performance on Feature Based Coding Method in Text Domain

Directory of Open Access Journals (Sweden)

Din Roshidi

2017-01-01

Full Text Available A main critical factor on embedding process in any text steganography method is a key used known as stego key. This factor will be influenced the success of the embedding process of text steganography method to hide a message from third party or any adversary. One of the important aspects on embedding process in text steganography method is the fitness performance of the stego key. Three parameters of the fitness performance of the stego key have been identified such as capacity ratio, embedded fitness ratio and saving space ratio. It is because a better as capacity ratio, embedded fitness ratio and saving space ratio offers of any stego key; a more message can be hidden. Therefore, main objective of this paper is to analyze three features coding based namely CALP, VERT and QUAD of stego keys in text steganography on their capacity ratio, embedded fitness ratio and saving space ratio. It is found that CALP method give a good effort performance compared to VERT and QUAD methods.

Identifying the plant-associated microbiome across aquatic and terrestrial environments: the effects of amplification method on taxa discovery

Energy Technology Data Exchange (ETDEWEB)

Jackrel, Sara L. [Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street Chicago IL 60637 USA; Owens, Sarah M. [Biosciences Division, Argonne National Laboratory, 9700 S. Cass Avenue Lemont IL 60439 USA; Gilbert, Jack A. [Biosciences Division, Argonne National Laboratory, 9700 S. Cass Avenue Lemont IL 60439 USA; The Microbiome Center, Department of Surgery, The University of Chicago, 5841 S Maryland Ave Chicago IL 60637 USA; Pfister, Catherine A. [Department of Ecology and Evolution, The University of Chicago, 1101 E 57th Street Chicago IL 60637 USA

2017-01-25

Plants in terrestrial and aquatic environments contain a diverse microbiome. Yet, the chloroplast and mitochondria organelles of the plant eukaryotic cell originate from free-living cyanobacteria and Rickettsiales. This represents a challenge for sequencing the plant microbiome with universal primers, as ~99% of 16S rRNA sequences may consist of chloroplast and mitochondrial sequences. Peptide nucleic acid clamps offer a potential solution by blocking amplification of host-associated sequences. We assessed the efficacy of chloroplast and mitochondria-blocking clamps against a range of microbial taxa from soil, freshwater and marine environments. While we found that the mitochondrial blocking clamps appear to be a robust method for assessing animal-associated microbiota, Proteobacterial 16S rRNA binds to the chloroplast-blocking clamp, resulting in a strong sequencing bias against this group. We attribute this bias to a conserved 14-bp sequence in the Proteobacteria that matches the 17-bp chloroplast-blocking clamp sequence. By scanning the Greengenes database, we provide a reference list of nearly 1500 taxa that contain this 14-bp sequence, including 48 families such as the Rhodobacteraceae, Phyllobacteriaceae, Rhizobiaceae, Kiloniellaceae and Caulobacteraceae. To determine where these taxa are found in nature, we mapped this taxa reference list against the Earth Microbiome Project database. These taxa are abundant in a variety of environments, particularly aquatic and semiaquatic freshwater and marine habitats. To facilitate informed decisions on effective use of organelle-blocking clamps, we provide a searchable database of microbial taxa in the Greengenes and Silva databases matching various n-mer oligonucleotides of each PNA sequence.

Efficient Key Management System for Large-scale Smart RFID Applications

Directory of Open Access Journals (Sweden)

Mohammad Fal Sadikin

2015-08-01

Full Text Available Due to low-cost and its practical solution, the integration of RFID tag to the sensor node called smart RFID has become prominent solution in various fields including industrial applications. Nevertheless, the constrained nature of smart RFID system introduces tremendous security and privacy problem. One of them is the problem in key management system. Indeed, it is not feasible to recall all RFID tags in order to update their security properties (e.g. update their private keys. On the other hand, using common key management solution like standard TLS/SSL is too heavy-weight that can drain and overload the limited resources. Furthermore, most of existing solutions are highly susceptible to various threats reaching from privacy threats, physical attacks to various technics of Man-in-the-Middle attacks. This paper introduces novel key management system, tailored to the limited resources of smart RFID system. It proposes light-weight mutual authentication and identity protection to mitigate the existing threats.

Variabilidade espacial da biomassa da forragem e taxa de lotação animal em pastagem de capim Marandu

Directory of Open Access Journals (Sweden)

Sabino Pereira da Silva Neto

2015-07-01

Full Text Available O objetivo deste estudo foi realizar a modelagem variográfica da disponibilidade de matéria seca da Urochloa brizantha cv. Marandu e a simulação da taxa de lotação animal por meio do ajuste dos modelos esférico, exponencial e gaussiano ao semivariograma experimental, bem como a robustez das predições. A biomassa da gramínea foi coletada em 50 pontos em uma área de 36,22 ha. A simulação da taxa de lotação foi realizada com base na disponibilidade de folhas verdes em cada ponto amostrado, consumo diário de matéria seca por cada unidade animal (UA e o tempo de pastejo. Os dados referentes às variáveis foram submetidos à análise descritiva, estudo geoestatístico e interpolação por krigagem ordinária. A modelagem variográfica da disponibilidade de matéria seca do capim marandu e a taxa de lotação foram caracterizadas pelos modelos esférico, exponencial e gaussiano. Entretanto, apesar da aparente precisão dos ajustes, o modelo esférico apresentou melhor inferência, segundo o critério de informação de Akaike e soma dos erros ao quadrado. Assim, a adoção de modelos com ajustes de critérios somente visuais levam a estimativas da disponibilidade de biomassa de forragem e da taxa de lotação animal que não refletem a realidade da área. Palavras–chave: Estrutura do pasto. Carga animal. Distribuição espacial. Pecuária de precisão. Produção animal. Semivariograma.

Comparative genomics in the Asteraceae reveals little evidence for parallel evolutionary change in invasive taxa.

Science.gov (United States)

Hodgins, Kathryn A; Bock, Dan G; Hahn, Min A; Heredia, Sylvia M; Turner, Kathryn G; Rieseberg, Loren H

2015-05-01

Asteraceae, the largest family of flowering plants, has given rise to many notorious invasive species. Using publicly available transcriptome assemblies from 35 Asteraceae, including six major invasive species, we examined evidence for micro- and macro-evolutionary genomic changes associated with invasion. To detect episodes of positive selection repeated across multiple introductions, we conducted comparisons between native and introduced genotypes from six focal species and identified genes with elevated rates of amino acid change (dN/dS). We then looked for evidence of positive selection at a broader phylogenetic scale across all taxa. As invasive species may experience founder events during colonization and spread, we also looked for evidence of increased genetic load in introduced genotypes. We rarely found evidence for parallel changes in orthologous genes in the intraspecific comparisons, but in some cases we identified changes in members of the same gene family. Using among-species comparisons, we detected positive selection in 0.003-0.69% and 2.4-7.8% of the genes using site and stochastic branch-site models, respectively. These genes had diverse putative functions, including defence response, stress response and herbicide resistance, although there was no clear pattern in the GO terms. There was no indication that introduced genotypes have a higher proportion of deleterious alleles than native genotypes in the six focal species, suggesting multiple introductions and admixture mitigated the impact of drift. Our findings provide little evidence for common genomic responses in invasive taxa of the Asteraceae and hence suggest that multiple evolutionary pathways may lead to adaptation during introduction and spread in these species. © 2014 John Wiley & Sons Ltd.

Cryptanalysis of Wang et al.’s lattice-based key exchange protocol

Directory of Open Access Journals (Sweden)

Daya Sagar Gupta

2016-09-01

Full Text Available Wang et al. proposed a new hard problem on lattices which is an extension of the small integer solution (SIS on lattices. This new generated hard problem is named to be bilateral in-homogeneous small integer solution (Bi-ISIS. Using the hardness of Bi-ISIS, Wang et al. proposed a new key exchange protocol, which is based on the lattice-based cryptography. In this paper, we signalize that Wang et al.’s lattice-based key exchange protocol is vulnerable to an attack, namely, man-in-the-middle (MITM attack. Through this attack, Eavesdropper can intercept the authenticated messages and communicate the unauthentic messages among the communicating parties.

Molecular Identification of Atlantic Bluefin Tuna (Thunnus thynnus, Scombridae Larvae and Development of a DNA Character-Based Identification Key for Mediterranean Scombrids.

Directory of Open Access Journals (Sweden)

Gregory Neils Puncher

Full Text Available The Atlantic bluefin tuna, Thunnus thynnus, is a commercially important species that has been severely over-exploited in the recent past. Although the eastern Atlantic and Mediterranean stock is now showing signs of recovery, its current status remains very uncertain and as a consequence their recovery is dependent upon severe management informed by rigorous scientific research. Monitoring of early life history stages can inform decision makers about the health of the species based upon recruitment and survival rates. Misidentification of fish larvae and eggs can lead to inaccurate estimates of stock biomass and productivity which can trigger demands for increased quotas and unsound management conclusions. Herein we used a molecular approach employing mitochondrial and nuclear genes (CO1 and ITS1, respectively to identify larvae (n = 188 collected from three spawning areas in the Mediterranean Sea by different institutions working with a regional fisheries management organization. Several techniques were used to analyze the genetic sequences (sequence alignments using search algorithms, neighbour joining trees, and a genetic character-based identification key and an extensive comparison of the results is presented. During this process various inaccuracies in related publications and online databases were uncovered. Our results reveal important differences in the accuracy of the taxonomic identifications carried out by different ichthyoplanktologists following morphology-based methods. While less than half of larvae provided were bluefin tuna, other dominant taxa were bullet tuna (Auxis rochei, albacore (Thunnus alalunga and little tunny (Euthynnus alletteratus. We advocate an expansion of expertise for a new generation of morphology-based taxonomists, increased dialogue between morphology-based and molecular taxonomists and increased scrutiny of public sequence databases.

Chemical Composition and Antioxidant Activity of Essential Oil of Six Pinus Taxa Native to China

OpenAIRE

Xie, Qing; Liu, Zhihong; Li, Zhouqi

2015-01-01

The essential oils obtained by steam distillation from needles of six China endemic Pinus taxa (P. tabulaeformis, P. tabulaeformis f. shekanensis, P. tabulaeformis var. mukdensis, P. tabulaeformis var. umbraculifera, P. henryi and P. massoniana) were analysed by GC/MS. A total of 72 components were separated and identified by GC/MS from the six taxa. The major constituents of the essential oils were: α-pinene (6.78%–20.55%), bornyl acetale (3.32%–12.71%), β-caryophellene (18.26%–26.31%), α-...

Mobility Based Key Management Technique for Multicast Security in Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

B. Madhusudhanan

2015-01-01

Full Text Available In MANET multicasting, forward and backward secrecy result in increased packet drop rate owing to mobility. Frequent rekeying causes large message overhead which increases energy consumption and end-to-end delay. Particularly, the prevailing group key management techniques cause frequent mobility and disconnections. So there is a need to design a multicast key management technique to overcome these problems. In this paper, we propose the mobility based key management technique for multicast security in MANET. Initially, the nodes are categorized according to their stability index which is estimated based on the link availability and mobility. A multicast tree is constructed such that for every weak node, there is a strong parent node. A session key-based encryption technique is utilized to transmit a multicast data. The rekeying process is performed periodically by the initiator node. The rekeying interval is fixed depending on the node category so that this technique greatly minimizes the rekeying overhead. By simulation results, we show that our proposed approach reduces the packet drop rate and improves the data confidentiality.

A cross-taxa study using environmental DNA/RNA metabarcoding to measure biological impacts of offshore oil and gas drilling and production operations

KAUST Repository

Laroche, Olivier

2017-12-01

Standardized ecosystem-based monitoring surveys are critical for providing information on marine ecosystem health. Environmental DNA/RNA (eDNA/eRNA) metabarcoding may facilitate such surveys by quickly and effectively characterizing multi-trophic levels. In this study, we assessed the suitability of eDNA/eRNA metabarcoding to evaluate changes in benthic assemblages of bacteria, Foraminifera and other eukaryotes along transects at three offshore oil and gas (O&G) drilling and production sites, and compared these to morphologically characterized macro-faunal assemblages. Bacterial communities were the most responsive to O&G activities, followed by Foraminifera, and macro-fauna (the latter assessed by morphology). The molecular approach enabled detection of hydrocarbon degrading taxa such as the bacteria Alcanivorax and Microbulbifer at petroleum impacted stations. Most identified indicator taxa, notably among macro-fauna, were highly specific to site conditions. Based on our results we suggest that eDNA/eRNA metabarcoding can be used as a stand-alone method for biodiversity assessment or as a complement to morphology-based monitoring approaches.

A cross-taxa study using environmental DNA/RNA metabarcoding to measure biological impacts of offshore oil and gas drilling and production operations

KAUST Repository

Laroche, Olivier; Wood, Susanna A.; Tremblay, Louis A.; Ellis, Joanne; Lear, Gavin; Pochon, Xavier

2017-01-01

Standardized ecosystem-based monitoring surveys are critical for providing information on marine ecosystem health. Environmental DNA/RNA (eDNA/eRNA) metabarcoding may facilitate such surveys by quickly and effectively characterizing multi-trophic levels. In this study, we assessed the suitability of eDNA/eRNA metabarcoding to evaluate changes in benthic assemblages of bacteria, Foraminifera and other eukaryotes along transects at three offshore oil and gas (O&G) drilling and production sites, and compared these to morphologically characterized macro-faunal assemblages. Bacterial communities were the most responsive to O&G activities, followed by Foraminifera, and macro-fauna (the latter assessed by morphology). The molecular approach enabled detection of hydrocarbon degrading taxa such as the bacteria Alcanivorax and Microbulbifer at petroleum impacted stations. Most identified indicator taxa, notably among macro-fauna, were highly specific to site conditions. Based on our results we suggest that eDNA/eRNA metabarcoding can be used as a stand-alone method for biodiversity assessment or as a complement to morphology-based monitoring approaches.

Network-Guided Key Gene Discovery for a Given Cellular Process

DEFF Research Database (Denmark)

He, Feng Q; Ollert, Markus

2018-01-01

Identification of key genes for a given physiological or pathological process is an essential but still very challenging task for the entire biomedical research community. Statistics-based approaches, such as genome-wide association study (GWAS)- or quantitative trait locus (QTL)-related analysis...... have already made enormous contributions to identifying key genes associated with a given disease or phenotype, the success of which is however very much dependent on a huge number of samples. Recent advances in network biology, especially network inference directly from genome-scale data...

Patients' Data Management System Protected by Identity-Based Authentication and Key Exchange.

Science.gov (United States)

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-03-31

A secure and distributed framework for the management of patients' information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients' data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

Early Cretaceous greenhouse pumped higher taxa diversification in spiders.

Science.gov (United States)

Shao, Lili; Li, Shuqiang

2018-05-24

The Cretaceous experienced one of the most remarkable greenhouse periods in geological history. During this time, ecosystem reorganizations significantly impacted the diversification of many groups of organisms. The rise of angiosperms marked a major biome turnover. Notwithstanding, relatively little remains known about how the Cretaceous global ecosystem impacted the evolution of spiders, which constitute one of the most abundant groups of predators. Herein, we evaluate the transcriptomes of 91 taxa representing more than half of the spider families. We add 23 newly sequenced taxa to the existing database to obtain a robust phylogenomic assessment. Phylogenetic reconstructions using different datasets and methods obtain novel placements of some groups, especially in the Synspermiata and the group having a retrolateral tibial apophysis (RTA). Molecular analyses indicate an expansion of the RTA clade at the Early Cretaceous with a hunting predatory strategy shift. Fossil analyses show a 7-fold increase of diversification rate at the same period, but this likely owes to the first occurrences spider in amber deposits. Additional analyses of fossil abundance show an accumulation of spider lineages in the Early Cretaceous. We speculate that the establishment of a warm greenhouse climate pumped the diversification of spiders, in particular among webless forms tracking the abundance of insect prey. Our study offers a new pathway for future investigations of spider phylogeny and diversification. Copyright © 2018. Published by Elsevier Inc.

Comparative lophotrochozoan neurogenesis and larval neuroanatomy: recent advances from previously neglected taxa

DEFF Research Database (Denmark)

Wanninger, A

2008-01-01

Recently, a number of neurodevelopmental studies of hitherto neglected taxa have become available, contributing to questions relating to the evolution of the nervous system of Lophotrochozoa (Spiralia + Lophophorata). As an example, neurogenesis of echiurans showed that these worm-shaped spiralia...

Ubi-RKE: A Rhythm Key Based Encryption Scheme for Ubiquitous Devices

Directory of Open Access Journals (Sweden)

Jae Dong Lee

2014-01-01

Full Text Available As intelligent ubiquitous devices become more popular, security threats targeting them are increasing; security is seen as one of the major challenges of the ubiquitous computing. Now a days, applying ubiquitous computing in number of fields for human safety and convenience was immensely increased in recent years. The popularity of the technology is rising day by day, and hence the security is becoming the main focused point with the advent and rising popularity of the applications. In particular, the number of wireless networks based on ubiquitous devices has increased rapidly; these devices support transmission for many types of data traffic. The convenient portability of ubiquitous devices makes them vulnerable to security threats, such as loss, theft, data modification, and wiretapping. Developers and users should seriously consider employing data encryption to protect data from such vulnerabilities. In this paper, we propose a Rhythm Key based Encryption scheme for ubiquitous devices (Ubi-RKE. The concept of Rhythm Key based Encryption has been applied to numerous real world applications in different domains. It provides key memorability and secure encryption through user touching rhythm on ubiquitous devices. Our proposed scheme is more efficient for users than existing schemes, by providing a strong cipher.

Scaling architecture-on-demand based optical networks

NARCIS (Netherlands)

Meyer, Hugo; Sancho, Jose Carlos; Mrdakovic, Milica; Peng, Shuping; Simeonidou, Dimitra; Miao, Wang; Calabretta, Nicola

2016-01-01

This paper analyzes methodologies that allow scaling properly Architecture-On-Demand (AoD) based optical networks. As Data Centers and HPC systems are growing in size and complexity, optical networks seem to be the way to scale the bandwidth of current network infrastructures. To scale the number of

Capacity of a dual enrollment system with two keys based on an SRAM-PUF

NARCIS (Netherlands)

Kusters, L.; Willems, F.M.J.

2018-01-01

We investigate the capacity of an SRAM-PUF based secrecy system that produces two secret keys during two consecutive enrollments. We determined the region of secret-key rates that are achievable and show that the total secret-key capacity is larger than for a single enrollment system. In our

Putting scales into evolutionary time: the divergence of major scale insect lineages (Hemiptera) predates the radiation of modern angiosperm hosts

Science.gov (United States)

Vea, Isabelle M.; Grimaldi, David A.

2016-01-01

The radiation of flowering plants in the mid-Cretaceous transformed landscapes and is widely believed to have fuelled the radiations of major groups of phytophagous insects. An excellent group to test this assertion is the scale insects (Coccomorpha: Hemiptera), with some 8,000 described Recent species and probably the most diverse fossil record of any phytophagous insect group preserved in amber. We used here a total-evidence approach (by tip-dating) employing 174 morphological characters of 73 Recent and 43 fossil taxa (48 families) and DNA sequences of three gene regions, to obtain divergence time estimates and compare the chronology of the most diverse lineage of scale insects, the neococcoid families, with the timing of the main angiosperm radiation. An estimated origin of the Coccomorpha occurred at the beginning of the Triassic, about 245 Ma [228–273], and of the neococcoids 60 million years later [210–165 Ma]. A total-evidence approach allows the integration of extinct scale insects into a phylogenetic framework, resulting in slightly younger median estimates than analyses using Recent taxa, calibrated with fossil ages only. From these estimates, we hypothesise that most major lineages of coccoids shifted from gymnosperms onto angiosperms when the latter became diverse and abundant in the mid- to Late Cretaceous. PMID:27000526

Broad-scale patterns of late jurassic dinosaur paleoecology.

Science.gov (United States)

Noto, Christopher R; Grossman, Ari

2010-09-03

There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure. This study applies Ecological Structure Analysis (ESA) to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome) based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident. This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at least one case of ecosystem convergence. The proportion of different ecomorphs, which

Large-scale gene flow in the barnacle Jehlius cirratus and contrasts with other broadly-distributed taxa along the Chilean coast

Directory of Open Access Journals (Sweden)

Baoying Guo

2017-02-01

Full Text Available We evaluate the population genetic structure of the intertidal barnacle Jehlius cirratus across a broad portion of its geographic distribution using data from the mitochondrial cytochrome oxidase I (COI gene region. Despite sampling diversity from over 3,000 km of the linear range of this species, there is only slight regional structure indicated, with overall Φ CT of 0.036 (p < 0.001 yet no support for isolation by distance. While these results suggest greater structure than previous studies of J. cirratus had indicated, the pattern of diversity is still far more subtle than in other similarly-distributed species with similar larval and life history traits. We compare these data and results with recent findings in four other intertidal species that have planktotrophic larvae. There are no clear patterns among these taxa that can be associated with intertidal depth or other known life history traits.

Biomarker responses to environmental contamination in estuaries: A comparative multi-taxa approach.

Science.gov (United States)

Duarte, Irina A; Reis-Santos, Patrick; França, Susana; Cabral, Henrique; Fonseca, Vanessa F

2017-08-01

Estuaries are highly productive ecosystems subjected to numerous anthropogenic pressures with consequent environmental quality degradation. In this study, multiple biomarker responses [superoxide dismutase (SOD), catalase (CAT), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) and DNA damage (DNAd)] were determined in two fish (Dicentrarchus labrax and Pomatoschistus microps) and four macroinvertebrate species (Carcinus maenas, Crangon crangon, Hediste diversicolor and Scrobicularia plana) from the Ria de Aveiro and Tejo estuaries over distinct months. Two sites per estuarine system were selected based on anthropogenic pressures and magnitude of environmental contamination. Antioxidant enzyme activities in fish species suggested a ubiquitous response to oxidative stress, while biotransformation and effect biomarkers exhibited higher spatial and temporal variation. In invertebrate species, biotransformation enzyme activity was clearly less variable than in fish evidencing lower xenobiotic transformation capability. Overall, largest biomarker responses were found in the most contaminated sites (Tejo), yet species-specific patterns were evident. These should be factored in multi-taxa approaches, considering that the differential functional traits of species, such as habitat use, life-stage, feeding or physiology can influence exposure routes and biomarker responses. The Integrated Biomarker Response index highlighted patterns in biomarker responses which were not immediately evident when analyzing biomarkers individually. Overall, results provided insights into the complexity of species responses to contamination in naturally varying estuarine environments. Ultimately, multi-taxa and multi-biomarker approaches provide a comprehensive and complementary view of ecosystem health, encompassing diverse forms of biological integration and exposure routes, and allow the validation of results among markers

Sea-land segmentation for infrared remote sensing images based on superpixels and multi-scale features

Science.gov (United States)

Lei, Sen; Zou, Zhengxia; Liu, Dunge; Xia, Zhenghuan; Shi, Zhenwei

2018-06-01

Sea-land segmentation is a key step for the information processing of ocean remote sensing images. Traditional sea-land segmentation algorithms ignore the local similarity prior of sea and land, and thus fail in complex scenarios. In this paper, we propose a new sea-land segmentation method for infrared remote sensing images to tackle the problem based on superpixels and multi-scale features. Considering the connectivity and local similarity of sea or land, we interpret the sea-land segmentation task in view of superpixels rather than pixels, where similar pixels are clustered and the local similarity are explored. Moreover, the multi-scale features are elaborately designed, comprising of gray histogram and multi-scale total variation. Experimental results on infrared bands of Landsat-8 satellite images demonstrate that the proposed method can obtain more accurate and more robust sea-land segmentation results than the traditional algorithms.

Quantum key distribution over multicore fiber based on silicon photonics

DEFF Research Database (Denmark)

Ding, Yunhong; Bacco, Davide; Dalgaard, Kjeld

on quantum physics. In order to exchange secure information between users, quantum key distribution (QKD), a branch of Quantum Communications (QCs), provides good prospects for ultimate security based on the laws of quantum mechanics [2–7]. Most of QKD systems are implemented in a point-to-point link using...... generations, to HD-entanglement distribution. Furthermore, MCFs are expected as a good candidate for overcoming the capacity limit of a current optical communication system, as example the record capacity of 661 Tbits/s was obtained last year with a 30-cores fiber [8]. Proof of concept experiment has already...... requirements in terms of key generation are needed. A solution may be represented by new technologies applied to quantum world. In particular multicore fiber (MCF) open a new scenario for quantum communications, from high-dimensional (HD) spatial entanglement generation, to HD QKD and multi-user key...

Academic Primer Series: Key Papers About Competency-Based Medical Education

Directory of Open Access Journals (Sweden)

Robert Cooney

2017-05-01

Full Text Available Introduction: Competency-based medical education (CBME presents a paradigm shift in medical training. This outcome-based education movement has triggered substantive changes across the globe. Since this transition is only beginning, many faculty members may not have experience with CBME nor a solid foundation in the grounding literature. We identify and summarize key papers to help faculty members learn more about CBME. Methods: Based on the online discussions of the 2016–2017 ALiEM Faculty Incubator program, a series of papers on the topic of CBME was developed. Augmenting this list with suggestions by a guest expert and by an open call on Twitter for other important papers, we were able to generate a list of 21 papers in total. Subsequently, we used a modified Delphi study methodology to narrow the list to key papers that describe the importance and significance for educators interested in learning about CBME. To determine the most impactful papers, the mixed junior and senior faculty authorship group used three-round voting methodology based upon the Delphi method. Results: Summaries of the five most highly rated papers on the topic of CBME, as determined by this modified Delphi approach, are presented in this paper. Major themes include a definition of core CBME themes, CBME principles to consider in the design of curricula, a history of the development of the CBME movement, and a rationale for changes to accreditation with CBME. The application of the study findings to junior faculty and faculty developers is discussed. Conclusion: We present five key papers on CBME that junior faculty members and faculty experts identified as essential to faculty development. These papers are a mix of foundational and explanatory papers that may provide a basis from which junior faculty members may build upon as they help to implement CBME programs.

Academic Primer Series: Key Papers About Competency-Based Medical Education.

Science.gov (United States)

Cooney, Robert; Chan, Teresa M; Gottlieb, Michael; Abraham, Michael; Alden, Sylvia; Mongelluzzo, Jillian; Pasirstein, Michael; Sherbino, Jonathan

2017-06-01

Competency-based medical education (CBME) presents a paradigm shift in medical training. This outcome-based education movement has triggered substantive changes across the globe. Since this transition is only beginning, many faculty members may not have experience with CBME nor a solid foundation in the grounding literature. We identify and summarize key papers to help faculty members learn more about CBME. Based on the online discussions of the 2016-2017 ALiEM Faculty Incubator program, a series of papers on the topic of CBME was developed. Augmenting this list with suggestions by a guest expert and by an open call on Twitter for other important papers, we were able to generate a list of 21 papers in total. Subsequently, we used a modified Delphi study methodology to narrow the list to key papers that describe the importance and significance for educators interested in learning about CBME. To determine the most impactful papers, the mixed junior and senior faculty authorship group used three-round voting methodology based upon the Delphi method. Summaries of the five most highly rated papers on the topic of CBME, as determined by this modified Delphi approach, are presented in this paper. Major themes include a definition of core CBME themes, CBME principles to consider in the design of curricula, a history of the development of the CBME movement, and a rationale for changes to accreditation with CBME. The application of the study findings to junior faculty and faculty developers is discussed. We present five key papers on CBME that junior faculty members and faculty experts identified as essential to faculty development. These papers are a mix of foundational and explanatory papers that may provide a basis from which junior faculty members may build upon as they help to implement CBME programs.

S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa.

Science.gov (United States)

Picariello, Orfeo; Feliciello, Isidoro; Chinali, Gianni

2016-02-01

S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species. We characterized S1 satellite DNA from the Anatolian brown frogs Rana macrocnemis, R. camerani, and R. holtzi in order to define their taxonomic rank and the structure of this satellite in this frog lineage. Southern blots of genomic DNA digested with KpnI, EcoRV, NdeI, NheI, or StuI produced the same pattern of satellite DNA bands. Moreover, quantitative dot blots showed that this satellite DNA accounts for 0.1 % of the genome in all taxa. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size (476 bp), the same most common sequence (MCS) and the same overall variability in all three taxa, and also in R. macrocnemis tavasensis. The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the 494-bp S1a repeat from European frogs. The S1a MCS has three variable positions (sequence WWTK in positions 183-186), due to the presence of two repeat subpopulations with motifs AATG and WWTT in all taxa. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

Model-based plant-wide optimization of large-scale lignocellulosic bioethanol plants

DEFF Research Database (Denmark)

Prunescu, Remus Mihail; Blanke, Mogens; Jakobsen, Jon Geest

2017-01-01

Second generation biorefineries transform lignocellulosic biomass into chemicals with higher added value following a conversion mechanism that consists of: pretreatment, enzymatic hydrolysis, fermentation and purification. The objective of this study is to identify the optimal operational point...... with respect to maximum economic profit of a large scale biorefinery plant using a systematic model-based plantwide optimization methodology. The following key process parameters are identified as decision variables: pretreatment temperature, enzyme dosage in enzymatic hydrolysis, and yeast loading per batch...... in fermentation. The plant is treated in an integrated manner taking into account the interactions and trade-offs between the conversion steps. A sensitivity and uncertainty analysis follows at the optimal solution considering both model and feed parameters. It is found that the optimal point is more sensitive...

Immunological change in a parasite-impoverished environment: divergent signals from four island taxa.

Directory of Open Access Journals (Sweden)

Jon S Beadell

2007-09-01

Full Text Available Dramatic declines of native Hawaiian avifauna due to the human-mediated emergence of avian malaria and pox prompted an examination of whether island taxa share a common altered immunological signature, potentially driven by reduced genetic diversity and reduced exposure to parasites. We tested this hypothesis by characterizing parasite prevalence, genetic diversity and three measures of immune response in two recently-introduced species (Neochmia temporalis and Zosterops lateralis and two island endemics (Acrocephalus aequinoctialis and A. rimitarae and then comparing the results to those observed in closely-related mainland counterparts. The prevalence of blood parasites was significantly lower in 3 of 4 island taxa, due in part to the absence of certain parasite lineages represented in mainland populations. Indices of genetic diversity were unchanged in the island population of N. temporalis; however, allelic richness was significantly lower in the island population of Z. lateralis while both allelic richness and heterozygosity were significantly reduced in the two island-endemic species examined. Although parasite prevalence and genetic diversity generally conformed to expectations for an island system, we did not find evidence for a pattern of uniformly altered immune responses in island taxa, even amongst endemic taxa with the longest residence times. The island population of Z. lateralis exhibited a significantly reduced inflammatory cell-mediated response while levels of natural antibodies remained unchanged for this and the other recently introduced island taxon. In contrast, the island endemic A. rimitarae exhibited a significantly increased inflammatory response as well as higher levels of natural antibodies and complement. These measures were unchanged or lower in A. aequinoctialis. We suggest that small differences in the pathogenic landscape and the stochastic history of mutation and genetic drift are likely to be important in

Silica-scaled chrysophytes of Lake Baikal

Directory of Open Access Journals (Sweden)

A. Yu. Bessudova

2017-12-01

Full Text Available The list of silica-scaled chrysophytes of Lake Baikal has been enlarged using electron microscopy. It has been supplemented with 12 species and 2 forms. Spiniferomonas takahashii has been observed for the first time in the water bodies of Russia. According to our data, the list of silica-scaled chrysophytes of Lake Baikal includes 25 species and intra-species taxa: Chrysosphaerella – 3, Paraphysomonas – 2, Clathromonas – 1, Spiniferomonas – 7, Mallomonas – 8 and Synura – 4. We have also analyzed their seasonal dynamics and observed algal species that are dominant in spring, summer and autumn.

First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity

Science.gov (United States)

David B. Clark; Paulo C. Olivas; Steven F. Oberbauer; Deborah A. Clark; Michael G. Ryan

2008-01-01

Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in...

Unconditionally secure key distillation from multi-photons in a single-photon polarization based quantum key distribution

CERN Document Server

Tamaki, K

2005-01-01

In this presentation, we show some counter-examples to a naive belief that the security of QKD is based on no-cloning theorem. One example is shown by explicitly proving that one can indeed generate an unconditionally secure key from Alice's two-photon emission part in "SARG04 protocol" proposed by V. Scarani et al, in Phys. Rev. Lett. 92, 057901 (2004). This protocol differs from BB84 only in the classical communication. It is, thus, interesting to see how only the classical communication of QKD protocol might qualitatively change its security. We also show that one can generate an unconditionally secure key from the single to the four-photon part in a generalized SARG04 that uses six states. Finally, we also compare the bit error rate threshold of these protocols with the one in BB84 and the original six-state protocol assuming a depolarizing channel.

Modal-pushover-based ground-motion scaling procedure

Science.gov (United States)

Kalkan, Erol; Chopra, Anil K.

2011-01-01

Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

Directory of Open Access Journals (Sweden)

Alexandra Rivero-García

2017-03-01

Full Text Available A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

Science.gov (United States)

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-01-01

A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed. PMID:28362328

Efficient biometric authenticated key agreements based on extended chaotic maps for telecare medicine information systems.

Science.gov (United States)

Lou, Der-Chyuan; Lee, Tian-Fu; Lin, Tsung-Hung

2015-05-01

Authenticated key agreements for telecare medicine information systems provide patients, doctors, nurses and health visitors with accessing medical information systems and getting remote services efficiently and conveniently through an open network. In order to have higher security, many authenticated key agreement schemes appended biometric keys to realize identification except for using passwords and smartcards. Due to too many transmissions and computational costs, these authenticated key agreement schemes are inefficient in communication and computation. This investigation develops two secure and efficient authenticated key agreement schemes for telecare medicine information systems by using biometric key and extended chaotic maps. One scheme is synchronization-based, while the other nonce-based. Compared to related approaches, the proposed schemes not only retain the same security properties with previous schemes, but also provide users with privacy protection and have fewer transmissions and lower computational cost.

Desempenho exportador brasileiro recente e taxa de câmbio real: uma análise setorial

Directory of Open Access Journals (Sweden)

Kannebley Júnior Sérgio

2002-01-01

Full Text Available Este artigo investiga a relação entre medidas alternativas de taxa de câmbio real e a evolução do quantum exportado para 13 setores exportadores nacionais, no período de 1985 a 1998. É possível concluir, por meio de análise descritiva e econométrica, que não existe uma relação de longo prazo estável entre a evolução do nível da taxa de câmbio real e o quantum exportado para a maioria dos setores analisados. Argumenta-se, entretanto, que a manutenção de um nível de taxa real de câmbio capaz de preservar a rentabilidade e/ou competitividade dos setores exportadores é condição necessária, porém não suficiente, para a expansão das exportações ao longo do tempo.

Diffie-Hellman Key Based Authentication in Proxy Mobile IPv6

Directory of Open Access Journals (Sweden)

HyunGon Kim

2010-01-01

Full Text Available Wireless communication service providers have been showing strong interest in Proxy Mobile IPv6 for providing network-based IP mobility management. This could be a prominent way to support IP mobility to mobile nodes, because Proxy Mobile IPv6 requires minimal functionalities on the mobile node. While several extensions for Proxy Mobile IPv6 are being developed in the Internet Engineering Task Force, there has been little attentions paid to developing efficient authentication mechanisms. An authentication scheme for a mobility protocol must protect signaling messages against various security threats, e.g., session stealing attack, intercept attack by redirection, replay attack, and key exposure, while minimizing authentication latency. In this paper, we propose a Diffie-Hellman key based authentication scheme that utilizes the low layer signaling to exchange Diffie-Hellman variables and allows mobility service provisioning entities to exchange mobile node's profile and ongoing sessions securely. By utilizing the low layer signaling and context transfer between relevant nodes, the proposed authentication scheme minimizes authentication latency when the mobile node moves across different networks. In addition, thanks to the use of the Diffie-Hellman key agreement, pre-established security associations between mobility service provisioning entities are not required in the proposed authentication scheme so that network scalability in an operationally efficient manner is ensured. To ascertain its feasibility, security analysis and performance analysis are presented.

Country-scale phosphorus balancing as a base for resources conservation

NARCIS (Netherlands)

Seyhan, D.

2009-01-01

In order to effectively conserve the non-renewable resource phosphorus (P), flows and stocks of P must be known at national, regional and global scales. P is a key non-renewable resource because its use as fertilizer cannot be substituted posing a constraint on the global food production in the

Base Station Placement Algorithm for Large-Scale LTE Heterogeneous Networks.

Science.gov (United States)

Lee, Seungseob; Lee, SuKyoung; Kim, Kyungsoo; Kim, Yoon Hyuk

2015-01-01

Data traffic demands in cellular networks today are increasing at an exponential rate, giving rise to the development of heterogeneous networks (HetNets), in which small cells complement traditional macro cells by extending coverage to indoor areas. However, the deployment of small cells as parts of HetNets creates a key challenge for operators' careful network planning. In particular, massive and unplanned deployment of base stations can cause high interference, resulting in highly degrading network performance. Although different mathematical modeling and optimization methods have been used to approach various problems related to this issue, most traditional network planning models are ill-equipped to deal with HetNet-specific characteristics due to their focus on classical cellular network designs. Furthermore, increased wireless data demands have driven mobile operators to roll out large-scale networks of small long term evolution (LTE) cells. Therefore, in this paper, we aim to derive an optimum network planning algorithm for large-scale LTE HetNets. Recently, attempts have been made to apply evolutionary algorithms (EAs) to the field of radio network planning, since they are characterized as global optimization methods. Yet, EA performance often deteriorates rapidly with the growth of search space dimensionality. To overcome this limitation when designing optimum network deployments for large-scale LTE HetNets, we attempt to decompose the problem and tackle its subcomponents individually. Particularly noting that some HetNet cells have strong correlations due to inter-cell interference, we propose a correlation grouping approach in which cells are grouped together according to their mutual interference. Both the simulation and analytical results indicate that the proposed solution outperforms the random-grouping based EA as well as an EA that detects interacting variables by monitoring the changes in the objective function algorithm in terms of system

Late Silurian fish microfossils from an East Baltic-derived erratic from Oosterhaule, with a description of new acanthodian taxa

NARCIS (Netherlands)

Vergoossen, JMJ

1999-01-01

Fish microfossils were extracted from an erratic. The taxa from the rich microvertebrate fauna of late Pridolian (latest Silurian) age ( P. punctatus Zone) are listed. A full description is given of two new Gomphonchus taxa, G. mediocostatus and G. boekschoteni. On the basis of old and new material,

Mobile Device Based Dynamic Key Management Protocols for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Chin-Ling Chen

2015-01-01

Full Text Available In recent years, wireless sensor network (WSN applications have tended to transmit data hop by hop, from sensor nodes through cluster nodes to the base station. As a result, users must collect data from the base station. This study considers two different applications: hop by hop transmission of data from cluster nodes to the base station and the direct access to cluster nodes data by mobile users via mobile devices. Due to the hardware limitations of WSNs, some low-cost operations such as symmetric cryptographic algorithms and hash functions are used to implement a dynamic key management. The session key can be updated to prevent threats of attack from each communication. With these methods, the data gathered in wireless sensor networks can be more securely communicated. Moreover, the proposed scheme is analyzed and compared with related schemes. In addition, an NS2 simulation is developed in which the experimental results show that the designed communication protocol is workable.

Nematode-associated microbial taxa do not correlate with host phylogeny, geographic region or feeding morphology in marine sediment habitats.

Science.gov (United States)

Schuelke, Taruna; Pereira, Tiago José; Hardy, Sarah M; Bik, Holly M

2018-04-01

Studies of host-associated microbes are critical for advancing our understanding of ecology and evolution across diverse taxa and ecosystems. Nematode worms are ubiquitous across most habitats on earth, yet little is known about host-associated microbial assemblages within the phylum. Free-living nematodes are globally abundant and diverse in marine sediments, with species exhibiting distinct buccal cavity (mouth) morphologies that are thought to play an important role in feeding ecology and life history strategies. Here, we investigated patterns in marine nematode microbiomes, by characterizing host-associated microbial taxa in 281 worms isolated from a range of habitat types (deep-sea, shallow water, methane seeps, Lophelia coral mounds, kelp holdfasts) across three distinct geographic regions (Arctic, Southern California and Gulf of Mexico). Microbiome profiles were generated from single worms spanning 33 distinct morphological genera, using a two-gene metabarcoding approach to amplify the V4 region of the 16S ribosomal RNA (rRNA) gene targeting bacteria/archaea and the V1-V2 region of the 18S rRNA gene targeting microbial eukaryotes. Contrary to our expectations, nematode microbiome profiles demonstrated no distinct patterns either globally (across depths and ocean basins) or locally (within site); prokaryotic and eukaryotic microbial assemblages did not correlate with nematode feeding morphology, host phylogeny or morphological identity, ocean region or marine habitat type. However, fine-scale analysis of nematode microbiomes revealed a variety of novel ecological interactions, including putative parasites and symbionts, and potential associations with bacterial/archaeal taxa involved in nitrogen and methane cycling. Our results suggest that in marine habitats, free-living nematodes may utilize diverse and generalist foraging strategies that are not correlated with host genotype or feeding morphology. Furthermore, some abiotic factors such as geographic region

Revocable identity-based proxy re-signature against signing key exposure.

Science.gov (United States)

Yang, Xiaodong; Chen, Chunlin; Ma, Tingchun; Wang, Jinli; Wang, Caifen

2018-01-01

Identity-based proxy re-signature (IDPRS) is a novel cryptographic primitive that allows a semi-trusted proxy to convert a signature under one identity into another signature under another identity on the same message by using a re-signature key. Due to this transformation function, IDPRS is very useful in constructing privacy-preserving schemes for various information systems. Key revocation functionality is important in practical IDPRS for managing users dynamically; however, the existing IDPRS schemes do not provide revocation mechanisms that allow the removal of misbehaving or compromised users from the system. In this paper, we first introduce a notion called revocable identity-based proxy re-signature (RIDPRS) to achieve the revocation functionality. We provide a formal definition of RIDPRS as well as its security model. Then, we present a concrete RIDPRS scheme that can resist signing key exposure and prove that the proposed scheme is existentially unforgeable against adaptive chosen identity and message attacks in the standard model. To further improve the performance of signature verification in RIDPRS, we introduce a notion called server-aided revocable identity-based proxy re-signature (SA-RIDPRS). Moreover, we extend the proposed RIDPRS scheme to the SA-RIDPRS scheme and prove that this extended scheme is secure against adaptive chosen message and collusion attacks. The analysis results show that our two schemes remain efficient in terms of computational complexity when implementing user revocation procedures. In particular, in the SA-RIDPRS scheme, the verifier needs to perform only a bilinear pairing and four exponentiation operations to verify the validity of the signature. Compared with other IDPRS schemes in the standard model, our SA-RIDPRS scheme greatly reduces the computation overhead of verification.

Type specimens of taxa of Artemisia L. (Asteraceae from Siberia and the Far East kept in the Herbarium of V.L. Komarov Botanical Insitute

Directory of Open Access Journals (Sweden)

A. A. Korobkov

2015-04-01

Full Text Available Typification of 97 Artemisia (Asteraceae taxa from Siberia and the Far East kept in the Herbarium of V.L. Komarov Botanical Institute was carried out. Holotypes for 39 taxa, lectotypes for 48 taxa, 28 syntypes and 4 isotypes are given.

Parallel keyed hash function construction based on chaotic maps

International Nuclear Information System (INIS)

Xiao Di; Liao Xiaofeng; Deng Shaojiang

2008-01-01

Recently, a variety of chaos-based hash functions have been proposed. Nevertheless, none of them works efficiently in parallel computing environment. In this Letter, an algorithm for parallel keyed hash function construction is proposed, whose structure can ensure the uniform sensitivity of hash value to the message. By means of the mechanism of both changeable-parameter and self-synchronization, the keystream establishes a close relation with the algorithm key, the content and the order of each message block. The entire message is modulated into the chaotic iteration orbit, and the coarse-graining trajectory is extracted as the hash value. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function. It is simple, efficient, practicable, and reliable. These properties make it a good choice for hash on parallel computing platform

Teoria da estrutura a termo das taxas de juros

OpenAIRE

Cox,John C.; Ingersoll Jr.,Jonathan E.; Ross,Stephen A.

2007-01-01

Este estudo usa um modelo intertemporal de equilíbrio geral de precificação de ativos para estudar a estrutura a termo das taxas de juros. Nesse modelo, expectativas, aversão ao risco, alternativas de investimento e preferências quanto ao momento do consumo atuam na determinação dos preços. Muitos fatores tradicionalmente mencionados como influentes sobre a estrutura a termo são, assim, incluídos de uma maneira plenamente condizente com o comportamento maximizador e as expectativas racionais....

Multi-party Measurement-Device-Independent Quantum Key Distribution Based on Cluster States

Science.gov (United States)

Liu, Chuanqi; Zhu, Changhua; Ma, Shuquan; Pei, Changxing

2018-03-01

We propose a novel multi-party measurement-device-independent quantum key distribution (MDI-QKD) protocol based on cluster states. A four-photon analyzer which can distinguish all the 16 cluster states serves as the measurement device for four-party MDI-QKD. Any two out of four participants can build secure keys after the analyzers obtains successful outputs and the two participants perform post-processing. We derive a security analysis for the protocol, and analyze the key rates under different values of polarization misalignment. The results show that four-party MDI-QKD is feasible over 280 km in the optical fiber channel when the key rate is about 10- 6 with the polarization misalignment parameter 0.015. Moreover, our work takes an important step toward a quantum communication network.

Road network selection for small-scale maps using an improved centrality-based algorithm

Directory of Open Access Journals (Sweden)

Roy Weiss

2014-12-01

Full Text Available The road network is one of the key feature classes in topographic maps and databases. In the task of deriving road networks for products at smaller scales, road network selection forms a prerequisite for all other generalization operators, and is thus a fundamental operation in the overall process of topographic map and database production. The objective of this work was to develop an algorithm for automated road network selection from a large-scale (1:10,000 to a small-scale database (1:200,000. The project was pursued in collaboration with swisstopo, the national mapping agency of Switzerland, with generic mapping requirements in mind. Preliminary experiments suggested that a selection algorithm based on betweenness centrality performed best for this purpose, yet also exposed problems. The main contribution of this paper thus consists of four extensions that address deficiencies of the basic centrality-based algorithm and lead to a significant improvement of the results. The first two extensions improve the formation of strokes concatenating the road segments, which is crucial since strokes provide the foundation upon which the network centrality measure is computed. Thus, the first extension ensures that roundabouts are detected and collapsed, thus avoiding interruptions of strokes by roundabouts, while the second introduces additional semantics in the process of stroke formation, allowing longer and more plausible strokes to built. The third extension detects areas of high road density (i.e., urban areas using density-based clustering and then locally increases the threshold of the centrality measure used to select road segments, such that more thinning takes place in those areas. Finally, since the basic algorithm tends to create dead-ends—which however are not tolerated in small-scale maps—the fourth extension reconnects these dead-ends to the main network, searching for the best path in the main heading of the dead-end.

Look-up-table approach for leaf area index retrieval from remotely sensed data based on scale information

Science.gov (United States)

Zhu, Xiaohua; Li, Chuanrong; Tang, Lingli

2018-03-01

Leaf area index (LAI) is a key structural characteristic of vegetation and plays a significant role in global change research. Several methods and remotely sensed data have been evaluated for LAI estimation. This study aimed to evaluate the suitability of the look-up-table (LUT) approach for crop LAI retrieval from Satellite Pour l'Observation de la Terre (SPOT)-5 data and establish an LUT approach for LAI inversion based on scale information. The LAI inversion result was validated by in situ LAI measurements, indicating that the LUT generated based on the PROSAIL (PROSPECT+SAIL: properties spectra + scattering by arbitrarily inclined leaves) model was suitable for crop LAI estimation, with a root mean square error (RMSE) of ˜0.31m2 / m2 and determination coefficient (R2) of 0.65. The scale effect of crop LAI was analyzed based on Taylor expansion theory, indicating that when the SPOT data aggregated by 200 × 200 pixel, the relative error is significant with 13.7%. Finally, an LUT method integrated with scale information was proposed in this article, improving the inversion accuracy with RMSE of 0.20 m2 / m2 and R2 of 0.83.

A Polynomial Subset-Based Efficient Multi-Party Key Management System for Lightweight Device Networks.

Science.gov (United States)

Mahmood, Zahid; Ning, Huansheng; Ghafoor, AtaUllah

2017-03-24

Wireless Sensor Networks (WSNs) consist of lightweight devices to measure sensitive data that are highly vulnerable to security attacks due to their constrained resources. In a similar manner, the internet-based lightweight devices used in the Internet of Things (IoT) are facing severe security and privacy issues because of the direct accessibility of devices due to their connection to the internet. Complex and resource-intensive security schemes are infeasible and reduce the network lifetime. In this regard, we have explored the polynomial distribution-based key establishment schemes and identified an issue that the resultant polynomial value is either storage intensive or infeasible when large values are multiplied. It becomes more costly when these polynomials are regenerated dynamically after each node join or leave operation and whenever key is refreshed. To reduce the computation, we have proposed an Efficient Key Management (EKM) scheme for multiparty communication-based scenarios. The proposed session key management protocol is established by applying a symmetric polynomial for group members, and the group head acts as a responsible node. The polynomial generation method uses security credentials and secure hash function. Symmetric cryptographic parameters are efficient in computation, communication, and the storage required. The security justification of the proposed scheme has been completed by using Rubin logic, which guarantees that the protocol attains mutual validation and session key agreement property strongly among the participating entities. Simulation scenarios are performed using NS 2.35 to validate the results for storage, communication, latency, energy, and polynomial calculation costs during authentication, session key generation, node migration, secure joining, and leaving phases. EKM is efficient regarding storage, computation, and communication overhead and can protect WSN-based IoT infrastructure.

Efeito da temperatura e velocidade do ar sobre a taxa de secagem da madeira de Pinus elliottii Engelm.

Directory of Open Access Journals (Sweden)

Elio José Santini

2010-08-01

Full Text Available Para avaliar o efeito da temperatura e velocidade do ar sobre a taxa de secagem, peças de madeira de Pinus elliottii de 25 x 125 x 750 mm foram submetidas à secagem em estufa semi-industrial de convecção forçada. O processo foi conduzido para duas temperaturas e duas velocidades de ar e controlado por meio de um sistema computadorizado. Os resultados mostraram que a taxa de secagem tem uma relação diretamente proporcional com a temperatura, velocidade do ar e umidade da madeira. Por meio da análise de regressão múltipla detectou-se efeito estatisticamente significativo da temperatura e da velocidade do ar sobre a taxa e o tempo de secagem, com um nível de confiança de 99%. Como a importância da velocidade do ar na secagem decresce com a diminuição do teor de umidade, sugere-se, por razões de economia, mais investigações acerca das relações entre as duas variáveis durante o período de taxa de secagem decrescente.

Predicting and setting conservation priorities for Bolivian mammals based on biological correlates of the risk of decline.

Science.gov (United States)

Peñaranda, Diego A; Simonetti, Javier A

2015-06-01

The recognition that growing proportions of species worldwide are endangered has led to the development of comparative analyses to elucidate why some species are more prone to extinction than others. Understanding factors and patterns of species vulnerability might provide an opportunity to develop proactive conservation strategies. Such comparative analyses are of special concern at national scales because this is the scale at which most conservation initiatives take place. We applied powerful ensemble learning models to test for biological correlates of the risk of decline among the Bolivian mammals to understand species vulnerability at a national scale and to predict the population trend for poorly known species. Risk of decline was nonrandomly distributed: higher proportions of large-sized taxa were under decline, whereas small-sized taxa were less vulnerable. Body mass, mode of life (i.e., aquatic, terrestrial, volant), geographic range size, litter size, home range, niche specialization, and reproductive potential were strongly associated with species vulnerability. Moreover, we found interacting and nonlinear effects of key traits on the risk of decline of mammals at a national scale. Our model predicted 35 data-deficient species in decline on the basis of their biological vulnerability, which should receive more attention in order to prevent their decline. Our results highlight the relevance of comparative analysis at relatively narrow geographical scales, reveal previously unknown factors related to species vulnerability, and offer species-by-species outcomes that can be used to identify targets for conservation, especially for insufficiently known species. © 2015 Society for Conservation Biology.

Comprehensive phylogenetic reconstruction of amoebozoa based on concatenated analyses of SSU-rDNA and actin genes.

Directory of Open Access Journals (Sweden)

Daniel J G Lahr

Full Text Available Evolutionary relationships within Amoebozoa have been the subject of controversy for two reasons: 1 paucity of morphological characters in traditional surveys and 2 haphazard taxonomic sampling in modern molecular reconstructions. These along with other factors have prevented the erection of a definitive system that resolves confidently both higher and lower-level relationships. Additionally, the recent recognition that many protosteloid amoebae are in fact scattered throughout the Amoebozoa suggests that phylogenetic reconstructions have been excluding an extensive and integral group of organisms. Here we provide a comprehensive phylogenetic reconstruction based on 139 taxa using molecular information from both SSU-rDNA and actin genes. We provide molecular data for 13 of those taxa, 12 of which had not been previously characterized. We explored the dataset extensively by generating 18 alternative reconstructions that assess the effect of missing data, long-branched taxa, unstable taxa, fast evolving sites and inclusion of environmental sequences. We compared reconstructions with each other as well as against previously published phylogenies. Our analyses show that many of the morphologically established lower-level relationships (defined here as relationships roughly equivalent to Order level or below are congruent with molecular data. However, the data are insufficient to corroborate or reject the large majority of proposed higher-level relationships (above the Order-level, with the exception of Tubulinea, Archamoebae and Myxogastrea, which are consistently recovered. Moreover, contrary to previous expectations, the inclusion of available environmental sequences does not significantly improve the Amoebozoa reconstruction. This is probably because key amoebozoan taxa are not easily amplified by environmental sequencing methodology due to high rates of molecular evolution and regular occurrence of large indels and introns. Finally, in an effort

Comprehensive phylogenetic reconstruction of amoebozoa based on concatenated analyses of SSU-rDNA and actin genes.

Science.gov (United States)

Lahr, Daniel J G; Grant, Jessica; Nguyen, Truc; Lin, Jian Hua; Katz, Laura A

2011-01-01

Evolutionary relationships within Amoebozoa have been the subject of controversy for two reasons: 1) paucity of morphological characters in traditional surveys and 2) haphazard taxonomic sampling in modern molecular reconstructions. These along with other factors have prevented the erection of a definitive system that resolves confidently both higher and lower-level relationships. Additionally, the recent recognition that many protosteloid amoebae are in fact scattered throughout the Amoebozoa suggests that phylogenetic reconstructions have been excluding an extensive and integral group of organisms. Here we provide a comprehensive phylogenetic reconstruction based on 139 taxa using molecular information from both SSU-rDNA and actin genes. We provide molecular data for 13 of those taxa, 12 of which had not been previously characterized. We explored the dataset extensively by generating 18 alternative reconstructions that assess the effect of missing data, long-branched taxa, unstable taxa, fast evolving sites and inclusion of environmental sequences. We compared reconstructions with each other as well as against previously published phylogenies. Our analyses show that many of the morphologically established lower-level relationships (defined here as relationships roughly equivalent to Order level or below) are congruent with molecular data. However, the data are insufficient to corroborate or reject the large majority of proposed higher-level relationships (above the Order-level), with the exception of Tubulinea, Archamoebae and Myxogastrea, which are consistently recovered. Moreover, contrary to previous expectations, the inclusion of available environmental sequences does not significantly improve the Amoebozoa reconstruction. This is probably because key amoebozoan taxa are not easily amplified by environmental sequencing methodology due to high rates of molecular evolution and regular occurrence of large indels and introns. Finally, in an effort to facilitate

Assessing the completeness of the fossil record using brachiopod Lazarus taxa

Science.gov (United States)

Gearty, W.; Payne, J.

2012-12-01

Lazarus taxa, organisms that disappear from the fossil record only to reappear later, provide a unique opportunity to assess the completeness of the fossil record. In this study, we apply logistic regression to quantify the associations of body size, geographic extent, and species diversity with the probability of being a Lazarus genus using the Phanerozoic fossil record of brachiopods. We find that both the geographic range and species diversity of a genus are inversely associated with the probability of being a Lazarus taxon in the preceding or succeeding stage. In contrast, body size exhibits little association with the probability of becoming a Lazarus taxon. A model including species diversity and geographic extent as predictors performs best among all combinations examined, whereas a model including only shell size as a predictor performs the worst - even worse than a model that assumes Lazarus taxa are randomly drawn from all available genera. These findings suggest that geographic range and species richness data can be used to improve estimates of extensions on the observed fossil ranges of genera and, thereby, better correct for sampling effects in estimates of taxonomic diversity change through the Phanerozoic.

Pollen morphology and its relationship to the taxonomy of the some taxa of helichrysum gaertner (asteraceae) in turkey

International Nuclear Information System (INIS)

Elkiran, O.; Bagci, E.

2017-01-01

Palynological studies of Helichrysum chionophilum, Helichrysum noeanum, Helichrysum arenarium subsp. aucheri, Helichrysum graveolens, H. plicatum subsp. plicatum and H. plicatum subsp. polyphyllum (Asteraceae) from Turkey have been carried out. H. chionophilum, H. noeanum and H. arenarium subsp. aucheri are endemics to Turkey. Pollen features of both taxa were observed with the Light and Scanning Electron Microscopy (SEM). The pollen type of both taxa were determined as tricolporate, pollen shapes were spheroidal and oblate-spheroidal, reticular pollen ornamentation was observed. The studies show that the pollen of the six taxa are very similar regarding pollen shapes, apertures, and ornamentation, but may be distinguished by colpus length (Clg), pore width (Plt) and pore length (Plg). The findings obtained from the study are discussed with each other and the genus patterns. (author)

Large-scale distribution patterns of mangrove nematodes: A global meta-analysis.

Science.gov (United States)

Brustolin, Marco C; Nagelkerken, Ivan; Fonseca, Gustavo

2018-05-01

Mangroves harbor diverse invertebrate communities, suggesting that macroecological distribution patterns of habitat-forming foundation species drive the associated faunal distribution. Whether these are driven by mangrove biogeography is still ambiguous. For small-bodied taxa, local factors and landscape metrics might be as important as macroecology. We performed a meta-analysis to address the following questions: (1) can richness of mangrove trees explain macroecological patterns of nematode richness? and (2) do local landscape attributes have equal or higher importance than biogeography in structuring nematode richness? Mangrove areas of Caribbean-Southwest Atlantic, Western Indian, Central Indo-Pacific, and Southwest Pacific biogeographic regions. We used random-effects meta-analyses based on natural logarithm of the response ratio (lnRR) to assess the importance of macroecology (i.e., biogeographic regions, latitude, longitude), local factors (i.e., aboveground mangrove biomass and tree richness), and landscape metrics (forest area and shape) in structuring nematode richness from 34 mangroves sites around the world. Latitude, mangrove forest area, and forest shape index explained 19% of the heterogeneity across studies. Richness was higher at low latitudes, closer to the equator. At local scales, richness increased slightly with landscape complexity and decreased with forest shape index. Our results contrast with biogeographic diversity patterns of mangrove-associated taxa. Global-scale nematode diversity may have evolved independently of mangrove tree richness, and diversity of small-bodied metazoans is probably more closely driven by latitude and associated climates, rather than local, landscape, or global biogeographic patterns.

A Dual Key-Based Activation Scheme for Secure LoRaWAN

Directory of Open Access Journals (Sweden)

Jaehyu Kim

2017-01-01

Full Text Available With the advent of the Internet of Things (IoT era, we are experiencing rapid technological progress. Billions of devices are connected to each other, and our homes, cities, hospitals, and schools are getting smarter and smarter. However, to realize the IoT, several challenging issues such as connecting resource-constrained devices to the Internet must be resolved. Recently introduced Low Power Wide Area Network (LPWAN technologies have been devised to resolve this issue. Among many LPWAN candidates, the Long Range (LoRa is one of the most promising technologies. The Long Range Wide Area Network (LoRaWAN is a communication protocol for LoRa that provides basic security mechanisms. However, some security loopholes exist in LoRaWAN’s key update and session key generation. In this paper, we propose a dual key-based activation scheme for LoRaWAN. It resolves the problem of key updates not being fully supported. In addition, our scheme facilitates each layer in generating its own session key directly, which ensures the independence of all layers. Real-world experimental results compared with the original scheme show that the proposed scheme is totally feasible in terms of delay and battery consumption.

Performance Assessment of Full-Scale Wastewater Treatment Plants Based on Seasonal Variability of Microbial Communities via High-Throughput Sequencing.

Directory of Open Access Journals (Sweden)

Tang Liu

Full Text Available Microbial communities of activated sludge (AS play a key role in the performance of wastewater treatment processes. However, seasonal variability of microbial population in varying AS-based processes has been poorly correlated with operation of full-scale wastewater treatment systems (WWTSs. In this paper, significant seasonal variability of AS microbial communities in eight WWTSs located in the city of Guangzhou were revealed in terms of 16S rRNA-based Miseq sequencing. Furthermore, variation redundancy analysis (RDA demonstrated that the microbial community compositions closely correlated with WWTS operation parameters such as temperature, BOD, NH4+-N and TN. Consequently, support vector regression models which reasonably predicted effluent BOD, SS and TN in WWTSs were established based on microbial community compositions. This work provided an alternative tool for rapid assessment on performance of full-scale wastewater treatment plants.

Practical private database queries based on a quantum-key-distribution protocol

International Nuclear Information System (INIS)

Jakobi, Markus; Simon, Christoph; Gisin, Nicolas; Bancal, Jean-Daniel; Branciard, Cyril; Walenta, Nino; Zbinden, Hugo

2011-01-01

Private queries allow a user, Alice, to learn an element of a database held by a provider, Bob, without revealing which element she is interested in, while limiting her information about the other elements. We propose to implement private queries based on a quantum-key-distribution protocol, with changes only in the classical postprocessing of the key. This approach makes our scheme both easy to implement and loss tolerant. While unconditionally secure private queries are known to be impossible, we argue that an interesting degree of security can be achieved by relying on fundamental physical principles instead of unverifiable security assumptions in order to protect both the user and the database. We think that the scope exists for such practical private queries to become another remarkable application of quantum information in the footsteps of quantum key distribution.

Lack of cross-scale linkages reduces robustness of community-based fisheries management.

Directory of Open Access Journals (Sweden)

Richard Cudney-Bueno

Full Text Available Community-based management and the establishment of marine reserves have been advocated worldwide as means to overcome overexploitation of fisheries. Yet, researchers and managers are divided regarding the effectiveness of these measures. The "tragedy of the commons" model is often accepted as a universal paradigm, which assumes that unless managed by the State or privatized, common-pool resources are inevitably overexploited due to conflicts between the self-interest of individuals and the goals of a group as a whole. Under this paradigm, the emergence and maintenance of effective community-based efforts that include cooperative risky decisions as the establishment of marine reserves could not occur. In this paper, we question these assumptions and show that outcomes of commons dilemmas can be complex and scale-dependent. We studied the evolution and effectiveness of a community-based management effort to establish, monitor, and enforce a marine reserve network in the Gulf of California, Mexico. Our findings build on social and ecological research before (1997-2001, during (2002 and after (2003-2004 the establishment of marine reserves, which included participant observation in >100 fishing trips and meetings, interviews, as well as fishery dependent and independent monitoring. We found that locally crafted and enforced harvesting rules led to a rapid increase in resource abundance. Nevertheless, news about this increase spread quickly at a regional scale, resulting in poaching from outsiders and a subsequent rapid cascading effect on fishing resources and locally-designed rule compliance. We show that cooperation for management of common-pool fisheries, in which marine reserves form a core component of the system, can emerge, evolve rapidly, and be effective at a local scale even in recently organized fisheries. Stakeholder participation in monitoring, where there is a rapid feedback of the systems response, can play a key role in reinforcing

An Efficient Key-Policy Attribute-Based Encryption Scheme with Constant Ciphertext Length

Directory of Open Access Journals (Sweden)

Changji Wang

2013-01-01

Full Text Available There is an acceleration of adoption of cloud computing among enterprises. However, moving the infrastructure and sensitive data from trusted domain of the data owner to public cloud will pose severe security and privacy risks. Attribute-based encryption (ABE is a new cryptographic primitive which provides a promising tool for addressing the problem of secure and fine-grained data sharing and decentralized access control. Key-policy attribute-based encryption (KP-ABE is an important type of ABE, which enables senders to encrypt messages under a set of attributes and private keys are associated with access structures that specify which ciphertexts the key holder will be allowed to decrypt. In most existing KP-ABE scheme, the ciphertext size grows linearly with the number of attributes embedded in ciphertext. In this paper, we propose a new KP-ABE construction with constant ciphertext size. In our construction, the access policy can be expressed as any monotone access structure. Meanwhile, the ciphertext size is independent of the number of ciphertext attributes, and the number of bilinear pairing evaluations is reduced to a constant. We prove that our scheme is semantically secure in the selective-set model based on the general Diffie-Hellman exponent assumption.

Shor-Preskill-type security proof for quantum key distribution without public announcement of bases

International Nuclear Information System (INIS)

Hwang, Won-Young; Wang Xiangbin; Matsumoto, Keiji; Kim, Jaewan; Lee, Hai-Woong

2003-01-01

We give a Shor-Preskill-type security proof to quantum key distribution without public announcement of bases [W.Y. Hwang et al., Phys. Lett. A 244, 489 (1998)]. First, we modify the Lo-Chau protocol once more so that it finally reduces to the quantum key distribution without public announcement of bases. Then we show how we can estimate the error rate in the code bits based on that in the checked bits in the proposed protocol, which is the central point of the proof. We discuss the problem of imperfect sources and that of large deviation in the error rate distributions. We discuss when the bases sequence must be discarded

Interferência da taxa de estímulo na avaliação do potencial evocado miogênico vestibular

Directory of Open Access Journals (Sweden)

Aline Tenório Lins Carnaúba

2013-10-01

Full Text Available Os potenciais miogênicos evocados vestibulares (VEMP vêm sendo empregados como exame complementar para estudos otoneurológicos, ainda pouco explorados clinicamente. Esse potencial avalia a função vestibular, especificamente do sáculo, nervo vestibular inferior e/ou núcleo vestibular. OBJETIVO: Verificar a maior taxa de estímulos possível (e confiável na obtenção do VEMP. MÉTODO: Foi registrado o potencial em 18 sujeitos, variando-se a taxa de estímulos entre 5,1 e 40,8 estímulos/s. Forma de estudo: Estudo de coorte contemporânea com corte transversal. RESULTADOS: As latências se mantiveram constantes e as amplitudes foram progressivamente reduzidas com o aumento da taxa de estimulação. Contudo, não houve diferença estatisticamente significativa entre os parâmetros simultaneamente, quando aplicados os testes ANOVA e Kruskal-Wallis. Os dados obtidos nesta pesquisa demonstraram que, quando comparadas as taxas de estimulação de 5,1 e 10,2 estímulos/s, houve ausência de diferença estatisticamente significativas para o parâmetro latência. CONCLUSÃO: Conclui-se que a maior taxa de estimulação confiável é a de 10,2 estímulos/s, para a amostra estudada de adultos jovens ouvintes normais.

Methods of Generating Key Sequences Based on Parameters of Handwritten Passwords and Signatures

Directory of Open Access Journals (Sweden)

Pavel Lozhnikov

2016-10-01

Full Text Available The modern encryption methods are reliable if strong keys (passwords are used, but the human factor issue cannot be solved by cryptographic methods. The best variant is binding all authenticators (passwords, encryption keys, and others to the identities. When a user is authenticated by biometrical characteristics, the problem of protecting a biometrical template stored on a remote server becomes a concern. The paper proposes several methods of generating keys (passwords by means of the fuzzy extractors method based on signature parameters without storing templates in an open way.

Public Key-Based Need-to-Know Authorization Engine Final Report CRADA No. TSB-1553-98

Energy Technology Data Exchange (ETDEWEB)

Mark, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-11-01

The goals of this project were to develop a public key-based authentication service plug-in based on LLNL's requirements, integrate the public key-based authentication with the Intra Verse authorization service adn the LLNL NTK server by developing a full-featured version of the prototyped Intra Verse need-to-know plug in; and to test the authorization and need-to-know plug-in in a secured extranet prototype among selected national Labs.

Location-Aware Dynamic Session-Key Management for Grid-Based Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

I-Hsien Lin

2010-08-01

Full Text Available Security is a critical issue for sensor networks used in hostile environments. When wireless sensor nodes in a wireless sensor network are distributed in an insecure hostile environment, the sensor nodes must be protected: a secret key must be used to protect the nodes transmitting messages. If the nodes are not protected and become compromised, many types of attacks against the network may result. Such is the case with existing schemes, which are vulnerable to attacks because they mostly provide a hop-by-hop paradigm, which is insufficient to defend against known attacks. We propose a location-aware dynamic session-key management protocol for grid-based wireless sensor networks. The proposed protocol improves the security of a secret key. The proposed scheme also includes a key that is dynamically updated. This dynamic update can lower the probability of the key being guessed correctly. Thus currently known attacks can be defended. By utilizing the local information, the proposed scheme can also limit the flooding region in order to reduce the energy that is consumed in discovering routing paths.

Same but different? Measurement invariance of the PIAAC motivation-to-learn scale across key socio-demographic groups

Directory of Open Access Journals (Sweden)

Julia Gorges

2017-07-01

Full Text Available Abstract Background Data from the Programme for the International Assessment of Adult Competencies (PIAAC revealed that countries systematically differ in their respondents’ literacy, numeracy, and problem solving in technology-rich environments skills; skill levels also vary by gender, age, level of education or migration background. Similarly, systematic differences have been documented with respect to adults’ participation in education, which can be considered as a means to develop and maintain skills. From a psychological perspective, motivation to learn is considered a key factor associated with both skill development and participation in (further education. In order to account for motivation when analyzing PIAAC data, four items from the PIAAC background questionnaire were recently compiled into a motivation-to-learn scale. This scale has been found to be invariant (i.e., showing full weak and partial strong measurement invariance across 21 countries. Methods This paper presents further analyses using multiple-group graded response models to scrutinize the validity of the motivation-to-learn scale for group comparisons. Results Results indicate at least partial strong measurement invariance across gender, age groups, level of education, and migration background in most countries under study (all CFI > .95, all RMSEA < .08. Thus, the scale is suitable for comparing both means and associations across these groups. Conclusions Results are discussed in light of country characteristics, challenges of measurement invariance testing, and potential future research using PIAAC data.

Consistency of effects of tropical-forest disturbance on species composition and richness relative to use of indicator taxa.

Science.gov (United States)

Stork, N E; Srivastava, D S; Eggleton, P; Hodda, M; Lawson, G; Leakey, R R B; Watt, A D

2017-08-01

Lawton et al. (1998) found, in a highly cited study, that the species richness of 8 taxa each responds differently to anthropogenic disturbance in Cameroon forests. Recent developments in conservation science suggest that net number of species is an insensitive measure of change and that understanding which species are affected by disturbance is more important. It is also recognized that all disturbance types are not equal in their effect on species and that grouping species according to function rather than taxonomy is more informative of responses of biodiversity to change. In a reanalysis of most of the original Cameroon data set (canopy and ground ants, termites, canopy beetles, nematodes, and butterflies), we focused on changes in species and functional composition rather than richness and used a more inclusive measure of forest disturbance based on 4 component drivers of change: years since disturbance, tree cover, soil compaction, and degree of tree removal. Effects of disturbance on compositional change were largely concordant between taxa. Contrary to Lawton et al.'s findings, species richness for most groups did not decline with disturbance level, providing support for the view that trends in species richness at local scales do not reflect the resilience of ecosystems to disturbance. Disturbance affected species composition more strongly than species richness for butterflies, canopy beetles, and litter ants. For these groups, disturbance caused species replacements rather than just species loss. Only termites showed effects of disturbance on species richness but not composition, indicating species loss without replacement. Although disturbance generally caused changes in composition, the strength of this relationship depended on the disturbance driver. Butterflies, litter ants, and nematodes were correlated with amount of tree cover, canopy beetles were most strongly correlated with time since disturbance, and termites were most strongly correlated with

Zero-leakage multiple key-binding scenarios for SRAM-PUF systems based on the XOR-method

NARCIS (Netherlands)

Kusters, C.J.; Ignatenko, T.; Willems, F.M.J.

2016-01-01

We show that the XOR-method based on linear error-correcting codes can be applied to achieve the secret-key capacity of binary-symmetric SRAM-PUFs. Then we focus on multiple key-bindings. We prove that no information is leaked by all the helper data about a single secret key both in the case where

Zero-leakage multiple key-binding scenarios for SRAM-PUF systems based on the XOR-Method

NARCIS (Netherlands)

Kusters, C.J.; Ignatenko, T.; Willems, F.M.J.

2016-01-01

We show that the XOR-method based on linear error-correcting codes can be applied to achieve the secret-key capacity of binary-symmetric SRAM-PUFs. Then we focus on multiple key-bindings. We prove that no information is leaked by all the helper data about a single secret key both in the case where

A general model for the scaling of offspring size and adult size.

Science.gov (United States)

Falster, Daniel S; Moles, Angela T; Westoby, Mark

2008-09-01

Understanding evolutionary coordination among different life-history traits is a key challenge for ecology and evolution. Here we develop a general quantitative model predicting how offspring size should scale with adult size by combining a simple model for life-history evolution with a frequency-dependent survivorship model. The key innovation is that larger offspring are afforded three different advantages during ontogeny: higher survivorship per time, a shortened juvenile phase, and advantage during size-competitive growth. In this model, it turns out that size-asymmetric advantage during competition is the factor driving evolution toward larger offspring sizes. For simplified and limiting cases, the model is shown to produce the same predictions as the previously existing theory on which it is founded. The explicit treatment of different survival advantages has biologically important new effects, mainly through an interaction between total maternal investment in reproduction and the duration of competitive growth. This goes on to explain alternative allometries between log offspring size and log adult size, as observed in mammals (slope = 0.95) and plants (slope = 0.54). Further, it suggests how these differences relate quantitatively to specific biological processes during recruitment. In these ways, the model generalizes across previous theory and provides explanations for some differences between major taxa.

Two-party quantum key agreement based on four-particle GHZ states

Science.gov (United States)

He, Ye-Feng; Ma, Wen-Ping

2016-04-01

Based on four-particle GHZ states, the double CNOT operation and the delayed measurement technique, a two-party quantum key agreement (QKA) protocols is proposed. The double CNOT operation makes each four-particle GHZ state collapse into two independent quantum states without any entanglement. Furthermore, one party can directly know the two quantum states and the other party can be aware of the two quantum states by using the corresponding measurement. According to the initial states of the two quantum states, two parties can extract the secret keys of each other by using the publicly announced value or by performing the delayed measurement, respectively. Then the protocol achieves the fair establishment of a shared key. The security analysis shows that the new protocol can resist against participant attacks, the Trojan horse attacks and other outsider attacks. Furthermore, the new protocol also has no information leakage problem and has high qubit efficiency.

Wavelets, vibrations and scalings

CERN Document Server

Meyer, Yves

1997-01-01

Physicists and mathematicians are intensely studying fractal sets of fractal curves. Mandelbrot advocated modeling of real-life signals by fractal or multifractal functions. One example is fractional Brownian motion, where large-scale behavior is related to a corresponding infrared divergence. Self-similarities and scaling laws play a key role in this new area. There is a widely accepted belief that wavelet analysis should provide the best available tool to unveil such scaling laws. And orthonormal wavelet bases are the only existing bases which are structurally invariant through dyadic dilations. This book discusses the relevance of wavelet analysis to problems in which self-similarities are important. Among the conclusions drawn are the following: 1) A weak form of self-similarity can be given a simple characterization through size estimates on wavelet coefficients, and 2) Wavelet bases can be tuned in order to provide a sharper characterization of this self-similarity. A pioneer of the wavelet "saga", Meye...

On System Engineering a Barter-Based Re-allocation of Space System Key Development Resources

Science.gov (United States)

Kosmann, William J.

NASA has had a decades-long problem with cost growth during the development of space science missions. Numerous agency-sponsored studies have produced average mission level development cost growths ranging from 23 to 77%. A new study of 26 historical NASA science instrument set developments using expert judgment to re-allocate key development resources has an average cost growth of 73.77%. Twice in history, during the Cassini and EOS-Terra science instrument developments, a barter-based mechanism has been used to re-allocate key development resources. The mean instrument set development cost growth was -1.55%. Performing a bivariate inference on the means of these two distributions, there is statistical evidence to support the claim that using a barter-based mechanism to re-allocate key instrument development resources will result in a lower expected cost growth than using the expert judgment approach. Agent-based discrete event simulation is the natural way to model a trade environment. A NetLogo agent-based barter-based simulation of science instrument development was created. The agent-based model was validated against the Cassini historical example, as the starting and ending instrument development conditions are available. The resulting validated agent-based barter-based science instrument resource re-allocation simulation was used to perform 300 instrument development simulations, using barter to re-allocate development resources. The mean cost growth was -3.365%. A bivariate inference on the means was performed to determine that additional significant statistical evidence exists to support a claim that using barter-based resource re-allocation will result in lower expected cost growth, with respect to the historical expert judgment approach. Barter-based key development resource re-allocation should work on science spacecraft development as well as it has worked on science instrument development. A new study of 28 historical NASA science spacecraft

Scaling earthquake ground motions for performance-based assessment of buildings

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

2011-01-01

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

Key Concept Identification: A Comprehensive Analysis of Frequency and Topical Graph-Based Approaches

Directory of Open Access Journals (Sweden)

Muhammad Aman

2018-05-01

Full Text Available Automatic key concept extraction from text is the main challenging task in information extraction, information retrieval and digital libraries, ontology learning, and text analysis. The statistical frequency and topical graph-based ranking are the two kinds of potentially powerful and leading unsupervised approaches in this area, devised to address the problem. To utilize the potential of these approaches and improve key concept identification, a comprehensive performance analysis of these approaches on datasets from different domains is needed. The objective of the study presented in this paper is to perform a comprehensive empirical analysis of selected frequency and topical graph-based algorithms for key concept extraction on three different datasets, to identify the major sources of error in these approaches. For experimental analysis, we have selected TF-IDF, KP-Miner and TopicRank. Three major sources of error, i.e., frequency errors, syntactical errors and semantical errors, and the factors that contribute to these errors are identified. Analysis of the results reveals that performance of the selected approaches is significantly degraded by these errors. These findings can help us develop an intelligent solution for key concept extraction in the future.

Diversity and distribution of Brachionidae (Rotifera in Thailand, with a key to the species

Directory of Open Access Journals (Sweden)

Sujeephon Athibai

2013-08-01

Full Text Available We investigated the diversity of brachionid rotifers in Thailand. Rotifers were collected from a wide range of habitat types (294 sites, 508 samples including canals, lakes, peat swamps, ponds, reservoirs, rice fields, rivers, swamps and temporary ponds from April 1998 to January 2004. Twenty-eight species including 11 infrasubspecific forms belonging to five genera were identified. The most frequently encountered species was Brachionus falcatus (50.7% of the sampling sites, followed by Keratella cochlearis (50%, B. angularis (49.7%, K. tropica (46.3% and B. forficula (45.9%. Less frequently encountered species were B. caudatus, B. durgae and B. urceolaris. These species were found in low abundances and only in a single site. Two sites in the Northeast – Nong Changpeuak and Bueng Srithat – recorded the greatest richness with 15 taxa, whereas no brachionid rotifers were found in 31 sites. On average, the species richness was five taxa per sampling site. A key to the genera and species of Thai brachionid rotifers is provided.

Key technologies of the server monitor and control system based on GSM short messages

International Nuclear Information System (INIS)

Chen Taiwei; Zhou Zhenliu; Liu Baoxu

2007-01-01

The network management based on SNMP protocol cannot effectively monitor and control application-system states and key-process states on the computer server. Furthermore, it needs the administrator's longtime surveillance. When the administrator leaves the computer, he can't receive the malfunction message in time. In this paper we present a server monitor and control system based on monitor agents and GSM short messages, introduce the key technology to realize it, and implement a model system in the real network environment. (authors)

Claves taxonómicas para el reconocimiento dentario en taxa del superorden Rajomorphii de Chile (Chondrichthyes, Batoidea Taxonomic dental keys for the Chilean taxa of the superorder Rajomorphii (Chondrichthyes, Batoidea

Directory of Open Access Journals (Sweden)

Sylvia Sáez

2012-07-01

Full Text Available Se presenta claves taxonómicas basadas en características morfológicas dentarias externas e internas, que permiten el reconocimiento de cada orden, familia y género de los batoídeos conocidos en Chile. En algunos casos, como en las familias Rhinobatidae, Torpedinidae, Narcinidae, Myliobatidae, Mobulidae, Dasyatidae y Urotrygonidae, las claves permiten el reconocimiento específico pero, en otros casos, sólo se puede discriminar hasta género, dadas las limitaciones impuestas por los conocimientos existentes. Estas claves son una herramienta complementaria a la diagnosis de rayas y están orientadas al reconocimiento de fragmentos dentales, hallazgos paleontológicos de dientes así como para las piezas dentales asociadas con la mandíbula. De esta manera, se entrega un apoyo taxonómico nuevo con características dentales diferentes a las consideradas actualmente para este superorden.A series of keys with external and internal dental morphologic features for the identification of each order, family and genus of rays and skates of the batoids known in Chile, are presented. In the case of families Rhinobatidae, Torpedinidae, Narcinidae, Myliobatidae, Mobulidae, Dasyatidae and Urotrygonidae, an identification at the species level is possible. In other cases, due to limitations imposed by the existing knowledge, only discrimination up to genus is allowed. These keys are a complementary tool for the diagnosis of rays suitable for the identification of dental fragments, paleontological discoveries of teeth as well as for jaw teeth. This tool offers a novel taxonomic support, which includes dental features different from those considered nowadays for this superorder.

Image encryption based on nonlinear encryption system and public-key cryptography

Science.gov (United States)

Zhao, Tieyu; Ran, Qiwen; Chi, Yingying

2015-03-01

Recently, optical asymmetric cryptosystem (OACS) has became the focus of discussion and concern of researchers. Some researchers pointed out that OACS was not tenable because of misunderstanding the concept of asymmetric cryptosystem (ACS). We propose an improved cryptosystem using RSA public-key algorithm based on existing OACS and the new system conforms to the basic agreement of public key cryptosystem. At the beginning of the encryption process, the system will produce an independent phase matrix and allocate the input image, which also conforms to one-time pad cryptosystem. The simulation results show that the validity of the improved cryptosystem and the high robustness against attack scheme using phase retrieval technique.

A FPGA-based identity authority method in quantum key distribution system

International Nuclear Information System (INIS)

Cui Ke; Luo Chunli; Zhang Hongfei; Lin Shengzhao; Jin Ge; Wang Jian

2012-01-01

In this article, an identity authority method realized in hardware is developed which is used in quantum key distribution (QKD) systems. This method is based on LFSR-Teoplitz hashing matrix. Its benefits relay on its easy implementation in hardware and high secure coefficient. It can gain very high security by means of splitting part of the final key generated from QKD systems as the seed where it is required in the identity authority method. We propose an specific flow of the identity authority method according to the problems and features of the hardware. The proposed method can satisfy many kinds of QKD systems. (authors)

Printed Identification Key or Web-Based Identification Guide: An Effective Tool for Species Identification?

Directory of Open Access Journals (Sweden)

Thomas Edison E. dela Cruz

2012-09-01

Full Text Available Species identification is often done with the aid of traditional dichotomous keys. This printed material is based on one’s decision between two alternatives, which is followed by another pair of alternatives until the final species name is reached. With the advent of internet technology, the use of an online database offers an updatable and accumulative approach to species identification. It can also be accessed anytime, and this is very useful for fast-changing groups of organisms. In this paper, we report the preference of sophomore Bachelor of Science (B.Sc. in Microbiology students to two identification guides as a tool in taxonomy. We wish to test our hypothesis that today’s students will prefer to use web-based ID guides over printed dichotomous keys. We also describe how these printed dichotomous key and web-based ID guides were used by the students as one of their laboratory activities in the course Biology of Algae and Fungi.  

Taxa de corte sustentável para manejo das florestas tropicais

Directory of Open Access Journals (Sweden)

Evaldo Muñoz Braz

2012-03-01

Full Text Available http://dx.doi.org/10.5902/198050985086Existe uma grande lacuna dos planos de manejo de florestas tropicais com relação à intensidade de extração e às taxas de corte, usualmente sendo definidas de forma arbitrária. Este trabalho visa definir intensidades de corte diferenciadas para grupos de espécies arbóreas comerciais, com diferentes ritmos de crescimento, por unidade de produção, no estado do Amazonas. Utilizou-se o incremento periódico anual percentual em volume, de 26 espécies arbóreas, obtido de parcelas permanentes. O incremento periódico anual, percentual em volume, para efeito diferenciador, considerou 1% como diferença limite. Foram identificadas três intensidades de corte, para as classes comerciais: 24,4% (grupo I, 35,4% (grupo II e 42,4% (grupo III. Considerando a exploração total sustentável por hectare, para as 26 espécies, seria de 11,5 m³ha-1 com intensidade de corte de 37%. O procedimento de cálculo é simples e pode ser utilizado pelos órgãos fiscalizadores, certificadores ou legisladores como balizador do ciclo de corte e taxa de corte.

Preferential flow from pore to landscape scales

Science.gov (United States)

Koestel, J. K.; Jarvis, N.; Larsbo, M.

2017-12-01

In this presentation, we give a brief personal overview of some recent progress in quantifying preferential flow in the vadose zone, based on our own work and those of other researchers. One key challenge is to bridge the gap between the scales at which preferential flow occurs (i.e. pore to Darcy scales) and the scales of interest for management (i.e. fields, catchments, regions). We present results of recent studies that exemplify the potential of 3-D non-invasive imaging techniques to visualize and quantify flow processes at the pore scale. These studies should lead to a better understanding of how the topology of macropore networks control key state variables like matric potential and thus the strength of preferential flow under variable initial and boundary conditions. Extrapolation of this process knowledge to larger scales will remain difficult, since measurement technologies to quantify macropore networks at these larger scales are lacking. Recent work suggests that the application of key concepts from percolation theory could be useful in this context. Investigation of the larger Darcy-scale heterogeneities that generate preferential flow patterns at the soil profile, hillslope and field scales has been facilitated by hydro-geophysical measurement techniques that produce highly spatially and temporally resolved data. At larger regional and global scales, improved methods of data-mining and analyses of large datasets (machine learning) may help to parameterize models as well as lead to new insights into the relationships between soil susceptibility to preferential flow and site attributes (climate, land uses, soil types).

Amsterdam Expeditions to the West Indian Islands, Report 14. The taxonomy and zoogeography of the family Bogidiellidae (Crustacea, Amphipoda), with emphasis on the West Indian taxa

NARCIS (Netherlands)

Stock, Jan H.

1981-01-01

The diagnosis of a family of groundwater Amphipoda, the Bogidiellidae, is revised. Based on a cladistic analysis, the former genus Bogidiella is subdivided. In its present conception, the Bogidiellidae comprise eleven named genera, seven subgenera, and 50 named species, whereas several other taxa

Connotations of pixel-based scale effect in remote sensing and the modified fractal-based analysis method

Science.gov (United States)

Feng, Guixiang; Ming, Dongping; Wang, Min; Yang, Jianyu

2017-06-01

Scale problems are a major source of concern in the field of remote sensing. Since the remote sensing is a complex technology system, there is a lack of enough cognition on the connotation of scale and scale effect in remote sensing. Thus, this paper first introduces the connotations of pixel-based scale and summarizes the general understanding of pixel-based scale effect. Pixel-based scale effect analysis is essentially important for choosing the appropriate remote sensing data and the proper processing parameters. Fractal dimension is a useful measurement to analysis pixel-based scale. However in traditional fractal dimension calculation, the impact of spatial resolution is not considered, which leads that the scale effect change with spatial resolution can't be clearly reflected. Therefore, this paper proposes to use spatial resolution as the modified scale parameter of two fractal methods to further analyze the pixel-based scale effect. To verify the results of two modified methods (MFBM (Modified Windowed Fractal Brownian Motion Based on the Surface Area) and MDBM (Modified Windowed Double Blanket Method)); the existing scale effect analysis method (information entropy method) is used to evaluate. And six sub-regions of building areas and farmland areas were cut out from QuickBird images to be used as the experimental data. The results of the experiment show that both the fractal dimension and information entropy present the same trend with the decrease of spatial resolution, and some inflection points appear at the same feature scales. Further analysis shows that these feature scales (corresponding to the inflection points) are related to the actual sizes of the geo-object, which results in fewer mixed pixels in the image, and these inflection points are significantly indicative of the observed features. Therefore, the experiment results indicate that the modified fractal methods are effective to reflect the pixel-based scale effect existing in remote sensing

Is evolutionary biology becoming too politically correct? A reflection on the scala naturae, phylogenetically basal clades, anatomically plesiomorphic taxa, and 'lower' animals.

Science.gov (United States)

Diogo, Rui; Ziermann, Janine M; Linde-Medina, Marta

2015-05-01

The notion of scala naturae dates back to thinkers such as Aristotle, who placed plants below animals and ranked the latter along a graded scale of complexity from 'lower' to 'higher' animals, such as humans. In the last decades, evolutionary biologists have tended to move from one extreme (i.e. the idea of scala naturae or the existence of a general evolutionary trend in complexity from 'lower' to "higher" taxa, with Homo sapiens as the end stage) to the other, opposite, extreme (i.e. to avoid using terms such as 'phylogenetically basal' and 'anatomically plesiomorphic' taxa, which are seen as the undesired vestige of old teleological theories). The latter view tries to avoid any possible connotations with the original anthropocentric idea of a scala naturae crowned by man and, in that sense, it can be regarded as a more politically correct view. In the past years and months there has been renewed interest in these topics, which have been discussed in various papers and monographs that tend to subscribe, in general, to the points defended in the more politically correct view. Importantly, most evolutionary and phylogenetic studies of tetrapods and other vertebrates, and therefore most discussions on the scala naturae and related issues have been based on hard tissue and, more recently, on molecular data. Here we provide the first discussion of these topics based on a comparative myological study of all the major vertebrate clades and of myological cladistic and Bayesian phylogenetic analyses of bony fish and tetrapods, including Primates. We specifically (i) contradict the notions of a scala naturae or evolutionary progressive trends leading to more complexity in 'higher' animals and culminating in Homo sapiens, and (ii) stress that the refutation of these old notions does not necessarily mean that one should not keep using the terms 'phylogenetically basal' and particularly 'anatomically plesiomorphic' to refer to groups such as the urodeles within the Tetrapoda

Key Management Scheme Based on Route Planning of Mobile Sink in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Ying Zhang

2016-01-01

Full Text Available In many wireless sensor network application scenarios the key management scheme with a Mobile Sink (MS should be fully investigated. This paper proposes a key management scheme based on dynamic clustering and optimal-routing choice of MS. The concept of Traveling Salesman Problem with Neighbor areas (TSPN in dynamic clustering for data exchange is proposed, and the selection probability is used in MS route planning. The proposed scheme extends static key management to dynamic key management by considering the dynamic clustering and mobility of MSs, which can effectively balance the total energy consumption during the activities. Considering the different resources available to the member nodes and sink node, the session key between cluster head and MS is established by modified an ECC encryption with Diffie-Hellman key exchange (ECDH algorithm and the session key between member node and cluster head is built with a binary symmetric polynomial. By analyzing the security of data storage, data transfer and the mechanism of dynamic key management, the proposed scheme has more advantages to help improve the resilience of the key management system of the network on the premise of satisfying higher connectivity and storage efficiency.

Key Management Scheme Based on Route Planning of Mobile Sink in Wireless Sensor Networks.

Science.gov (United States)

Zhang, Ying; Liang, Jixing; Zheng, Bingxin; Jiang, Shengming; Chen, Wei

2016-01-29

In many wireless sensor network application scenarios the key management scheme with a Mobile Sink (MS) should be fully investigated. This paper proposes a key management scheme based on dynamic clustering and optimal-routing choice of MS. The concept of Traveling Salesman Problem with Neighbor areas (TSPN) in dynamic clustering for data exchange is proposed, and the selection probability is used in MS route planning. The proposed scheme extends static key management to dynamic key management by considering the dynamic clustering and mobility of MSs, which can effectively balance the total energy consumption during the activities. Considering the different resources available to the member nodes and sink node, the session key between cluster head and MS is established by modified an ECC encryption with Diffie-Hellman key exchange (ECDH) algorithm and the session key between member node and cluster head is built with a binary symmetric polynomial. By analyzing the security of data storage, data transfer and the mechanism of dynamic key management, the proposed scheme has more advantages to help improve the resilience of the key management system of the network on the premise of satisfying higher connectivity and storage efficiency.

Key Techniques for the Development of Web-Based PDM System

Institute of Scientific and Technical Information of China (English)

WANG Li-juan; ZHANG Xu; NING Ru-xin

2006-01-01

Some key techniques for the development of web-based product data management (PDM) system are introduced. The four-tiered B/S architecture of a PDM system-BITPDM is introduced first, followed by its design and implementation, including virtual data vault, flexible coding system, document management,product structure and configuration management, workflow/process and product maturity management. BITPDM can facilitate the activities from new product introduction phase to manufacturing, and manage the product data and their dynamic changing history. Based on Microsoft. NET, XML, web service and SOAP techniques, BITPDM realizes the integration and efficient management of product information.

Biogeography of key mesozooplankton species in the North Atlantic, by manual counting methods, and egg production of Calanus finmarchicus

DEFF Research Database (Denmark)

Melle, W.; Runge, J. A.; Head, E.

2015-01-01

Here we present a new, pan-Atlantic compilation of data on key mesozooplankton species, including the possibly most important copepod, Calanus finmarchicus. Distributional data of ten representative zooplankton taxa, from recent (2000–2009) Continuous Plankton Recorder data, are presented, along ...... scientists and their institutions. http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393....

Key characteristics for tool choice in indicator-based sustainability assessment at farm level

Directory of Open Access Journals (Sweden)

Fleur Marchand

2014-09-01

Full Text Available Although the literature on sustainability assessment tools to support decision making in agriculture is rapidly growing, little attention has been paid to the actual tool choice. We focused on the choice of more complex integrated indicator-based tools at the farm level. The objective was to determine key characteristics as criteria for tool choice. This was done with an in-depth comparison of 2 cases: the Monitoring Tool for Integrated Farm Sustainability and the Public Goods Tool. They differ in characteristics that may influence tool choice: data, time, and budgetary requirements. With an enhanced framework, we derived 11 key characteristics to describe differences between the case tools. Based on the key characteristics, we defined 2 types of indicator-based tools: full sustainability assessment (FSA and rapid sustainability assessment (RSA. RSA tools are more oriented toward communicating and learning. They are therefore more suitable for use by a larger group of farmers, can help to raise awareness, trigger farmers to become interested in sustainable farming, and highlight areas of good or bad performance. If and when farmers increase their commitment to on-farm sustainability, they can gain additional insight by using an FSA tool. Based on complementary and modular use of the tools, practical recommendations for the different end users, i.e., researchers, farmers, advisers, and so forth, have been suggested.

Abiotic stressors and stress responses: What commonalities appear between species across biological organization levels?

International Nuclear Information System (INIS)

Sulmon, Cécile; Baaren, Joan van; Cabello-Hurtado, Francisco; Gouesbet, Gwenola; Hennion, Françoise; Mony, Cendrine; Renault, David; Bormans, Myriam; El Amrani, Abdelhak; Wiegand, Claudia; Gérard, Claudia

2015-01-01

Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), we review how organisms respond and adapt to chemical- and temperature-induced stresses from molecular to population level. Using field-realistic studies, our integrative analysis aims to compare i) how molecular and physiological mechanisms related to protection, repair and energy allocation can impact life history traits of stressed organisms, and ii) to what extent trait responses influence individual and population responses. Common response mechanisms are evident at molecular and cellular scales but become rather difficult to define at higher levels due to evolutionary distance and environmental complexity. We provide new insights into the understanding of the impact of molecular and cellular responses on individual and population dynamics and assess the potential related effects on communities and ecosystem functioning. - Highlights: • Responses to chemical and thermal stressors are reviewed across organization levels. • Common responses between taxa are evident at the molecular and cellular scales. • At individual level, energy allocation connects species-specific stress responses. • Commonality decreases at higher levels due to increasing environmental complexity. - The commonality of stress responses to chemical and thermal stressors among taxa is evident at the molecular and cellular scales but remains unclear at higher levels of organization

OS IMPACTOS DA POLÍTICA MONETÁRIA NA TAXA DE CÂMBIO NO BRASIL: IDENTIFICAÇÃO VIA HETEROCEDASTICIDADE

Directory of Open Access Journals (Sweden)

Sílvia Verônica Vilarinho Couto

2017-12-01

Full Text Available RESUMO O presente trabalho busca analisar os efeitos da política monetária brasileira sobre a taxa de câmbio, no período de 2004-2016, considerando o problema de endogeneidade da política monetária. Para tratar do problema da endogeneidade da política monetária é empregado o método de identificação via heterocedasticidade. A principal vantagem deste método é que ele se baseia no comportamento estatístico das séries, não sendo necessário realizar suposições arbitrárias de identificação. Os resultados mostram que há uma relação positiva entre a taxa de juros e a taxa de câmbio no Brasil.

Dynamic test of the ITER blanket key and ceramic insulated pad

International Nuclear Information System (INIS)

Khomyakov, S.; Sysoev, G.; Strebkov, Yu.; Kucherov, A.; Ioki, K.

2010-01-01

The dynamic testing of the blanket module's key integrated into ITER vacuum vessel portion has been performed in 2008 to investigate its capability to react the electro-magnetic (EM) loads. The preliminary analysis showed the large dynamic amplification factor (DAF) of the reactions because of technological gaps between the blanket module and key. Shock load may yield the bronze pads, which protect the blanket electrical insulation from damage. However the dynamic analysis of such particularly non-linear system needs an experimental ground and confirmation. Toward this end, as well as demonstration of the key reliability, the special test facility has been made, and the full-scale mock-up of the inboard intermodular key was tested. So as not to scale non-linear dynamic parameters, 1-ton mass was built on the single flexible support. The key was welded in a 60-mm thick steel plate modeled with a fragment of the VV. The different gaps were set in between the bronze pad of the key and the mass shock worker. This system (supplemented with some additional constraints) has natural oscillations like as the 4-ton module built on four flexible supports. Thus the most critical radial torque might be modeled with a straight force. The objectives of the test were as follows: dynamic response, DAF and damping factor determination; measurement of the strain oscillations in the key's base and in the weld seam; comparison of the measured data with computation results. The paper will present the analytical grounds of the testing conditions, test facility description, analytical adaptation of the facility, experimental results, its comparison with analysis and discussion, and guidelines for the next experimental phase.

Blockchain-based Public Key Infrastructure for Inter-Domain Secure Routing

OpenAIRE

de la Rocha Gómez-Arevalillo , Alfonso; Papadimitratos , Panos

2017-01-01

International audience; A gamut of secure inter-domain routing protocols has been proposed in the literature. They use traditional PGP-like and centralized Public Key Infrastructures for trust management. In this paper, we propose our alternative approach for managing security associations, Secure Blockchain Trust Management (SBTM), a trust management system that instantiates a blockchain-based PKI for the operation of securerouting protocols. A main motivation for SBTM is to facilitate gradu...

Noiseless Linear Amplifiers in Entanglement-Based Continuous-Variable Quantum Key Distribution

Directory of Open Access Journals (Sweden)

Yichen Zhang

2015-06-01

Full Text Available We propose a method to improve the performance of two entanglement-based continuous-variable quantum key distribution protocols using noiseless linear amplifiers. The two entanglement-based schemes consist of an entanglement distribution protocol with an untrusted source and an entanglement swapping protocol with an untrusted relay. Simulation results show that the noiseless linear amplifiers can improve the performance of these two protocols, in terms of maximal transmission distances, when we consider small amounts of entanglement, as typical in realistic setups.

Avaliação da floco-decantação de manta de lodo associada à decantação de alta taxa no tratamento de águas de consumo humano Evaluation of sludge blanket settler flocculator associated to high rate sedimentation applied on water treatment for human consumption

Directory of Open Access Journals (Sweden)

Tarso Luís Cavazzana

2008-06-01

Full Text Available O presente trabalho objetiva avaliar a eficiência de uma unidade-piloto de floco-decantação de manta de lodo associada à decantação de alta taxa na remoção de turbidez, utilizando polímero catiônico como coagulante primário. Avaliaram-se três taxas de aplicação superficial, para águas de estudo apresentando turbidez de 3 a 100 uT e cor verdadeira praticamente nula. As dosagens de polímero foram definidas em ensaios de jar test. O desempenho da unidade-piloto mostrou-se plenamente satisfatório, para as três taxas avaliadas, com resultados coerentes aos obtidos em escala de bancada. Esta performance abre a perspectiva do emprego da tecnologia em escala real para sistemas de abastecimento público, mesmo para a potabilização de águas naturais de baixa turbidez.This paper aims the efficiency evaluation, in pilot scale, of a sludge blanket flocculator associated to a high rate settler using a cationic polymer as the primary coagulant. Three surface loading rates and different synthetic waters, with variable turbidities (from 3 to 100 NTU, were evaluated. The polymer dosages applied on the pilot scale were set up after jar tests. This technology showed a good performance for all rates and the results for all synthetic waters were similar with those obtained in the bench scale. This performance provides a clear feasibility of its use in actual scale for water supply systems, even to treat natural waters with low turbidity.

From ratites to rats: the size of fleshy fruits shapes species' distributions and continental rainforest assembly.

Science.gov (United States)

Rossetto, Maurizio; Kooyman, Robert; Yap, Jia-Yee S; Laffan, Shawn W

2015-12-07

Seed dispersal is a key process in plant spatial dynamics. However, consistently applicable generalizations about dispersal across scales are mostly absent because of the constraints on measuring propagule dispersal distances for many species. Here, we focus on fleshy-fruited taxa, specifically taxa with large fleshy fruits and their dispersers across an entire continental rainforest biome. We compare species-level results of whole-chloroplast DNA analyses in sister taxa with large and small fruits, to regional plot-based samples (310 plots), and whole-continent patterns for the distribution of woody species with either large (more than 30 mm) or smaller fleshy fruits (1093 taxa). The pairwise genomic comparison found higher genetic distances between populations and between regions in the large-fruited species (Endiandra globosa), but higher overall diversity within the small-fruited species (Endiandra discolor). Floristic comparisons among plots confirmed lower numbers of large-fruited species in areas where more extreme rainforest contraction occurred, and re-colonization by small-fruited species readily dispersed by the available fauna. Species' distribution patterns showed that larger-fruited species had smaller geographical ranges than smaller-fruited species and locations with stable refugia (and high endemism) aligned with concentrations of large fleshy-fruited taxa, making them a potentially valuable conservation-planning indicator. © 2015 The Author(s).

Nine endangered taxa, one recovering ecosystem: Identifying common ground for recovery on Santa Cruz Island, California

Science.gov (United States)

McEachern, A. Kathryn; Wilken, Dieter H.

2011-01-01

It is not uncommon to have several rare and listed taxa occupying habitats in one landscape or management area where conservation amounts to defense against the possibility of further loss. It is uncommon and extremely exciting, however, to have several listed taxa occupying one island that is managed cooperatively for conservation and recovery. On Santa Cruz Island, the largest of the northern California island group in the Santa Barbara Channel, we have a golden opportunity to marry ecological knowledge and institutional "good will" in a field test of holistic rare plant conservation. Here, the last feral livestock have been removed, active weed control is underway, and management is focused on understanding and demonstrating system response to conservation management. Yet funding limitations still exist and we need to plan the most fiscally conservative and marketable approach to rare plant restoration. We still experience the tension between desirable quick results and the ecological pace of system recovery. Therefore, our research has focused on identifying fundamental constraints on species recovery at individual, demographic, habitat, and ecosystem levels, and then developing suites of actions that might be taken across taxa and landscapes. At the same time, we seek a performance middle ground that balances an institutional need for quick demonstration of hands-on positive results with a contrasting approach that allows ecosystem recovery to facilitate species recovery in the long term. We find that constraints vary across breeding systems, life-histories, and island locations. We take a hybrid approach in which we identify several actions that we can take now to enhance population size or habitat occupancy for some taxa by active restoration, while allowing others to recover at the pace of ecosystem change. We make our recommendations on the basis of data we have collected over the last decade, so that management is firmly grounded in ecological observation.

Bias and sensitivity in the placement of fossil taxa resulting from interpretations of missing data.

Science.gov (United States)

Sansom, Robert S

2015-03-01

The utility of fossils in evolutionary contexts is dependent on their accurate placement in phylogenetic frameworks, yet intrinsic and widespread missing data make this problematic. The complex taphonomic processes occurring during fossilization can make it difficult to distinguish absence from non-preservation, especially in the case of exceptionally preserved soft-tissue fossils: is a particular morphological character (e.g., appendage, tentacle, or nerve) missing from a fossil because it was never there (phylogenetic absence), or just happened to not be preserved (taphonomic loss)? Missing data have not been tested in the context of interpretation of non-present anatomy nor in the context of directional shifts and biases in affinity. Here, complete taxa, both simulated and empirical, are subjected to data loss through the replacement of present entries (1s) with either missing (?s) or absent (0s) entries. Both cause taxa to drift down trees, from their original position, toward the root. Absolute thresholds at which downshift is significant are extremely low for introduced absences (two entries replaced, 6% of present characters). The opposite threshold in empirical fossil taxa is also found to be low; two absent entries replaced with presences causes fossil taxa to drift up trees. As such, only a few instances of non-preserved characters interpreted as absences will cause fossil organisms to be erroneously interpreted as more primitive than they were in life. This observed sensitivity to coding non-present morphology presents a problem for all evolutionary studies that attempt to use fossils to reconstruct rates of evolution or unlock sequences of morphological change. Stem-ward slippage, whereby fossilization processes cause organisms to appear artificially primitive, appears to be a ubiquitous and problematic phenomenon inherent to missing data, even when no decay biases exist. Absent characters therefore require explicit justification and taphonomic

Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: Implications for resilience

Science.gov (United States)

Gothe, Emma; Sandin, Leonard; Allen, Craig R.; Angeler, David G.

2014-01-01

The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

A multihop key agreement scheme for wireless ad hoc networks based on channel characteristics.

Science.gov (United States)

Hao, Zhuo; Zhong, Sheng; Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

Final report on RMO Vickers key comparison COOMET M.H-K1

Science.gov (United States)

Aslanyan, E.; Menelao, F.; Herrmann, K.; Aslanyan, A.; Pivovarov, V.; Galat, E.; Dovzhenko, Y.; Zhamanbalin, M.

2013-01-01

This report describes a COOMET key comparison on Vickers hardness scales involving five National Metrology Institutes: PTB (Germany), BelGIM (Belarus), NSC IM (Ukraine), KazInMetr (Kazakhstan) and VNIIFTRI (Russia). The pilot laboratory was VNIIFTRI, and PTB acted as the linking institute to key comparisons CCM.H-K1.b and CCM.H-K1.c conducted for the Vickers hardness scales HV1 and HV30, respectively. The comparison was also conducted for the HV5 Vickers hardness scale, since this scale is most frequently used in practice in Russia and CIS countries that work according to GOST standards. In the key comparison, two sets of hardness reference blocks for the Vickers hardness scales HV1, HV5 and HV30 consisting each of three hardness reference blocks with hardness levels of 450 HV and 750 HV were used. The measurement results and uncertainty assessments for HV1 and HV30 hardness scales, as announced by BelGIM, NSC IM, KazInMetr and VNIIFTRI, are in good agreement with the key comparison reference values of CCM.H-K1.b and CCM.H-K1.c. The comparison results for the HV5 hardness scale are viewed as additional information, since up to today no CCM key comparisons on this scale have yet been carried out. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

[Analysis of phylogenetic criteria for estimation of the rank of taxa in methane-oxidizing bacteria].

Science.gov (United States)

Romanovskaia, V A; Rokitko, P V

2011-01-01

To determine a possibility of application of phylogenetic criteria for estimating the taxa rank, the intra- and interspecies, as well as intergeneric relatedness of methanotrophs on the basis of 16S rRNA gene sequences was estimated. We used sequences of 16S rRNA genes of the studied isolates of obligate methanotrophs which have been deposited in UCM (Ukrainian Collection of Microorganisms), and of type strains of other obligate methanotrophs species (from GenBank database). It is shown, that the levels of interspecies and intergeneric relatedness in different families of methanotrophs are not identical, and therefore they can be used for differentiation of taxa only within one family. The carried out analysis has shown, that it is necessary to reconsider taxonomic position: (1) of two phenotypically similar species of Methylomonas (M. aurantiaca and M. fodinarum), similarity of 16S rRNA genes which is 99.4%, similarity of their total DNA--up to 80% that rather testifies to strain differences, than to species differences; (2) of species Methylomicrobium agile and M album which are phylogenetically more related to genus Methylobacter (97% of affinity), than Methylomicrobium (94% of affinity); (3) of genera of the family Beijerinckiaceae (Methylocella and Methylocapsa), and also genera of the family Methylocystaceae (Methylosinus and Methylocystis), whereas high level of relatedness (97% and more) of these bacteria with other methanotrophic genera (within one family) practically corresponds to a range of relatedness of species (within some genera) in the family Methylococcaceae. When determining phylogenetic criteria which can characterize the ranks of taxa, it was revealed, that the levels of interspecies relatedness of methanotrophic genera of the families Methylocystaceae and Beijerinckiaceae (97.8-99.1% and 97.8%, accordingly) considerably exceed the level of genera formation in the family Methylococcaceae (94.0-98.2%) and, moreover, approach the value of

Securing Metering Infrastructure of Smart Grid: A Machine Learning and Localization Based Key Management Approach

Directory of Open Access Journals (Sweden)

Imtiaz Parvez

2016-08-01

Full Text Available In smart cities, advanced metering infrastructure (AMI of the smart grid facilitates automated metering, control and monitoring of power distribution by employing a wireless network. Due to this wireless nature of communication, there exist potential threats to the data privacy in AMI. Decoding the energy consumption reading, injecting false data/command signals and jamming the networks are some hazardous measures against this technology. Since a smart meter possesses limited memory and computational capability, AMI demands a light, but robust security scheme. In this paper, we propose a localization-based key management system for meter data encryption. Data are encrypted by the key associated with the coordinate of the meter and a random key index. The encryption keys are managed and distributed by a trusted third party (TTP. Localization of the meter is proposed by a method based on received signal strength (RSS using the maximum likelihood estimator (MLE. The received packets are decrypted at the control center with the key mapped with the key index and the meter’s coordinates. Additionally, we propose the k-nearest neighbors (kNN algorithm for node/meter authentication, capitalizing further on data transmission security. Finally, we evaluate the security strength of a data packet numerically for our method.

SCOR based key success factors in cooking oil supply chain buyers perspective in Padang City

Science.gov (United States)

Zahara, Fatimah; Hadiguna, Rika Ampuh

2017-11-01

Supply chain of cooking oil is a network of companies from palm oil as raw material to retailers which work to create the value and deliver products into the end consumers. This paper is aimed to study key success factors based on consumer's perspective as the last stage in the supply chain. Consumers who are examined in this study are restaurants management or owners. Restaurant is the biggest consumption of cooking oil. The factors is studied based on Supply Chain Operation Reference (SCOR) version 10.0. Factors used are formulated based on the third-level metrics of SCOR Model. Factors are analyzed using factors analysis. This study found factors which become key success factors in managing supply chain of cooking oil encompass reliability, responsiveness and agility. Key success factors can be applied by governments as policy making and cooking oil companies as formulation of the distribution strategies.

Modified Principal Component Analysis for Identifying Key Environmental Indicators and Application to a Large-Scale Tidal Flat Reclamation

Directory of Open Access Journals (Sweden)

Kejian Chu

2018-01-01

Full Text Available Identification of the key environmental indicators (KEIs from a large number of environmental variables is important for environmental management in tidal flat reclamation areas. In this study, a modified principal component analysis approach (MPCA has been developed for determining the KEIs. The MPCA accounts for the two important attributes of the environmental variables: pollution status and temporal variation, in addition to the commonly considered numerical divergence attribute. It also incorporates the distance correlation (dCor to replace the Pearson’s correlation to measure the nonlinear interrelationship between the variables. The proposed method was applied to the Tiaozini sand shoal, a large-scale tidal flat reclamation region in China. Five KEIs were identified as dissolved inorganic nitrogen, Cd, petroleum in the water column, Hg, and total organic carbon in the sediment. The identified KEIs were shown to respond well to the biodiversity of phytoplankton. This demonstrated that the identified KEIs adequately represent the environmental condition in the coastal marine system. Therefore, the MPCA is a practicable method for extracting effective indicators that have key roles in the coastal and marine environment.

Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora

Directory of Open Access Journals (Sweden)

Barna Páll-Gergely

2015-01-01

Full Text Available Vietnamese species from the family Plectopylidae are revised based on the type specimens of all known taxa, more than 600 historical non-type museum lots, and almost 200 newly-collected samples. Altogether more than 7000 specimens were investigated. The revision has revealed that species diversity of the Vietnamese Plectopylidae was previously overestimated. Overall, thirteen species names (anterides Gude, 1909, bavayi Gude, 1901, congesta Gude, 1898, fallax Gude, 1909, gouldingi Gude, 1909, hirsuta Möllendorff, 1901, jovia Mabille, 1887, moellendorffi Gude, 1901, persimilis Gude, 1901, pilsbryana Gude, 1901, soror Gude, 1908, tenuis Gude, 1901, verecunda Gude, 1909 were synonymised with other species. In addition to these, Gudeodiscus hemmeni sp. n. and G. messageri raheemi ssp. n. are described from north-western Vietnam. Sixteen species and two subspecies are recognized from Vietnam. The reproductive anatomy of eight taxa is described. Based on anatomical information, Halongella gen. n. is erected to include Plectopylis schlumbergeri and P. fruhstorferi. Additionally, the genus Gudeodiscus is subdivided into two subgenera (Gudeodiscus and Veludiscus subgen. n. on the basis of the morphology of the reproductive anatomy and the radula. The Chinese G. phlyarius werneri Páll-Gergely, 2013 is moved to synonymy of G. phlyarius. A spermatophore was found in the organ situated next to the gametolytic sac in one specimen. This suggests that this organ in the Plectopylidae is a diverticulum. Statistically significant evidence is presented for the presence of calcareous hook-like granules inside the penis being associated with the absence of embryos in the uterus in four genera. This suggests that these probably play a role in mating periods before disappearing when embryos develop. Sicradiscus mansuyi is reported from China for the first time.

TAXAS DE INFECÇÃO HOSPITALAR EM UMA UNIDADE DE TERAPIA INTENSIVA NEONATAL

Directory of Open Access Journals (Sweden)

Waleska de Oliveira Bittencourt

2009-09-01

Full Text Available Trata-se de uma pesquisa descritiva quantitativa que teve o seguinte objetivo: identificar as taxas de infecção hospitalar relacionadas ao trato vascular em recém-nascidos hospitalizados na Unidade de Terapia Intensiva Neonatal de um Hospital Universitário localizado no estado do Rio de Janeiro no período de 2005 a 2007. A amostra foi constituída todos os recém-nascidos internados em 2005 e 2007. Os resultados indicaram que, embora a taxa de infecções hospitalares em 2007 seja menor que no ano de 2005, a proporção de infecções relacionadas ao trato vascular sofreu um discreto aumento considerando as demais topografias. Embora a educação continuada seja empregada na unidade, acredita-se que fatores como a alta rotatividade de profissionais e o uso de mais cateteres venosos centrais na rotina reduzam sua efetividade. Desta forma, foram elaboradas algumas propostas para a redução das infecções hospitalares na unidade estudada.

Statistical amplitude scale estimation for quantization-based watermarking

NARCIS (Netherlands)

Shterev, I.D.; Lagendijk, I.L.; Heusdens, R.

2004-01-01

Quantization-based watermarking schemes are vulnerable to amplitude scaling. Therefore the scaling factor has to be accounted for either at the encoder, or at the decoder, prior to watermark decoding. In this paper we derive the marginal probability density model for the watermarked and attacked

Quantum key management

Energy Technology Data Exchange (ETDEWEB)

Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

2016-11-29

Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

Designing key-dependent chaotic S-box with larger key space

International Nuclear Information System (INIS)

Yin Ruming; Yuan Jian; Wang Jian; Shan Xiuming; Wang Xiqin

2009-01-01

The construction of cryptographically strong substitution boxes (S-boxes) is an important concern in designing secure cryptosystems. The key-dependent S-boxes designed using chaotic maps have received increasing attention in recent years. However, the key space of such S-boxes does not seem to be sufficiently large due to the limited parameter range of discretized chaotic maps. In this paper, we propose a new key-dependent S-box based on the iteration of continuous chaotic maps. We explore the continuous-valued state space of chaotic systems, and devise the discrete mapping between the input and the output of the S-box. A key-dependent S-box is constructed with the logistic map in this paper. We show that its key space could be much larger than the current key-dependent chaotic S-boxes.

Integration of Genome Scale Metabolic Networks and Gene Regulation of Metabolic Enzymes With Physiologically Based Pharmacokinetics.

Science.gov (United States)

Maldonado, Elaina M; Leoncikas, Vytautas; Fisher, Ciarán P; Moore, J Bernadette; Plant, Nick J; Kierzek, Andrzej M

2017-11-01

The scope of physiologically based pharmacokinetic (PBPK) modeling can be expanded by assimilation of the mechanistic models of intracellular processes from systems biology field. The genome scale metabolic networks (GSMNs) represent a whole set of metabolic enzymes expressed in human tissues. Dynamic models of the gene regulation of key drug metabolism enzymes are available. Here, we introduce GSMNs and review ongoing work on integration of PBPK, GSMNs, and metabolic gene regulation. We demonstrate example models. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

A molecular analysis of the Gelechiidae (Lepidoptera, Gelechioidea) with an interpretative grouping of its taxa

DEFF Research Database (Denmark)

Karsholt, Ole; Mutanen, Marko; Lee, Sangmi

2013-01-01

, Isocitrate dehydrogenase, Cytosolic malate dehydrogenase, Glyceraldehyde-3-phosphate dehydrogenase and Carbamoylphosphate synthase domain protein). Fifty-two taxa representing nearly all established subfamilies and tribes of Gelechiidae, and about 10% of described gelechiid genera, in addition to five...

Ecological characterization and molecular differentiation of Culex pipiens complex taxa and Culex torrentium in eastern Austria.

Science.gov (United States)

Zittra, Carina; Flechl, Eva; Kothmayer, Michael; Vitecek, Simon; Rossiter, Heidemarie; Zechmeister, Thomas; Fuehrer, Hans-Peter

2016-04-11

Culex pipiens complex taxa differ in behaviour, ecophysiology and epidemiologic importance. Despite their epidemiologic significance, information on genetic diversity, occurrence and seasonal and spatial distribution patterns of the Cx. pipiens complex is still insufficient. Assessment of seasonal and spatial distribution patterns of Culex pipiens forms and their congener Cx. torrentium is crucial for the understanding of their vector-pathogen dynamics. Female mosquitoes were trapped from April-October 2014 twice a month for a 24-h time period with BG-sentinel traps at 24 sampling sites in eastern Austria, using carbon dioxide as attractant. Ecological forms of Cx. pipiens s.l. and their hybrids were differentiated using the CQ11 locus, and Cx. pipiens forms and their congener Cx. torrentium using the ACE-2 gene. Differential exploitation of ecological niches by Cx. pipiens forms and Cx. torrentium was analysed using likelihood ratio tests. Possible effects of environmental parameters on these taxa were tested using PERMANOVA based on distance matrices and, if significant, were modelled in nMDS ordination space to estimate non-linear relationships. For this study, 1476 Culex spp. were sampled. Culex pipiens f. pipiens representing 87.33 % of the total catch was most abundant, followed by hybrids of both forms (5.62 %), Cx. torrentium (3.79 %) and Cx. pipiens f. molestus (3.25 %). Differences in proportional abundances were found between land cover classes. Ecological parameters affecting seasonal and spatial distribution of these taxa in eastern Austria are precipitation duration, air temperature, sunlight and the interaction term of precipitation amount and the Danube water level, which can be interpreted as a proxy for breeding habitat availability. The Cx. pipiens complex of eastern Austria comprises both ecologically different forms, the mainly ornithophilic form pipiens and the mainly mammalophilic and anthropophilic form molestus. Heterogeneous agricultural

Chemical Composition of the Essential Oil and Antimicrobial Activity of Scaligeria DC. Taxa and Implications for Taxonomy

Directory of Open Access Journals (Sweden)

Ayşe Baldemir

2018-01-01

Full Text Available Six different Scaligeria DC. taxa (Apiaceae essential oils (EOs obtained by hydrodistillation from herba with the flowers collected from different sites from Turkey. The oils were analyzed and characterized by gas chromatography-flame ionization detector (GC-FID and gas chromatography–mass spectrometry (GC–MS simultaneously. A total of 133 different compounds were identified and relative qualitative and quantitative differences were observed among the evaluated samples. Analytical profiles of the Scaligeria EOs showed characteristic differences in terms of different main chemical constituents, between the two taxa S. lazica Boiss. and S. tripartita (Kalen. Tamamsch; and S. napiformis (Sprengel Grande, S. meifolia (Fenzl Boiss., S. capillifolia Post, S. hermonis Post, S. glaucescens (DC. Boiss. taxa, respectively. The main component germacrene D can be utilized as marker for the chemical discrimination of the Scaligeria genus. In addition, Scaligeria EOs were evaluated in vitro for their antimicrobial activity against pathogenic Gram positive (Staphylococcus aureus and Bacillus cereus, Gram negative (Pseudomonas aeruginosa and yeast (Candida albicans, C. parapsilosis, and C. krusei standard strains by using a micro-dilution assay. As a general result, the oils showed moderate inhibitory range when compared with standard antimicrobial agents.

The Scaling LInear Macroweather model (SLIM): using scaling to forecast global scale macroweather from months to decades

Science.gov (United States)

Lovejoy, S.; del Rio Amador, L.; Hébert, R.

2015-03-01

At scales of ≈ 10 days (the lifetime of planetary scale structures), there is a drastic transition from high frequency weather to low frequency macroweather. This scale is close to the predictability limits of deterministic atmospheric models; so that in GCM macroweather forecasts, the weather is a high frequency noise. But neither the GCM noise nor the GCM climate is fully realistic. In this paper we show how simple stochastic models can be developped that use empirical data to force the statistics and climate to be realistic so that even a two parameter model can outperform GCM's for annual global temperature forecasts. The key is to exploit the scaling of the dynamics and the enormous stochastic memories that it implies. Since macroweather intermittency is low, we propose using the simplest model based on fractional Gaussian noise (fGn): the Scaling LInear Macroweather model (SLIM). SLIM is based on a stochastic ordinary differential equations, differing from usual linear stochastic models (such as the Linear Inverse Modelling, LIM) in that it is of fractional rather than integer order. Whereas LIM implicitly assumes there is no low frequency memory, SLIM has a huge memory that can be exploited. Although the basic mathematical forecast problem for fGn has been solved, we approach the problem in an original manner notably using the method of innovations to obtain simpler results on forecast skill and on the size of the effective system memory. A key to successful forecasts of natural macroweather variability is to first remove the low frequency anthropogenic component. A previous attempt to use fGn for forecasts had poor results because this was not done. We validate our theory using hindcasts of global and Northern Hemisphere temperatures at monthly and annual resolutions. Several nondimensional measures of forecast skill - with no adjustable parameters - show excellent agreement with hindcasts and these show some skill even at decadal scales. We also compare

Financial Key Ratios

OpenAIRE

Tănase Alin-Eliodor

2014-01-01

This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

Key Durability Issues with Mullite-Based Environmental Barrier Coatings for Si-Based Ceramics

Science.gov (United States)

Lee, Kang N.

2000-01-01

Plasma-sprayed mullite (3Al2O3.2SiO2) and mullite/yttria-stabilized-zirconia (YSZ) dual layer coatings have been developed to protect silicon -based ceramics from environmental attack. Mullite-based coating systems show excellent durability in air. However, in combustion environments, corrosive species such as molten salt or water vapor penetrate through cracks in the coating and attack the Si-based ceramics along the interface. Thus the modification of the coating system for enhanced crack-resistance is necessary for long-term durability in combustion environments. Other key durability issues include interfacial contamination and coating/substrate bonding. Interfacial contamination leads to enhanced oxidation and interfacial pore formation, while a weak coating/substrate bonding leads to rapid attack of the interface by corrosive species, both of which can cause a premature failure of the coating. Interfacial contamination can be minimized by limiting impurities in coating and substrate materials. The interface may be modified to improve the coating/substrate bond.

Chaotic maps and biometrics-based anonymous three-party authenticated key exchange protocol without using passwords

International Nuclear Information System (INIS)

Xie Qi; Hu Bin; Chen Ke-Fei; Liu Wen-Hao; Tan Xiao

2015-01-01

In three-party password authenticated key exchange (AKE) protocol, since two users use their passwords to establish a secure session key over an insecure communication channel with the help of the trusted server, such a protocol may suffer the password guessing attacks and the server has to maintain the password table. To eliminate the shortages of password-based AKE protocol, very recently, according to chaotic maps, Lee et al. [2015 Nonlinear Dyn. 79 2485] proposed a first three-party-authenticated key exchange scheme without using passwords, and claimed its security by providing a well-organized BAN logic test. Unfortunately, their protocol cannot resist impersonation attack, which is demonstrated in the present paper. To overcome their security weakness, by using chaotic maps, we propose a biometrics-based anonymous three-party AKE protocol with the same advantages. Further, we use the pi calculus-based formal verification tool ProVerif to show that our AKE protocol achieves authentication, security and anonymity, and an acceptable efficiency. (paper)

Exploring key determinants of virtual worlds business success based on users' experience and perception

OpenAIRE

Xu , Xiaobo (Bob)

2010-01-01

Given the growth and popularity of virtual worlds, companies have a strong interest in presenting themselves successfully in virtual worlds. We designed an experimental study to identify the key determinants of virtual worlds business success based on users’ experience and perception. The preliminary results indicate that Starbucks, McDonalds, and Paris are the 3 most favorite sites. Furthermore, 5 key determinants (entertainment, functionality, interactivity, reality, and s...

Phylogenetic overview of the genus Genea (Pezizales, Ascomycota) with an emphasis on European taxa.

Science.gov (United States)

Alvarado, Pablo; Cabero, Julio; Moreno, Gabriel; Bratek, Zoltán; van Vooren, Nicolas; Kaounas, Vasileios; Konstantinidis, Giorgos; Agnello, Carlo; Merényi, Zsolt; Smith, Matthew E; Vizzini, Alfredo; Trappe, James M

2016-01-01

We constructed a comprehensive phylogeny of the genus Genea, with new molecular data from samples collected in several countries in temperate and Mediterranean Europe, as well as North America. Type specimens and authentic material of most species were examined to support identifications. The molecular identity of the most common species in Genea was compared with nuc rDNA internal transcribed spacer (ITS), D1-D2 domains of 28S nuc rDNA (28S rDNA) and translation elongation factor 1-α ene (TEF1) profiles of 10 recently proposed taxa, G. brunneocarpa, G. compressa, G. dentata, G. fageticola, G. lobulata, G. oxygala, G. pinicola, G. pseudobalsleyi, G. pseudoverrucosa and G. tuberculata, supporting their status as distinct species. Genea mexicana and G. thaxteri on the one hand and G. sphaerica and G. lespiaultii on the other are closely related. Multiple lineages were recorded for G. verrucosa and G. fragrans, but we found no morphological traits to discriminate among them, so we tentatively interpreted them as cryptic species. A key to species of the genus Genea is provided to facilitate identification. We provide macroscopic images of fresh specimens and of representative spores of most species. Finally, we conducted a molecular analysis of the divergence time for Genea and discuss the implications of our results. © 2016 by The Mycological Society of America.

Phylogenetic assessment of global Suillus ITS sequences supports morphologically defined species and reveals synonymous and undescribed taxa.

Science.gov (United States)

Nguyen, Nhu H; Vellinga, Else C; Bruns, Thomas D; Kennedy, Peter G

The genus Suillus represents one of the most recognizable groups of mushrooms in conifer forests throughout the Northern Hemisphere. Although for decades the genus has been relatively well defined morphologically, previous molecular phylogenetic assessments have provided important yet preliminary insights into its evolutionary history. We present the first large-scale phylogenetic study of the boundaries of each species in the genus Suillus based on the most current internal transcribed spacer (ITS) barcode sequences available inPUBLIC databases, as well as sequencing of 224 vouchered specimens and cultures, 15 of which were type specimens from North America. We found that species boundaries delimited by morphological data are broadly congruent with those based on ITS sequences. However, some species appear to have been described several times under different names, several species groups cannot be resolved by ITS sequences alone, and undescribed taxa are apparent, especially in Asia. Therefore, we elevated S. tomentosus var. discolor to S. discolor; proposed synonymies of S. neoalbidipes with S. glandulosipes, S. borealis with S. brunnescens, Boletus serotinus and B. solidipes with Suillus elbensis, S. lactifluus with S. granulatus, S. himalayensis with S. americanus; and proposed usage of the names S. clintonianus in the place of the North American S. grevillei, S. weaverae for North American S. granulatus, S. ampliporus in the place of the North American S. cavipes, and S. elbensis in place of the North American S. viscidus. We showed that the majority of Suillus species have strong affinities for particular host genera. Although deep node support was low, geographic differentiation was apparent, with species from North America, Eurasia, and Asia often forming their own clades. Collectively, this comprehensive genus-level phylogenetic integration of currently available Suillus ITS molecular data and metadata will aid future taxonomic and ecological work on an

Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata in support of a new classification

Directory of Open Access Journals (Sweden)

Timothy D. O'Hara

2018-03-01

Full Text Available A new classification of Ophiuroidea, considering family rank and above, is presented. The new family and superfamily taxa in O’Hara et al. (2017 were proposed to ensure a better readability of the new phylogeny but are unavailable under the provisions of the ICZN. Here, the morphological diagnoses to all 33 families and five superfamilies are provided. Ten new families, Ophiosphalmidae fam. nov., Ophiomusaidae fam. nov., Ophiocamacidae fam. nov., Ophiopteridae fam. nov., Clarkcomidae fam. nov., Ophiopezidae fam. nov., Ophiernidae fam. nov., Amphilimnidae fam. nov., Ophiothamnidae fam. nov. and Ophiopholidae fam. nov., are described. The family Ophiobyrsidae Matsumoto, 1915, not yet discovered in the previous publication, is added, based on new molecular data. A new phylogenetic reconstruction is presented. Definitions of difficult-to-apply morphological characters are given.

Key-phrase based classification of public health web pages.

Science.gov (United States)

Dolamic, Ljiljana; Boyer, Célia

2013-01-01

This paper describes and evaluates the public health web pages classification model based on key phrase extraction and matching. Easily extendible both in terms of new classes as well as the new language this method proves to be a good solution for text classification faced with the total lack of training data. To evaluate the proposed solution we have used a small collection of public health related web pages created by a double blind manual classification. Our experiments have shown that by choosing the adequate threshold value the desired value for either precision or recall can be achieved.

Estimation of Handgrip Force from SEMG Based on Wavelet Scale Selection.

Science.gov (United States)

Wang, Kai; Zhang, Xianmin; Ota, Jun; Huang, Yanjiang

2018-02-24

This paper proposes a nonlinear correlation-based wavelet scale selection technology to select the effective wavelet scales for the estimation of handgrip force from surface electromyograms (SEMG). The SEMG signal corresponding to gripping force was collected from extensor and flexor forearm muscles during the force-varying analysis task. We performed a computational sensitivity analysis on the initial nonlinear SEMG-handgrip force model. To explore the nonlinear correlation between ten wavelet scales and handgrip force, a large-scale iteration based on the Monte Carlo simulation was conducted. To choose a suitable combination of scales, we proposed a rule to combine wavelet scales based on the sensitivity of each scale and selected the appropriate combination of wavelet scales based on sequence combination analysis (SCA). The results of SCA indicated that the scale combination VI is suitable for estimating force from the extensors and the combination V is suitable for the flexors. The proposed method was compared to two former methods through prolonged static and force-varying contraction tasks. The experiment results showed that the root mean square errors derived by the proposed method for both static and force-varying contraction tasks were less than 20%. The accuracy and robustness of the handgrip force derived by the proposed method is better than that obtained by the former methods.

Análise comparativa de risco de câmbio e das taxas de juros na crise cambial de 1999

Directory of Open Access Journals (Sweden)

Hélio Rosseti Júnior

2009-09-01

Full Text Available É nos momentos de crise que os novos paradigmas surgem em substituição dos antigos, ocorrendo, assim, o renovar das formas de se entender os mecanismos de funcionamento da sociedade, as relações de produção e os modelos de consumo. A crise cambial brasileira de 1999 trouxe dificuldades para a população e para o país, exigindo mudanças de postura do governo e dos organismos da sociedade. A crise provocou uma retração de produção do Brasil, uma elevação dos juros e, por conseguinte, do endividamento do país. Uma crise que teve como centro a taxa de câmbio acabou tendo seus maiores desdobramentos nas taxas de juros, tanto do governo como no mercado. Este trabalho de pesquisa procura analisar o comportamento dos juros efetivamente praticados no mundo financeiro nacional, a partir da flutuação das taxas de câmbio, no ano da crise. Para tanto, são estudados os números diários e mensais de relatórios do Banco Central e os dados da evolução dessas taxas.

Validação de equações de predição da taxa metabólica basal em mulheres residentes em Porto Alegre, RS, Brasil

Directory of Open Access Journals (Sweden)

Wahrlich Vivian

2001-01-01

Full Text Available OBJETIVO: Medir a taxa metabólica basal em mulheres de 20 a 40 anos, não-gestantes ou lactantes, e comparar o valor medido com os valores de taxa metabólica basal estimados por equações de predição. MÉTODOS: A taxa metabólica basal foi medida por calorimetria indireta, pela manhã, durante a fase folicular do ciclo menstrual, em 60 voluntárias residentes no município de Porto Alegre, RS, sob condições padronizadas de jejum, repouso e ambiente. RESULTADOS: A média (± desvio-padrão da taxa metabólica basal medida foi 1.185,3±148,6 kcal em 24 horas. A taxa metabólica basal, estimada por equações, foi significativamente maior (7% a 17% do que a taxa metabólica basal medida. CONCLUSÕES: Os dados evidenciaram que as equações de predição não são adequadas para estimar a taxa metabólica basal nas mulheres avaliadas. O emprego dessas equações podem superestimar os requerimentos energéticos para mulheres com características semelhantes.

Validação de equações de predição da taxa metabólica basal em mulheres residentes em Porto Alegre, RS, Brasil

Directory of Open Access Journals (Sweden)

Vivian Wahrlich

2001-02-01

Full Text Available OBJETIVO: Medir a taxa metabólica basal em mulheres de 20 a 40 anos, não-gestantes ou lactantes, e comparar o valor medido com os valores de taxa metabólica basal estimados por equações de predição. MÉTODOS: A taxa metabólica basal foi medida por calorimetria indireta, pela manhã, durante a fase folicular do ciclo menstrual, em 60 voluntárias residentes no município de Porto Alegre, RS, sob condições padronizadas de jejum, repouso e ambiente. RESULTADOS: A média (± desvio-padrão da taxa metabólica basal medida foi 1.185,3±148,6 kcal em 24 horas. A taxa metabólica basal, estimada por equações, foi significativamente maior (7% a 17% do que a taxa metabólica basal medida. CONCLUSÕES: Os dados evidenciaram que as equações de predição não são adequadas para estimar a taxa metabólica basal nas mulheres avaliadas. O emprego dessas equações podem superestimar os requerimentos energéticos para mulheres com características semelhantes.

Desiccation as a mitigation tool to manage biofouling risks: trials on temperate taxa to elucidate factors influencing mortality rates.

Science.gov (United States)

Hopkins, Grant A; Prince, Madeleine; Cahill, Patrick L; Fletcher, Lauren M; Atalah, Javier

2016-01-01

The desiccation tolerance of biofouling taxa (adults and early life-stages) was determined under both controlled and 'realistic' field conditions. Adults of the ascidian Ciona spp. died within 24 h. Mortality in the adult blue mussel Mytilus galloprovincialis occurred within 11 d under controlled conditions, compared with 7 d when held outside. The Pacific oyster Crassostrea gigas was the most desiccation-tolerant taxon tested (up to 34 d under controlled conditions). Biofouling orientated to direct sunlight showed faster mortality rates for all the taxa tested. Mortality in Mytilus juveniles took up to 24 h, compared with 8 h for Ciona, with greater survival at the higher temperature (18.5°C) and humidity (~95% RH) treatment combination. This study demonstrated that desiccation can be an effective mitigation method for a broad range of fouling taxa, especially their early life-stages. Further work is necessary to assess risks from other high-risk species such as algae and cyst forming species.

Multi-scale thermal stability of a hard thermoplastic protein-based material

Science.gov (United States)

Latza, Victoria; Guerette, Paul A.; Ding, Dawei; Amini, Shahrouz; Kumar, Akshita; Schmidt, Ingo; Keating, Steven; Oxman, Neri; Weaver, James C.; Fratzl, Peter; Miserez, Ali; Masic, Admir

2015-09-01

Although thermoplastic materials are mostly derived from petro-chemicals, it would be highly desirable, from a sustainability perspective, to produce them instead from renewable biopolymers. Unfortunately, biopolymers exhibiting thermoplastic behaviour and which preserve their mechanical properties post processing are essentially non-existent. The robust sucker ring teeth (SRT) from squid and cuttlefish are one notable exception of thermoplastic biopolymers. Here we describe thermoplastic processing of squid SRT via hot extrusion of fibres, demonstrating the potential suitability of these materials for large-scale thermal forming. Using high-resolution in situ X-ray diffraction and vibrational spectroscopy, we elucidate the molecular and nanoscale features responsible for this behaviour and show that SRT consist of semi-crystalline polymers, whereby heat-resistant, nanocrystalline β-sheets embedded within an amorphous matrix are organized into a hexagonally packed nanofibrillar lattice. This study provides key insights for the molecular design of biomimetic protein- and peptide-based thermoplastic structural biopolymers with potential biomedical and 3D printing applications.

Data and performance profiles applying an adaptive truncation criterion, within linesearch-based truncated Newton methods, in large scale nonconvex optimization

Directory of Open Access Journals (Sweden)

Andrea Caliciotti

2018-04-01

Full Text Available In this paper, we report data and experiments related to the research article entitled “An adaptive truncation criterion, for linesearch-based truncated Newton methods in large scale nonconvex optimization” by Caliciotti et al. [1]. In particular, in Caliciotti et al. [1], large scale unconstrained optimization problems are considered by applying linesearch-based truncated Newton methods. In this framework, a key point is the reduction of the number of inner iterations needed, at each outer iteration, to approximately solving the Newton equation. A novel adaptive truncation criterion is introduced in Caliciotti et al. [1] to this aim. Here, we report the details concerning numerical experiences over a commonly used test set, namely CUTEst (Gould et al., 2015 [2]. Moreover, comparisons are reported in terms of performance profiles (Dolan and Moré, 2002 [3], adopting different parameters settings. Finally, our linesearch-based scheme is compared with a renowned trust region method, namely TRON (Lin and Moré, 1999 [4].

Information hiding based on double random-phase encoding and public-key cryptography.

Science.gov (United States)

Sheng, Yuan; Xin, Zhou; Alam, Mohammed S; Xi, Lu; Xiao-Feng, Li

2009-03-02

A novel information hiding method based on double random-phase encoding (DRPE) and Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. In the proposed technique, the inherent diffusion property of DRPE is cleverly utilized to make up the diffusion insufficiency of RSA public-key cryptography, while the RSA cryptosystem is utilized for simultaneous transmission of the cipher text and the two phase-masks, which is not possible under the DRPE technique. This technique combines the complementary advantages of the DPRE and RSA encryption techniques and brings security and convenience for efficient information transmission. Extensive numerical simulation results are presented to verify the performance of the proposed technique.

Iris recognition based on key image feature extraction.

Science.gov (United States)

Ren, X; Tian, Q; Zhang, J; Wu, S; Zeng, Y

2008-01-01

In iris recognition, feature extraction can be influenced by factors such as illumination and contrast, and thus the features extracted may be unreliable, which can cause a high rate of false results in iris pattern recognition. In order to obtain stable features, an algorithm was proposed in this paper to extract key features of a pattern from multiple images. The proposed algorithm built an iris feature template by extracting key features and performed iris identity enrolment. Simulation results showed that the selected key features have high recognition accuracy on the CASIA Iris Set, where both contrast and illumination variance exist.

Validating DNA barcodes: A non-destructive extraction protocol enables simultaneous vouchering of DNA and morphological vouchers

Science.gov (United States)

Morphology-based keys support accurate identification of many taxa. However, identification can be difficult for taxa that are not well studied, very small, members of cryptic species complexes, or represented by immature stages. For such cases, DNA barcodes may provide diagnostic characters. Ecolog...

Integrating macro and micro scale approaches in the agent-based modeling of residential dynamics

Science.gov (United States)

Saeedi, Sara

2018-06-01

With the advancement of computational modeling and simulation (M&S) methods as well as data collection technologies, urban dynamics modeling substantially improved over the last several decades. The complex urban dynamics processes are most effectively modeled not at the macro-scale, but following a bottom-up approach, by simulating the decisions of individual entities, or residents. Agent-based modeling (ABM) provides the key to a dynamic M&S framework that is able to integrate socioeconomic with environmental models, and to operate at both micro and macro geographical scales. In this study, a multi-agent system is proposed to simulate residential dynamics by considering spatiotemporal land use changes. In the proposed ABM, macro-scale land use change prediction is modeled by Artificial Neural Network (ANN) and deployed as the agent environment and micro-scale residential dynamics behaviors autonomously implemented by household agents. These two levels of simulation interacted and jointly promoted urbanization process in an urban area of Tehran city in Iran. The model simulates the behavior of individual households in finding ideal locations to dwell. The household agents are divided into three main groups based on their income rank and they are further classified into different categories based on a number of attributes. These attributes determine the households' preferences for finding new dwellings and change with time. The ABM environment is represented by a land-use map in which the properties of the land parcels change dynamically over the simulation time. The outputs of this model are a set of maps showing the pattern of different groups of households in the city. These patterns can be used by city planners to find optimum locations for building new residential units or adding new services to the city. The simulation results show that combining macro- and micro-level simulation can give full play to the potential of the ABM to understand the driving

A DNA barcode library for ground beetles (Insecta, Coleoptera, Carabidae) of Germany: The genus Bembidion Latreille, 1802 and allied taxa.

Science.gov (United States)

Raupach, Michael J; Hannig, Karsten; Morinière, Jérome; Hendrich, Lars

2016-01-01

As molecular identification method, DNA barcoding based on partial cytochrome c oxidase subunit 1 (COI) sequences has been proven to be a useful tool for species determination in many insect taxa including ground beetles. In this study we tested the effectiveness of DNA barcodes to discriminate species of the ground beetle genus Bembidion and some closely related taxa of Germany. DNA barcodes were obtained from 819 individuals and 78 species, including sequences from previous studies as well as more than 300 new generated DNA barcodes. We found a 1:1 correspondence between BIN and traditionally recognized species for 69 species (89%). Low interspecific distances with maximum pairwise K2P values below 2.2% were found for three species pairs, including two species pairs with haplotype sharing (Bembidion atrocaeruleum/Bembidion varicolor and Bembidion guttula/Bembidion mannerheimii). In contrast to this, deep intraspecific sequence divergences with distinct lineages were revealed for two species (Bembidion geniculatum/Ocys harpaloides). Our study emphasizes the use of DNA barcodes for the identification of the analyzed ground beetles species and represents an important step in building-up a comprehensive barcode library for the Carabidae in Germany and Central Europe as well.

Impactos da volatilidade da taxa de câmbio no comércio setorial do Mercosul

Directory of Open Access Journals (Sweden)

Mauricio V. L. Bittencourt

2007-12-01

Full Text Available Este estudo capta o impacto da volatilidade da taxa de câmbio real bilateral no comércio. Estima-se um modelo gravitacional setorial utilizando-se duas medidas de volatilidade da taxa de câmbio. Os resultados mostram que uma redução na volatilidade da taxa de câmbio, o crescimento da renda e a redução das tarifas comerciais contribuem para aumentar o comércio bilateral no Mercosul. Este estudo sugere a inclusão e implementação de políticas comuns, estáveis e integradas entre os países do Mercosul, de modo a reduzir os impactos adversos da volatilidade cambial no comércio dos países envolvidos.This study captures the impact of real bilateral exchange rate volatility on trade. A sectoral gravity model is estimated under two different measures of exchange rate volatility. Results show that a reduction in exchange rate volatility, an increase in the country’s income, and a reduction in trade tariffs can increase bilateral trade in Mercosur. This study suggests the inclusion and implementation of common, stable, and integrated policies among Mercosur countries, aiming to reduce the adverse effects of the exchange rate volatility on bilateral trade among these countries.

Birds and butterflies respond to soil-induced habitat heterogeneity in experimental plantings of tallgrass prairie species managed as agroenergy feedstocks in Iowa, USA

Science.gov (United States)

The positive association between habitat heterogeneity and species diversity has been well-documented for many taxa at various spatial and temporal scales, and the maintenance of habitat heterogeneity in agricultural landscapes has been promoted as a key strategy in efforts to conserve biodiversity....

Centennial-scale vegetation and climate changes in the Middle Atlas, Morocco: new insights from multi-proxy investigations at Lake Sidi Ali

Science.gov (United States)

Fletcher, William; Campbell, Jennifer; Joannin, Sebastien; Mischke, Steffen; Zielhofer, Christoph; de Batist, Marc; Mikdad, Abdes

2016-04-01

The karstic lakes of the Middle Atlas, Morocco, represent a valuable archive of environmental and climatic change for Northwest Africa. Here we present the results of centennial-scale palynological and charcoal analyses as part of a multiproxy palaeolimnological study of sediment cores from Lake Sidi Ali in the Middle Atlas, Morocco (33° 03 N, 05° 00 W; 2,080 m a.s.l.). Supported by absolute dating including 23 more than twenty AMS 14C dates on pollen concentrates, the record covers the entire Holocene and offers insights into vegetation and climate change at a regionally unprecedented centennial-scale. Pollen assemblages are dominated by steppic herbs, evergreen oaks (Quercus), junipers (Cupressaceae) and Atlantic cedar (Cedrus atlantica). A long-term evolution of the montane vegetation is recorded, reflecting progressive changes in the dominant arboreal taxa and leading to the full establishment of the emblematic cedar forests of the area during the mid-Holocene by 6000 cal BP. Orbital-scale changes in seasonality and growing season moisture availability linked to declining summer insolation are implicated, with a transition from (a) warm, dry summers associated with summer drought tolerant taxa especially evergreen Quercus, high algal productivity in the lake, and high background levels of microcharcoal reflecting distant fire activity during the early Holocene, to (b) cool, relatively humid summers with dominance of montane conifers, declining algal productivity in the lake, and episodic local fire activity during the mid- to late Holocene. Superimposed on the long-term environmental changes are recurrent centennial-scale fluctuations in vegetation composition, reflecting competitive dynamics between the major taxa, initially between steppic and arboreal elements, and later between the major tree taxa. Parallels with hydrological proxies including stable O and C isotopes suggest common responses to climatic drivers (fluctuations in moisture sources and

Investigation on the dominant key to achieve superior Ge surface passivation by GeOx based on the ozone oxidation

International Nuclear Information System (INIS)

Wang, Xiaolei; Xiang, Jinjuan; Wang, Wenwu; Xiong, Yuhua; Zhang, Jing; Zhao, Chao

2015-01-01

Highlights: • The dominant key to achieve superior Ge passivation by GeO x is investigated. • The interface state density decreases with increasing the GeO x thickness. • The Ge 3+ oxide component is the dominant key to passivate the Ge surface. • The atomic structure at the GeO x /Ge interface is built by XPS. - Abstract: The dominant key to achieve superior Ge surface passivation by GeO x interfacial layer is investigated based on ozone oxidation. The interface state density (D it ) measured from low temperature conduction method is found to decrease with increasing the GeO x thickness (0.26–1.06 nm). The X-ray photoelectron spectroscopy (XPS) is employed to demonstrate the interfacial structure of GeO x /Ge with different GeO x thicknesses. And the XPS results show that Ge 3+ oxide component is responsible to the decrease of the D it due to the effective passivation of Ge dangling bonds. Therefore, the formation of Ge 3+ component is the dominant key to achieve low D it for Ge gate stacks. Our work confirms that the same physical mechanism determines the Ge surface passivation by the GeO x regardless of the oxidation methods to grow the GeO x interfacial layer. As a result, to explore a growth process that can realize sufficient Ge 3+ component in the GeO x interlayer as thin as possible is important to achieve both equivalent oxide thickness scaling and superior interfacial property simultaneously. This conclusion is helpful to engineer the optimization of the Ge gate stacks.

Comparative Anatomical Investigations on six Endemic Tanacetum (Asteraceae) Taxa from Turkey

International Nuclear Information System (INIS)

Tekin, M.; Kartal, C.

2016-01-01

Tanacetum is one of the large genera, belonging to the Anthemideae tribe of Asteraceae family and has numerous medicinal plants and widely usage in folk medicine. In this study, anatomical features of six endemic species to Turkey viz. Tanacetum albipannosum, T. argenteum subsp. argenteum, T. cappadocicum, T. densum subsp. sivasicum, T. haussknechtii and T. heterotomum, were investigated for the first time. The specimens were collected from their natural habitats in Sivas province (Turkey). Transverse sections of root, stem, petiole and leaflet were observed under light microscope for various anatomical features. The results showed that, root included periderm in the outer. There were parenchymatous cortex, endodermis and pericycle under the periderm respectively. Primary xylem ridges were triarch in T. albipannosum, T. densum subsp. sivasicum, T. haussknechtii and T. heterotomum, pentarch in T. cappadocicum and hexarch in T. argenteum subsp. argenteum, and pith was filled with xylem elements. Stem was made up epidermis, parenchymatous cortex, endodermis, vascular bundles and parenchymatous pith from exterior to interior. T. heterotomum had a cavity formed by the disintegration of the cells in the center. The amphistomatic leaflets had a single layered epidermis with usually silvery or whitish tomentose indumentum and equifacial mesophyll. Stomata are anomocytic. There were significant difference among examined taxa in respect to contour of petiole, structure of cortex parenchyma and organization of vascular bundles. The anatomical characteristic features of petiole proved to be a useful tool for the taxonomic discrimination of the six studied taxa. (author)

A Scenario-Based Protocol Checker for Public-Key Authentication Scheme

Science.gov (United States)

Saito, Takamichi

Security protocol provides communication security for the internet. One of the important features of it is authentication with key exchange. Its correctness is a requirement of the whole of the communication security. In this paper, we introduce three attack models realized as their attack scenarios, and provide an authentication-protocol checker for applying three attack-scenarios based on the models. We also utilize it to check two popular security protocols: Secure SHell (SSH) and Secure Socket Layer/Transport Layer Security (SSL/TLS).

Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

Directory of Open Access Journals (Sweden)

Emma Göthe

2014-09-01

Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm

Science.gov (United States)

Zhang, B.; Sang, Jun; Alam, Mohammad S.

2013-03-01

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm was proposed. Firstly, the original secret image was encrypted into two phase-only masks M1 and M2 via cascaded iterative Fourier transform (CIFT) algorithm. Then, the public-key encryption algorithm RSA was adopted to encrypt M2 into M2' . Finally, a host image was enlarged by extending one pixel into 2×2 pixels and each element in M1 and M2' was multiplied with a superimposition coefficient and added to or subtracted from two different elements in the 2×2 pixels of the enlarged host image. To recover the secret image from the stego-image, the two masks were extracted from the stego-image without the original host image. By applying public-key encryption algorithm, the key distribution was facilitated, and also compared with the image hiding method based on optical interference, the proposed method may reach higher robustness by employing the characteristics of the CIFT algorithm. Computer simulations show that this method has good robustness against image processing.

A model-based framework for incremental scale-up of wastewater treatment processes

DEFF Research Database (Denmark)

Mauricio Iglesias, Miguel; Sin, Gürkan

Scale-up is traditionally done following specific ratios or rules of thumb which do not lead to optimal results. We present a generic framework to assist in scale-up of wastewater treatment processes based on multiscale modelling, multiobjective optimisation and a validation of the model at the new...... large scale. The framework is illustrated by the scale-up of a complete autotropic nitrogen removal process. The model based multiobjective scaleup offers a promising improvement compared to the rule of thumbs based emprical scale up rules...

Development of an Agent-Based Model (ABM) to Simulate the Immune System and Integration of a Regression Method to Estimate the Key ABM Parameters by Fitting the Experimental Data

Science.gov (United States)

Tong, Xuming; Chen, Jinghang; Miao, Hongyu; Li, Tingting; Zhang, Le

2015-01-01

Agent-based models (ABM) and differential equations (DE) are two commonly used methods for immune system simulation. However, it is difficult for ABM to estimate key parameters of the model by incorporating experimental data, whereas the differential equation model is incapable of describing the complicated immune system in detail. To overcome these problems, we developed an integrated ABM regression model (IABMR). It can combine the advantages of ABM and DE by employing ABM to mimic the multi-scale immune system with various phenotypes and types of cells as well as using the input and output of ABM to build up the Loess regression for key parameter estimation. Next, we employed the greedy algorithm to estimate the key parameters of the ABM with respect to the same experimental data set and used ABM to describe a 3D immune system similar to previous studies that employed the DE model. These results indicate that IABMR not only has the potential to simulate the immune system at various scales, phenotypes and cell types, but can also accurately infer the key parameters like DE model. Therefore, this study innovatively developed a complex system development mechanism that could simulate the complicated immune system in detail like ABM and validate the reliability and efficiency of model like DE by fitting the experimental data. PMID:26535589

Public key infrastructure for DOE security research

Energy Technology Data Exchange (ETDEWEB)

Aiken, R.; Foster, I.; Johnston, W.E. [and others

1997-06-01

This document summarizes the Department of Energy`s Second Joint Energy Research/Defence Programs Security Research Workshop. The workshop, built on the results of the first Joint Workshop which reviewed security requirements represented in a range of mission-critical ER and DP applications, discussed commonalties and differences in ER/DP requirements and approaches, and identified an integrated common set of security research priorities. One significant conclusion of the first workshop was that progress in a broad spectrum of DOE-relevant security problems and applications could best be addressed through public-key cryptography based systems, and therefore depended upon the existence of a robust, broadly deployed public-key infrastructure. Hence, public-key infrastructure ({open_quotes}PKI{close_quotes}) was adopted as a primary focus for the second workshop. The Second Joint Workshop covered a range of DOE security research and deployment efforts, as well as summaries of the state of the art in various areas relating to public-key technologies. Key findings were that a broad range of DOE applications can benefit from security architectures and technologies built on a robust, flexible, widely deployed public-key infrastructure; that there exists a collection of specific requirements for missing or undeveloped PKI functionality, together with a preliminary assessment of how these requirements can be met; that, while commercial developments can be expected to provide many relevant security technologies, there are important capabilities that commercial developments will not address, due to the unique scale, performance, diversity, distributed nature, and sensitivity of DOE applications; that DOE should encourage and support research activities intended to increase understanding of security technology requirements, and to develop critical components not forthcoming from other sources in a timely manner.

Reconsiderando o efeito Fisher: uma análise de cointegração entre taxa de juros e inflação

Directory of Open Access Journals (Sweden)

Francisco G. Carneiro

2009-05-01

Full Text Available O paper analisa a validade do efeito Fisher nas economias da Argentina, do Brasil e do México no período 1980-1997. Através da análise de cointegração, apresenta-se evidência a favor de uma relação de equilíbrio estável no longo prazo entre taxa de juros e inflação, apenas para os casos da Argentina e do Brasil. Os resultados sugerem, portanto, que, para estes países, a taxa de juros é a variável que se move para se ajustar a choques na taxa de inflação.

Upgrading Wood-Based Industries: Harnessing the Social Network of Small-Scale Furniture Producers and Their Institutions

Directory of Open Access Journals (Sweden)

Melati ,

2011-05-01

Full Text Available Furniture is a major export commodity in Indonesia with a total value of USD 1.96 million in 2007.  Jepara District is one of the key location for wood furniture production with 15,271 furniture related business units employing 176,469 workers.  However, inefficiencies and power imbalances throughout the furniture value chain have resulted in overharvesting and uneven distribution of gains among the industry’s actors.  In contrast to price-setting international furniture retailers, small-scale producers enjoy the least value from their products.  In order to increase added value and competitiveness, small-scale furniture producers have made efforts to upgrade by harnessing their social network and institutions.  This paper describes small-scale furniture producers’ efforts to upgrade by utilising their social network and institutions in Jepara.  Data was collected through in-depth interviews with members of the small-scale furniture producers’ association.  The research provides insight into the nature of social networks and information flow and develops future scenarios to upgrade.  The scenarios will not only benefit the furniture industry in Jepara, but may also be adopted for similar industries throughout Indonesia and the world, and potentially improve many people’s economies and livelihoods.Keywords: wood-based industry, furniture, small-scale, social network, institution

Scaling Irrational Beliefs in the General Attitude and Belief Scale

Directory of Open Access Journals (Sweden)

Lindsay R. Owings

2013-04-01

Full Text Available Accurate measurement of key constructs is essential to the continued development of Rational-Emotive Behavior Therapy (REBT. The General Attitude and Belief Scale (GABS, a contemporary inventory of rational and irrational beliefs based on current REBT theory, is one of the most valid and widely used instruments available, and recent research has continued to improve its psychometric standing. In this study of 544 students, item response theory (IRT methods were used (a to identify the most informative item in each irrational subscale of the GABS, (b to determine the level of irrationality represented by each of those items, and (c to suggest a condensed form of the GABS for further study with clinical populations. Administering only the most psychometrically informative items to clients could result in economies of time and effort. Further research based on the scaling of items could clarify the specific patterns of irrational beliefs associated with particular clinical syndromes.

A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods.

Science.gov (United States)

Campione, Nicolás E; Evans, David C

2012-07-10

Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a

A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods

Directory of Open Access Journals (Sweden)

Campione Nicolás E

2012-07-01

Full Text Available Abstract Background Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Results Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. Conclusions The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in

Cross correlations of quantum key distribution based on single-photon sources

International Nuclear Information System (INIS)

Dong Shuangli; Wang Xiaobo; Zhang Guofeng; Sun Jianhu; Zhang Fang; Xiao Liantuan; Jia Suotang

2009-01-01

We theoretically analyze the second-order correlation function in a quantum key distribution system with real single-photon sources. Based on single-event photon statistics, the influence of the modification caused by an eavesdropper's intervention and the effects of background signals on the cross correlations between authorized partners are presented. On this basis, we have shown a secure range of correlation against the intercept-resend attacks.

[Ants’ higher taxa as surrogates of species richness in a chronosequence of fallows, old-grown forests and agroforestry systems in the Eastern Amazon, Brazil].

Science.gov (United States)

Muñoz Gutiérrez, Jhonatan Andrés; Roussea, Guillaume Xavier; Andrade-Silva, Joudellys; Delabie, Jacques Hubert Charles

2017-03-01

Deforestation in Amazon forests is one of the main causes for biodiversity loss worldwide. Ants are key into the ecosystem because act like engineers; hence, the loss of ants’ biodiversity may be a guide to measure the loss of essential functions into the ecosystems. The aim of this study was to evaluate soil ant’s richness and to estimate whether higher taxa levels (Subfamily and Genus) can be used as surrogates of species richness in different vegetation types (fallows, old-growth forests and agroforestry systems) in Eastern Amazon. The samples were taken in 65 areas in the Maranhão and Pará States in the period 2011-2014. The sampling scheme followed the procedure of Tropical Soil Biology and Fertility (TSBF). Initially, the vegetation types were characterized according to their age and estimated species richness. Linear and exponential functions were applied to evaluate if higher taxa can be used as surrogates and correlated with the Pearson coefficient. In total, 180 species distributed in 60 genera were identified. The results showed that ant species richness was higher in intermediate fallows (88) and old secondary forest (76), and was lower in agroforestry systems (38) and mature riparian forest (35). The genus level was the best surrogate to estimate the ant’s species richness across the different vegetation types, and explained 72-97 % (P agroforestry systems may contribute in the conservation of Eastern Amazon ant community.

Supporting biodiversity by prescribed burning in grasslands - A multi-taxa approach.

Science.gov (United States)

Valkó, Orsolya; Deák, Balázs; Magura, Tibor; Török, Péter; Kelemen, András; Tóth, Katalin; Horváth, Roland; Nagy, Dávid D; Debnár, Zsuzsanna; Zsigrai, György; Kapocsi, István; Tóthmérész, Béla

2016-12-01

There are contrasting opinions on the use of prescribed burning management in European grasslands. On the one hand, prescribed burning can be effectively used for the management of open landscapes, controlling dominant species, reducing accumulated litter or decreasing wildfire risk. On the other hand burning can have a detrimental impact on grassland biodiversity by supporting competitor grasses and by threatening several rare and endangered species, especially arthropods. We studied the effects of prescribed burning in alkaline grasslands of high conservation interest. Our aim was to test whether dormant-season prescribed burning can be an alternative conservation measure in these grasslands. We selected six sites in East-Hungary: in three sites, a prescribed fire was applied in November 2011, while three sites remained unburnt. We studied the effects of burning on soil characteristics, plant biomass and on the composition of vegetation and arthropod assemblages (isopods, spiders, ground beetles and rove beetles). Soil pH, organic matter, potassium and phosphorous did not change, but soluble salt content increased significantly in the burnt sites. Prescribed burning had several positive effects from the nature conservation viewpoint. Shannon diversity and the number of flowering shoots were higher, and the cover of the dominant grass Festuca pseudovina was lower in the burnt sites. Graminoid biomass was lower, while total, green and forb biomass were higher in the burnt plots compared to the control. The key finding of our study was that prescribed burning did not decrease the abundance and diversity of arthropod taxa. Species-level analyses showed that out of the most abundant invertebrate species, 10 were not affected, 1 was negatively and 1 was positively affected by burning. Moreover, our results suggest that prescribed burning leaving unburnt patches can be a viable management tool in open landscapes, because it supports plant diversity and does not threaten

Conditionally Rare Taxa Contribute but Do Not Account for Changes in Soil Prokaryotic Community Structure

Directory of Open Access Journals (Sweden)

Rachel Kaminsky

2018-04-01

Full Text Available The rare biosphere is predicted to aid in maintaining functional redundancy as well as contributing to community turnover across many environments. Recent developments have partially confirmed these hypotheses, while also giving new insights into dormancy and activity among rare communities. However, less attention has been paid to the rare biosphere in soils. This study provides insight into the rare biosphere’s contribution to soil microbial diversity through the study of 781 soil samples representing 24 edaphically diverse sites. Results show that Bray–Curtis dissimilarity for time-sensitive conditionally rare taxa (CRT does not correlate with whole community dissimilarity, while dissimilarity for space-sensitive CRT only weakly correlate with whole community dissimilarity. This adds to current understanding of spatiotemporal filtering of rare taxa, showing that CRT do not account for community variance across tested soils, but are under the same selective pressure as the whole community.

Chemical composition and antioxidant activity of essential oil of six pinus taxa native to China.

Science.gov (United States)

Xie, Qing; Liu, Zhihong; Li, Zhouqi

2015-05-21

The essential oils obtained by steam distillation from needles of six China endemic Pinus taxa (P. tabulaeformis, P. tabulaeformis f. shekanensis, P. tabulaeformis var. mukdensis, P. tabulaeformis var. umbraculifera, P. henryi and P. massoniana) were analysed by GC/MS. A total of 72 components were separated and identified by GC/MS from the six taxa. The major constituents of the essential oils were: α-pinene (6.78%-20.55%), bornyl acetale (3.32%-12.71%), β-caryophellene (18.26%-26.31%), α-guaiene (1.23%-8.19%), and germacrene D (1.26%-9.93%). Moreover, the essential oils were evaluated for antioxidant potential by three assays (DPPH, FRAP and ABTS) and tested for their total phenolic content. The results showed that all essential oils exhibited acceptable antioxidant activities and these strongly suggest that these pine needles may serve as a potential source of natural antioxidants for food and medical purposes.

Integrated vehicle-based safety systems light-vehicle field operational test key findings report.

Science.gov (United States)

2011-01-01

"This document presents key findings from the light-vehicle field operational test conducted as part of the Integrated Vehicle-Based Safety Systems program. These findings are the result of analyses performed by the University of Michigan Transportat...

Multi-scale magnetic field intermittence in the plasma sheet

Directory of Open Access Journals (Sweden)

Z. Vörös

2003-09-01

Full Text Available This paper demonstrates that intermittent magnetic field fluctuations in the plasma sheet exhibit transitory, localized, and multi-scale features. We propose a multifractal-based algorithm, which quantifies intermittence on the basis of the statistical distribution of the "strength of burstiness", estimated within a sliding window. Interesting multi-scale phenomena observed by the Cluster spacecraft include large-scale motion of the current sheet and bursty bulk flow associated turbulence, interpreted as a cross-scale coupling (CSC process.Key words. Magnetospheric physics (magnetotail; plasma sheet – Space plasma physics (turbulence

Nonmarket economic user values of the Florida Keys/Key West

Science.gov (United States)

Vernon R. Leeworthy; J. Michael Bowker

1997-01-01

This report provides estimates of the nonmarket economic user values for recreating visitors to the Florida Keys/Key West that participated in natural resource-based activities. Results from estimated travel cost models are presented, including visitor’s responses to prices and estimated per person-trip user values. Annual user values are also calculated and presented...

Previsão dos preços de commodities por meio das taxas de câmbio

Directory of Open Access Journals (Sweden)

Davi Rosolen

2013-12-01

Full Text Available Este trabalho procura modelar e prever o comportamento dos preços de commodities utilizando taxas de câmbio de países exportadores de commodities. A compreensão do comportamento desses preços é importante para um apropriado controle da inflação e planejamento da produção. Os resultados obtidos apontam para uma relação de causalidade entre a taxa de câmbio e os preços de commodities para os países estudados, com exceção da África do Sul e Argentina. Para Austrália, Brasil, Canadá, Chile, Colômbia e Nova Zelândia, a taxa de câmbio se mostra uma informação significativa para previsões de preços de commodities para o período dentro da amostra. No caso da Austrália e do Canadá, a relação também é significativa para o período fora da amostra. Os resultados encontrados confirmam os obtidos por Chen, Rogoff e Rossi (2010, além de estender aquele trabalho aos casos da Argentina, Brasil e Colômbia.

Cambro-ordovician sea-level fluctuations and sequence boundaries: The missing record and the evolution of new taxa

Science.gov (United States)

Lehnert, O.; Miller, J.F.; Leslie, Stephen A.; Repetski, J.E.; Ethington, Raymond L.

2005-01-01

The evolution of early Palaeozoic conodont faunas shows a clear connection to sea-level changes. One way that this connection manifests itself is that thick successions of carbonates are missing beneath major sequence boundaries due to karstification and erosion. From this observation arises the question of how many taxa have been lost from different conodont lineages in these incomplete successions. Although many taxa suffered extinction due to the environmental stresses associated with falling sea-levels, some must have survived in these extreme conditions. The number of taxa missing in the early Palaeozoic tropics always will be unclear, but it will be even more difficult to evaluate the missing record in detrital successions of higher latitudes. A common pattern in the evolution of Cambrian-Ordovician conodont lineages is appearances of new species at sea-level rises and disappearances at sea-level drops. This simple picture can be complicated by intervals that consistently have no representatives of a particular lineage, even after extensive sampling of the most complete sections. Presumably the lineages survived in undocumented refugia. In this paper, we give examples of evolution in Cambrian-Ordovician shallowmarine conodont faunas and highlight problems of undiscovered or truly missing segments of lineages. ?? The Palaeontological Association.

Cytological and genome size data analyzed in a phylogenetic frame: Evolutionary implications concerning Sisyrinchium taxa (Iridaceae: Iridoideae

Directory of Open Access Journals (Sweden)

Paula Burchardt

2018-03-01

Full Text Available Abstract Sisyrinchium is the largest genus of Iridaceae in the Americas and has the greatest amount of cytological data available. This study aimed at investigating how genomes evolved in this genus. Chromosome number, genome size and altitude from species of sect. Viperella were analyzed in a phylogenetic context. Meiotic and pollen analyses were performed to assess reproductive success of natural populations, especially from those polyploid taxa. Character optimizations revealed that the common ancestor of sect. Viperella was probably diploid (2n = 2x =18 with two subsequent polyplodization events. Total DNA content (2C varied considerably across the phylogeny with larger genomes detected mainly in polyploid species. Altitude also varied across the phylogeny, however no significant relationship was found between DNA content changes and altitude in our data set. All taxa presented regular meiosis and pollen viability (> 87%, except for S. sp. nov. aff. alatum (22.70%, suggesting a recent hybrid origin. Chromosome number is mostly constant within this section and polyploidy is the only source of modification. Although 2C varied considerably among the 20 taxa investigated, the diversity observed cannot be attributed only to polyploidy events because large variations of DNA content were also observed among diploids.

An allometric scaling relation based on logistic growth of cities

International Nuclear Information System (INIS)

Chen, Yanguang

2014-01-01

Highlights: • An allometric scaling based on logistic process can be used to model urban growth. • The traditional allometry is based on exponential growth instead of logistic growth. • The exponential allometry represents a local scaling of urban growth. • The logistic allometry represents a global scaling of urban growth. • The exponential allometry is an approximation relation of the logistic allometry. - Abstract: The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed “exponential allometry”, which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the above mentioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed “logistic allometry”. The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The proper range of the allometric scaling exponent value is reconsidered through the logistic process. Then, a medium-sized city of Henan Province, China, is employed as an example to validate the new allometric relation. The logistic allometry is helpful for further understanding the fractal property and self-organized process of urban evolution in the right perspective

Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance following Toxic Shock Loading

KAUST Repository

Saikaly, Pascal

2010-12-14

Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30 min IC50 or the concentration of toxicant that results in a 50% reduction in oxygen utilization rate compared to a referential state represented by a control receiving no toxicant. Biodiversity of dominant bacterial taxa was assessed using polymerase chain reaction-terminal restriction fragment length polymorphism (PCR-T-RFLP) targeting the 16S ribosomal RNA (16S rRNA) gene. Statistical analysis of 30 min IC50 values and PCR-T-RFLP data showed a significant positive correlation (P<0.05) between functional resistance and microbial diversity for each of the three toxicants tested. To our knowledge, this is the first study showing a positive correlation between biodiversity of dominant bacterial taxa in activated sludge and functional resistance. In this system, activated sludge bacterial communities with higher biodiversity are functionally more resistant to disturbance caused by toxic shock loading. © 2010 Springer Science+Business Media, LLC.

Image-based Exploration of Large-Scale Pathline Fields

KAUST Repository

Nagoor, Omniah H.

2014-05-27

While real-time applications are nowadays routinely used in visualizing large nu- merical simulations and volumes, handling these large-scale datasets requires high-end graphics clusters or supercomputers to process and visualize them. However, not all users have access to powerful clusters. Therefore, it is challenging to come up with a visualization approach that provides insight to large-scale datasets on a single com- puter. Explorable images (EI) is one of the methods that allows users to handle large data on a single workstation. Although it is a view-dependent method, it combines both exploration and modification of visual aspects without re-accessing the original huge data. In this thesis, we propose a novel image-based method that applies the concept of EI in visualizing large flow-field pathlines data. The goal of our work is to provide an optimized image-based method, which scales well with the dataset size. Our approach is based on constructing a per-pixel linked list data structure in which each pixel contains a list of pathlines segments. With this view-dependent method it is possible to filter, color-code and explore large-scale flow data in real-time. In addition, optimization techniques such as early-ray termination and deferred shading are applied, which further improves the performance and scalability of our approach.

A Validation of the Group-Based Medical Mistrust Scale in Formerly Incarcerated Black and Latino Men.

Science.gov (United States)

Valera, Pamela; Boyas, Javier F; Bernal, Camila; Chiongbian, Victoria Briones; Chang, Yvonne; Shelton, Rachel C

2016-05-04

While there is a growing body of literature on medical mistrust and its relevance to public health, research on formerly incarcerated Black and Latino men and their perception of mistrust toward medical providers and medical institutions remains scant. Very little is known about whether formerly incarcerated Black and Latino men mistrust medical and clinical providers given their previous experiences with the criminal justice system. It is important to determine whether medical mistrust play a key role in the health and health behaviors of released Black and Latino men. The purpose of this study is to validate and assess the psychometric properties of the Group-Based Medical Mistrust Scale for use among formerly incarcerated Black and Latino men in New York City. The findings of the exploratory and confirmatory factor analyses state that a two-factor structure fit the data best. Two dimensions emerged as important subscales: discrimination and suspicion. The current findings suggest the two-factor Group-Based Medical Mistrust Scale is a valid and reliable assessment tool to discern medical mistrust levels among formerly incarcerated Black and Latino men. © The Author(s) 2016.

Neue Taxa von Lunatipula Edwards aus der mediterranen Subregion der Palaearktis (Diptera, Tipulidae, Tipula Linnaeus)

NARCIS (Netherlands)

Theischinger, Günther

1979-01-01

Eight new species and three new subspecies of Lunatipula Edwards are described and their affinities are discussed. The new taxa are: Tipula (Lunatipula) rocina from Spain, T. (L.) antichasia, T. (L.) hera, T. (L.) klytaimnestra, T. (L.) pythia. T. (L.) caudispina parnonensis, T. (L.) penelope

An assessment of the effectiveness of a large, national-scale invasive alien plant control strategy in South Africa

CSIR Research Space (South Africa)

Van Wilgen, BW

2012-04-01

Full Text Available extent of invasive species control operations, assessments of the effectiveness of biological control, and smaller-scale studies. The 19 most important invasive taxa, mainly trees, in terrestrial biomes were identified. The effectiveness of control...

Phylogenetic distribution of extant richness suggests metamorphosis is a key innovation driving diversification in insects.

Directory of Open Access Journals (Sweden)

James L Rainford

Full Text Available Insects and their six-legged relatives (Hexapoda comprise more than half of all described species and dominate terrestrial and freshwater ecosystems. Understanding the macroevolutionary processes generating this richness requires a historical perspective, but the fossil record of hexapods is patchy and incomplete. Dated molecular phylogenies provide an alternative perspective on divergence times and have been combined with birth-death models to infer patterns of diversification across a range of taxonomic groups. Here we generate a dated phylogeny of hexapod families, based on previously published sequence data and literature derived constraints, in order to identify the broad pattern of macroevolutionary changes responsible for the composition of the extant hexapod fauna. The most prominent increase in diversification identified is associated with the origin of complete metamorphosis, confirming this as a key innovation in promoting insect diversity. Subsequent reductions are recovered for several groups previously identified as having a higher fossil diversity during the Mesozoic. In addition, a number of recently derived taxa are found to have radiated following the development of flowering plant (angiosperm floras during the mid-Cretaceous. These results reveal that the composition of the modern hexapod fauna is a product of a key developmental innovation, combined with multiple and varied evolutionary responses to environmental changes from the mid Cretaceous floral transition onward.

An Enhanced Biometric Based Authentication with Key-Agreement Protocol for Multi-Server Architecture Based on Elliptic Curve Cryptography.

Science.gov (United States)

Reddy, Alavalapati Goutham; Das, Ashok Kumar; Odelu, Vanga; Yoo, Kee-Young

2016-01-01

Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.'s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN) logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.'s protocol and existing similar protocols.

Identifying tier one key suppliers.

Science.gov (United States)

Wicks, Steve

2013-01-01

In today's global marketplace, businesses are becoming increasingly reliant on suppliers for the provision of key processes, activities, products and services in support of their strategic business goals. The result is that now, more than ever, the failure of a key supplier has potential to damage reputation, productivity, compliance and financial performance seriously. Yet despite this, there is no recognised standard or guidance for identifying a tier one key supplier base and, up to now, there has been little or no research on how to do so effectively. This paper outlines the key findings of a BCI-sponsored research project to investigate good practice in identifying tier one key suppliers, and suggests a scalable framework process model and risk matrix tool to help businesses effectively identify their tier one key supplier base.

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

Science.gov (United States)

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

2012-05-01

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

A microeconomic analysis of decentralized small scale biomass based CHP plants—The case of Germany

International Nuclear Information System (INIS)

Wittmann, Nadine; Yildiz, Özgür

2013-01-01

Alternative energy sources, such as biomass CHP plants, have recently gained significantly in importance and action is due both on the large scale corporate level and on the small scale. Hence, making the scope and economic outline of such projects easily intelligible without losing relevant details seems a key factor to further promote the necessary developments. The model setup presented in this paper may therefore serve as a starting point for generating numerical results based on real life cases or scenarios. Its focus lies on the economic analysis of decentralized biomass CHP plants. It presents a new approach to analyzing the economic aspects of biomass CHP plants implementing a formal microeconomic approach. As Germany claims a leading role in the market for renewable energy production, the paper also takes a closer look on the effects of German energy policy with respect to biomass CHP plants. - Highlights: • A formal microeconomic model is used to analyse a decentralized biomass CHP plant. • Model setup is used to generate numerical results based on real life scenarios. • Nested CES production function is a new approach to model economics of biomass CHP. • Analysis presents insight into microeconomics and cost drivers of biomass CHP. • Evaluation of energy policy design with respect to environmental policy goals

Scaling-Up Youth-Led Social Justice Efforts through an Online School-Based Social Network.

Science.gov (United States)

Kornbluh, Mariah; Neal, Jennifer Watling; Ozer, Emily J

2016-06-01

The exploration of social networking sites (SNS) in promoting social change efforts offers great potential within the field of community psychology. Online communities on SNS provide opportunities for bridging across groups, thus fostering the exchange of novel ideas and practices. Currently, there have only been limited efforts to examine SNS within the context of youth-led efforts. To explore the potential of SNS to facilitate the diffusion of social justice efforts between distinct youth groups, we linked three school-based youth-led participatory action research projects involving 54 high school students through a SNS. This study offers an innovative methodological approach and framework, utilizing social network analysis and strategic sampling of key student informants to investigate what individual behaviors and online network features predict student adoption of social change efforts. Findings highlight prospective facilitators and barriers to diffusion processes within a youth-led online network, as well as key constructs that may inform future research. We conclude by providing suggestions for scholars and practitioners interested in examining how SNS can be used to enhance the diffusion of social justice strategies, youth-led engagement efforts, and large-scale civic organizing. © Society for Community Research and Action 2016.

Scale-invariant entropy-based theory for dynamic ordering

International Nuclear Information System (INIS)

Mahulikar, Shripad P.; Kumari, Priti

2014-01-01

Dynamically Ordered self-organized dissipative structure exists in various forms and at different scales. This investigation first introduces the concept of an isolated embedding system, which embeds an open system, e.g., dissipative structure and its mass and/or energy exchange with its surroundings. Thereafter, scale-invariant theoretical analysis is presented using thermodynamic principles for Order creation, existence, and destruction. The sustainability criterion for Order existence based on its structured mass and/or energy interactions with the surroundings is mathematically defined. This criterion forms the basis for the interrelationship of physical parameters during sustained existence of dynamic Order. It is shown that the sufficient condition for dynamic Order existence is approached if its sustainability criterion is met, i.e., its destruction path is blocked. This scale-invariant approach has the potential to unify the physical understanding of universal dynamic ordering based on entropy considerations

A Survey of Public Key Infrastructure-Based Security for Mobile Communication Systems

Directory of Open Access Journals (Sweden)

Mohammed Ramadan

2016-08-01

Full Text Available Mobile communication security techniques are employed to guard the communication between the network entities. Mobile communication cellular systems have become one of the most important communication systems in recent times and are used by millions of people around the world. Since the 1990s, considerable efforts have been taken to improve both the communication and security features of the mobile communications systems. However, these improvements divide the mobile communications field into different generations according to the communication and security techniques such as A3, A5 and A8 algorithms for 2G-GSM cellular system, 3G-authentication and key agreement (AKA, evolved packet system-authentication and key agreement (EPS-AKA, and long term evolution-authentication and key agreement (LTE-AKA algorithms for 3rd generation partnership project (3GPP systems. Furthermore, these generations have many vulnerabilities, and huge security work is involved to solve such problems. Some of them are in the field of the public key cryptography (PKC which requires a high computational cost and more network flexibility to be achieved. As such, the public key infrastructure (PKI is more compatible with the modern generations due to the superior communications features. This paper surveys the latest proposed works on the security of GSM, CDMA, and LTE cellular systems using PKI. Firstly, we present the security issues for each generation of mobile communication systems, then we study and analyze the latest proposed schemes and give some comparisons. Finally, we introduce some new directions for the future scope. This paper classifies the mobile communication security schemes according to the techniques used for each cellular system and covers some of the PKI-based security techniques such as authentication, key agreement, and privacy preserving.

TAXA DE PREDAÇÃO DE NINHOS ARTIFICIAIS EM UMA ÁREA DE MANEJO FLORESTAL SUSTENTÁVEL NA AMAZÔNIA CENTRAL

Directory of Open Access Journals (Sweden)

Roberta Souza de Moura

2017-01-01

Full Text Available A predação de ninhos vem sendo sugerida como uma das causas do declínio de populações de aves, influenciando a estrutura e funcionamento das comunidades.  Apesar de diversos estudos terem avaliado fatores relacionados às variações nas taxas de predação de ninhos, poucos verificaram os efeitos do manejo florestal sustentável sobre estas taxas. O presente trabalho teve como objetivo avaliar a influência do manejo florestal sustentável sobre a taxa de predação de ninhos artificiais em uma floresta de terra firme na Amazônia Central. Para isso foram instalados ninhos artificiais em três áreas entre 11/2014 e 06/2015. Dos 240 ninhos montados 72 foram predados, sendo 29 na área não manejada, 24 na Área de Preservação Permanente e 19 na área manejada. Dos 72 ninhos predados 55,56% foram ninhos de sub-bosque e 44,44% ninhos de solo. A menor taxa de predação na área manejada pode estar relacionada às alterações na estrutura da vegetação e ao consequente afugentamento dos predadores.

Fan-out Estimation in Spin-based Quantum Computer Scale-up.

Science.gov (United States)

Nguyen, Thien; Hill, Charles D; Hollenberg, Lloyd C L; James, Matthew R

2017-10-17

Solid-state spin-based qubits offer good prospects for scaling based on their long coherence times and nexus to large-scale electronic scale-up technologies. However, high-threshold quantum error correction requires a two-dimensional qubit array operating in parallel, posing significant challenges in fabrication and control. While architectures incorporating distributed quantum control meet this challenge head-on, most designs rely on individual control and readout of all qubits with high gate densities. We analysed the fan-out routing overhead of a dedicated control line architecture, basing the analysis on a generalised solid-state spin qubit platform parameterised to encompass Coulomb confined (e.g. donor based spin qubits) or electrostatically confined (e.g. quantum dot based spin qubits) implementations. The spatial scalability under this model is estimated using standard electronic routing methods and present-day fabrication constraints. Based on reasonable assumptions for qubit control and readout we estimate 10 2 -10 5 physical qubits, depending on the quantum interconnect implementation, can be integrated and fanned-out independently. Assuming relatively long control-free interconnects the scalability can be extended. Ultimately, the universal quantum computation may necessitate a much higher number of integrated qubits, indicating that higher dimensional electronics fabrication and/or multiplexed distributed control and readout schemes may be the preferredstrategy for large-scale implementation.

Quantum-key-distribution protocol with pseudorandom bases

Science.gov (United States)

Trushechkin, A. S.; Tregubov, P. A.; Kiktenko, E. O.; Kurochkin, Y. V.; Fedorov, A. K.

2018-01-01

Quantum key distribution (QKD) offers a way for establishing information-theoretical secure communications. An important part of QKD technology is a high-quality random number generator for the quantum-state preparation and for post-processing procedures. In this work, we consider a class of prepare-and-measure QKD protocols, utilizing additional pseudorandomness in the preparation of quantum states. We study one of such protocols and analyze its security against the intercept-resend attack. We demonstrate that, for single-photon sources, the considered protocol gives better secret key rates than the BB84 and the asymmetric BB84 protocols. However, the protocol strongly requires single-photon sources.

Neue Taxa von Lunatipula Edwards aus der mediterranen Subregion der Palaearktis (Diptera, Tipulidae, Tipula Linnaeus)

NARCIS (Netherlands)

Theischinger, Günther

1987-01-01

12 new species and 3 new subspecies of Lunatipula Edwards from Greece and Turkey are described or defined. The new taxa are: T. (L.) montifer tasucuensis, T. (L.) musensis, T. (L.) vermooleni, T. (L.) lyrion, Tipula (Lunatipula) paravelox, T. (L.) soosi izmirensis, T. (L.) brinki, T. (L.)

Chemical Composition and Antioxidant Activity of Essential Oil of Six Pinus Taxa Native to China

Directory of Open Access Journals (Sweden)

Qing Xie

2015-05-01

Full Text Available The essential oils obtained by steam distillation from needles of six China endemic Pinus taxa (P. tabulaeformis, P. tabulaeformis f. shekanensis, P. tabulaeformis var. mukdensis, P. tabulaeformis var. umbraculifera, P. henryi and P. massoniana were analysed by GC/MS. A total of 72 components were separated and identified by GC/MS from the six taxa. The major constituents of the essential oils were: α-pinene (6.78%–20.55%, bornyl acetale (3.32%–12.71%, β-caryophellene (18.26%–26.31%, α-guaiene (1.23%–8.19%, and germacrene D (1.26%–9.93%. Moreover, the essential oils were evaluated for antioxidant potential by three assays (DPPH, FRAP and ABTS and tested for their total phenolic content. The results showed that all essential oils exhibited acceptable antioxidant activities and these strongly suggest that these pine needles may serve as a potential source of natural antioxidants for food and medical purposes.

Integration, Provenance, and Temporal Queries for Large-Scale Knowledge Bases

OpenAIRE

Gao, Shi

2016-01-01

Knowledge bases that summarize web information in RDF triples deliver many benefits, including support for natural language question answering and powerful structured queries that extract encyclopedic knowledge via SPARQL. Large scale knowledge bases grow rapidly in terms of scale and significance, and undergo frequent changes in both schema and content. Two critical problems have thus emerged: (i) how to support temporal queries that explore the history of knowledge bases or flash-back to th...

Secure Trust Based Key Management Routing Framework for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Jugminder Kaur

2016-01-01

Full Text Available Security is always a major concern in wireless sensor networks (WSNs. Several trust based routing protocols are designed that play an important role in enhancing the performance of a wireless network. However they still have some disadvantages like limited energy resources, susceptibility to physical capture, and little protection against various attacks due to insecure wireless communication channels. This paper presents a secure trust based key management (STKF routing framework that establishes a secure trustworthy route depending upon the present and past node to node interactions. This route is then updated by isolating the malicious or compromised nodes from the route, if any, and a dedicated link is created between every pair of nodes in the selected route with the help of “q” composite random key predistribution scheme (RKPS to ensure data delivery from source to destination. The performance of trust aware secure routing framework (TSRF is compared with the proposed routing scheme. The results indicate that STKF provides an effective mechanism for finding out a secure route with better trustworthiness than TSRF which avoids the data dropping, thereby increasing the data delivery ratio. Also the distance required to reach the destination in the proposed protocol is less hence effectively utilizing the resources.

Assessment of global stellarator confinement: Status of the international stellarator confinement scaling data base

International Nuclear Information System (INIS)

Dinklage, A.; Beidler, C.D.; Dose, V.; Geiger, J.; Kus, A.; Preuss, R.; Ascasibar, E.; Tribaldos, V.; Harris, J.H.; Murakami, S.; Sano, F.; Okamura, S.; Suzuki, Y.; Watanabe, K.Y.; Yamada, H.; Yokoyama, M.; Stroth, U.; Talmadge, J.

2005-01-01

Different stellarator/heliotron devices along with their respective flexibility cover a large magnetic configuration space. Since the ultimate goal of stellarator research aims at an alternative fusion reactor concept, the exploration of the most promising configurations requires a comparative assessment of the plasma performance and how different aspects of a 3D configuration influence it. Therefore, the International Stellarator Confinement Database (ISCDB) has been re- initiated in 2004 and the ISS95 database has been extended to roughly 3000 discharges from eight different devices. Further data-sets are continuously added. A revision of a data set restricted to comparable scenarios lead to the ISS04 scaling law which confirmed ISS95 but also revealed clearly the necessity to incorporate configuration descriptive parameters. In other words, an extension beyond the set of regression parameters used for ISS95/ISS04 appears to be necessary and candidates, such as the elongation are investigated. Since grouping of data is a key-issue for deriving ISS04, basic assumptions are revised, e.g. the dependence on the heating scheme. Moreover, an assessment of statistical approaches is investigated with respect to their impact on the scaling. A crucial issue is the weighting of data groups which is discussed in terms of error-in-variable techniques and Bayesian model comparison. The latter is employed for testing scaling ansatzes depending on scaling invariance principles hence allowing the assessment of applicability of theory-based scaling laws on stellarator confinement. 1. ISCDB resources are jointly hosted by NIFS and IPP, see http://iscdb.nifs.ac.jp and http://www.ipp.mpg.de/ISS. (author)

Molecular evolutionary patterns of NAD+/Sirtuin aging signaling pathway across taxa.

Directory of Open Access Journals (Sweden)

Uma Gaur

Full Text Available A deeper understanding of the conserved molecular mechanisms in different taxa have been made possible only because of the evolutionary conservation of crucial signaling pathways. In the present study, we explored the molecular evolutionary pattern of selection signatures in 51 species for 10 genes which are important components of NAD+/Sirtuin pathway and have already been directly linked to lifespan extension in worms and mice. Selection pressure analysis using PAML program revealed that MRPS5 and PPARGC1A were under significant constraints because of their functional significance. FOXO3a also displayed strong purifying selection. All three sirtuins, which were SIRT1, SIRT2 and SIRT6, displayed a great degree of conservation between taxa, which is consistent with the previous report. A significant evolutionary constraint is seen on the anti-oxidant gene, SOD3. As expected, TP53 gene was under significant selection pressure in mammals, owing to its major role in tumor progression. Poly-ADP-ribose polymerase (PARP genes displayed the most sites under positive selection. Further 3D structural analysis of PARP1 and PARP2 protein revealed that some of these positively selected sites caused a change in the electrostatic potential of the protein structure, which may allow a change in its interaction with other proteins and molecules ultimately leading to difference in the function. Although the functional significance of the positively selected sites could not be established in the variants databases, yet it will be interesting to see if these sites actually affect the function of PARP1 and PARP2.

A mixed-methods study of system-level sustainability of evidence-based practices in 12 large-scale implementation initiatives.

Science.gov (United States)

Scudder, Ashley T; Taber-Thomas, Sarah M; Schaffner, Kristen; Pemberton, Joy R; Hunter, Leah; Herschell, Amy D

2017-12-07

In recent decades, evidence-based practices (EBPs) have been broadly promoted in community behavioural health systems in the United States of America, yet reported EBP penetration rates remain low. Determining how to systematically sustain EBPs in complex, multi-level service systems has important implications for public health. This study examined factors impacting the sustainability of parent-child interaction therapy (PCIT) in large-scale initiatives in order to identify potential predictors of sustainment. A mixed-methods approach to data collection was used. Qualitative interviews and quantitative surveys examining sustainability processes and outcomes were completed by participants from 12 large-scale initiatives. Sustainment strategies fell into nine categories, including infrastructure, training, marketing, integration and building partnerships. Strategies involving integration of PCIT into existing practices and quality monitoring predicted sustainment, while financing also emerged as a key factor. The reported factors and strategies impacting sustainability varied across initiatives; however, integration into existing practices, monitoring quality and financing appear central to high levels of sustainability of PCIT in community-based systems. More detailed examination of the progression of specific activities related to these strategies may aide in identifying priorities to include in strategic planning of future large-scale initiatives. ClinicalTrials.gov ID NCT02543359 ; Protocol number PRO12060529.

High-dimensional quantum key distribution based on multicore fiber using silicon photonic integrated circuits

DEFF Research Database (Denmark)

Ding, Yunhong; Bacco, Davide; Dalgaard, Kjeld

2017-01-01

is intrinsically limited to 1 bit/photon. Here we propose and experimentally demonstrate, for the first time, a high-dimensional quantum key distribution protocol based on space division multiplexing in multicore fiber using silicon photonic integrated lightwave circuits. We successfully realized three mutually......-dimensional quantum states, and enables breaking the information efficiency limit of traditional quantum key distribution protocols. In addition, the silicon photonic circuits used in our work integrate variable optical attenuators, highly efficient multicore fiber couplers, and Mach-Zehnder interferometers, enabling...

Small-scale genetic structure in an endangered wetland specialist: possible effects of landscape change and population recovery

Science.gov (United States)

van Rees, Charles B.; Reed, J. Michael; Wilson, Robert E.; Underwood, Jared G.; Sonsthagen, Sarah A.

2018-01-01

The effects of anthropogenic landscape change on genetic population structure are well studied, but the temporal and spatial scales at which genetic structure can develop, especially in taxa with high dispersal capabilities like birds, are less well understood. We investigated population structure in the Hawaiian gallinule (Gallinula galeata sandvicensis), an endangered wetland specialist bird on the island of O`ahu (Hawai`i, USA). Hawaiian gallinules have experienced a gradual population recovery from near extinction in the 1950s, and have recolonized wetlands on O`ahu in the context of a rapidly urbanizing landscape. We genotyped 152 Hawaiian gallinules at 12 microsatellite loci and sequenced a 520 base-pair fragment of the ND2 region of mitochondrial DNA (mtDNA) from individuals captured at 13 wetland locations on O`ahu in 2014–2016. We observed moderate to high genetic structuring (overall microsatellite FST = 0.098, mtDNA FST = 0.248) among populations of Hawaiian gallinules occupying wetlands at very close geographic proximity (e.g., 1.5–55 km). Asymmetry in gene flow estimates suggests that Hawaiian gallinules may have persisted in 2–3 strongholds which served as source populations that recolonized more recently restored habitats currently supporting large numbers of birds. Our results highlight that genetic structure can develop in taxa that are expanding their range after severe population decline, and that biologically significant structuring can occur over small geographic distances, even in avian taxa.

The ScaLIng Macroweather Model (SLIMM): using scaling to forecast global-scale macroweather from months to decades

Science.gov (United States)

Lovejoy, S.; del Rio Amador, L.; Hébert, R.

2015-09-01

On scales of ≈ 10 days (the lifetime of planetary-scale structures), there is a drastic transition from high-frequency weather to low-frequency macroweather. This scale is close to the predictability limits of deterministic atmospheric models; thus, in GCM (general circulation model) macroweather forecasts, the weather is a high-frequency noise. However, neither the GCM noise nor the GCM climate is fully realistic. In this paper we show how simple stochastic models can be developed that use empirical data to force the statistics and climate to be realistic so that even a two-parameter model can perform as well as GCMs for annual global temperature forecasts. The key is to exploit the scaling of the dynamics and the large stochastic memories that we quantify. Since macroweather temporal (but not spatial) intermittency is low, we propose using the simplest model based on fractional Gaussian noise (fGn): the ScaLIng Macroweather Model (SLIMM). SLIMM is based on a stochastic ordinary differential equation, differing from usual linear stochastic models (such as the linear inverse modelling - LIM) in that it is of fractional rather than integer order. Whereas LIM implicitly assumes that there is no low-frequency memory, SLIMM has a huge memory that can be exploited. Although the basic mathematical forecast problem for fGn has been solved, we approach the problem in an original manner, notably using the method of innovations to obtain simpler results on forecast skill and on the size of the effective system memory. A key to successful stochastic forecasts of natural macroweather variability is to first remove the low-frequency anthropogenic component. A previous attempt to use fGn for forecasts had disappointing results because this was not done. We validate our theory using hindcasts of global and Northern Hemisphere temperatures at monthly and annual resolutions. Several nondimensional measures of forecast skill - with no adjustable parameters - show excellent

The effect of Web-based Braden Scale training on the reliability and precision of Braden Scale pressure ulcer risk assessments.

Science.gov (United States)

Magnan, Morris A; Maklebust, Joann

2008-01-01

To evaluate the effect of Web-based Braden Scale training on the reliability and precision of pressure ulcer risk assessments made by registered nurses (RN) working in acute care settings. Pretest-posttest, 2-group, quasi-experimental design. Five hundred Braden Scale risk assessments were made on 102 acute care patients deemed to be at various levels of risk for pressure ulceration. Assessments were made by RNs working in acute care hospitals at 3 different medical centers where the Braden Scale was in regular daily use (2 medical centers) or new to the setting (1 medical center). The Braden Scale for Predicting Pressure Sore Risk was used to guide pressure ulcer risk assessments. A Web-based version of the Detroit Medical Center Braden Scale Computerized Training Module was used to teach nurses correct use of the Braden Scale and selection of risk-based pressure ulcer prevention interventions. In the aggregate, RN generated reliable Braden Scale pressure ulcer risk assessments 65% of the time after training. The effect of Web-based Braden Scale training on reliability and precision of assessments varied according to familiarity with the scale. With training, new users of the scale made reliable assessments 84% of the time and significantly improved precision of their assessments. The reliability and precision of Braden Scale risk assessments made by its regular users was unaffected by training. Technology-assisted Braden Scale training improved both reliability and precision of risk assessments made by new users of the scale, but had virtually no effect on the reliability or precision of risk assessments made by regular users of the instrument. Further research is needed to determine best approaches for improving reliability and precision of Braden Scale assessments made by its regular users.

Preliminary assessment of biogeographic affinities of selected insect taxa of the state of Sonora, Mexico

Science.gov (United States)

Robert W. Jones; Alejandro Obregon-Zuniga; Sandra Guzman-Rodriguez

2013-01-01

The biogeographic affinites of butterflies (Lepidoptera: Papilionoidea and Hesperidae), damsel and dragonflies (Odonata), and ants (Hymenoptera: Formicidae) reported from the State of Sonora, Mexico were analyzed using published species lists. The combined distribution of these taxa was proportionally greater (47.4%) for those species within the Mega-Mexico3...

Key issues regarding digital libraries evaluation and integration

CERN Document Server

Shen, Rao; Fox, Edward A

2013-01-01

This is the second book based on the 5S (Societies, Scenarios, Spaces, Structures, Streams) approach to digital libraries (DLs). Leveraging the first volume, on Theoretical Foundations, we focus on the key issues of evaluation and integration. These cross-cutting issues serve as a bridge for those interested in DLs, connecting the introduction and formal discussion in the first book, with the coverage of key technologies in the third book, and of illustrative applications in the fourth book. These two topics have central importance in the DL field, allowing it to be treated scientifically as well as practically. In the scholarly world, we only really understand something if we know how to measure and evaluate it. In the Internet era of distributed information systems, we only can be practical at scale if we integrate across both systems and their associated content. Evaluation of DLs must take place atmultiple levels,so we can address the different entities and their associated measures. Thus, for digital obj...

River Discharge and Local Scale Habitat Influence LIFE Score Macroinvertebrate LIFE Scores

DEFF Research Database (Denmark)

Dunbar, Michael J.; Pedersen, Morten Lauge; Cadman, Dan

2010-01-01

Midlands of the U.K., we describe how local-scale habitat features (indexed through River Habitat Survey or Danish Habitat Quality Survey) and changing river flow (discharge) influence the response of a macroinvertebrate community index. The approach has broad applicability in developing regional flow...... Invertebrate index for Flow Evaluation (LIFE), an average of abundance-weighted flow groups which indicate the microhabitat preferences of each taxon for higher velocities and clean gravel/cobble substrata or slow/still velocities and finer substrata. 3. For the Danish fauna, the LIFE score responded to three...... of the channel (negative). In both cases, LIFE responded negatively to features associated with historical channel modification. We suggest that there are several mechanisms for these relationships, including the narrower tolerances of taxa preferring high velocity habitat; these taxa are also continually...

Nesting, Subsidiarity, and Community-based environmental Governance beyond the Local Scale

Directory of Open Access Journals (Sweden)

Graham Marshall

2007-11-01

Full Text Available Community-based approaches to environmental management have become widely adopted over the last two decades. From their origins in grassroots frustrations with governmental inabilities to solve local environmental problems, these approaches are now sponsored frequently by governments as a way of dealing with such problems at much higher spatial levels. However, this 'up-scaling' of community-based approaches has run well ahead of knowledge about how they might work. This article explores how Elinor Ostrom's 'nesting principle' for robust common property governance of large-scale common-pool resources might inform future up-scaling efforts. In particular, I consider how the design of nested governance systems for large-scale environmental problems might be guided by the principle of subsidiarity. The challenges of applying this principle are illustrated by Australia's experience in up-scaling community-based natural resource management from local groups comprising 20-30 members to regional bodies representing hundreds of thousands of people. Seven lessons are distilled for fostering community-based environmental governance as a multi-level system of nested enterprises.

Betweenness-based algorithm for a partition scale-free graph

International Nuclear Information System (INIS)

Zhang Bai-Da; Wu Jun-Jie; Zhou Jing; Tang Yu-Hua

2011-01-01

Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom—up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top—down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches. (interdisciplinary physics and related areas of science and technology)

Quantifying multi-dimensional attributes of human activities at various geographic scales based on smartphone tracking.

Science.gov (United States)

Zhou, Xiaolu; Li, Dongying

2018-05-09

Advancement in location-aware technologies, and information and communication technology in the past decades has furthered our knowledge of the interaction between human activities and the built environment. An increasing number of studies have collected data regarding individual activities to better understand how the environment shapes human behavior. Despite this growing interest, some challenges exist in collecting and processing individual's activity data, e.g., capturing people's precise environmental contexts and analyzing data at multiple spatial scales. In this study, we propose and implement an innovative system that integrates smartphone-based step tracking with an app and the sequential tile scan techniques to collect and process activity data. We apply the OpenStreetMap tile system to aggregate positioning points at various scales. We also propose duration, step and probability surfaces to quantify the multi-dimensional attributes of activities. Results show that, by running the app in the background, smartphones can measure multi-dimensional attributes of human activities, including space, duration, step, and location uncertainty at various spatial scales. By coordinating Global Positioning System (GPS) sensor with accelerometer sensor, this app can save battery which otherwise would be drained by GPS sensor quickly. Based on a test dataset, we were able to detect the recreational center and sports center as the space where the user was most active, among other places visited. The methods provide techniques to address key issues in analyzing human activity data. The system can support future studies on behavioral and health consequences related to individual's environmental exposure.

The INES scale

International Nuclear Information System (INIS)

2014-01-01

This document presents the International Nuclear Event Scale (INES) which has been created to classify nuclear and radiological events in terms of severity. This scale comprises eight levels from 0 to 7, from a slight but noticeable shift with respect to nominal operation to a major accident. Criteria used for incident and accident classification are indicated; they are based on consequences outside the site, consequences within the site, degradation of in-depth defence. The benefit and weaknesses of this scale are briefly indicated. The major concerned actors are the IAEA, the NEA and the ASN. Some key figures are given (number of declared events and incidents), and a ranking of the main nuclear events is proposed with a brief description of the event: Chernobyl, Fukushima, Kyshtym, Three Mile Island, Sellafield, Tokaimura, Saint-Laurent-des-Eaux. Countries which have adopted INES are indicated, as well as the number of incidents reports in France to the ASN

Taxonomic significance of leaf micromorphology in some selected taxa of Acanthaceae (Peninsular Malaysia)

Science.gov (United States)

Nurul-Aini, C. A. C.; Noraini, T.; Latiff, A.; Amirul-Aiman, A. J.; Ruzi, A. R.; Idris, S.

2014-09-01

Comparative leaf micromorphology study was conducted in eight taxa of Acanthaceae from Peninsular Malaysia. Eight chosen taxa were Acanthus ebracteatus Vahl, A. ilicifolius L., A. volubilis Wall, A. montanus T. Anderson, Andrographis paniculata (Burm.f.) Wall. ex Nees, Asystasia gangetica subsp. micrantha (Nees) Ensermu, Chroesthes longifolia (Wight) B. Hansen and Peristrophe roxburghiana (Schult.) Bremek. The objective of this study was to identify the leaf micromorphological characteristics that can be used in species identification and also as supportive data in classification. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Findings in this study have demonstrated the similarities and variations in leaf micromorphological characteristics such as in type of epicuticular waxes, cuticular ornamentations, stomata characteristics and in the presence of trichomes. Six types of epicuticular waxes and five types of trichomes were observed. Variations in cuticular ornamentations and stomata structure can be used to differentiate species. One diagnostic character was found and proven to be very useful to identify Acanthus via the presence of simple trichomes (short-conicle like). In conclusion, the results of this study have shown that leaf micromorphological characteristics have taxonomic significance that can be useful in classifications and identification especially at species level.

Antimicrobial and antioxidative activity of various leaf extracts of Amphoricarpos vis. (Asteraceae taxa

Directory of Open Access Journals (Sweden)

Gavrilović Milan

2016-01-01

Full Text Available The antimicrobial and antioxidative activities of diethyl ether, 80% methanol and 50% acetone extracts of the leaves of three Amphoricarpos taxa (Asteraceae; A. neumayerianus, A. autariatus ssp. autariatus and A. autariatus ssp. bertisceus from the Balkan Peninsula were investigated. The antimicrobial activity was determined by the broth microdilution assay against eight bacterial and eight fungal species. The in vitro antioxidative activity was assessed by the DPPH assay. The total phenolic and flavonoid contents were also determined. The most sensitive bacterial species were Bacillus cereus and Staphylococcus aureus. The best antibacterial potential was obtained for the methanol extract of A. neumayerianus, while the diethyl ether extract of this species showed the lowest effect. In general, the tested extracts showed higher activity than the commercial antibiotics streptomycin and ampicillin. Also, all micromycetes were sensitive to the tested extracts. The most sensitive was Trichoderma viride. The highest and lowest antifungal effect was determined in A. a. ssp. autariatus for the diethyl ether and acetone extracts, respectively. The highest total phenolic and flavonoid contents were determined in the methanol extract of A. a. autariatus. The best antioxidative activity was demonstrated by the methanol extract of A. a. ssp. autariatus as comparing to matching extracts from the other two taxa.

Hydrocarbon degraders establish at the costs of microbial richness, abundance and keystone taxa after crude oil contamination in permafrost environments

Science.gov (United States)

Yang, Sizhong; Wen, Xi; Shi, Yulan; Liebner, Susanne; Jin, Huijun; Perfumo, Amedea

2016-01-01

Oil spills from pipeline ruptures are a major source of terrestrial petroleum pollution in cold regions. However, our knowledge of the bacterial response to crude oil contamination in cold regions remains to be further expanded, especially in terms of community shifts and potential development of hydrocarbon degraders. In this study we investigated changes of microbial diversity, population size and keystone taxa in permafrost soils at four different sites along the China-Russia crude oil pipeline prior to and after perturbation with crude oil. We found that crude oil caused a decrease of cell numbers together with a reduction of the species richness and shifts in the dominant phylotypes, while bacterial community diversity was highly site-specific after exposure to crude oil, reflecting different environmental conditions. Keystone taxa that strongly co-occurred were found to form networks based on trophic interactions, that is co-metabolism regarding degradation of hydrocarbons (in contaminated samples) or syntrophic carbon cycling (in uncontaminated samples). With this study we demonstrate that after severe crude oil contamination a rapid establishment of endemic hydrocarbon degrading communities takes place under favorable temperature conditions. Therefore, both endemism and trophic correlations of bacterial degraders need to be considered in order to develop effective cleanup strategies. PMID:27886221

Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa

Directory of Open Access Journals (Sweden)

Anna M. Calvert

2009-12-01

Full Text Available For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring throughout the migratory life cycle can critically alter the demography of many migrant species. Herein, we build upon recent syntheses of avian migration research to review the role of non-breeding seasons in determining the population dynamics and fitness of diverse migratory taxa, including salmonid fishes, marine mammals, ungulates, sea turtles, butterflies, and numerous bird groups. We discuss several similarities across these varied migrants: (i non-breeding survivorship tends to be a strong driver of population growth; (ii non-breeding events can affect fitness in subsequent seasons through seasonal interactions at individual- and population-levels; (iii broad-scale climatic influences often alter non-breeding resources and migration timing, and may amplify population impacts through covariation among seasonal vital rates; and (iv changes to both stationary and migratory non-breeding habitats can have important consequences for abundance and population trends. Finally, we draw on these patterns to recommend that future conservation research for seasonal migrants will benefit from: (1 more explicit recognition of the important parallels among taxonomically diverse migratory animals; (2 an expanded research perspective focused on quantification of all seasonal vital rates and their interactions; and (3 the development of detailed population projection models that account for complexity and uncertainty in migrant population dynamics.

Metagenomics, paratransgenesis and the Anopheles microbiome: a portrait of the geographical distribution of the anopheline microbiota based on a meta-analysis of reported taxa.

Science.gov (United States)

Villegas, Luis Martínez; Pimenta, Paulo Filemon Paolucci

2014-08-01

Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current "omics" era and the available data are mostly scattered or in "tables" that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.

AGREGADOS TUBULARES DE RETÍCULO ENDOPLASMÁTICO LISO EM OVÓCITOS HUMANOS E SUA INFLUÊNCIA NAS TAXAS DE FERTILIZAÇÃO E GRAVIDEZ

OpenAIRE

Luis, A.; Sá, R.; Oliveira, E.; Oliveira, C.; Silva, J.; Barros, A.; Sousa, M.

2010-01-01

O impacto da presença de anomalias morfológicas ovocitárias na fertilização e taxas de gravidez é um tema controverso na literatura. A presença de agregados tubulares de retículo endoplasmático liso (AT-REL) foi associada a taxas de gravidez mais baixas e a maior incidência de complicações obstétricas. A estrutura ultramiscroscópica destes AT-REL não está descrita. Este trabalho teve como objectivos: a) determinar a influência da presença de AT-REL nas taxas de fertilização e gravidez; ...

Application and comparison of the SCS-CN-based rainfall-runoff model in meso-scale watershed and field scale

Science.gov (United States)

Luo, L.; Wang, Z.

2010-12-01

Soil Conservation Service Curve Number (SCS-CN) based hydrologic model, has widely been used for agricultural watersheds in recent years. However, there will be relative error when applying it due to differentiation of geographical and climatological conditions. This paper introduces a more adaptable and propagable model based on the modified SCS-CN method, which specializes into two different scale cases of research regions. Combining the typical conditions of the Zhanghe irrigation district in southern part of China, such as hydrometeorologic conditions and surface conditions, SCS-CN based models were established. The Xinbu-Qiao River basin (area =1207 km2) and the Tuanlin runoff test area (area =2.87 km2)were taken as the study areas of basin scale and field scale in Zhanghe irrigation district. Applications were extended from ordinary meso-scale watershed to field scale in Zhanghe paddy field-dominated irrigated . Based on actual measurement data of land use, soil classification, hydrology and meteorology, quantitative evaluation and modifications for two coefficients, i.e. preceding loss and runoff curve, were proposed with corresponding models, table of CN values for different landuse and AMC(antecedent moisture condition) grading standard fitting for research cases were proposed. The simulation precision was increased by putting forward a 12h unit hydrograph of the field area, and 12h unit hydrograph were simplified. Comparison between different scales show that it’s more effectively to use SCS-CN model on field scale after parameters calibrated in basin scale These results can help discovering the rainfall-runoff rule in the district. Differences of established SCS-CN model's parameters between the two study regions are also considered. Varied forms of landuse and impacts of human activities were the important factors which can impact the rainfall-runoff relations in Zhanghe irrigation district.

New species of Ancistrocerus (Vespidae, Eumeninae) from the Neotropics with a checklist and key to all species south of the Rio Grande

Science.gov (United States)

Piekarski, Patrick K.; Carpenter, James M.; Sharanowski, Barbara J.

2017-01-01

Abstract A new species of potter wasp from South America, Ancistrocerus sur sp. n., is described. A species key and checklist for all described Ancistrocerus that occur south of the Rio Grande are provided. New synonymy includes Odynerus bolivianus Brèthes = Ancistrocerus pilosus (de Saussure), while the subspecies bustamente discopictus Bequaert, lineativentris kamloopsensis Bequaert, lineativentris sinopis Bohart, tuberculocephalussutterianus (de Saussure), and pilosus ecuadorianus Bertoni, are all sunk under their respective nominotypical taxa. PMID:29290718

The reward-based eating drive scale: a self-report index of reward-based eating.

Directory of Open Access Journals (Sweden)

Elissa S Epel

Full Text Available Why are some individuals more vulnerable to persistent weight gain and obesity than are others? Some obese individuals report factors that drive overeating, including lack of control, lack of satiation, and preoccupation with food, which may stem from reward-related neural circuitry. These are normative and common symptoms and not the sole focus of any existing measures. Many eating scales capture these common behaviors, but are confounded with aspects of dysregulated eating such as binge eating or emotional overeating. Across five studies, we developed items that capture this reward-based eating drive (RED. Study 1 developed the items in lean to obese individuals (n = 327 and examined changes in weight over eight years. In Study 2, the scale was further developed and expert raters evaluated the set of items. Study 3 tested psychometric properties of the final 9 items in 400 participants. Study 4 examined psychometric properties and race invariance (n = 80 women. Study 5 examined psychometric properties and age/gender invariance (n = 381. Results showed that RED scores correlated with BMI and predicted earlier onset of obesity, greater weight fluctuations, and greater overall weight gain over eight years. Expert ratings of RED scale items indicated that the items reflected characteristics of reward-based eating. The RED scale evidenced high internal consistency and invariance across demographic factors. The RED scale, designed to tap vulnerability to reward-based eating behavior, appears to be a useful brief tool for identifying those at higher risk of weight gain over time. Given the heterogeneity of obesity, unique brief profiling of the reward-based aspect of obesity using a self-report instrument such as the RED scale may be critical for customizing effective treatments in the general population.

Consumer Perception of Retail Pork Bacon Attributes Using Adaptive Choice-based Conjoint Analysis and Maximum Differential Scaling.

Science.gov (United States)

McLean, K G; Hanson, D J; Jervis, S M; Drake, M A

2017-11-01

Bacon is one of the most recognizable consumer pork products and is differentiated by appearance, flavor, thickness, and several possible product claims. The objective of this study was to explore the attributes of retail bacon that influence consumers to purchase and consume bacon. An Adaptive Choice-Based Conjoint (ACBC) survey was designed for attributes of raw American-style bacon. An ACBC survey (N = 1410 consumers) and Kano questioning were applied to determine the key attributes that influenced consumer purchase. Attributes included package size, brand, thickness, label claims, flavor, price, and images of the bacon package displaying fat:lean ratio. Maximum Difference Scaling (MaxDiff) was used to rank appeal of 20 different bacon images with variable fat:lean ration and slice shape. The most important attribute for bacon purchase was price followed by fat:lean appearance and then flavor. Three consumer clusters were identified with distinct preferences. For 2 clusters, price was not the primary attribute. Understanding preferences of distinct consumer clusters will enable manufacturers to target consumers and make more appealing bacon. Adaptive Choice-Based Conjoint (ACBC) is a research technique that allows consumers to react to assembled products and identify product attributes that they prefer. Kano questions allow researchers to look at the individual aspects of a product and understand consumer sentiment and expectations towards those product qualities while Maximum Difference scaling allows consumers to directly rank single attributes of a product relative to one another. A combination of these 3 approaches can provide key understandings on consumer perception of retail bacon allowing companies to optimize and maximize their development and advertising resources. © 2017 Institute of Food Technologists®.

An Enhanced Biometric Based Authentication with Key-Agreement Protocol for Multi-Server Architecture Based on Elliptic Curve Cryptography

Science.gov (United States)

Reddy, Alavalapati Goutham; Das, Ashok Kumar; Odelu, Vanga; Yoo, Kee-Young

2016-01-01

Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.’s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN) logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.’s protocol and existing similar protocols. PMID:27163786

An Enhanced Biometric Based Authentication with Key-Agreement Protocol for Multi-Server Architecture Based on Elliptic Curve Cryptography.

Directory of Open Access Journals (Sweden)

Alavalapati Goutham Reddy

Full Text Available Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.'s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.'s protocol and existing similar protocols.

KALwEN+: Practical Key Management Schemes for Gossip-Based Wireless Medical Sensor Networks

NARCIS (Netherlands)

Gong, Zheng; Tang, Qiang; Law, Y.W.; Chen, Hongyang; Lai, X.; Yung, M.

2010-01-01

The constrained resources of sensors restrict the design of a key management scheme for wireless sensor networks (WSNs). In this work, we first formalize the security model of ALwEN, which is a gossip-based wireless medical sensor network (WMSN) for ambient assisted living. Our security model

Multi-scale Exploration of the Technical, Economic, and Environmental Dimensions of Bio-based Chemical Production

DEFF Research Database (Denmark)

Zhuang, Kai; Herrgard, Markus

2014-01-01

of a variety of policies and practices (e.g. land-usage, energy source mixture, CO2 emission cap), as well as trade offs between different objectives (e.g. profits for different sectors, emission minimization) for key stakeholders involved in the biochemical value chain (agriculture, energy, and biotechnology......In recent years, bio-based chemicals have gained traction as a sustainable alternative topetrochemicals. In order to maximize the impacts of researches and investments, there is a need to focus on the most promising combinations of feedstocks, biochemical products, and bioprocesses. To address...... this issue, we developed a multiscale framework that integrates modeling approaches across scales of cellular metabolism, bioreactor, bioprocess, and economy/ecosystem, and is able to simultaneously assess biological, technological, economic and environmental feasibility of different production scenarios...

New mescaline concentrations from 14 taxa/cultivars of Echinopsis spp. (Cactaceae) ("San Pedro") and their relevance to shamanic practice.

Science.gov (United States)

Ogunbodede, Olabode; McCombs, Douglas; Trout, Keeper; Daley, Paul; Terry, Martin

2010-09-15

The aim of the present study is to determine in a procedurally uniform manner the mescaline concentrations in stem tissue of 14 taxa/cultivars of the subgenus Trichocereus of the genus Echinopsis (Cactaceae) and to evaluate the relationship (if any) between mescaline concentration and actual shamanic use of these plants. Columnar cacti of the genus Echinopsis, some of which are used for diagnostic and therapeutic purposes by South American shamans in traditional medicine, were selected for analysis because they were vegetative clones of plants of documented geographic origin and/or because they were known to be used by practitioners of shamanism. Mescaline content of the cortical stem chlorenchyma of each cactus was determined by Soxhlet extraction with methanol, followed by acid-base extraction with water and dichloromethane, and high-pressure liquid chromatography (HPLC). By virtue of the consistent analytical procedures used, comparable alkaloid concentrations were obtained that facilitated the ranking of the various selected species and cultivars of Echinopsis, all of which exhibited positive mescaline contents. The range of mescaline concentrations across the 14 taxa/cultivars spanned two orders of magnitude, from 0.053% to 4.7% by dry weight. The mescaline concentrations reported here largely support the hypothesis that plants with the highest mescaline concentrations - particularly E. pachanoi from Peru - are most associated with documented shamanic use. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Space-based observatories providing key data for climate change applications

Science.gov (United States)

Lecomte, J.; Juillet, J. J.

2016-12-01

The Sentinel-1 & 3 mission are part of the Copernicus program, previously known as GMES (Global Monitoring for Environment and Security), whose overall objective is to support Europe's goals regarding sustainable development and global governance of the environment by providing timely and quality data, information, services and knowledge. This European Earth Observation program is led by the European Commission and the space infrastructure is developed under the European Space Agency leadership. Many services will be developed through the Copernicus program among different thematic areas. The climate change is one of this thematic area and the Sentinel-1 & 3 satellites will provide key space-based observations in this area. The Sentinel-1 mission is based on a constellation of 2 identical satellites each one embarking C-SAR Instrument and provides capability for continuous radar mapping of the Earth with enhanced revisit frequency, coverage, timeliness and reliability for operational services and applications requiring long time series. In particular, Sentinel 1 provides all-weather, day-and-night estimates of soil moisture, wind speed and direction, sea ice, continental ice sheets and glaciers. The Sentinel-3 mission will mainly be devoted to the provision of Ocean observation data in routine, long term (20 years of operations) and continuous fashion with a consistent quality and a very high level of availability. Among these data, very accurate surface temperatures and topography measurements will be provided and will constitute key indicators, once ingested in climate change models, for identifying climate drivers and expected climate impacts. The paper will briefly recall the satellite architectures, their main characteristics and performance. The inflight performance and key features of their images or data of the 3 satellites namely Sentinel 1A, 1B and 3A will be reviewed to demonstrate the quality and high scientific potential of the data as well as their

Process optimization by decoupled control of key microbial populations: distribution of activity and abundance of polyphosphate-accumulating organisms and nitrifying populations in a full-scale IFAS-EBPR plant

DEFF Research Database (Denmark)

Onnis-Hayden, Annalisa; Majed, Nehreen; Schramm, Andreas

2011-01-01

This study investigated the abundance and distribution of key functional microbial populations and their activities in a full-scale integrated fixed film activated sludgeeenhanced biological phosphorus removal (IFAS-EBPR) process. Polyphosphate accumulating organisms (PAOs) including Accumulibacter...

Upconversion-based receivers for quantum hacking-resistant quantum key distribution

Science.gov (United States)

Jain, Nitin; Kanter, Gregory S.

2016-07-01

We propose a novel upconversion (sum frequency generation)-based quantum-optical system design that can be employed as a receiver (Bob) in practical quantum key distribution systems. The pump governing the upconversion process is produced and utilized inside the physical receiver, making its access or control unrealistic for an external adversary (Eve). This pump facilitates several properties which permit Bob to define and control the modes that can participate in the quantum measurement. Furthermore, by manipulating and monitoring the characteristics of the pump pulses, Bob can detect a wide range of quantum hacking attacks launched by Eve.

On Tree-Based Phylogenetic Networks.

Science.gov (United States)

Zhang, Louxin

2016-07-01

A large class of phylogenetic networks can be obtained from trees by the addition of horizontal edges between the tree edges. These networks are called tree-based networks. We present a simple necessary and sufficient condition for tree-based networks and prove that a universal tree-based network exists for any number of taxa that contains as its base every phylogenetic tree on the same set of taxa. This answers two problems posted by Francis and Steel recently. A byproduct is a computer program for generating random binary phylogenetic networks under the uniform distribution model.

Sustainability of the Tourism Industry, Based on Financial Key Performance Indicators

Directory of Open Access Journals (Sweden)

Adriana Dutescu

2014-11-01

Full Text Available Even if there is a real need of a set of key performance indicators for small and medium sized enterprises, this is not yet considered to be satisfied. Our research is focused on two main aspects, each of them individually important for the users of accounting information: the basic indicators specific for analysing operational performance and for decision making and the trend of the key performance indicators in the context of the economic crisis. The starting point of the study is a questionnaire addressed to small and medium sized enterprises activating in the tourism area, especially in the hotel industry. The respondents answered the questions in perfect anonymity by choosing one of the multiple choices for some of them and offering open answers to the others. Our analysis reveals a fair view of the dynamic of the most used key performance indicators in Romanian hotel industry, the limits of their interpretation and usage and the evolution of the financial and economic performance. The declared purpose of the research is to set the bases of a starting point in order to provide solutions for improving the relevance and the usage of these indicators in this domain, in the context of a sustainable business, taking into account the nowadays status of the economy in general and in particular the hotel industry.

A dynamic re-partitioning strategy based on the distribution of key in Spark

Science.gov (United States)

Zhang, Tianyu; Lian, Xin

2018-05-01

Spark is a memory-based distributed data processing framework, has the ability of processing massive data and becomes a focus in Big Data. But the performance of Spark Shuffle depends on the distribution of data. The naive Hash partition function of Spark can not guarantee load balancing when data is skewed. The time of job is affected by the node which has more data to process. In order to handle this problem, dynamic sampling is used. In the process of task execution, histogram is used to count the key frequency distribution of each node, and then generate the global key frequency distribution. After analyzing the distribution of key, load balance of data partition is achieved. Results show that the Dynamic Re-Partitioning function is better than the default Hash partition, Fine Partition and the Balanced-Schedule strategy, it can reduce the execution time of the task and improve the efficiency of the whole cluster.

Fully predictive simulation of real-scale cable tray fire based on small-scale laboratory experiments

Energy Technology Data Exchange (ETDEWEB)

Beji, Tarek; Merci, Bart [Ghent Univ. (Belgium). Dept. of Flow, Heat and Combustion Mechanics; Bonte, Frederick [Bel V, Brussels (Belgium)

2015-12-15

This paper presents a computational fluid dynamics (CFD)-based modelling strategy for real-scale cable tray fires. The challenge was to perform fully predictive simulations (that could be called 'blind' simulations) using solely information from laboratory-scale experiments, in addition to the geometrical arrangement of the cables. The results of the latter experiments were used (1) to construct the fuel molecule and the chemical reaction for combustion, and (2) to estimate the overall pyrolysis and burning behaviour. More particularly, the strategy regarding the second point consists of adopting a surface-based pyrolysis model. Since the burning behaviour of each cable could not be tracked individually (due to computational constraints), 'groups' of cables were modelled with an overall cable surface area equal to the actual value. The results obtained for one large-scale test (a stack of five horizontal trays) are quite encouraging, especially for the peak Heat Release Rate (HRR) that was predicted with a relative deviation of 3 %. The time to reach the peak is however overestimated by 4.7 min (i.e. 94 %). Also, the fire duration is overestimated by 5 min (i.e. 24 %). These discrepancies are mainly attributed to differences in the HRRPUA (heat release rate per unit area) profiles between the small-scale and large-scale. The latter was calculated by estimating the burning area of cables using video fire analysis (VFA).

[Modeling continuous scaling of NDVI based on fractal theory].

Science.gov (United States)

Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

2013-07-01

Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.

A Nuclear Scale System Based on LabVIEW

International Nuclear Information System (INIS)

Liu Shixing; Gu Qindong

2009-01-01

Nuclear mass scales measure the weight of materials which absorb and attenuate the nuclear radiation when the low energy γ-ray through it and is a non-contact continuous measurement device with simple structure and reliable operation. LabVIEW as a graphical programming language is a standard data acquisition and instrument control software. Based on the principle of nuclear mass scale measuring system, monitoring software for nuclear scale system is designed using LabVIEW programming environment. Software architecture mainly composed of three basic modules which include the monitoring software, databases and Web services. It achieves measurement data acquisition, status monitoring, and data management and has networking functions. (authors)

Symmetric Stream Cipher using Triple Transposition Key Method and Base64 Algorithm for Security Improvement

Science.gov (United States)

Nurdiyanto, Heri; Rahim, Robbi; Wulan, Nur

2017-12-01

Symmetric type cryptography algorithm is known many weaknesses in encryption process compared with asymmetric type algorithm, symmetric stream cipher are algorithm that works on XOR process between plaintext and key, to improve the security of symmetric stream cipher algorithm done improvisation by using Triple Transposition Key which developed from Transposition Cipher and also use Base64 algorithm for encryption ending process, and from experiment the ciphertext that produced good enough and very random.

Auto-Scaling of Geo-Based Image Processing in an OpenStack Cloud Computing Environment

Directory of Open Access Journals (Sweden)

Sanggoo Kang

2016-08-01

Full Text Available Cloud computing is a base platform for the distribution of large volumes of data and high-performance image processing on the Web. Despite wide applications in Web-based services and their many benefits, geo-spatial applications based on cloud computing technology are still developing. Auto-scaling realizes automatic scalability, i.e., the scale-out and scale-in processing of virtual servers in a cloud computing environment. This study investigates the applicability of auto-scaling to geo-based image processing algorithms by comparing the performance of a single virtual server and multiple auto-scaled virtual servers under identical experimental conditions. In this study, the cloud computing environment is built with OpenStack, and four algorithms from the Orfeo toolbox are used for practical geo-based image processing experiments. The auto-scaling results from all experimental performance tests demonstrate applicable significance with respect to cloud utilization concerning response time. Auto-scaling contributes to the development of web-based satellite image application services using cloud-based technologies.

Investigating measurement equivalence of visual analogue scales and Likert-type scales in Internet-based personality questionnaires.

Science.gov (United States)

Kuhlmann, Tim; Dantlgraber, Michael; Reips, Ulf-Dietrich

2017-12-01

Visual analogue scales (VASs) have shown superior measurement qualities in comparison to traditional Likert-type response scales in previous studies. The present study expands the comparison of response scales to properties of Internet-based personality scales in a within-subjects design. A sample of 879 participants filled out an online questionnaire measuring Conscientiousness, Excitement Seeking, and Narcissism. The questionnaire contained all instruments in both answer scale versions in a counterbalanced design. Results show comparable reliabilities, means, and SDs for the VAS versions of the original scales, in comparison to Likert-type scales. To assess the validity of the measurements, age and gender were used as criteria, because all three constructs have shown non-zero correlations with age and gender in previous research. Both response scales showed a high overlap and the proposed relationships with age and gender. The associations were largely identical, with the exception of an increase in explained variance when predicting age from the VAS version of Excitement Seeking (B10 = 1318.95, ΔR(2) = .025). VASs showed similar properties to Likert-type response scales in most cases.

Dynamic Symmetric Key Mobile Commerce Scheme Based on Self-Verified Mechanism

Directory of Open Access Journals (Sweden)

Jiachen Yang

2014-01-01

Full Text Available In terms of the security and efficiency of mobile e-commerce, the authors summarized the advantages and disadvantages of several related schemes, especially the self-verified mobile payment scheme based on the elliptic curve cryptosystem (ECC and then proposed a new type of dynamic symmetric key mobile commerce scheme based on self-verified mechanism. The authors analyzed the basic algorithm based on self-verified mechanisms and detailed the complete transaction process of the proposed scheme. The authors analyzed the payment scheme based on the security and high efficiency index. The analysis shows that the proposed scheme not only meets the high efficiency of mobile electronic payment premise, but also takes the security into account. The user confirmation mechanism at the end of the proposed scheme further strengthens the security of the proposed scheme. In brief, the proposed scheme is more efficient and practical than most of the existing schemes.

An Improved Dynamic ID-Based Remote User Authentication with Key Agreement Scheme

Directory of Open Access Journals (Sweden)

Juan Qu

2013-01-01

Full Text Available In recent years, several dynamic ID-based remote user authentication schemes have been proposed. In 2012, Wen and Li proposed a dynamic ID-based remote user authentication with key agreement scheme. They claimed that their scheme can resist impersonation attack and insider attack and provide anonymity for the users. However, we will show that Wen and Li's scheme cannot withstand insider attack and forward secrecy, does not provide anonymity for the users, and inefficiency for error password login. In this paper, we propose a novel ECC-based remote user authentication scheme which is immune to various known types of attack and is more secure and practical for mobile clients.

Development of authentication code for multi-access optical code division multiplexing based quantum key distribution

Science.gov (United States)

Taiwo, Ambali; Alnassar, Ghusoon; Bakar, M. H. Abu; Khir, M. F. Abdul; Mahdi, Mohd Adzir; Mokhtar, M.

2018-05-01

One-weight authentication code for multi-user quantum key distribution (QKD) is proposed. The code is developed for Optical Code Division Multiplexing (OCDMA) based QKD network. A unique address assigned to individual user, coupled with degrading probability of predicting the source of the qubit transmitted in the channel offer excellent secure mechanism against any form of channel attack on OCDMA based QKD network. Flexibility in design as well as ease of modifying the number of users are equally exceptional quality presented by the code in contrast to Optical Orthogonal Code (OOC) earlier implemented for the same purpose. The code was successfully applied to eight simultaneous users at effective key rate of 32 bps over 27 km transmission distance.

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

Science.gov (United States)

Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie

2018-01-01

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content. PMID:29652811

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

Directory of Open Access Journals (Sweden)

Zhenming Zhang

2018-04-01

Full Text Available Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content.