What strategy is needed for attaining the EU air quality regulations under future climate change scenarios? A sensitivity analysis over Europe

NASA Astrophysics Data System (ADS)

Jiménez-Guerrero, P.; Baró, R.; Gómez-Navarro, J. J.; Lorente-Plazas, R.; García-Valero, J. A.; Hernández, Z.; Montávez, J. P.

2012-04-01

A wide number of studies show that several areas over Europe exceed some of the air quality thresholds established in the legislation. These exceedances will become more frequent under future climate change scenarios, since the policies aimed at improving air quality in the EU directives have not accounted for the variations in the climate. Climate change alone will influence the future concentrations of atmospheric pollutants through modifications of gas-phase chemistry, transport, removal, and natural emissions. In this sense, chemistry transport models (CTMs) play a key role in assessing and understanding the emissions abatement plans through the use of sensitivity analysis strategies. These sensitivity analyses characterize the change in model output due to variations in model input parameters. Since the management strategies of air pollutant emission is one of the predominant factors for controlling urban air quality, this work assesses the impact of various emission reduction scenarios in air pollution levels over Europe under two climate change scenarios. The methodology includes the use of a climate version of the meteorological model MM5 coupled with the CHIMERE chemistry transport model. Experiments span the periods 1971-2000, as a reference, and 2071-2100, as two future enhanced greenhouse gas and aerosol scenarios (SRES A2 and B2). The atmospheric simulations have an horizontal resolution of 25 km and 23 vertical layers up to 100 hPa, and are driven by the global climate model ECHO-G . In order to represent the sensitivity of the chemistry and transport of aerosols, tropospheric ozone and other photochemical species, several hypothetical scenarios of emission control have been implemented to quantify the influence of diverse emission sources in the area, such as on-road traffic, port and industrial emissions, among others. The modeling strategy lies on a sensitivity analysis to determine the emission reduction and strategy needed in the target area in order to attain the standards and thresholds set in the European Directive 2008/50/EC. Results depict that the system is able to characterize the exceedances occurring in Europe, mainly related to the maximum 8h moving average exceeding the target value of 120 μg/m3, mainly over southern Europe. Also, compliance of the PM10 daily limit values (50 μg/m3) is not achieved over wide areas in Europe. The sensitivity analysis indicates that large reductions of precursors emissions are needed in all the scenarios examined for attaining the thresholds set in the European Directive. In most cases this abatement strategy is hard to take into practice (e.g. unrealistic percentage of emission reductions in on-road traffic, industry or harbor activity); however, ozone and particulate matter air pollution improve considerably in most of the scenarios included. Results also unveil the propagation of uncertainties from the meteorological projections into future air quality and claim for future studies aimed at deepening the knowledge about the parameterized processes, the definition of emissions and, last, reducing uncertainties.

Attached biofilms and suspended aggregates are distinct microbial lifestyles emanating from differing hydraulics.

PubMed

Niederdorfer, Robert; Peter, Hannes; Battin, Tom J

2016-10-03

Small-scale hydraulics affects microbial behaviour at the cell level 1 , trophic interactions in marine aggregates 2 and the physical structure and function of stream biofilms 3,4 . However, it remains unclear how hydraulics, predictably changing from small streams to large rivers, impacts the structure and biodiversity of complex microbial communities in these ecosystems. Here, we present experimental evidence unveiling hydraulics as a hitherto poorly recognized control of microbial lifestyle differentiation in fluvial ecosystems. Exposing planktonic source communities from stream and floodplain ecosystems to different hydraulic environments revealed strong selective hydraulic pressures but only minor founder effects on the differentiation of attached biofilms and suspended aggregates and their biodiversity dynamics. Key taxa with a coherent phylogenetic underpinning drove this differentiation. Only a few resident and phylogenetically related taxa formed the backbone of biofilm communities, whereas numerous resident taxa characterized aggregate communities. Our findings unveil fundamental differences between biofilms and aggregates and build the basis for a mechanistic understanding of how hydraulics drives the distribution of microbial diversity along the fluvial continuum 5-7 .

Unveiling the functional diversity of the Alpha-Beta hydrolase fold in plants

PubMed Central

Mindrebo, Jeffrey T.; Nartey, Charisse M.; Seto, Yoshiya; Burkart, Michael D.; Noel, Joseph P.

2017-01-01

The alpha/beta hydrolase (ABH) superfamily is a widespread and functionally malleable protein fold recognized for its diverse biochemical activities across all three domains of life. ABH enzymes possess unexpected catalytic activity in the green plant lineage through selective alterations in active site architecture and chemistry. Furthermore, the ABH fold serves as the core structure for phytohormone and ligand receptors in the gibberellin, strigolactone, and karrikin signaling pathways in plants. Despite recent discoveries, the ABH family is sparsely characterized in plants, a sessile kingdom known to evolve complex and specialized chemical adaptations as survival responses to widely varying biotic and abiotic ecologies. This review calls attention to the ABH superfamily in the plant kingdom to highlight the functional adaptability of the ABH fold. PMID:27662376

Microbial Dark Matter Investigations: How Microbial Studies Transform Biological Knowledge and Empirically Sketch a Logic of Scientific Discovery

PubMed Central

Bernard, Guillaume; Pathmanathan, Jananan S; Lannes, Romain; Lopez, Philippe; Bapteste, Eric

2018-01-01

Abstract Microbes are the oldest and most widespread, phylogenetically and metabolically diverse life forms on Earth. However, they have been discovered only 334 years ago, and their diversity started to become seriously investigated even later. For these reasons, microbial studies that unveil novel microbial lineages and processes affecting or involving microbes deeply (and repeatedly) transform knowledge in biology. Considering the quantitative prevalence of taxonomically and functionally unassigned sequences in environmental genomics data sets, and that of uncultured microbes on the planet, we propose that unraveling the microbial dark matter should be identified as a central priority for biologists. Based on former empirical findings of microbial studies, we sketch a logic of discovery with the potential to further highlight the microbial unknowns. PMID:29420719

Systematics and biogeography of the Automolus infuscatus complex (Aves; Furnariidae): Cryptic diversity reveals western Amazonia as the origin of a transcontinental radiation.

PubMed

Schultz, Eduardo D; Burney, Curtis W; Brumfield, Robb T; Polo, Erico M; Cracraft, Joel; Ribas, Camila C

2017-02-01

A revision of the avian Neotropical genus Automolus and the Furnariidae family points to the paraphyly of A. infuscatus and reveals a species complex comprising A. infuscatus, A. ochrolaemus, A. paraensis, A. leucophthalmus, A. lammi and A. subulatus, the latter historically classified in the genus Hyloctistes. Detailed knowledge of the taxonomy, geographic distribution, phylogenetic relationship and divergence times of a taxon allows exploration of its evolutionary history and the testing of different scenarios of diversification. In this context, we studied the A. infuscatus complex using molecular data in order to unveil its cryptic diversity and reveal its evolutionary history. For that we sequenced two mitochondrial (ND2 and cytb) and three nuclear markers (G3PDH, ACO, Fib7) for 302 individuals belonging to all species in the complex and most described subspecies. Our analysis supports the paraphyly of A. infuscatus, indicating the existence of at least two distinct clades not closely related. The remaining species were all recovered as monophyletic. Notwithstanding, a well-structured intraspecific diversity was found with 19 lineages suggesting substantial cryptic diversity within the described species. A. subulatus was recovered within the complex, corroborating its position inside the genus. In spite of the high congruence between distributions of different lineages, with several sister lineages currently separated by the same barriers, the temporal incongruence between divergences over the same barriers reveals a complex evolutionary history. While older events might be related to the emergence of barriers such as the Andes and major Amazonian rivers, younger events suggest dispersal after the consolidation of those barriers. Our analysis suggests that the complex had its origin around 6million years (Ma) and inhabited Western Amazonia in Late Miocene-Early Pliocene. Considering the riparian habit of species in its sister clade, the rise and early diversifications of the complex may be related to the establishment of terra firme forests as it changed from a floodplain to a fluvial system. The late Amazonian colonization by A. subulatus and A. ochrolaemus lineages may have been hampered by the previous existence of well established A. infuscatus lineages in the region. Copyright © 2016 Elsevier Inc. All rights reserved.

In the shadows: Phylogenomics and coalescent species delimitation unveil cryptic diversity in a Cerrado endemic lizard (Squamata: Tropidurus).

PubMed

Domingos, Fabricius M C B; Colli, Guarino R; Lemmon, Alan; Lemmon, Emily Moriarty; Beheregaray, Luciano B

2017-02-01

The recognition of cryptic diversity within geographically widespread species is gradually becoming a trend in the highly speciose Neotropical biomes. The statistical methods to recognise such cryptic lineages are rapidly advancing, but have rarely been applied to genomic-scale datasets. Herein, we used phylogenomic data to investigate phylogenetic history and cryptic diversity within Tropidurus itambere, a lizard endemic to the Cerrado biodiversity hotspot. We applied a series of phylogenetic methods to reconstruct evolutionary relationships and a coalescent Bayesian species delimitation approach (BPP) to clarify species limits. The BPP results suggest that the widespread nominal taxon comprises a complex of 5 highly supported and geographically structured cryptic species. We highlight and discuss the different topological patterns recovered by concatenated and coalescent species tree methods for these closely related lineages. Finally, we suggest that the existence of cryptic lineages in the Cerrado is much more common than traditionally thought, highlighting the value of using NGS data and coalescent techniques to investigate patterns of species diversity. Copyright © 2016 Elsevier Inc. All rights reserved.

Structural and functional diversity in Listeria cell wall teichoic acids.

PubMed

Shen, Yang; Boulos, Samy; Sumrall, Eric; Gerber, Benjamin; Julian-Rodero, Alicia; Eugster, Marcel R; Fieseler, Lars; Nyström, Laura; Ebert, Marc-Olivier; Loessner, Martin J

2017-10-27

Wall teichoic acids (WTAs) are the most abundant glycopolymers found on the cell wall of many Gram-positive bacteria, whose diverse surface structures play key roles in multiple biological processes. Despite recent technological advances in glycan analysis, structural elucidation of WTAs remains challenging due to their complex nature. Here, we employed a combination of ultra-performance liquid chromatography-coupled electrospray ionization tandem-MS/MS and NMR to determine the structural complexity of WTAs from Listeria species. We unveiled more than 10 different types of WTA polymers that vary in their linkage and repeating units. Disparity in GlcNAc to ribitol connectivity, as well as variable O -acetylation and glycosylation of GlcNAc contribute to the structural diversity of WTAs. Notably, SPR analysis indicated that constitution of WTA determines the recognition by bacteriophage endolysins. Collectively, these findings provide detailed insight into Listeria cell wall-associated carbohydrates, and will guide further studies on the structure-function relationship of WTAs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Unveiling the diversification dynamics of Australasian predaceous diving beetles in the Cenozoic.

PubMed

Toussaint, Emmanuel F A; Condamine, Fabien L; Hawlitschek, Oliver; Watts, Chris H; Porch, Nick; Hendrich, Lars; Balke, Michael

2015-01-01

During the Cenozoic, Australia experienced major climatic shifts that have had dramatic ecological consequences for the modern biota. Mesic tropical ecosystems were progressively restricted to the coasts and replaced by arid-adapted floral and faunal communities. Whilst the role of aridification has been investigated in a wide range of terrestrial lineages, the response of freshwater clades remains poorly investigated. To gain insights into the diversification processes underlying a freshwater radiation, we studied the evolutionary history of the Australasian predaceous diving beetles of the tribe Hydroporini (147 described species). We used an integrative approach including the latest methods in phylogenetics, divergence time estimation, ancestral character state reconstruction, and likelihood-based methods of diversification rate estimation. Phylogenies and dating analyses were reconstructed with molecular data from seven genes (mitochondrial and nuclear) for 117 species (plus 12 outgroups). Robust and well-resolved phylogenies indicate a late Oligocene origin of Australasian Hydroporini. Biogeographic analyses suggest an origin in the East Coast region of Australia, and a dynamic biogeographic scenario implying dispersal events. The group successfully colonized the tropical coastal regions carved by a rampant desertification, and also colonized groundwater ecosystems in Central Australia. Diversification rate analyses suggest that the ongoing aridification of Australia initiated in the Miocene contributed to a major wave of extinctions since the late Pliocene probably attributable to an increasing aridity, range contractions and seasonally disruptions resulting from Quaternary climatic changes. When comparing subterranean and epigean genera, our results show that contrasting mechanisms drove their diversification and therefore current diversity pattern. The Australasian Hydroporini radiation reflects a combination of processes that promoted both diversification, resulting from new ecological opportunities driven by initial aridification, and a subsequent loss of mesic adapted diversity due to increasing aridity. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DNA barcode reference library for Iberian butterflies enables a continental-scale preview of potential cryptic diversity

PubMed Central

Dincă, Vlad; Montagud, Sergio; Talavera, Gerard; Hernández-Roldán, Juan; Munguira, Miguel L.; García-Barros, Enrique; Hebert, Paul D. N.; Vila, Roger

2015-01-01

How common are cryptic species - those overlooked because of their morphological similarity? Despite its wide-ranging implications for biology and conservation, the answer remains open to debate. Butterflies constitute the best-studied invertebrates, playing a similar role as birds do in providing models for vertebrate biology. An accurate assessment of cryptic diversity in this emblematic group requires meticulous case-by-case assessments, but a preview to highlight cases of particular interest will help to direct future studies. We present a survey of mitochondrial genetic diversity for the butterfly fauna of the Iberian Peninsula with unprecedented resolution (3502 DNA barcodes for all 228 species), creating a reliable system for DNA-based identification and for the detection of overlooked diversity. After compiling available data for European butterflies (5782 sequences, 299 species), we applied the Generalized Mixed Yule-Coalescent model to explore potential cryptic diversity at a continental scale. The results indicate that 27.7% of these species include from two to four evolutionary significant units (ESUs), suggesting that cryptic biodiversity may be higher than expected for one of the best-studied invertebrate groups and regions. The ESUs represent important units for conservation, models for studies of evolutionary and speciation processes, and sentinels for future research to unveil hidden diversity. PMID:26205828

Predicting Plant Diversity Patterns in Madagascar: Understanding the Effects of Climate and Land Cover Change in a Biodiversity Hotspot

PubMed Central

Brown, Kerry A.; Parks, Katherine E.; Bethell, Colin A.; Johnson, Steig E.; Mulligan, Mark

2015-01-01

Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar’s plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future. PMID:25856241

Predicting plant diversity patterns in Madagascar: understanding the effects of climate and land cover change in a biodiversity hotspot.

PubMed

Brown, Kerry A; Parks, Katherine E; Bethell, Colin A; Johnson, Steig E; Mulligan, Mark

2015-01-01

Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar's plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future.

Nucleophile Promiscuity of Natural and Engineered Aldolases.

PubMed

Clapes, Pere; Hernández, Karel; Szekrenyi, Anna

2018-04-12

Asymmetric aldol addition reaction mediated by aldolases is recognized as a green and sustainable way for carbon-carbon bond formation. Research in this line has unveiled their unprecedented synthetic potentiality toward diverse new chemical structures, novel product families and even as a technology for industrial manufacturing processes. Despite that, aldolases have long been regarded as strictly selective catalysts, particularly for the nucleophilic substrate, limiting their broad applicability. In recent years, the advances in screening technologies and metagenomics uncovered novel C-C biocatalysts from superfamilies of widely known lyases. Moreover, protein engineering revealed the extraordinary malleability of different carboligases, offering a toolbox of biocatalysts active towards a large structural diversity of nucleophile substrates. In this paper, the nucleophile ambiguity of native and engineered aldolases is discussed with recent examples proving this novel concept. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unveiling the functional diversity of the alpha/beta hydrolase superfamily in the plant kingdom.

PubMed

Mindrebo, Jeffrey T; Nartey, Charisse M; Seto, Yoshiya; Burkart, Michael D; Noel, Joseph P

2016-12-01

The alpha/beta hydrolase (ABH) superfamily is a widespread and functionally malleable protein fold recognized for its diverse biochemical activities across all three domains of life. ABH enzymes possess unexpected catalytic activity in the green plant lineage through selective alterations in active site architecture and chemistry. Furthermore, the ABH fold serves as the core structure for phytohormone and ligand receptors in the gibberellin, strigolactone, and karrikin signaling pathways in plants. Despite recent discoveries, the ABH family is sparsely characterized in plants, a sessile kingdom known to evolve complex and specialized chemical adaptations as survival responses to widely varying biotic and abiotic ecologies. This review calls attention to the ABH superfamily in the plant kingdom to highlight the functional adaptability of the ABH fold. Copyright © 2016. Published by Elsevier Ltd.

Systematic exploration of efficient strategies to manage solid waste in U.S. municipalities: perspectives from the solid waste optimization life-cycle framework (SWOLF).

PubMed

Levis, James W; Barlaz, Morton A; Decarolis, Joseph F; Ranjithan, S Ranji

2014-04-01

Solid waste management (SWM) systems must proactively adapt to changing policy requirements, waste composition, and an evolving energy system to sustainably manage future solid waste. This study represents the first application of an optimizable dynamic life-cycle assessment framework capable of considering these future changes. The framework was used to draw insights by analyzing the SWM system of a hypothetical suburban U.S. city of 100 000 people over 30 years while considering changes to population, waste generation, and energy mix and costs. The SWM system included 3 waste generation sectors, 30 types of waste materials, and 9 processes for waste separation, treatment, and disposal. A business-as-usual scenario (BAU) was compared to three optimization scenarios that (1) minimized cost (Min Cost), (2) maximized diversion (Max Diversion), and (3) minimized greenhouse gas (GHG) emissions (Min GHG) from the system. The Min Cost scenario saved $7.2 million (12%) and reduced GHG emissions (3%) relative to the BAU scenario. Compared to the Max Diversion scenario, the Min GHG scenario cost approximately 27% less and more than doubled the net reduction in GHG emissions. The results illustrate how the timed-deployment of technologies in response to changes in waste composition and the energy system results in more efficient SWM system performance compared to what is possible from static analyses.

Scenario studies as a synthetic and integrative research activity for Long-Term Ecological Research

Treesearch

Jonathan R. Thompson; Arnim Wiek; Frederick J. Swanson; Stephen R. Carpenter; Nancy Fresco; Teresa Hollingsworth; Thomas A. Spies; David R. Foster

2012-01-01

Scenario studies have emerged as a powerful approach for synthesizing diverse forms of research and for articulating and evaluating alternative socioecological futures. Unlike predictive modeling, scenarios do not attempt to forecast the precise or probable state of any variable at a given point in the future. Instead, comparisons among a set of contrasting scenarios...

Expression variability of co-regulated genes differentiates Saccharomyces cerevisiae strains

PubMed Central

2011-01-01

Background Saccharomyces cerevisiae (Baker's yeast) is found in diverse ecological niches and is characterized by high adaptive potential under challenging environments. In spite of recent advances on the study of yeast genome diversity, little is known about the underlying gene expression plasticity. In order to shed new light onto this biological question, we have compared transcriptome profiles of five environmental isolates, clinical and laboratorial strains at different time points of fermentation in synthetic must medium, during exponential and stationary growth phases. Results Our data unveiled diversity in both intensity and timing of gene expression. Genes involved in glucose metabolism and in the stress response elicited during fermentation were among the most variable. This gene expression diversity increased at the onset of stationary phase (diauxic shift). Environmental isolates showed lower average transcript abundance of genes involved in the stress response, assimilation of nitrogen and vitamins, and sulphur metabolism, than other strains. Nitrogen metabolism genes showed significant variation in expression among the environmental isolates. Conclusions Wild type yeast strains respond differentially to the stress imposed by nutrient depletion, ethanol accumulation and cell density increase, during fermentation of glucose in synthetic must medium. Our results support previous data showing that gene expression variability is a source of phenotypic diversity among closely related organisms. PMID:21507216

Effects of the proposed California WaterFix North Delta Diversion on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento-San Joaquin River Delta, northern California

USGS Publications Warehouse

Perry, Russell W.; Pope, Adam C.

2018-05-11

The California Department of Water Resources and Bureau of Reclamation propose new water intake facilities on the Sacramento River in northern California that would convey some of the water for export to areas south of the Sacramento-San Joaquin River Delta (hereinafter referred to as the Delta) through tunnels rather than through the Delta. The collection of water intakes, tunnels, pumping facilities, associated structures, and proposed operations are collectively referred to as California WaterFix. The water intake facilities, hereinafter referred to as the North Delta Diversion (NDD), are proposed to be located on the Sacramento River downstream of the city of Sacramento and upstream of the first major river junction where Sutter Slough branches from the Sacramento River. The NDD can divert a maximum discharge of 9,000 cubic feet per second (ft3 /s) from the Sacramento River, which reduces the amount of Sacramento River inflow into the Delta. In this report, we conduct four analyses to investigate the effect of the NDD and its proposed operation on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha). All analyses used the results of a Bayesian survival model that allowed us to simulate travel time, migration routing, and survival of juvenile Chinook salmon migrating through the Delta in response to NDD operations, which affected both inflows to the Delta and operation of the Delta Cross Channel (DCC). For the first analysis, we evaluated the effect of the NDD bypass rules on salmon survival. The NDD bypass rules are a set of operational rule curves designed to provide adaptive levels of fish protection by defining allowable diversion rates as a function of (1) Sacramento River discharge as measured at Freeport, and (2) time of year when endangered runs requiring the most protection are present. We determined that all bypass rule curves except constant low-level pumping (maximum diversion of 900 ft3 /s) could cause a sizeable decrease in survival by as much as 6–10 percentage points. The maximum decrease in survival occurred at an intermediate Sacramento River flow of about 20,000–30,000 ft3 /s. Diversion rates increased rapidly as Sacramento River flows increased from 20,000 ft3 /s to 30,000 ft3 /s, until a maximum diversion rate was reached at 9,000 ft3 /s. Because through-Delta survival increases sharply over this range of Sacramento River flow before beginning to level off with further flow increases, increasing diversion rates over this flow range causes a large decrease in survival relative to no diversion.  For the second analysis, we applied the survival model to 82 years of daily simulated flows under the Proposed Action (PA) and No Action Alternative (NAA). The PA includes operation of the Central Valley Project/State Water Project with implementation of the NDD and its operations prescribed by the NDD bypass rules, whereas the NAA assumes system operations without implementation of the NDD. We also evaluated a “Level 1” (L1) scenario, which was similar to the PA scenario but applied the most protective bypass rule known as Level 1 post-pulse operations. We noted a high probability that survival under the PA scenario was lower than under the NAA scenario, and that travel time was longer under PA relative to NAA in most simulation years. However, the largest survival differences between the PA and NAA scenarios occurred during October–November and May–June. Although bypass rules are less restrictive during these periods, we determined that more frequent use of the DCC under PA led to the largest differences in survival between the two scenarios. Additionally, we noted no difference in median survival decreases between the PA and L1 scenarios, although in some years the L1 scenario had a lower survival decrease than the PA scenario. For the third analysis, we proposed a quantitative approach for developing NDD rule curves (that is, prescribed diversion flows for given inflows) by using the survival model to identify diversion rates that meet a criterion of a having a small probability of exceeding a given decrease in survival. We examined diversion rates that led to a 10% chance of exceeding a given decrease in survival for a range of absolute and relative decreases in survival. To maintain a given constant level of protection across the range of river flows, our analysis indicated that diversions had to increase at a much slower rate with respect to Sacramento River flow relative to the rule curves defined in the NDD bypass table. Additionally, we determined that diversion rates could be higher than under the bypass table rule curves at river flows less than 20,000 ft3 /s, but diversions had to be less than defined by NDD bypass rules at higher flows. For the fourth analysis, we simulated the effect of “real-time operations” on salmon survival, where bypass flow rates were determined by the presence of juvenile salmon entering the Delta, as indicated by juvenile salmon catch in a rotary screw trap upstream of the Delta. For this analysis, we evaluated NDD operations as defined by the L1 scenario and an additional scenario (Unlimited Pulse Protection [UPP]) that provided protection to an unlimited number of fish pulses. This analysis indicated that the highest catches occurred during flow pulses when daily survival was high, which caused annual survival to be weighted towards periods of high daily survival, resulting in a high annual survival. We determined that the mean annual survival decreased by 1–4 percentage points, and annual survival decreases were more frequently smaller for the UPP scenario. Additionally, because the UPP scenario protected an unlimited number of fish pulses, decreases in daily survival under the UPP scenario were less than under the L1 scenario.

Clinical and genetic diversity of SMN1-negative proximal spinal muscular atrophies

PubMed Central

Jordanova, Albena

2014-01-01

Hereditary spinal muscular atrophy is a motor neuron disorder characterized by muscle weakness and atrophy due to degeneration of the anterior horn cells of the spinal cord. Initially, the disease was considered purely as an autosomal recessive condition caused by loss-of-function SMN1 mutations on 5q13. Recent developments in next generation sequencing technologies, however, have unveiled a growing number of clinical conditions designated as non-5q forms of spinal muscular atrophy. At present, 16 different genes and one unresolved locus are associated with proximal non-5q forms, having high phenotypic variability and diverse inheritance patterns. This review provides an overview of the current knowledge regarding the phenotypes, causative genes, and disease mechanisms associated with proximal SMN1-negative spinal muscular atrophies. We describe the molecular and cellular functions enriched among causative genes, and discuss the challenges in the post-genomics era of spinal muscular atrophy research. PMID:24970098

The Genetic Diversity, Haplotype Analysis, and Phylogenetic Relationship of Aedes albopictus (Diptera: Culicidae) Based on the Cytochrome Oxidase 1 Marker: A Malaysian Scenario.

PubMed

Ismail, Nurul-Ain; Adilah-Amrannudin, Nurul; Hamsidi, Mayamin; Ismail, Rodziah; Dom, Nazri Che; Ahmad, Abu Hassan; Mastuki, Mohd Fahmi; Camalxaman, Siti Nazrina

2017-11-07

The global expansion of Ae. albopictus from its native range in Southeast Asia has been implicated in the recent emergence of dengue endemicity in Malaysia. Genetic variability studies of Ae. albopictus are currently lacking in the Malaysian setting, yet are crucial to enhancing the existing vector control strategies. The study was conducted to establish the genetic variability of maternally inherited mitochondrial DNA encoding for cytochrome oxidase subunit 1 (CO1) gene in Ae. albopictus. Twelve localities were selected in the Subang Jaya district based on temporal indices utilizing 120 mosquito samples. Genetic polymorphism and phylogenetic analysis were conducted to unveil the genetic variability and geographic origins of Ae. albopictus. The haplotype network was mapped to determine the genealogical relationship of sequences among groups of population in the Asian region. Comparison of Malaysian CO1 sequences with sequences derived from five Asian countries revealed genetically distinct Ae. albopictus populations. Phylogenetic analysis revealed that all sequences from other Asian countries descended from the same genetic lineage as the Malaysian sequences. Noteworthy, our study highlights the discovery of 20 novel haplotypes within the Malaysian population which to date had not been reported. These findings could help determine the genetic variation of this invasive species, which in turn could possibly improve the current dengue vector surveillance strategies, locally and regionally. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Additive Partitioning of Coral Reef Fish Diversity across Hierarchical Spatial Scales throughout the Caribbean

PubMed Central

Francisco-Ramos, Vanessa; Arias-González, Jesús Ernesto

2013-01-01

There is an increasing need to examine regional patterns of diversity in coral-reef systems since their biodiversity is declining globally. In this sense, additive partitioning might be useful since it quantifies the contribution of alpha and beta to total diversity across different scales. We applied this approach using an unbalanced design across four hierarchical scales (80 sites, 22 subregions, six ecoregions, and the Caribbean basin). Reef-fish species were compiled from the Reef Environmental Education Foundation (REEF) database and distributions were confirmed with published data. Permutation tests were used to compare observed values to those expected by chance. The primary objective was to identify patterns of reef-fish diversity across multiple spatial scales under different scenarios, examining factors such as fisheries and demographic connectivity. Total diversity at the Caribbean scale was attributed to β-diversity (nearly 62% of the species), with the highest β-diversity at the site scale. α¯-diversity was higher than expected by chance in all scenarios and at all studied scales. This suggests that fish assemblages are more homogenous than expected, particularly at the ecoregion scale. Within each ecoregion, diversity was mainly attributed to alpha, except for the Southern ecoregion where there was a greater difference in species among sites. β-components were lower than expected in all ecoregions, indicating that fishes within each ecoregion are a subsample of the same species pool. The scenario involving the effects of fisheries showed a shift in dominance for β-diversity from regions to subregions, with no major changes to the diversity patterns. In contrast, demographic connectivity partially explained the diversity pattern. β-components were low within connectivity regions and higher than expected by chance when comparing between them. Our results highlight the importance of ecoregions as a spatial scale to conserve local and regional coral reef-fish diversity. PMID:24205311

Rapid Evolution of piRNA Pathway in the Teleost Fish: Implication for an Adaptation to Transposon Diversity

PubMed Central

Yi, Minhan; Chen, Feng; Luo, Majing; Cheng, Yibin; Zhao, Huabin; Cheng, Hanhua; Zhou, Rongjia

2014-01-01

The Piwi-interacting RNA (piRNA) pathway is responsible for germline specification, gametogenesis, transposon silencing, and genome integrity. Transposable elements can disrupt genome and its functions. However, piRNA pathway evolution and its adaptation to transposon diversity in the teleost fish remain unknown. This article unveils evolutionary scene of piRNA pathway and its association with diverse transposons by systematically comparative analysis on diverse teleost fish genomes. Selective pressure analysis on piRNA pathway and miRNA/siRNA (microRNA/small interfering RNA) pathway genes between teleosts and mammals showed an accelerated evolution of piRNA pathway genes in the teleost lineages, and positive selection on functional PAZ (Piwi/Ago/Zwille) and Tudor domains involved in the Piwi–piRNA/Tudor interaction, suggesting that the amino acid substitutions are adaptive to their functions in piRNA pathway in the teleost fish species. Notably five piRNA pathway genes evolved faster in the swamp eel, a kind of protogynous hermaphrodite fish, than the other teleosts, indicating a differential evolution of piRNA pathway between the swamp eel and other gonochoristic fishes. In addition, genome-wide analysis showed higher diversity of transposons in the teleost fish species compared with mammals. Our results suggest that rapidly evolved piRNA pathway in the teleost fish is likely to be involved in the adaption to transposon diversity. PMID:24846630

Effects of Different Regeneration Scenarios and Fertilizer Treatments on Soil Microbial Ecology in Reclaimed Opencast Mining Areas on the Loess Plateau, China

PubMed Central

Li, Junjian; Zheng, Yuanming; Yan, Junxia; Li, Hongjian; Wang, Xiang; He, Jizheng; Ding, Guangwei

2013-01-01

The soil microbial community in reclaimed mining areas is fundamental to vegetative establishment. However, how this community responds to different regeneration scenarios and fertilizer treatments is poorly understood. This research evaluated plant and soil microbial communities from different regeneration scenarios and different fertilizer treatments. Regeneration scenarios significantly influenced soil bacterial, archaeal, and fungal rDNA abundance. The ratios of fungi to bacteria or archaea were increased with fertilizer application. The diversity of both plants and microbes was lowest in Lotus corniculatus grasslands. Regeneration scenario, fertilizer treatment, and their interaction influenced soil microbial richness, diversity and evenness indices. Labile carbon pool 2 was a significant factor affected plant and microbe communities in July, suggesting that plants and microbes may be competing for nutrients. The higher ratios of positive to negative association were found in soil bacteria and total microbe than in archaea and fungi. Stronger clustering of microbial communities from the same regeneration scenario indicated that the vegetative composition of regeneration site may have a greater influence on soil microbial communities than fertilizer treatment. PMID:23658819

Global status of and prospects for protection of terrestrial geophysical diversity.

PubMed

Sanderson, Eric W; Segan, Daniel B; Watson, James E M

2015-06-01

Conservation of representative facets of geophysical diversity may help conserve biological diversity as the climate changes. We conducted a global classification of terrestrial geophysical diversity and analyzed how land protection varies across geophysical diversity types. Geophysical diversity was classified in terms of soil type, elevation, and biogeographic realm and then compared to the global distribution of protected areas in 2012. We found that 300 (45%) of 672 broad geophysical diversity types currently meet the Convention on Biological Diversity's Aichi Target 11 of 17% terrestrial areal protection, which suggested that efforts to implement geophysical diversity conservation have a substantive basis on which to build. However, current protected areas were heavily biased toward high elevation and low fertility soils. We assessed 3 scenarios of protected area expansion and found that protection focused on threatened species, if fully implemented, would also protect an additional 29% of geophysical diversity types, ecoregional-focused protection would protect an additional 24%, and a combined scenario would protect an additional 42%. Future efforts need to specifically target low-elevation sites with productive soils for protection and manage for connectivity among geophysical diversity types. These efforts may be hampered by the sheer number of geophysical diversity facets that the world contains, which makes clear target setting and prioritization an important next step. © 2015 Society for Conservation Biology.

The Use of Bioinformatics for Studying HIV Evolutionary and Epidemiological History in South America

PubMed Central

Bello, Gonzalo; Soares, Marcelo A.; Schrago, Carlos G.

2011-01-01

The South American human immunodeficiency virus type 1 (HIV-1) epidemic is driven by several subtypes (B, C, and F1) and circulating and unique recombinant forms derived from those subtypes. Those variants are heterogeneously distributed around the continent in a country-specific manner. Despite some inconsistencies mainly derived from sampling biases and analytical constrains, most of studies carried out in the area agreed in pointing out specificities in the evolutionary dynamics of the circulating HIV-1 lineages. In this paper, we covered the theoretical basis, and the application of bioinformatics methods to reconstruct the HIV spatial-temporal dynamics, unveiling relevant information to understand the origin, geographical dissemination and the current molecular scenario of the HIV epidemic in the continent, particularly in the countries of Southern Cone. PMID:22162803

Information filtering based on corrected redundancy-eliminating mass diffusion.

PubMed

Zhu, Xuzhen; Yang, Yujie; Chen, Guilin; Medo, Matus; Tian, Hui; Cai, Shi-Min

2017-01-01

Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects' attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is based on a spreading process on the network. Extensive experiments on three benchmark data sets-Movilens, Netflix and Amazon-show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices.

WILDLIFE HABITAT

EPA Science Inventory

Habitat change statistics were used to estimate the effects of alternative future scenarios for agriculture on non-fish vertebrate diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future scenarios w...

Unveiling self-sensitized photodegradation pathways by DFT calculations: A case of sunscreen p-aminobenzoic acid.

PubMed

Zhang, Siyu; Chen, Jingwen; Zhao, Qing; Xie, Qing; Wei, Xiaoxuan

2016-11-01

Self-sensitized photodegradation has been observed for diverse aquatic organic pollutants. However, photodegradation pathways have not been clarified in previous experimental studies. Here, we attempted to probe self-sensitized photodegradation pathways of organic pollutants employing both photolytic experiments and density functional theory calculations. By performing photolytic experiments, we found that singlet state oxygen ((1)O2) play an essential role in photodegradation of a sunscreen p-aminobenzoic acid (PABA). PABA can photogenerate (1)O2 and react fast with (1)O2. We hypothesized that PABA underwent (1)O2 induced self-sensitized photodegradation. By calculating transition states, intermediates and reaction barriers, we found that (1)O2 can oxidize PABA through electrophilic attacks on the benzene ring to abstract one H atom of the amino group following a 1,3-addition mechanism or to induce decarboxylation. Either pathway produces a hydroperoxide. O-O bond cleavage of the hydroperoxides occurring at ground states or the lowest triplet excited states can produce phenoxyl radical precursors of 4-amino-3-hydroxybenzoic acid and 4-aminophenol, which are photodegradation products detected in experiments. Thus, a viable (1)O2 self-sensitized photodegradation mechanism was unveiled for PABA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes of statistical structural fluctuations unveils an early compacted degraded stage of PNS myelin

NASA Astrophysics Data System (ADS)

Poccia, Nicola; Campi, Gaetano; Ricci, Alessandro; Caporale, Alessandra S.; di Cola, Emanuela; Hawkins, Thomas A.; Bianconi, Antonio

2014-06-01

Degradation of the myelin sheath is a common pathology underlying demyelinating neurological diseases from Multiple Sclerosis to Leukodistrophies. Although large malformations of myelin ultrastructure in the advanced stages of Wallerian degradation is known, its subtle structural variations at early stages of demyelination remains poorly characterized. This is partly due to the lack of suitable and non-invasive experimental probes possessing sufficient resolution to detect the degradation. Here we report the feasibility of the application of an innovative non-invasive local structure experimental approach for imaging the changes of statistical structural fluctuations in the first stage of myelin degeneration. Scanning micro X-ray diffraction, using advances in synchrotron x-ray beam focusing, fast data collection, paired with spatial statistical analysis, has been used to unveil temporal changes in the myelin structure of dissected nerves following extraction of the Xenopus laevis sciatic nerve. The early myelin degeneration is a specific ordered compacted phase preceding the swollen myelin phase of Wallerian degradation. Our demonstration of the feasibility of the statistical analysis of SµXRD measurements using biological tissue paves the way for further structural investigations of degradation and death of neurons and other cells and tissues in diverse pathological states where nanoscale structural changes may be uncovered.

The Orion Bullets: New GEMS MCAO images

NASA Astrophysics Data System (ADS)

Ginsburg, Adam; Bally, John; Youngblood, Allison

2013-07-01

The Orion A molecular cloud (OMC1) is the nearest site of massive star formation at a distance of 414 pc. The BN/KL region within it contains signs of a massive explosion triggered 500 years ago by decay of a non- hierarchical multiple system of massive stars. We present observations of the OMC1 core at high spatial resolution (<0.1") in narrow-band [Fe II] 1.64um and H2 S(1) 1-0 2.12um filters. The new data reveal compact (0.1" to 0.5") knots with unique excitation and chemical properties, unveiling new details about the three-dimensional structure of the explosion. Bright H2 emission from these compact, high proper-motion knots and compact [Fe II] features are consistent with scenario proposed by Bally et al. (2011) in which they are interpreted to be high density (n > 10^8 cm^{-3}) disk fragments launched from within a few AU of a massive star by a > three-body dynamical interaction that led to the ejection of the BN objects and the formation of a compact (separation < few AU) binary, most likely radio source I. The proper motions are as high as 400 km/s, hinting at the enormous energy unleashed in the explosion. The data also unveiled a population of obscured close binary systems. This new population will allow a comparison of embedded young binary systems with the older, un-obscured, visual binary population to test models of the evolution of multiplicity statistics in the Orion Nebula Cluster.

Spin-Orbital Excitations in Ca2 RuO4 Revealed by Resonant Inelastic X-Ray Scattering

NASA Astrophysics Data System (ADS)

Das, L.; Forte, F.; Fittipaldi, R.; Fatuzzo, C. G.; Granata, V.; Ivashko, O.; Horio, M.; Schindler, F.; Dantz, M.; Tseng, Yi; McNally, D. E.; Rønnow, H. M.; Wan, W.; Christensen, N. B.; Pelliciari, J.; Olalde-Velasco, P.; Kikugawa, N.; Neupert, T.; Vecchione, A.; Schmitt, T.; Cuoco, M.; Chang, J.

2018-01-01

The strongly correlated insulator Ca2 RuO4 is considered as a paradigmatic realization of both spin-orbital physics and a band-Mott insulating phase, characterized by orbitally selective coexistence of a band and a Mott gap. We present a high resolution oxygen K -edge resonant inelastic x-ray scattering study of the antiferromagnetic Mott insulating state of Ca2 RuO4 . A set of low-energy (about 80 and 400 meV) and high-energy (about 1.3 and 2.2 eV) excitations are reported, which show strong incident light polarization dependence. Our results strongly support a spin-orbit coupled band-Mott scenario and explore in detail the nature of its exotic excitations. Guided by theoretical modeling, we interpret the low-energy excitations as a result of composite spin-orbital excitations. Their nature unveils the intricate interplay of crystal-field splitting and spin-orbit coupling in the band-Mott scenario. The high-energy excitations correspond to intra-atomic singlet-triplet transitions at an energy scale set by Hund's coupling. Our findings give a unifying picture of the spin and orbital excitations in the band-Mott insulator Ca2 RuO4 .

Body Covering and Body Image: A Comparison of Veiled and Unveiled Muslim Women, Christian Women, and Atheist Women Regarding Body Checking, Body Dissatisfaction, and Eating Disorder Symptoms.

PubMed

Wilhelm, Leonie; Hartmann, Andrea S; Becker, Julia C; Kişi, Melahat; Waldorf, Manuel; Vocks, Silja

2018-02-21

Although Islam is the fastest growing religion worldwide, only few studies have investigated body image in Muslim women, and no study has investigated body checking. Therefore, the present study examined whether body image, body checking, and disordered eating differ between veiled and unveiled Muslim women, Christian women, and atheist women. While the groups did not differ regarding body dissatisfaction, unveiled Muslim women reported more checking than veiled Muslim and Christian women, and higher bulimia scores than Christian. Thus, prevention against eating disorders should integrate all women, irrespective of religious affiliation or veiling, with a particular focus on unveiled Muslim women.

Forest species diversity reduces disease risk in a generalist plant pathogen invasion

Treesearch

Sarah E. Haas; Mevin B. Hooten; David M. Rizzo; Ross K. Meentemeyer

2011-01-01

Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the diversity-disease hypothesis for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum...

Genetic diversity and distribution of Senegalia senegal (L.) Britton under climate change scenarios in West Africa.

PubMed

Lyam, Paul Terwase; Duque-Lazo, Joaquín; Durka, Walter; Hauenschild, Frank; Schnitzler, Jan; Michalak, Ingo; Ogundipe, Oluwatoyin Temitayo; Muellner-Riehl, Alexandra Nora

2018-01-01

Climate change is predicted to impact species' genetic diversity and distribution. We used Senegalia senegal (L.) Britton, an economically important species distributed in the Sudano-Sahelian savannah belt of West Africa, to investigate the impact of climate change on intraspecific genetic diversity and distribution. We used ten nuclear and two plastid microsatellite markers to assess genetic variation, population structure and differentiation across thirteen sites in West Africa. We projected suitable range, and potential impact of climate change on genetic diversity using a maximum entropy approach, under four different climate change scenarios. We found higher genetic and haplotype diversity at both nuclear and plastid markers than previously reported. Genetic differentiation was strong for chloroplast and moderate for the nuclear genome. Both genomes indicated three spatially structured genetic groups. The distribution of Senegalia senegal is strongly correlated with extractable nitrogen, coarse fragments, soil organic carbon stock, precipitation of warmest and coldest quarter and mean temperature of driest quarter. We predicted 40.96 to 6.34 per cent of the current distribution to favourably support the species' ecological requirements under future climate scenarios. Our results suggest that climate change is going to affect the population genetic structure of Senegalia senegal, and that patterns of genetic diversity are going to influence the species' adaptive response to climate change. Our study contributes to the growing evidence predicting the loss of economically relevant plants in West Africa in the next decades due to climate change.

Genetic diversity and distribution of Senegalia senegal (L.) Britton under climate change scenarios in West Africa

PubMed Central

Duque-Lazo, Joaquín; Durka, Walter; Hauenschild, Frank; Schnitzler, Jan; Michalak, Ingo; Ogundipe, Oluwatoyin Temitayo; Muellner-Riehl, Alexandra Nora

2018-01-01

Climate change is predicted to impact species’ genetic diversity and distribution. We used Senegalia senegal (L.) Britton, an economically important species distributed in the Sudano-Sahelian savannah belt of West Africa, to investigate the impact of climate change on intraspecific genetic diversity and distribution. We used ten nuclear and two plastid microsatellite markers to assess genetic variation, population structure and differentiation across thirteen sites in West Africa. We projected suitable range, and potential impact of climate change on genetic diversity using a maximum entropy approach, under four different climate change scenarios. We found higher genetic and haplotype diversity at both nuclear and plastid markers than previously reported. Genetic differentiation was strong for chloroplast and moderate for the nuclear genome. Both genomes indicated three spatially structured genetic groups. The distribution of Senegalia senegal is strongly correlated with extractable nitrogen, coarse fragments, soil organic carbon stock, precipitation of warmest and coldest quarter and mean temperature of driest quarter. We predicted 40.96 to 6.34 per cent of the current distribution to favourably support the species’ ecological requirements under future climate scenarios. Our results suggest that climate change is going to affect the population genetic structure of Senegalia senegal, and that patterns of genetic diversity are going to influence the species’ adaptive response to climate change. Our study contributes to the growing evidence predicting the loss of economically relevant plants in West Africa in the next decades due to climate change. PMID:29659603

Building Capacity in Urban Sustainability Assessment through Use of a Scenarios Game

ERIC Educational Resources Information Center

Taylor, Rhys E.; Rutledge, Daniel T.; van Roon, Henri

2011-01-01

Urban form, the patterns of cities, in New Zealand is explored 50 years into the future through a scenarios game, published on the Internet. Four diverse scenarios provide a means to explore the present situation and envision how it may change over time with different trend drivers. Wild card events introduce uncertainty in a way that resonates…

Impact of the Headscarf Ban Policy on the Identity Development of Part-Time Unveilers in Turkish Higher Education

ERIC Educational Resources Information Center

Seggie, Fatma Nevra; Austin, Ann E.

2010-01-01

This qualitative study examines the impact of the Turkish higher education headscarf ban policy on the plural self-identities (i.e., as Turkish citizens, as Muslims, and as females) of part-time unveilers, female students who cover their hair in their private life but who remove the headscarf (or conceal it to appear unveiled) while at a Turkish…

Interactive effects of water diversion and climate change for juvenile chinook salmon in the lemhi river basin (USA.).

PubMed

Walters, Annika W; Bartz, Krista K; McClure, Michelle M

2013-12-01

The combined effects of water diversion and climate change are a major conservation challenge for freshwater ecosystems. In the Lemhi Basin, Idaho (U.S.A.), water diversion causes changes in streamflow, and climate change will further affect streamflow and temperature. Shifts in streamflow and temperature regimes can affect juvenile salmon growth, movement, and survival. We examined the potential effects of water diversion and climate change on juvenile Chinook salmon (Oncorhynchus tshawytscha), a species listed as threatened under the U.S. Endangered Species Act (ESA). To examine the effects for juvenile survival, we created a model relating 19 years of juvenile survival data to streamflow and temperature and found spring streamflow and summer temperature were good predictors of juvenile survival. We used these models to project juvenile survival for 15 diversion and climate-change scenarios. Projected survival was 42-58% lower when streamflows were diverted than when streamflows were undiverted. For diverted streamflows, 2040 climate-change scenarios (ECHO-G and CGCM3.1 T47) resulted in an additional 11-39% decrease in survival. We also created models relating habitat carrying capacity to streamflow and made projections for diversion and climate-change scenarios. Habitat carrying capacity estimated for diverted streamflows was 17-58% lower than for undiverted streamflows. Climate-change scenarios resulted in additional decreases in carrying capacity for the dry (ECHO-G) climate model. Our results indicate climate change will likely pose an additional stressor that should be considered when evaluating the effects of anthropogenic actions on salmon population status. Thus, this type of analysis will be especially important for evaluating effects of specific actions on a particular species. Efectos Interactivos de la Desviación del Agua y el Cambio Climático en Individuos Juveniles de Salmón Chinook en la Cuenca del Río Lemhi (E.U.A.). Conservation Biology © 2013 Society for Conservation Biology No claim to original US government works.

Intermediary metabolism in protists: a sequence-based view of facultative anaerobic metabolism in evolutionarily diverse eukaryotes.

PubMed

Ginger, Michael L; Fritz-Laylin, Lillian K; Fulton, Chandler; Cande, W Zacheus; Dawson, Scott C

2010-12-01

Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2-3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H(2) in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes. Copyright © 2010 Elsevier GmbH. All rights reserved.

Deep COI sequencing of standardized benthic samples unveils overlooked diversity of Jordanian coral reefs in the northern Red Sea.

PubMed

Al-Rshaidat, Mamoon M D; Snider, Allison; Rosebraugh, Sydney; Devine, Amanda M; Devine, Thomas D; Plaisance, Laetitia; Knowlton, Nancy; Leray, Matthieu

2016-09-01

High-throughput sequencing (HTS) of DNA barcodes (metabarcoding), particularly when combined with standardized sampling protocols, is one of the most promising approaches for censusing overlooked cryptic invertebrate communities. We present biodiversity estimates based on sequencing of the cytochrome c oxidase subunit 1 (COI) gene for coral reefs of the Gulf of Aqaba, a semi-enclosed system in the northern Red Sea. Samples were obtained from standardized sampling devices (Autonomous Reef Monitoring Structures (ARMS)) deployed for 18 months. DNA barcoding of non-sessile specimens >2 mm revealed 83 OTUs in six phyla, of which only 25% matched a reference sequence in public databases. Metabarcoding of the 2 mm - 500 μm and sessile bulk fractions revealed 1197 OTUs in 15 animal phyla, of which only 4.9% matched reference barcodes. These results highlight the scarcity of COI data for cryptobenthic organisms of the Red Sea. Compared with data obtained using similar methods, our results suggest that Gulf of Aqaba reefs are less diverse than two Pacific coral reefs but much more diverse than an Atlantic oyster reef at a similar latitude. The standardized approaches used here show promise for establishing baseline data on biodiversity, monitoring the impacts of environmental change, and quantifying patterns of diversity at regional and global scales.

Intermediary Metabolism in Protists: a Sequence-based View of Facultative Anaerobic Metabolism in Evolutionarily Diverse Eukaryotes

PubMed Central

Ginger, Michael L.; Fritz-Laylin, Lillian K.; Fulton, Chandler; Cande, W. Zacheus; Dawson, Scott C.

2011-01-01

Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2–3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H2 in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes. PMID:21036663

Rapid evolution of piRNA pathway in the teleost fish: implication for an adaptation to transposon diversity.

PubMed

Yi, Minhan; Chen, Feng; Luo, Majing; Cheng, Yibin; Zhao, Huabin; Cheng, Hanhua; Zhou, Rongjia

2014-05-19

The Piwi-interacting RNA (piRNA) pathway is responsible for germline specification, gametogenesis, transposon silencing, and genome integrity. Transposable elements can disrupt genome and its functions. However, piRNA pathway evolution and its adaptation to transposon diversity in the teleost fish remain unknown. This article unveils evolutionary scene of piRNA pathway and its association with diverse transposons by systematically comparative analysis on diverse teleost fish genomes. Selective pressure analysis on piRNA pathway and miRNA/siRNA (microRNA/small interfering RNA) pathway genes between teleosts and mammals showed an accelerated evolution of piRNA pathway genes in the teleost lineages, and positive selection on functional PAZ (Piwi/Ago/Zwille) and Tudor domains involved in the Piwi-piRNA/Tudor interaction, suggesting that the amino acid substitutions are adaptive to their functions in piRNA pathway in the teleost fish species. Notably five piRNA pathway genes evolved faster in the swamp eel, a kind of protogynous hermaphrodite fish, than the other teleosts, indicating a differential evolution of piRNA pathway between the swamp eel and other gonochoristic fishes. In addition, genome-wide analysis showed higher diversity of transposons in the teleost fish species compared with mammals. Our results suggest that rapidly evolved piRNA pathway in the teleost fish is likely to be involved in the adaption to transposon diversity. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Community dynamics and ecosystem simplification in a high-CO2 ocean.

PubMed

Kroeker, Kristy J; Gambi, Maria Cristina; Micheli, Fiorenza

2013-07-30

Disturbances are natural features of ecosystems that promote variability in the community and ultimately maintain diversity. Although it is recognized that global change will affect environmental disturbance regimes, our understanding of the community dynamics governing ecosystem recovery and the maintenance of functional diversity in future scenarios is very limited. Here, we use one of the few ecosystems naturally exposed to future scenarios of environmental change to examine disturbance and recovery dynamics. We examine the recovery patterns of marine species from a physical disturbance across different acidification regimes caused by volcanic CO2 vents. Plots of shallow rocky reef were cleared of all species in areas of ambient, low, and extreme low pH that correspond to near-future and extreme scenarios for ocean acidification. Our results illustrate how acidification decreases the variability of communities, resulting in homogenization and reduced functional diversity at a landscape scale. Whereas the recovery trajectories in ambient pH were highly variable and resulted in a diverse range of assemblages, recovery was more predictable with acidification and consistently resulted in very similar algal-dominated assemblages. Furthermore, low pH zones had fewer signs of biological disturbance (primarily sea urchin grazing) and increased recovery rates of the dominant taxa (primarily fleshy algae). Together, our results highlight how environmental change can cause ecosystem simplification via environmentally mediated changes in community dynamics in the near future, with cascading impacts on functional diversity and ecosystem function.

The evolution of the competition-dispersal trade-off affects α- and β-diversity in a heterogeneous metacommunity.

PubMed

Laroche, Fabien; Jarne, Philippe; Perrot, Thomas; Massol, Francois

2016-04-27

Difference in dispersal ability is a key driver of species coexistence in metacommunities. However, the available frameworks for interpreting species diversity patterns in natura often overlook trade-offs and evolutionary constraints associated with dispersal. Here, we build a metacommunity model accounting for dispersal evolution and a competition-dispersal trade-off. Depending on the distribution of carrying capacities among communities, species dispersal values are distributed either around a single strategy (evolutionarily stable strategy, ESS), or around distinct strategies (evolutionary branching, EB). We show that limited dispersal generates spatial aggregation of dispersal traits in ESS and EB scenarios, and that the competition-dispersal trade-off strengthens the pattern in the EB scenario. Importantly, individuals in larger (respectively (resp.) smaller) communities tend to harbour lower (resp. higher) dispersal, especially under the EB scenario. We explore how dispersal evolution affects species diversity patterns by comparing those from our model to the predictions of a neutral metacommunity model. The most marked difference is detected under EB, with distinctive values of both α- and β-diversity (e.g. the dissimilarity in species composition between small and large communities was significantly larger than neutral predictions). We conclude that, from an empirical perspective, jointly assessing community carrying capacity with species dispersal strategies should improve our understanding of diversity patterns in metacommunities. © 2016 The Author(s).

Computer-aided testing of pilot response to critical in-flight events

NASA Technical Reports Server (NTRS)

Giffin, W. C.; Rockwell, T. H.

1984-01-01

This research on pilot response to critical in-flight events employs a unique methodology including an interactive computer-aided scenario-testing system. Navigation displays, instrument-panel displays, and assorted textual material are presented on a touch-sensitive CRT screen. Problem diagnosis scenarios, destination-diversion scenarios and combined destination/diagnostic tests are available. A complete time history of all data inquiries and responses is maintained. Sample results of diagnosis scenarios obtained from testing 38 licensed pilots are presented and discussed.

The Mexican Oil Industry: Governance, Resource and Social Concerns

DTIC Science & Technology

2011-10-28

Baker Institute: Mexico could become oil importer by 2010”, Oil & Gas Journal 31 “Mexico unveils new deepwater drilling regulations”, energy-pedia...Efficiency: The Politics of Investment Policies in the Oil Industry”, 17. 56 Ibid 57 “Mexico unveils new deepwater drilling regulations”, energy...Bogan, “With Easy Oil Gone, Pemex Sobers Up” 60 “Mexico unveils new deepwater drilling regulations”, energy-pedia news 61 Jeremy Martin “Oil in

Climate-suitable planting as a strategy for maintaining forest productivity and functional diversity.

PubMed

Duveneck, Matthew J; Scheller, Robert M

2015-09-01

Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000-2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-as-usual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass).

Contributions of axionlike particles to lepton dipole moments

DOE PAGES

Marciano, W. J.; Masiero, A.; Paradisi, P.; ...

2016-12-30

We examined contributions of a spin-0 axionlike particle (ALP) to lepton dipole moments, g - 2 and EDMs. Barr-Zee and light-by-light loop effects from a light pseudoscalar ALP are found to be capable of resolving the longstanding muon g - 2 discrepancy at the expense of relatively large ALP - γ γ couplings. We also discussed the compatibility of such large couplings with direct experimental constraints and perturbative unitarity bounds. Future tests of such a scenario are described. For C P -violating ALP couplings, the electron EDM is found to probe much smaller, theoretically more easily accommodated ALP interactions. Wemore » advocate future planned improvements in electron EDM searches as a way to not only significantly constrain ALP parameters, but also potentially unveil a new source of C P violation which could have far-reaching ramifications.« less

Detailed Experimental Study of Ion Acceleration by Interaction of an Ultra-Short Intense Laser with an Underdense Plasma

PubMed Central

Kahaly, S.; Sylla, F.; Lifschitz, A.; Flacco, A.; Veltcheva, M.; Malka, V.

2016-01-01

Ion acceleration from intense (Iλ2 > 1018 Wcm−2 μm2) laser-plasma interaction is experimentally studied within a wide range of He gas densities. Focusing an ultrashort pulse (duration  ion plasma period) on a newly designed submillimetric gas jet system, enabled us to inhibit total evacuation of electrons from the central propagation channel reducing the radial ion acceleration associated with ponderomotive Coulomb explosion, a mechanism predominant in the long pulse scenario. New ion acceleration mechanism have been unveiled in this regime leading to non-Maxwellian quasi monoenergetic features in the ion energy spectra. The emitted nonthermal ion bunches show a new scaling of the ion peak energy with plasma density. The scaling identified in this new regime differs from previously reported studies. PMID:27531755

The recent evolution of the question "What is life"?

PubMed

Morange, Michel

2012-01-01

The question "What is life?" is absent from the writings of present-day biologists and scientists. However, an answer to this question, even if only partial, is needed for successful completion of projects in astrobiology and synthetic biology. The reasons for this absence are metaphysical, epistemological, and historical. No one has a full answer to this question, but there are many good reasons to keep posing it. Answers are no longer sought in the existence of strengths or mechanisms specific to life. The secret of life has been unveiled and it is nothing other than physical chemistry. What remains to be understood is the way the characteristics of organisms have emerged and been combined within one unique "object." The answer to the question "What is life?" is now looked for in the scenario that generated life.

Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress

PubMed Central

Rukhlenko, Oleksii S.; Dudchenko, Olga A.; Zlobina, Ksenia E.; Guria, Georgy Th.

2015-01-01

Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines. PMID:26222505

Unveiling consumer's privacy paradox behaviour in an economic exchange.

PubMed

Motiwalla, Luvai F; Li, Xiao-Bai

2016-01-01

Privacy paradox is of great interest to IS researchers and firms gathering personal information. It has been studied from social, behavioural, and economic perspectives independently. However, prior research has not examined the degrees of influence these perspectives contribute to the privacy paradox problem. We combine both economic and behavioural perspectives in our study of the privacy paradox with a price valuation of personal information through an economic experiment combined with a behavioural study on privacy paradox. Our goal is to reveal more insights on the privacy paradox through economic valuation on personal information. Results indicate that general privacy concerns or individual disclosure concerns do not have a significant influence on the price valuation of personal information. Instead, prior disclosure behaviour in specific scenario, like with healthcare providers or social networks, is a better indicator of consumer price valuations.

Unveiling consumer’s privacy paradox behaviour in an economic exchange

PubMed Central

Li, Xiao-Bai

2015-01-01

Privacy paradox is of great interest to IS researchers and firms gathering personal information. It has been studied from social, behavioural, and economic perspectives independently. However, prior research has not examined the degrees of influence these perspectives contribute to the privacy paradox problem. We combine both economic and behavioural perspectives in our study of the privacy paradox with a price valuation of personal information through an economic experiment combined with a behavioural study on privacy paradox. Our goal is to reveal more insights on the privacy paradox through economic valuation on personal information. Results indicate that general privacy concerns or individual disclosure concerns do not have a significant influence on the price valuation of personal information. Instead, prior disclosure behaviour in specific scenario, like with healthcare providers or social networks, is a better indicator of consumer price valuations. PMID:27708687

Models of chromatin spatial organisation in the cell nucleus

NASA Astrophysics Data System (ADS)

Nicodemi, Mario

2014-03-01

In the cell nucleus chromosomes have a complex architecture serving vital functional purposes. Recent experiments have started unveiling the interaction map of DNA sites genome-wide, revealing different levels of organisation at different scales. The principles, though, which orchestrate such a complex 3D structure remain still mysterious. I will overview the scenario emerging from some classical polymer physics models of the general aspect of chromatin spatial organisation. The available experimental data, which can be rationalised in a single framework, support a picture where chromatin is a complex mixture of differently folded regions, self-organised across spatial scales according to basic physical mechanisms. I will also discuss applications to specific DNA loci, e.g. the HoxB locus, where models informed with biological details, and tested against targeted experiments, can help identifying the determinants of folding.

PLANT DIVERSITY

EPA Science Inventory

Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

Jupiter's Water Worlds

NASA Technical Reports Server (NTRS)

Pappalardo, R. T.

2004-01-01

When the twin Voyager spacecraft cruised past Jupiter in 1979, they did more than rewrite the textbooks on the giant planet. Their cameras also unveiled the astounding diversity of the four planet-size moons of ice and stone known as the Galilean satellites. The Voyagers revealed the cratered countenance of Callisto, the valleys and ridges of Ganymede, the cracked face of Europa, and the spewing volcanoes of Io. But it would take a spacecraft named for Italian scientist Galileo, who discovered the moons in 1610, to reveal the true complexity of these worlds and to begin to divulge their interior secrets. Incredibly, the Galileo data strongly suggest that Jupiter's three large icy moons (all but rocky Io) hide interior oceans.

Information filtering based on corrected redundancy-eliminating mass diffusion

PubMed Central

Zhu, Xuzhen; Yang, Yujie; Chen, Guilin; Medo, Matus; Tian, Hui

2017-01-01

Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects’ attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is based on a spreading process on the network. Extensive experiments on three benchmark data sets—Movilens, Netflix and Amazon—show that when used in recommendation, the CRE yields significant improvements in terms of recommendation accuracy and diversity. A detailed analysis is presented to unveil the origins of the observed differences between the CRE and mainstream similarity indices. PMID:28749976

Unveiling in situ interactions between marine protists and bacteria through single cell sequencing

PubMed Central

Martinez-Garcia, Manuel; Brazel, David; Poulton, Nicole J; Swan, Brandon K; Gomez, Monica Lluesma; Masland, Dashiell; Sieracki, Michael E; Stepanauskas, Ramunas

2012-01-01

Heterotrophic protists are a highly diverse and biogeochemically significant component of marine ecosystems, yet little is known about their species-specific prey preferences and symbiotic interactions in situ. Here we demonstrate how these previously unresolved questions can be addressed by sequencing the eukaryote and bacterial SSU rRNA genes from individual, uncultured protist cells collected from their natural marine environment and sorted by flow cytometry. We detected Pelagibacter ubique in association with a MAST-4 protist, an actinobacterium in association with a chrysophyte and three bacteroidetes in association with diverse protist groups. The presence of identical phylotypes among the putative prey and the free bacterioplankton in the same sample provides evidence for predator–prey interactions. Our results also suggest a discovery of novel symbionts, distantly related to Rickettsiales and the candidate divisions ZB3 and TG2, associated with Cercozoa and Chrysophyta cells. This study demonstrates the power of single cell sequencing to untangle ecological interactions between uncultured protists and prokaryotes. PMID:21938022

Dopant-Modulating Mechanism of Lithium Adsorption and Diffusion at the Graphene /Li2S Interface

NASA Astrophysics Data System (ADS)

Guo, Lichao; Li, Jiajun; Wang, Huayu; Zhao, Naiqin; Shi, Chunsheng; Ma, Liying; He, Chunnian; He, Fang; Liu, Enzuo

2018-02-01

Graphene modification is one of the most effective routes to enhance the electrochemical properties of the transition-metal sulfide anode for Li-ion batteries and the Li2S cathode for Li-S batteries. Boron, nitrogen, oxygen, phosphorus, and sulfur doping greatly affect the electrochemical properties of Li2S /graphene . Here, we investigate the interfacial binding energy, lithium adsorption energy, interface diffusion barrier, and electronic structure by first-principles calculations to unveil the diverse effects of different dopants during interfacial lithiation reactions. The interfacial lithium storage follows the pseudocapacitylike mechanism with intercalation character. Two different mechanisms are revealed to enhance the interfacial lithium adsorption and diffusion, which are the electron-deficiency host doping and the vacancylike structure evolutions with bond breaking. The synergistic effect between different dopants with diverse doping effects is also proposed. The results give a theoretical basis for the materials design with doped graphene as advanced materials modification for energy storage.

Metabolomic unveiling of a diverse range of green tea (Camellia sinensis) metabolites dependent on geography.

PubMed

Lee, Jang-Eun; Lee, Bum-Jin; Chung, Jin-Oh; Kim, Hak-Nam; Kim, Eun-Hee; Jung, Sungheuk; Lee, Hyosang; Lee, Sang-Jun; Hong, Young-Shick

2015-05-01

Numerous factors such as geographical origin, cultivar, climate, cultural practices, and manufacturing processes influence the chemical compositions of tea, in the same way as growing conditions and grape variety affect wine quality. However, the relationships between these factors and tea chemical compositions are not well understood. In this study, a new approach for non-targeted or global analysis, i.e., metabolomics, which is highly reproducible and statistically effective in analysing a diverse range of compounds, was used to better understand the metabolome of Camellia sinensis and determine the influence of environmental factors, including geography, climate, and cultural practices, on tea-making. We found a strong correlation between environmental factors and the metabolome of green, white, and oolong teas from China, Japan, and South Korea. In particular, multivariate statistical analysis revealed strong inter-country and inter-city relationships in the levels of theanine and catechin derivatives found in green and white teas. This information might be useful for assessing tea quality or producing distinct tea products across different locations, and highlights simultaneous identification of diverse tea metabolites through an NMR-based metabolomics approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

ARC-2012-ACD12-0016-004

NASA Image and Video Library

2012-01-25

Dr. Brauch Blumberg portrait unveiling ceremony held at the Syverston Auditorium (N-201) NASA Ames Researc Center, Moffett Field, CA. Lynn Harper and Estelle Dotson (of NASA Astrobilolgy Institute) unveil portrait.

A formal framework for scenario development in support of environmental decision-making

USGS Publications Warehouse

Mahmoud, M.; Liu, Yajing; Hartmann, H.; Stewart, S.; Wagener, T.; Semmens, D.; Stewart, R.; Gupta, H.; Dominguez, D.; Dominguez, F.; Hulse, D.; Letcher, R.; Rashleigh, Brenda; Smith, C.; Street, R.; Ticehurst, J.; Twery, M.; van, Delden H.; Waldick, R.; White, D.; Winter, L.

2009-01-01

Scenarios are possible future states of the world that represent alternative plausible conditions under different assumptions. Often, scenarios are developed in a context relevant to stakeholders involved in their applications since the evaluation of scenario outcomes and implications can enhance decision-making activities. This paper reviews the state-of-the-art of scenario development and proposes a formal approach to scenario development in environmental decision-making. The discussion of current issues in scenario studies includes advantages and obstacles in utilizing a formal scenario development framework, and the different forms of uncertainty inherent in scenario development, as well as how they should be treated. An appendix for common scenario terminology has been attached for clarity. Major recommendations for future research in this area include proper consideration of uncertainty in scenario studies in particular in relation to stakeholder relevant information, construction of scenarios that are more diverse in nature, and sharing of information and resources among the scenario development research community. ?? 2008 Elsevier Ltd.

NANO SCENARIO: Role-Playing to Appreciate the Societal Effects of Nanotechnology

ERIC Educational Resources Information Center

Jarmon, Leslie; Keating, Elizabeth

2008-01-01

This article describes a university-sponsored experiential-based simulation, the NANO SCENARIO, to increase the public's awareness and affect attitudes on the societal implications of nanoscience and nanotechnology by bringing together diverse stakeholders' perspectives in a participatory learning environment. Nanotechnology has the potential for…

Examining the Societal Impacts of Nanotechnology through Simulation: NANO SCENARIO

ERIC Educational Resources Information Center

Jarmon, Leslie; Keating, Elizabeth; Toprac, Paul

2008-01-01

This article describes a university-sponsored experiential-based simulation, the NANO SCENARIO, to increase the public's awareness and affect attitudes on the societal implications of nanoscience and nanotechnology by bringing together diverse stakeholders' perspectives in a participatory learning environment. Nanotechnology has the potential for…

Modeling Pollinator Community Response to Contrasting Bioenergy Scenarios

PubMed Central

Bennett, Ashley B.; Meehan, Timothy D.; Gratton, Claudio; Isaacs, Rufus

2014-01-01

In the United States, policy initiatives aimed at increasing sources of renewable energy are advancing bioenergy production, especially in the Midwest region, where agricultural landscapes dominate. While policy directives are focused on renewable fuel production, biodiversity and ecosystem services will be impacted by the land-use changes required to meet production targets. Using data from field observations, we developed empirical models for predicting abundance, diversity, and community composition of flower-visiting bees based on land cover. We used these models to explore how bees might respond under two contrasting bioenergy scenarios: annual bioenergy crop production and perennial grassland bioenergy production. In the two scenarios, 600,000 ha of marginal annual crop land or marginal grassland were converted to perennial grassland or annual row crop bioenergy production, respectively. Model projections indicate that expansion of annual bioenergy crop production at this scale will reduce bee abundance by 0 to 71%, and bee diversity by 0 to 28%, depending on location. In contrast, converting annual crops on marginal soil to perennial grasslands could increase bee abundance from 0 to 600% and increase bee diversity between 0 and 53%. Our analysis of bee community composition suggested a similar pattern, with bee communities becoming less diverse under annual bioenergy crop production, whereas bee composition transitioned towards a more diverse community dominated by wild bees under perennial bioenergy crop production. Models, like those employed here, suggest that bioenergy policies have important consequences for pollinator conservation. PMID:25365559

How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans

PubMed Central

Campião, Karla Magalhães; Ribas, Augusto Cesar de Aquino; Morais, Drausio Honorio; da Silva, Reinaldo José; Tavares, Luiz Eduardo Roland

2015-01-01

There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts’ phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts’ phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts’ clade diversification suggests it is strongly influenced by ecological and contemporary constrains. PMID:26473593

Diversity patterns and activity of uncultured marine heterotrophic flagellates unveiled with pyrosequencing

PubMed Central

Logares, Ramiro; Audic, Stephane; Santini, Sebastien; Pernice, Massimo C; de Vargas, Colomban; Massana, Ramon

2012-01-01

Flagellated heterotrophic microeukaryotes have key roles for the functioning of marine ecosystems as they channel large amounts of organic carbon to the upper trophic levels and control the population sizes of bacteria and archaea. Still, we know very little on the diversity patterns of most groups constituting this evolutionary heterogeneous assemblage. Here, we investigate 11 groups of uncultured flagellates known as MArine STramenopiles (MASTs). MASTs are ecologically very important and branch at the base of stramenopiles. We explored the diversity patterns of MASTs using pyrosequencing (18S rDNA) in coastal European waters. We found that MAST groups range from highly to lowly diversified. Pyrosequencing (hereafter ‘454') allowed us to approach to the limits of taxonomic diversity for all MAST groups, which varied in one order of magnitude (tens to hundreds) in terms of operational taxonomic units (98% similarity). We did not evidence large differences in activity, as indicated by ratios of DNA:RNA-reads. Most groups were strictly planktonic, although we found some groups that were active in sediments and even in anoxic waters. The proportion of reads per size fraction indicated that most groups were composed of very small cells (∼2–5 μm). In addition, phylogenetically different assemblages appeared to be present in different size fractions, depths and geographic zones. Thus, MAST diversity seems to be highly partitioned in spatial scales. Altogether, our results shed light on these ecologically very important but poorly known groups of uncultured marine flagellates. PMID:22534609

How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

PubMed

Campião, Karla Magalhães; Ribas, Augusto Cesar de Aquino; Morais, Drausio Honorio; da Silva, Reinaldo José; Tavares, Luiz Eduardo Roland

2015-01-01

There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR). We also test whether parasite diversity is related to hosts' phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts' phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts' clade diversification suggests it is strongly influenced by ecological and contemporary constrains.

The conservation of diversity in forest trees

Treesearch

F. Thomas Ledig

1988-01-01

Deforestation, pollution, and climatic change threaten forest diversity all over the world. And because forests are the habitats for diverse organisms, the threat is extended to all the flora and fauna associated with forests, not only forest trees. In a worst case scenario, if the tropical forest in Latin America was reduced to the areas now set aside in parks and...

The Formation and Evolution of Galactic Disks with APOGEE and the Gaia Survey

NASA Astrophysics Data System (ADS)

Li, Chengdong; Zhao, Gang; Zhai, Meng; Jia, Yunpeng

2018-06-01

We explore the structure and evolutionary history of Galactic disks with Apache Point Observatory Galactic Evolution Experiment data release 13 (DR13 hereafter) and Gaia Tycho-Gaia Astrometric Solution data. We use the [α/M] ratio to allocate stars into particular Galactic components to elucidate the chemical and dynamical properties of the thin and thick disks. The spatial motions of the sample stars are obtained in Galactic Cartesian and cylindrical coordinates. We analyze the abundance trends and metallicity and [α/M] gradients of the thick and thin disks. We confirm the existence of metal-weak thick-disk stars in Galactic disks. A kinematical method is used to select the thin- and thick-disk stars for comparison. We calculate the scale length and scale height of the kinematically and chemically selected thick and thin disks based on the axisymmetric Jeans equation. We conclude that the scale length of the thick disk is approximately equal to that of the thin disk via a kinematical approach. For the chemical selection, this disparity is about 1 kpc. Finally, we get the stellar orbital parameters and try to unveil the formation scenario of the thick disk. We conclude that the gas-rich merger and radial migration are more reasonable formation scenarios for the thick disk.

Volcano seismicity and ground deformation unveil the gravity-driven magma discharge dynamics of a volcanic eruption.

PubMed

Ripepe, Maurizio; Donne, Dario Delle; Genco, Riccardo; Maggio, Giuseppe; Pistolesi, Marco; Marchetti, Emanuele; Lacanna, Giorgio; Ulivieri, Giacomo; Poggi, Pasquale

2015-05-18

Effusive eruptions are explained as the mechanism by which volcanoes restore the equilibrium perturbed by magma rising in a chamber deep in the crust. Seismic, ground deformation and topographic measurements are compared with effusion rate during the 2007 Stromboli eruption, drawing an eruptive scenario that shifts our attention from the interior of the crust to the surface. The eruption is modelled as a gravity-driven drainage of magma stored in the volcanic edifice with a minor contribution of magma supplied at a steady rate from a deep reservoir. Here we show that the discharge rate can be predicted by the contraction of the volcano edifice and that the very-long-period seismicity migrates downwards, tracking the residual volume of magma in the shallow reservoir. Gravity-driven magma discharge dynamics explain the initially high discharge rates observed during eruptive crises and greatly influence our ability to predict the evolution of effusive eruptions.

Unveiling the past of the Galactic nucleus with X-ray echoes

NASA Astrophysics Data System (ADS)

Chuard, D.; Terrier, R.; Goldwurm, A.; Clavel, M.; Soldi, S.; Morris, M. R.; Ponti, G.; Walls, M.; Chernyakova, M.

2017-12-01

Giant molecular clouds populating the central molecular zone have a high enough column density to reflect X-rays coming from strong compact sources in their neighbourhood, including possible powerful outbursts from the Galactic supermassive black hole SgrA. From observations of the molecular complex Sgr C made with the X-ray observatories XMM and Chandra between 2000 and 2014, we confirm this reflection scenario, even though the region hosts several objects (including two PWN candidates) that may be responsible for intense cosmic-ray production. By comparing data to Monte Carlo simulated reflection spectra, we are able to put the best constraints to date on the line-of-sight positions of the main bright clumps of the molecular complex. Ultimately, extending this approach by the inclusion of other molecular complexes allows us to partially reconstruct the past lightcurve of the Galactic supermassive black hole.

The Evolution of Building a Diverse Geosciences in the United States

NASA Astrophysics Data System (ADS)

Keane, Christopher; Houlton, Heather; Leahy, P. Patrick

2016-04-01

Since the 1960s, the United States has had numerous systematic efforts to support diversity in all parts of society. The American Geosciences Institute has had active ongoing research and diversity promotion programs in the geosciences since 1972. Over this time, the drivers and goals of promoting a diverse discipline have evolved, including in the scope and definition of diversity. The success of these efforts have been mixed, largely driven by wildly different responses by specific gender and racial subsets of the population. Some critical cultural barriers have been solidly identified and mitigation approaches promoted. For example, the use of field work in promotion of geoscience careers and education programs is viewed as a distinct negative by many African American and Hispanic communities as it equates geoscience as non-professional work. Similarly, efforts at improving gender diversity have had great success, especially in the private sector, as life-balance policies and mitigations of implicit biases have been addressed. Yet success in addressing some of these cultural and behavioral issues has also started to unveil other overarching factors, such as the role of socio-economic and geographic location. Recent critical changes in the definition of diversity that have been implemented will be discussed. These include dropping Asian races as underrepresented, the introduction of the multiracial definition, evolution of the nature of gender, and the increased awareness of persons with disabilities as a critical diverse population. This has been coupled with dramatic changes in the drivers for promoting diversity in the geosciences in the U.S. from a moral and ethical good to one of economic imperative and recognizing the way to access the best talent in the population as the U.S. rapidly approaches being a majority minority society. These changes are leading to new approaches and strategies, for which we will highlight specific programmatic efforts both by AGI and other leading US geoscience diversity efforts.

So These Numbers Really Mean Something? A Role Playing Scenario-Based Approach to the Undergraduate Instrumental Analysis Laboratory

ERIC Educational Resources Information Center

Grannas, Amanda M.; Lagalante, Anthony F.

2010-01-01

A new curricular approach in our undergraduate second-year instrumental analysis laboratory was implemented. Students work collaboratively on scenarios in diverse fields including pharmaceuticals, forensics, gemology, art conservation, and environmental chemistry. Each laboratory section (approximately 12 students) is divided into three groups…

Genomics-inspired discovery of natural products.

PubMed

Winter, Jaclyn M; Behnken, Swantje; Hertweck, Christian

2011-02-01

The massive surge in genome sequencing projects has opened our eyes to the overlooked biosynthetic potential and metabolic diversity of microorganisms. While traditional approaches have been successful at identifying many useful therapeutic agents from these organisms, new tactics are needed in order to exploit their true biosynthetic potential. Several genomics-inspired strategies have been successful in unveiling new metabolites that were overlooked under standard fermentation and detection conditions. In addition, genome sequences have given us valuable insight for genetically engineering biosynthesis gene clusters that remain silent or are poorly expressed in the absence of a specific trigger. As more genome sequences are becoming available, we are noticing the emergence of underexplored or neglected organisms as alternative resources for new therapeutic agents. Copyright © 2010 Elsevier Ltd. All rights reserved.

Emerging insights on intestinal dysbiosis during bacterial infections☆

PubMed Central

Pham, Tu Anh N; Lawley, Trevor D

2014-01-01

Infection of the gastrointestinal tract is commonly linked to pathological imbalances of the resident microbiota, termed dysbiosis. In recent years, advanced high-throughput genomic approaches have allowed us to examine the microbiota in an unprecedented manner, revealing novel biological insights about infection-associated dysbiosis at the community and individual species levels. A dysbiotic microbiota is typically reduced in taxonomic diversity and metabolic function, and can harbour pathobionts that exacerbate intestinal inflammation or manifest systemic disease. Dysbiosis can also promote pathogen genome evolution, while allowing the pathogens to persist at high density and transmit to new hosts. A deeper understanding of bacterial pathogenicity in the context of the intestinal microbiota should unveil new approaches for developing diagnostics and therapies for enteropathogens. PMID:24581695

Energy Structure and Energy Security under Climate Mitigation Scenarios in China

PubMed Central

Matsumoto, Ken’ichi

2015-01-01

This study investigates how energy structure and energy security in China will change in the future under climate mitigation policy scenarios using Representative Concentration Pathways in a computable general equilibrium model. The findings suggest that to reduce greenhouse gas emissions, China needs to shift its energy structure from fossil fuel dominance to renewables and nuclear. The lower the allowable emissions, the larger the shifts required. Among fossil fuels, coal use particularly must significantly decrease. Such structural shifts will improve energy self-sufficiency, thus enhancing energy security. Under the policy scenarios, energy-source diversity as measured by the Herfindahl Index improves until 2050, after which diversity declines because of high dependence on a specific energy source (nuclear and biomass). Overall, however, it is revealed that energy security improves along with progress in climate mitigation. These improvements will also contribute to the economy by reducing energy procurement risks. PMID:26660094

"We Are All for Diversity, but . . .": How Faculty Hiring Committees Reproduce Whiteness and Practical Suggestions for How They Can Change

ERIC Educational Resources Information Center

Sensoy, Özlem; DiAngelo, Robin

2017-01-01

Despite stated commitments to diversity, predominantly White academic institutions still have not increased racial diversity among their faculty. In this article Robin DiAngelo and Özlem Sensoy focus on one entry point for doing so--the faculty hiring process. They analyze a typical faculty hiring scenario and identify the most common practices…

Assessing the phylogeographic history of the montane caddisfly Thremma gallicum using mitochondrial and restriction-site-associated DNA (RAD) markers

PubMed Central

Macher, Jan-Niklas; Rozenberg, Andrey; Pauls, Steffen U; Tollrian, Ralph; Wagner, Rüdiger; Leese, Florian

2015-01-01

Repeated Quaternary glaciations have significantly shaped the present distribution and diversity of several European species in aquatic and terrestrial habitats. To study the phylogeography of freshwater invertebrates, patterns of intraspecific variation have been examined primarily using mitochondrial DNA markers that may yield results unrepresentative of the true species history. Here, population genetic parameters were inferred for a montane aquatic caddisfly, Thremma gallicum, by sequencing a 658-bp fragment of the mitochondrial CO1 gene, and 12,514 nuclear RAD loci. T. gallicum has a highly disjunct distribution in southern and central Europe, with known populations in the Cantabrian Mountains, Pyrenees, Massif Central, and Black Forest. Both datasets represented rangewide sampling of T. gallicum. For the CO1 dataset, this included 352 specimens from 26 populations, and for the RAD dataset, 17 specimens from eight populations. We tested 20 competing phylogeographic scenarios using approximate Bayesian computation (ABC) and estimated genetic diversity patterns. Support for phylogeographic scenarios and diversity estimates differed between datasets with the RAD data favouring a southern origin of extant populations and indicating the Cantabrian Mountains and Massif Central populations to represent highly diverse populations as compared with the Pyrenees and Black Forest populations. The CO1 data supported a vicariance scenario (north–south) and yielded inconsistent diversity estimates. Permutation tests suggest that a few hundred polymorphic RAD SNPs are necessary for reliable parameter estimates. Our results highlight the potential of RAD and ABC-based hypothesis testing to complement phylogeographic studies on non-model species. PMID:25691988

"More Alike than Different": Learning about Diversity from People with Disabilities

ERIC Educational Resources Information Center

Anderson, Jenn; Westwick, Joshua; Anderson, Justin

2016-01-01

Courses: Interpersonal Communication, Health Communication, Intercultural Communication. Objectives: After completing this semester-long activity students, should be able to (1) apply course concepts (i.e., stereotypes, identity, listening, language, and conflict) to diverse real-world scenarios; (2) explain the utility of intergroup contact…

Disaggregating sorghum yield reductions under warming scenarios exposes narrow genetic diversity in US breeding programs

PubMed Central

Tack, Jesse; Lingenfelser, Jane; Jagadish, S. V. Krishna

2017-01-01

Historical adaptation of sorghum production to arid and semiarid conditions has provided promise regarding its sustained productivity under future warming scenarios. Using Kansas field-trial sorghum data collected from 1985 to 2014 and spanning 408 hybrid cultivars, we show that sorghum productivity under increasing warming scenarios breaks down. Through extensive regression modeling, we identify a temperature threshold of 33 °C, beyond which yields start to decline. We show that this decline is robust across both field-trial and on-farm data. Moderate and higher warming scenarios of 2 °C and 4 °C resulted in roughly 17% and 44% yield reductions, respectively. The average reduction across warming scenarios from 1 to 5 °C is 10% per degree Celsius. Breeding efforts over the last few decades have developed high-yielding cultivars with considerable variability in heat resilience, but even the most tolerant cultivars did not offer much resilience to warming temperatures. This outcome points to two concerns regarding adaption to global warming, the first being that adaptation will not be as simple as producers’ switching among currently available cultivars and the second being that there is currently narrow genetic diversity for heat resilience in US breeding programs. Using observed flowering dates and disaggregating heat-stress impacts, both pre- and postflowering stages were identified to be equally important for overall yields. These findings suggest the adaptation potential for sorghum under climate change would be greatly facilitated by introducing wider genetic diversity for heat resilience into ongoing breeding programs, and that there should be additional efforts to improve resilience during the preflowering phase. PMID:28808013

Evaluating the impact of irrigation on surface water - groundwater interaction and stream temperature in an agricultural watershed.

PubMed

Essaid, Hedeff I; Caldwell, Rodney R

2017-12-01

Changes in groundwater discharge to streams caused by irrigation practices can influence stream temperature. Observations along two currently flood-irrigated reaches in the 640-square-kilometer upper Smith River watershed, an important agricultural and recreational fishing area in west-central Montana, showed a downstream temperature decrease resulting from groundwater discharge to the stream. A watershed-scale coupled surface water and groundwater flow model was used to examine changes in streamflow, groundwater discharge to the stream and stream temperature resulting from irrigation practices. The upper Smith River watershed was used to develop the model framework including watershed climate, topography, hydrography, vegetation, soil properties and current irrigation practices. Model results were used to compare watershed streamflow, groundwater recharge, and groundwater discharge to the stream for three scenarios: natural, pre-irrigation conditions (PreIrr); current irrigation practices involving mainly stream diversion for flood and sprinkler irrigation (IrrCurrent); and a hypothetical scenario with only groundwater supplying sprinkler irrigation (IrrGW). Irrigation increased groundwater recharge relative to natural PreIrr conditions because not all applied water was removed by crop evapotranspiration. Groundwater storage and groundwater discharge to the stream increased relative to natural PreIrr conditions when the source of irrigation water was mainly stream diversion as in the IrrCurrent scenario. The hypothetical IrrGW scenario, in which groundwater withdrawals were the sole source of irrigation water, resulted in widespread lowering of the water table and associated decreases in groundwater storage and groundwater discharge to the stream. A mixing analysis using model predicted groundwater discharge along the reaches suggests that stream diversion and flood irrigation, represented in the IrrCurrent scenario, has led to cooling of stream temperatures relative to natural PreIrr conditions improving fish thermal habitat. However, the decrease in groundwater discharge in the IrrGW scenario resulting from large-scale groundwater withdrawal for irrigation led to warmer than natural stream temperatures and possible degradation of fish habitat. Published by Elsevier B.V.

Evaluating the impact of irrigation on surface water – groundwater interaction and stream temperature in an agricultural watershed

USGS Publications Warehouse

Essaid, Hedeff I.; Caldwell, Rodney R.

2017-01-01

Changes in groundwater discharge to streams caused by irrigation practices can influence stream temperature. Observations along two currently flood-irrigated reaches in the 640-square-kilometer upper Smith River watershed, an important agricultural and recreational fishing area in west-central Montana, showed a downstream temperature decrease resulting from groundwater discharge to the stream. A watershed-scale coupled surface water and groundwater flow model was used to examine changes in streamflow, groundwater discharge to the stream and stream temperature resulting from irrigation practices. The upper Smith River watershed was used to develop the model framework including watershed climate, topography, hydrography, vegetation, soil properties and current irrigation practices. Model results were used to compare watershed streamflow, groundwater recharge, and groundwater discharge to the stream for three scenarios: natural, pre-irrigation conditions (PreIrr); current irrigation practices involving mainly stream diversion for flood and sprinkler irrigation (IrrCurrent); and a hypothetical scenario with only groundwater supplying sprinkler irrigation (IrrGW). Irrigation increased groundwater recharge relative to natural PreIrr conditions because not all applied water was removed by crop evapotranspiration. Groundwater storage and groundwater discharge to the stream increased relative to natural PreIrr conditions when the source of irrigation water was mainly stream diversion as in the IrrCurrent scenario. The hypothetical IrrGW scenario, in which groundwater withdrawals were the sole source of irrigation water, resulted in widespread lowering of the water table and associated decreases in groundwater storage and groundwater discharge to the stream. A mixing analysis using model predicted groundwater discharge along the reaches suggests that stream diversion and flood irrigation, represented in the IrrCurrent scenario, has led to cooling of stream temperatures relative to natural PreIrr conditions improving fish thermal habitat. However, the decrease in groundwater discharge in the IrrGW scenario resulting from large-scale groundwater withdrawal for irrigation led to warmer than natural stream temperatures and possible degradation of fish habitat.

Metal-ligand cooperation in catalytic intramolecular hydroamination: a computational study of iridium-pyrazolato cooperative activation of aminoalkenes.

PubMed

Tobisch, Sven

2012-06-04

The present study comprehensively explores diverse mechanistic pathways for intramolecular hydroamination of prototype 2,2-dimethyl-4-penten-1-amine by Cp*Ir chloropyrazole (1; Cp*=pentamethylcyclopentadienyl) in the presence of KOtBu base with the aid of density functional theory (DFT) calculations. The most accessible mechanistic pathway for catalytic turnover commences from Cp*Ir pyrazolato (Pz) substrate adduct 2⋅S, representing the catalytically competent compound and proceeds via initial electrophilic activation of the olefin C=C bond by the metal centre. It entails 1) facile and reversible anti nucleophilic amine attack on the iridium-olefin linkage; 2) Ir-C bond protonolysis via stepwise transfer of the ammonium N-H proton at the zwitterionic [Cp*IrPz-alkyl] intermediate onto the metal that is linked to turnover-limiting, reductive, cycloamine elimination commencing from a high-energy, metastable [Cp*IrPz-hydrido-alkyl] species; and 3) subsequent facile cycloamine liberation to regenerate the active catalyst species. The amine-iridium bound 2 a⋅S likely corresponds to the catalyst resting state and the catalytic reaction is expected to proceed with a significant primary kinetic isotope. This study unveils the vital role of a supportive hydrogen-bonded network involving suitably aligned β-basic pyrazolato and cycloamido moieties together with an external amine molecule in facilitating metal protonation and reductive elimination. Cooperative hydrogen bonding thus appears pivotal for effective catalysis. The mechanistic scenario is consonant with catalyst performance data and furthermore accounts for the variation in performance for [Cp*IrPz] compounds featuring a β- or γ-basic pyrazolato unit. As far as the route that involves amine N-H bond activation is concerned, a thus far undocumented pathway for concerted amidoalkene → cycloamine conversion through olefin protonation by the pyrazole N-H concurrent with N-C ring closure is disclosed as a favourable scenario. Although not practicable in the present system, this pathway describes a novel mechanistic variant in late transition metal-ligand bifunctional hydroamination catalysis that can perhaps be viable for tailored catalyst designs. The insights revealed herein concerning the operative mechanism and the structure-reactivity relationships will likely govern the rational design of late transition metal-ligand bifunctional catalysts and facilitate further conceptual advances in the area. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Forecasting landscape effects of Mississippi River diversions on elevation and accretion in Louisiana deltaic wetlands under future environmental uncertainty scenarios

USGS Publications Warehouse

Wang, Hongqing; Steyer, Gregory D.; Couvillion, Brady R.; John M. Rybczyk,; Beck, Holly J.; William J. Sleavin,; Ehab A. Meselhe,; Mead A. Allison,; Ronald G. Boustany,; Craig J. Fischenich,; Victor H. Rivera-Monroy,

2014-01-01

Large sediment diversions are proposed and expected to build new wetlands to alleviate the extensive wetland loss (5,000 km2) affecting coastal Louisiana during the last 78 years. Current assessment and prediction of the impacts of sediment diversions have focused on the capture and dispersal of both water and sediment on the adjacent river side and the immediate outfall marsh area. However, little is known about the effects of sediment diversions on existing wetland surface elevation and vertical accretion dynamics in the receiving basin at the landscape scale. In this study, we used a spatial wetland surface elevation model developed in support of Louisiana's 2012 Coastal Master Plan to examine such landscape-scale effects of sediment diversions. Multiple sediment diversion projects were incorporated in the model to simulate surface elevation and vertical accretion for the next 50 years (2010-2060) under two environmental (moderate and less optimistic) scenarios. Specifically, we examined landscape-scale surface elevation and vertical accretion trends under diversions with different geographical locations, diverted discharge rates, and geomorphic characteristics of the receiving basin. Model results indicate that small diversions (< 283 m3 s-1) tend to have limited effects of reducing landscape-scale elevation loss (< 3%) compared to a future without action (FWOA) condition. Large sediment diversions (> 1,500 m3 s-1) are required to achieve landscape-level benefits to promote surface elevation via vertical accretion to keep pace with rising sea level.

Diversity modelling for electrical power system simulation

NASA Astrophysics Data System (ADS)

Sharip, R. M.; Abu Zarim, M. A. U. A.

2013-12-01

This paper considers diversity of generation and demand profiles against the different future energy scenarios and evaluates these on a technical basis. Compared to previous studies, this research applied a forecasting concept based on possible growth rates from publically electrical distribution scenarios concerning the UK. These scenarios were created by different bodies considering aspects such as environment, policy, regulation, economic and technical. In line with these scenarios, forecasting is on a long term timescale (up to every ten years from 2020 until 2050) in order to create a possible output of generation mix and demand profiles to be used as an appropriate boundary condition for the network simulation. The network considered is a segment of rural LV populated with a mixture of different housing types. The profiles for the 'future' energy and demand have been successfully modelled by applying a forecasting method. The network results under these profiles shows for the cases studied that even though the value of the power produced from each Micro-generation is often in line with the demand requirements of an individual dwelling there will be no problems arising from high penetration of Micro-generation and demand side management for each dwellings considered. The results obtained highlight the technical issues/changes for energy delivery and management to rural customers under the future energy scenarios.

QND &NDASH; DESIGNING A PARTICIPATORY SCENARIO MODELING TOOL TO INTEGRATE TECHNOLOGY, ECOLOGY, AND SOCIOLOGY IN GUATEMALA&RSQUO;S MAYA BIOSPHERE RESERVE AND BEYOND

EPA Science Inventory

Participatory scenario modeling – an interactive method for visualizing the future – is one of the most promising tools for achieving sustainable land use agreements amongst diverse stakeholder groups. The method has the potential to bridge the gap between the high...

NASA's Prediction Of Worldwide Energy Resource (POWER) Project Unveils a New Geospatial Data Portal

Atmospheric Science Data Center

2018-03-16

NASA's Prediction Of Worldwide Energy Resource (POWER) Project Unveils a New Geospatial Data Portal ... current POWER home page. The new POWER will include improved solar and meteorological data with all parameters available on a 0.5-degree ...

Interval-parameter semi-infinite fuzzy-stochastic mixed-integer programming approach for environmental management under multiple uncertainties.

PubMed

Guo, P; Huang, G H

2010-03-01

In this study, an interval-parameter semi-infinite fuzzy-chance-constrained mixed-integer linear programming (ISIFCIP) approach is developed for supporting long-term planning of waste-management systems under multiple uncertainties in the City of Regina, Canada. The method improves upon the existing interval-parameter semi-infinite programming (ISIP) and fuzzy-chance-constrained programming (FCCP) by incorporating uncertainties expressed as dual uncertainties of functional intervals and multiple uncertainties of distributions with fuzzy-interval admissible probability of violating constraint within a general optimization framework. The binary-variable solutions represent the decisions of waste-management-facility expansion, and the continuous ones are related to decisions of waste-flow allocation. The interval solutions can help decision-makers to obtain multiple decision alternatives, as well as provide bases for further analyses of tradeoffs between waste-management cost and system-failure risk. In the application to the City of Regina, Canada, two scenarios are considered. In Scenario 1, the City's waste-management practices would be based on the existing policy over the next 25 years. The total diversion rate for the residential waste would be approximately 14%. Scenario 2 is associated with a policy for waste minimization and diversion, where 35% diversion of residential waste should be achieved within 15 years, and 50% diversion over 25 years. In this scenario, not only landfill would be expanded, but also CF and MRF would be expanded. Through the scenario analyses, useful decision support for the City's solid-waste managers and decision-makers has been generated. Three special characteristics of the proposed method make it unique compared with other optimization techniques that deal with uncertainties. Firstly, it is useful for tackling multiple uncertainties expressed as intervals, functional intervals, probability distributions, fuzzy sets, and their combinations; secondly, it has capability in addressing the temporal variations of the functional intervals; thirdly, it can facilitate dynamic analysis for decisions of facility-expansion planning and waste-flow allocation within a multi-facility, multi-period and multi-option context. Copyright 2009 Elsevier Ltd. All rights reserved.

Monitoring Temporal Variation to Assess Changes in the Structure of Subtropical Atlantic Forest Butterfly Communities.

PubMed

Iserhard, Cristiano Agra; Romanowski, Helena Piccoli; Richter, Aline; Mendonça, Milton de Souza

2017-08-01

The study of fauna through long-term surveys is important in unveiling how temporal patterns shape the structure of communities in tropical habitats. The butterfly assemblage of the subtropical Atlantic Forest may be considered highly diverse and shows changes in diversity and composition over time, highlighting the importance of long-term inventories. This work assessed temporal diversity patterns in the distribution and composition of butterfly assemblages in an Atlantic Forest site in southern Brazil using combined data from three years of standardized sampling with entomological nets, increasing the knowledge on this group in the Neotropics for monitoring and conservation. The butterfly fauna was analyzed in terms of richness, abundance, and composition. The inventories reached 401 species, with 14,442 butterfly individuals sampled. All the diversity parameters evaluated show significant differences between the first year of sampling compared to the second and third years. The latter had higher values of richness and abundance, followed by the first and second years. Hesperiidae was the richest family, followed by Nymphalidae and Lycaenidae, indicating a good representation of the assemblage as a whole. The results of this work are important for developing conservation programs in the Atlantic Forest and other forested environments in the neotropics, especially concerning reliable diversity assessments for the monitoring and management of protected areas. Decision making and public policy might also benefit from knowledge on temporal patterns of diversity regarding the maintenance of native habitats and integrity of biomes and their associated fauna. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Unexpected high diversity of galling insects in the Amazonian upper canopy: the savanna out there.

PubMed

Julião, Genimar R; Venticinque, Eduardo M; Fernandes, G Wilson; Price, Peter W

2014-01-01

A relatively large number of studies reassert the strong relationship between galling insect diversity and extreme hydric and thermal status in some habitats, and an overall pattern of a greater number of galling species in the understory of scleromorphic vegetation. We compared galling insect diversity in the forest canopy and its relationship with tree richness among upland terra firme, várzea, and igapó floodplains in Amazonia, Brazil. The soils of these forest types have highly different hydric and nutritional status. Overall, we examined the upper layer of 1,091 tree crowns. Galling species richness and abundance were higher in terra firme forests compared to várzea and igapó forests. GLM-ANCOVA models revealed that the number of tree species sampled in each forest type was determinant in the gall-forming insect diversity. The ratio between galling insect richness and number of tree species sampled (GIR/TSS ratio) was higher in the terra firme forest and in seasonally flooded igapó, while the várzea presented the lowest GIR/TSS ratio. In this study, we recorded unprecedented values of galling species diversity and abundance per sampling point. The GIR/TSS ratio from várzea was approximately 2.5 times higher than the highest value of this ratio ever reported in the literature. Based on this fact, we ascertained that várzea and igapó floodplain forests (with lower GIA and GIR), together with the speciose terra firme galling community emerge as the gall diversity apex landscape among all biogeographic regions already investigated. Contrary to expectation, our results also support the "harsh environment hypothesis", and unveil the Amazonian upper canopy as similar to Mediterranean vegetation habitats, hygrothermically stressed environments with leaf temperature at lethal limits and high levels of leaf sclerophylly.

Contrasting Microbial Community Assembly Hypotheses: A Reconciling Tale from the Río Tinto

PubMed Central

Palacios, Carmen; Zettler, Erik; Amils, Ricardo; Amaral-Zettler, Linda

2008-01-01

Background The Río Tinto (RT) is distinguished from other acid mine drainage systems by its natural and ancient origins. Microbial life from all three domains flourishes in this ecosystem, but bacteria dominate metabolic processes that perpetuate environmental extremes. While the patchy geochemistry of the RT likely influences the dynamics of bacterial populations, demonstrating which environmental variables shape microbial diversity and unveiling the mechanisms underlying observed patterns, remain major challenges in microbial ecology whose answers rely upon detailed assessments of community structures coupled with fine-scale measurements of physico-chemical parameters. Methodology/Principal Findings By using high-throughput environmental tag sequencing we achieved saturation of richness estimators for the first time in the RT. We found that environmental factors dictate the distribution of the most abundant taxa in this system, but stochastic niche differentiation processes, such as mutation and dispersal, also contribute to observed diversity patterns. Conclusions/Significance We predict that studies providing clues to the evolutionary and ecological processes underlying microbial distributions will reconcile the ongoing debate between the Baas Becking vs. Hubbell community assembly hypotheses. PMID:19052647

Contrasting microbial community assembly hypotheses: a reconciling tale from the Río Tinto.

PubMed

Palacios, Carmen; Zettler, Erik; Amils, Ricardo; Amaral-Zettler, Linda

2008-01-01

The Río Tinto (RT) is distinguished from other acid mine drainage systems by its natural and ancient origins. Microbial life from all three domains flourishes in this ecosystem, but bacteria dominate metabolic processes that perpetuate environmental extremes. While the patchy geochemistry of the RT likely influences the dynamics of bacterial populations, demonstrating which environmental variables shape microbial diversity and unveiling the mechanisms underlying observed patterns, remain major challenges in microbial ecology whose answers rely upon detailed assessments of community structures coupled with fine-scale measurements of physico-chemical parameters. By using high-throughput environmental tag sequencing we achieved saturation of richness estimators for the first time in the RT. We found that environmental factors dictate the distribution of the most abundant taxa in this system, but stochastic niche differentiation processes, such as mutation and dispersal, also contribute to observed diversity patterns. We predict that studies providing clues to the evolutionary and ecological processes underlying microbial distributions will reconcile the ongoing debate between the Baas Becking vs. Hubbell community assembly hypotheses.

Biomedical Applications of Carbon Nanotubes: A Critical Review.

PubMed

Sharma, Priyanka; Mehra, Neelesh Kumar; Jain, Keerti; Jain, N K

2016-08-01

The convergence of nano and biotechnology is enabling scientific and technical knowledge for improving human well being. Carbon nanotubes have become most fascinating material to be studied and unveil new avenues in the field of nanobiotechnology. The nanometer size and high aspect ratio of the CNTs are the two distinct features, which have contributed to diverse biomedical applications. They have captured the attention as nanoscale materials due to their nanometric structure and remarkable list of superlative and extravagant properties that encouraged their exploitation for promising applications. Significant progress has been made in order to overcome some of the major hurdles towards biomedical application of nanomaterials, especially on issues regarding the aqueous solubility/dispersion and safety of CNTs. Functionalized CNTs have been used in drug targeting, imaging, and in the efficient delivery of gene and nucleic acids. CNTs have also demonstrated great potential in diverse biomedical uses like drug targeting, imaging, cancer treatment, tissue regeneration, diagnostics, biosensing, genetic engineering and so forth. The present review highlights the possible potential of CNTs in diagnostics, imaging and targeted delivery of bioactives and also outlines the future opportunities for biomedical applications.

Metagenomic chromosome conformation capture (meta3C) unveils the diversity of chromosome organization in microorganisms

PubMed Central

Marbouty, Martial; Cournac, Axel; Flot, Jean-François; Marie-Nelly, Hervé; Mozziconacci, Julien; Koszul, Romain

2014-01-01

Genomic analyses of microbial populations in their natural environment remain limited by the difficulty to assemble full genomes of individual species. Consequently, the chromosome organization of microorganisms has been investigated in a few model species, but the extent to which the features described can be generalized to other taxa remains unknown. Using controlled mixes of bacterial and yeast species, we developed meta3C, a metagenomic chromosome conformation capture approach that allows characterizing individual genomes and their average organization within a mix of organisms. Not only can meta3C be applied to species already sequenced, but a single meta3C library can be used for assembling, scaffolding and characterizing the tridimensional organization of unknown genomes. By applying meta3C to a semi-complex environmental sample, we confirmed its promising potential. Overall, this first meta3C study highlights the remarkable diversity of microorganisms chromosome organization, while providing an elegant and integrated approach to metagenomic analysis. DOI: http://dx.doi.org/10.7554/eLife.03318.001 PMID:25517076

Genetic Polymorphism in Wine Yeasts: Mechanisms and Methods for Its Detection

PubMed Central

Guillamón, José M.; Barrio, Eladio

2017-01-01

The processes of yeast selection for using as wine fermentation starters have revealed a great phenotypic diversity both at interspecific and intraspecific level, which is explained by a corresponding genetic variation among different yeast isolates. Thus, the mechanisms involved in promoting these genetic changes are the main engine generating yeast biodiversity. Currently, an important task to understand biodiversity, population structure and evolutionary history of wine yeasts is the study of the molecular mechanisms involved in yeast adaptation to wine fermentation, and on remodeling the genomic features of wine yeast, unconsciously selected since the advent of winemaking. Moreover, the availability of rapid and simple molecular techniques that show genetic polymorphisms at species and strain levels have enabled the study of yeast diversity during wine fermentation. This review will summarize the mechanisms involved in generating genetic polymorphisms in yeasts, the molecular methods used to unveil genetic variation, and the utility of these polymorphisms to differentiate strains, populations, and species in order to infer the evolutionary history and the adaptive evolution of wine yeasts, and to identify their influence on their biotechnological and sensorial properties. PMID:28522998

Exploring the uncultured microeukaryote majority in the oceans: reevaluation of ribogroups within stramenopiles.

PubMed

Massana, Ramon; del Campo, Javier; Sieracki, Michael E; Audic, Stéphane; Logares, Ramiro

2014-04-01

Molecular surveys in planktonic marine systems have unveiled a large novel diversity of small protists. A large part of this diversity belongs to basal heterotrophic stramenopiles and is distributed in a set of polyphyletic ribogroups (described from rDNA sequences) collectively named as MAST (MArine STramenopiles). In the few groups investigated, MAST cells are globally distributed and abundant bacterial grazers, therefore having a putatively large impact on marine ecosystem functioning. The main aim of this study is to reevaluate the MAST ribogroups described so far and to determine whether additional groups can be found. For this purpose, we used traditional and state-of-the-art molecular tools, combining 18S rDNA sequences from publicly available clone libraries, single amplified genomes (SAGs) of planktonic protists, and a pyrosequencing survey from coastal waters and sediments. Our analysis indicated a final set of 18 MAST groups plus 5 new ribogroups within Ochrophyta (named as MOCH). The MAST ribogroups were then analyzed in more detail. Seven were typical of anoxic systems and one of oxic sediments. The rest were clearly members of oxic marine picoplankton. We characterized the genetic diversity within each MAST group and defined subclades for the more diverse (46 subclades in 8 groups). The analyses of sequences within subclades revealed further ecological specializations. Our data provide a renovated framework for phylogenetic classification of the numerous MAST ribogroups and support the notion of a tight link between phylogeny and ecological distribution. These diverse and largely uncultured protists are widespread and ecologically relevant members of marine microbial assemblages.

Global survey of mRNA levels and decay rates of Chlamydia trachomatis trachoma and lymphogranuloma venereum biovars.

PubMed

Ferreira, Rita; Borges, Vítor; Borrego, Maria José; Gomes, João Paulo

2017-07-01

Interpreting the intricate bacterial transcriptomics implies understanding the dynamic relationship established between de novo transcription and the degradation of transcripts. Here, we performed a comparative overview of gene expression levels and mRNA decay rates for different-biovar (trachoma and lymphogranuloma venereum) strains of the obligate intracellular bacterium Chlamydia trachomatis . By using RNA-sequencing to measure gene expression levels at mid developmental stage and mRNA decay rates upon rifampicin-based transcription blockage, we observed that: i ) 60-70% of the top-50 expressed genes encode proteins with unknown function and proteins involved in "Translation, ribosomal structure and biogenesis" for all strains; ii ) the expression ranking by genes' functional categories was in general concordant among different-biovar strains; iii ) the median of the half-life time (t 1/2 ) values of transcripts were 15-17 min, indicating that the degree of transcripts' stability seems to correlate with the bacterial intracellular life-style, as these values are considerably higher than the ones observed in other studies for facultative intracellular and free-living bacteria; iv ) transcript decay rates were highly heterogeneous within each C. trachomatis strain and did not correlate with steady-state expression levels; v ) only at very few instances (essentially at gene functional category level) was possible to unveil dissimilarities potentially underlying phenotypic differences between biovars. In summary, the unveiled transcriptomic scenario, marked by a general lack of correlation between transcript production and degradation and a huge inter-transcript heterogeneity in decay rates, likely reflects the challenges underlying the unique biphasic developmental cycle of C. trachomatis and its intricate interactions with the human host, which probably exacerbate the complexity of the bacterial transcription regulation.

Oligomerization of G protein-coupled receptors: computational methods.

PubMed

Selent, J; Kaczor, A A

2011-01-01

Recent research has unveiled the complexity of mechanisms involved in G protein-coupled receptor (GPCR) functioning in which receptor dimerization/oligomerization may play an important role. Although the first high-resolution X-ray structure for a likely functional chemokine receptor dimer has been deposited in the Protein Data Bank, the interactions and mechanisms of dimer formation are not yet fully understood. In this respect, computational methods play a key role for predicting accurate GPCR complexes. This review outlines computational approaches focusing on sequence- and structure-based methodologies as well as discusses their advantages and limitations. Sequence-based approaches that search for possible protein-protein interfaces in GPCR complexes have been applied with success in several studies, but did not yield always consistent results. Structure-based methodologies are a potent complement to sequence-based approaches. For instance, protein-protein docking is a valuable method especially when guided by experimental constraints. Some disadvantages like limited receptor flexibility and non-consideration of the membrane environment have to be taken into account. Molecular dynamics simulation can overcome these drawbacks giving a detailed description of conformational changes in a native-like membrane. Successful prediction of GPCR complexes using computational approaches combined with experimental efforts may help to understand the role of dimeric/oligomeric GPCR complexes for fine-tuning receptor signaling. Moreover, since such GPCR complexes have attracted interest as potential drug target for diverse diseases, unveiling molecular determinants of dimerization/oligomerization can provide important implications for drug discovery.

Biodiversity evaluation in tropical agricultural systems - How will rubber cultivation and land use change effect species diversity in SW China

NASA Astrophysics Data System (ADS)

Cotter, M.; Grenz, J.; Sauerborn, J.

2012-04-01

The Greater Mekong Subregion is a known hotspot of biodiversity, which faces drastic changes due to human impact particularly with regard to infrastructure and economy. Within the framework of the Sino-German research project "Living Landscapes China" (LILAC), we have developed a biodiversity evaluation tool based on the combination of approaches from landscape ecology with detailed empirical data on species diversity and habitat characteristics of tropical plant and arthropod communities in a Geographical Information System. We use field ecological data to assess different spatial and qualitative aspects of the diversity and spatial distribution of species throughout the research area, a watershed in south-western Yunnan province, PR China. In addition, scenarios on the impact of land use change have been analyzed and compared in order to highlight the implications these possible future scenarios would have on species diversity within the research area. The aim of the presented tool is to provide scientists and policy makers who have to evaluate the consequences of scenarios of future land use with information on the current and likely future state of biodiversity in their research area or administrative region. This will enable them to assess the likely impacts of land use changes on structural and ecological diversity and allow for informed land use planning. The methodology developed for this tool can also be applied outside of the Greater Mekong Subregion, as the model structure allows for an easy adaption to other research areas and challenges, be it oil palm production in Southeast Asia or small scale farming in central Africa or the Amazon basin.

Explaining the Ba, Y, Sr, and Eu abundance scatter in metal-poor halo stars: constraints to the r-process

NASA Astrophysics Data System (ADS)

Cescutti, G.; Chiappini, C.

2014-05-01

Context. Thanks to the heroic observational campaigns carried out in recent years we now have large samples of metal-poor stars for which measurements of detailed abundances exist. In particular, large samples of stars with metallicities -5 < [Fe/H] <-1 and measured abundances of Sr, Ba, Y, and Eu are now available. These data hold important clues on the nature of the contribution of the first stellar generations to the enrichment of our Galaxy. Aims: We aim to explain the scatter in Sr, Ba, Y, and Eu abundance ratio diagrams unveiled by the metal-poor halo stars. Methods: We computed inhomogeneous chemical evolution models for the Galactic halo assuming different scenarios for the r-process site: the electron-capture (EC) supernovae and the magnetorotationally driven (MRD) supernovae scenarios. We also considered models with and without the contribution of fast-rotating massive stars (spinstars) to an early enrichment by the s-process. A detailed comparison with the now large sample of stars with measured abundances of Sr, Ba, Y, Eu, and Fe is provided (both in terms of scatter plots and number distributions for several abundance ratios). Results: The scatter observed in these abundance ratios of the very metal-poor stars (with [Fe/H] <-2.5) can be explained by combining the s-process production in spinstars, and the r-process contribution coming from massive stars. For the r-process we have developed models for both the EC and the MRD scenarios that match the observations. Conclusions: With the present observational and theoretical constraints we cannot distinguish between the EC and the MRD scenarios in the Galactic halo. Independently of the r-process scenarios adopted, the production of elements by an s-process in spinstars is needed to reproduce the spread in abundances of the light neutron capture elements (Sr and Y) over heavy neutron capture elements (Ba and Eu). We provide a way to test our suggestions by means of the distribution of the Ba isotopic ratios in a [Ba/Fe] or [Sr/Ba] vs. [Fe/H] diagram. Appendix A is available in electronic form at http://www.aanda.org

The Changing Experiences of Primary Teachers: Responding to Scenarios Involving Diverse Sexualities

ERIC Educational Resources Information Center

van Leent, Lisa; Ryan, Mary

2016-01-01

Sex education and diverse sexualities are controversial topics within the primary school arena. Concepts of childhood innocence have influenced sex education curriculum, policy development and teaching practices within schools. However, research shows that primary school-aged students are aware of and talk about sexualities. The aim of this…

Phylogenetic approaches reveal biodiversity threats under climate change

NASA Astrophysics Data System (ADS)

González-Orozco, Carlos E.; Pollock, Laura J.; Thornhill, Andrew H.; Mishler, Brent D.; Knerr, Nunzio; Laffan, Shawn W.; Miller, Joseph T.; Rosauer, Dan F.; Faith, Daniel P.; Nipperess, David A.; Kujala, Heini; Linke, Simon; Butt, Nathalie; Külheim, Carsten; Crisp, Michael D.; Gruber, Bernd

2016-12-01

Predicting the consequences of climate change for biodiversity is critical to conservation efforts. Extensive range losses have been predicted for thousands of individual species, but less is known about how climate change might impact whole clades and landscape-scale patterns of biodiversity. Here, we show that climate change scenarios imply significant changes in phylogenetic diversity and phylogenetic endemism at a continental scale in Australia using the hyper-diverse clade of eucalypts. We predict that within the next 60 years the vast majority of species distributions (91%) across Australia will shrink in size (on average by 51%) and shift south on the basis of projected suitable climatic space. Geographic areas currently with high phylogenetic diversity and endemism are predicted to change substantially in future climate scenarios. Approximately 90% of the current areas with concentrations of palaeo-endemism (that is, places with old evolutionary diversity) are predicted to disappear or shift their location. These findings show that climate change threatens whole clades of the phylogenetic tree, and that the outlined approach can be used to forecast areas of biodiversity losses and continental-scale impacts of climate change.

Nervous systems and scenarios for the invertebrate-to-vertebrate transition

PubMed Central

Holland, Nicholas D.

2016-01-01

Older evolutionary scenarios for the origin of vertebrates often gave nervous systems top billing in accordance with the notion that a big-brained Homo sapiens crowned a tree of life shaped mainly by progressive evolution. Now, however, tree thinking positions all extant organisms equidistant from the tree's root, and molecular phylogenies indicate that regressive evolution is more common than previously suspected. Even so, contemporary theories of vertebrate origin still focus on the nervous system because of its functional importance, its richness in characters for comparative biology, and its central position in the two currently prominent scenarios for the invertebrate-to-vertebrate transition, which grew out of the markedly neurocentric annelid and enteropneust theories of the nineteenth century. Both these scenarios compare phyla with diverse overall body plans. This diversity, exacerbated by the scarcity of relevant fossil data, makes it challenging to establish plausible homologies between component parts (e.g. nervous system regions). In addition, our current understanding of the relation between genotype and phenotype is too preliminary to permit us to convert gene network data into structural features in any simple way. These issues are discussed here with special reference to the evolution of nervous systems during proposed transitions from invertebrates to vertebrates. PMID:26598728

[Evolutionary process unveiled by the maximum genetic diversity hypothesis].

PubMed

Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi

2013-05-01

As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.

Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica.

PubMed

Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C; Amaral-Zettler, Linda

2014-10-01

We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and March 2008). We tested hypotheses on the relationship between species richness and environmental conditions including environmental extremes, nutrient status, and day length. On the basis of the unique environment that exists in these high-latitude lakes, we expected that novel taxa would be present. Alpha diversity analyses showed that extreme conditions-that is, high salinity, low oxygen, and extreme changes in day length-did not impact ciliate richness; however, ciliate richness was 30% higher in samples with higher dissolved organic matter. Beta diversity analyses revealed that ciliate communities clustered by dissolved oxygen, depth, and salinity, but not by season (i.e., day length). The permutational analysis of variance test indicated that depth, dissolved oxygen, and salinity had significant influences on the ciliate community for the abundance matrices of resampled data, while lake and season were not significant. This result suggests that the vertical trends in dissolved oxygen concentration and salinity may play a critical role in structuring ciliate communities. A PCR-based strategy capitalizing on divergent eukaryotic V9 hypervariable region ribosomal RNA gene targets unveiled two new genera in these lakes. A novel taxon belonging to an unknown class most closely related to Cryptocaryon irritans was also inferred from separate gene phylogenies. © 2014 Marine Biological Laboratory.

The Freshwater Sponge Ephydatia fluviatilis Harbours Diverse Pseudomonas Species (Gammaproteobacteria, Pseudomonadales) with Broad-Spectrum Antimicrobial Activity

PubMed Central

Keller-Costa, Tina; Jousset, Alexandre; van Overbeek, Leo; van Elsas, Jan Dirk; Costa, Rodrigo

2014-01-01

Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is rudimentary. We assessed the diversity, structure and antimicrobial activities of Pseudomonas spp. in the freshwater sponge Ephydatia fluviatilis. Polymerase Chain Reaction – Denaturing Gradient Gel Electrophoresis (PCR-DGGE) fingerprints of the global regulator gene gacA revealed distinct structures between sponge-associated and free-living Pseudomonas communities, unveiling previously unsuspected diversity of these assemblages in freshwater. Community structures varied across E. fluviatilis specimens, yet specific gacA phylotypes could be detected by PCR-DGGE in almost all sponge individuals sampled over two consecutive years. By means of whole-genome fingerprinting, 39 distinct genotypes were found within 90 fluorescent Pseudomonas isolates retrieved from E. fluviatilis. High frequency of in vitro antibacterial (49%), antiprotozoan (35%) and anti-oomycetal (32%) activities was found among these isolates, contrasting less-pronounced basidiomycetal (17%) and ascomycetal (8%) antagonism. Culture extracts of highly predation-resistant isolates rapidly caused complete immobility or lysis of cells of the protozoan Colpoda steinii. Isolates tentatively identified as P. jessenii, P. protegens and P. oryzihabitans showed conspicuous inhibitory traits and correspondence with dominant sponge-associated phylotypes registered by cultivation-independent analysis. Our findings suggest that E. fluviatilis hosts both transient and persistent Pseudomonas symbionts displaying antimicrobial activities of potential ecological and biotechnological value. PMID:24533086

Tracing shifts of oceanic fronts using the cryptic diversity of the planktonic foraminifera Globorotalia inflata

NASA Astrophysics Data System (ADS)

Morard, Raphaël.; Reinelt, Melanie; Chiessi, Cristiano M.; Groeneveld, Jeroen; Kucera, Michal

2016-09-01

The use of planktonic foraminifera in paleoceanographic studies relies on the assumption that morphospecies represent biological species with ecological preferences that are stable through time and space. However, genetic surveys unveiled a considerable level of diversity in most morphospecies of planktonic foraminifera. This diversity is significant for paleoceanographic applications because cryptic species were shown to display distinct ecological preferences that could potentially help refine paleoceanographic proxies. Subtle morphological differences between cryptic species of planktonic foraminifera have been reported, but so far, their applicability within paleoceanographic studies remains largely unexplored. Here we show how information on genetic diversity can be transferred to paleoceanography using Globorotalia inflata as a case study. The two cryptic species of G. inflata are separated by the Brazil-Malvinas Confluence (BMC), a major oceanographic feature in the South Atlantic. Based on this observation, we developed a morphological model of cryptic species detection in core top material. The application of the cryptic species detection model to Holocene samples implies latitudinal oscillations in the position of the confluence that are largely consistent with reconstructions obtained from stable isotope data. We show that the occurrence of cryptic species in G. inflata can be detected in the fossil record and used to trace the migration of the BMC. Since a similar degree of morphological separation as in G. inflata has been reported from other species of planktonic foraminifera, the approach presented in this study can potentially yield a wealth of new paleoceanographical proxies.

Genetic Diversity and Population Structure of the Critically Endangered Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis) as Revealed by Mitochondrial and Microsatellite DNA

PubMed Central

Chen, Minmin; Zheng, Jinsong; Wu, Min; Ruan, Rui; Zhao, Qingzhong; Wang, Ding

2014-01-01

Ecological surveys have indicated that the population of the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. Genetic conservation of this population will be an important component of the long-term conservation effort. We used a 597 base pair mitochondrial DNA (mtDNA) control region and 11 microsatellite loci to analyze the genetic diversity and population structure of the YFP. The analysis of both mtDNA and microsatellite loci suggested that the genetic diversity of the YFP will possibly decrease in the future if the population keeps declining at a rapid rate, even though these two types of markers revealed different levels of genetic diversity. In addition, mtDNA revealed strong genetic differentiation between one local population, Xingchang–Shishou (XCSS), and the other five downstream local populations; furthermore, microsatellite DNA unveiled fine but significant genetic differentiation between three of the local populations (not only XCSS but also Poyang Lake (PY) and Tongling (TL)) and the other local populations. With an increasing number of distribution gaps appearing in the Yangtze main steam, the genetic differentiation of local populations will likely intensify in the future. The YFP is becoming a genetically fragmented population. Therefore, we recommend attention should be paid to the genetic conservation of the YFP. PMID:24968271

Diversity of Pico- to Mesoplankton along the 2000 km Salinity Gradient of the Baltic Sea

PubMed Central

Hu, Yue O. O.; Karlson, Bengt; Charvet, Sophie; Andersson, Anders F.

2016-01-01

Microbial plankton form the productive base of both marine and freshwater ecosystems and are key drivers of global biogeochemical cycles of carbon and nutrients. Plankton diversity is immense with representations from all major phyla within the three domains of life. So far, plankton monitoring has mainly been based on microscopic identification, which has limited sensitivity and reproducibility, not least because of the numerical majority of plankton being unidentifiable under the light microscope. High-throughput sequencing of taxonomic marker genes offers a means to identify taxa inaccessible by traditional methods; thus, recent studies have unveiled an extensive previously unknown diversity of plankton. Here, we conducted ultra-deep Illumina sequencing (average 105 sequences/sample) of rRNA gene amplicons of surface water eukaryotic and bacterial plankton communities sampled in summer along a 2000 km transect following the salinity gradient of the Baltic Sea. Community composition was strongly correlated with salinity for both bacterial and eukaryotic plankton assemblages, highlighting the importance of salinity for structuring the biodiversity within this ecosystem. In contrast, no clear trends in alpha-diversity for bacterial or eukaryotic communities could be detected along the transect. The distribution of major planktonic taxa followed expected patterns as observed in monitoring programs, but groups novel to the Baltic Sea were also identified, such as relatives to the coccolithophore Emiliana huxleyi detected in the northern Baltic Sea. This study provides the first ultra-deep sequencing-based survey on eukaryotic and bacterial plankton biogeography in the Baltic Sea. PMID:27242706

Temperature Induced Syllable Breaking Unveils Nonlinearly Interacting Timescales in Birdsong Motor Pathway

PubMed Central

Goldin, Matías A.; Alonso, Leandro M.; Alliende, Jorge A.; Goller, Franz; Mindlin, Gabriel B.

2013-01-01

The nature of telencephalic control over premotor and motor circuits is debated. Hypotheses range from complete usurping of downstream circuitry to highly interactive mechanisms of control. We show theoretically and experimentally, that telencephalic song motor control in canaries is consistent with a highly interactive strategy. As predicted from a theoretical model of respiratory control, mild cooling of a forebrain nucleus (HVC) led to song stretching, but further cooling caused progressive restructuring of song, consistent with the hypothesis that respiratory gestures are subharmonic responses to a timescale present in the output of HVC. This interaction between a life-sustaining motor function (respiration) and telencephalic song motor control suggests a more general mechanism of how nonlinear integration of evolutionarily new brain structures into existing circuitry gives rise to diverse, new behavior. PMID:23818988

Cholangiocarcinoma

PubMed Central

Razumilava, Nataliya; Gores, Gregory J

2014-01-01

Cholangiocarcinoma represents a diverse group of epithelial cancers united by late diagnosis and poor outcomes. Specific diagnostic and therapeutic approaches are undertaken for cholangiocarcinomas of different anatomical locations (intrahepatic, perihilar, and distal). Mixed hepatocellular cholangiocarcinomas have emerged as a distinct subtype of primary liver cancer. Clinicians need to be aware of intrahepatic cholangiocarcinomas arising in cirrhosis and properly assess liver masses in this setting for cholangiocarcinoma. Management of biliary obstruction is obligatory in perihilar cholangiocarcinoma, and advanced cytological tests such as fluorescence in-situ hybridisation for aneusomy are helpful in the diagnosis. Liver transplantation is a curative option for selected patients with perihilar but not with intrahepatic or distal cholangiocarcinoma. International efforts of clinicians and scientists are helping to identify the genetic drivers of cholangiocarcinoma progression, which will unveil early diagnostic markers and direct development of individualised therapies. PMID:24581682

Cross-sectional fluctuation scaling in the high-frequency illiquidity of Chinese stocks

NASA Astrophysics Data System (ADS)

Cai, Qing; Gao, Xing-Lu; Zhou, Wei-Xing; Stanley, H. Eugene

2018-03-01

Taylor's law of temporal and ensemble fluctuation scaling has been ubiquitously observed in diverse complex systems including financial markets. Stock illiquidity is an important nonadditive financial quantity, which is found to comply with Taylor's temporal fluctuation scaling law. In this paper, we perform the cross-sectional analysis of the 1 min high-frequency illiquidity time series of Chinese stocks and unveil the presence of Taylor's law of ensemble fluctuation scaling. The estimated daily Taylor scaling exponent fluctuates around 1.442. We find that Taylor's scaling exponents of stock illiquidity do not relate to the ensemble mean and ensemble variety of returns. Our analysis uncovers a new scaling law of financial markets and might stimulate further investigations for a better understanding of financial markets' dynamics.

Temperature induced syllable breaking unveils nonlinearly interacting timescales in birdsong motor pathway.

PubMed

Goldin, Matías A; Alonso, Leandro M; Alliende, Jorge A; Goller, Franz; Mindlin, Gabriel B

2013-01-01

The nature of telencephalic control over premotor and motor circuits is debated. Hypotheses range from complete usurping of downstream circuitry to highly interactive mechanisms of control. We show theoretically and experimentally, that telencephalic song motor control in canaries is consistent with a highly interactive strategy. As predicted from a theoretical model of respiratory control, mild cooling of a forebrain nucleus (HVC) led to song stretching, but further cooling caused progressive restructuring of song, consistent with the hypothesis that respiratory gestures are subharmonic responses to a timescale present in the output of HVC. This interaction between a life-sustaining motor function (respiration) and telencephalic song motor control suggests a more general mechanism of how nonlinear integration of evolutionarily new brain structures into existing circuitry gives rise to diverse, new behavior.

Nerves in northern Norway: the communication of emotions, illness experiences, and health-seeking behaviors.

PubMed

Foss, Nina

2002-02-01

The nature of nerves is the subject of a growing and dynamic body of anthropological research. The term nerves is often conceptualized as hard to define. Its meaning carries ambiguities, inconsistencies, and variation, although it is connected to reactions to the hardships of life. In the West, it is often associated with psychiatric problems. In this study, the researcher unveiled peoples' pragmatic use of the term nerves through diverse social settings in a coastal community in Northern Norway. The term was connected to psychological or psychiatric problems, privacy, and stigma, but had the capacity to communicate a continuum from normal emotional problems to severe mental illness. This study also showed the effect of the term in encounters between patients and professional health workers.

Deconstructing Pancreas Developmental Biology

PubMed Central

Benitez, Cecil M.; Goodyer, William R.

2012-01-01

The relentless nature and increasing prevalence of human pancreatic diseases, in particular, diabetes mellitus and adenocarcinoma, has motivated further understanding of pancreas organogenesis. The pancreas is a multifunctional organ whose epithelial cells govern a diversity of physiologically vital endocrine and exocrine functions. The mechanisms governing the birth, differentiation, morphogenesis, growth, maturation, and maintenance of the endocrine and exocrine components in the pancreas have been discovered recently with increasing tempo. This includes recent studies unveiling mechanisms permitting unexpected flexibility in the developmental potential of immature and mature pancreatic cell subsets, including the ability to interconvert fates. In this article, we describe how classical cell biology, genetic analysis, lineage tracing, and embryological investigations are being complemented by powerful modern methods including epigenetic analysis, time-lapse imaging, and flow cytometry-based cell purification to dissect fundamental processes of pancreas development. PMID:22587935

Inflammasome complexes: emerging mechanisms and effector functions

PubMed Central

Rathinam, Vijay A. K.; Fitzgerald, Katherine A.

2017-01-01

Canonical activation of the inflammasome is critical to promote caspase-1-dependent maturation of the proinflammatory cytokines IL-1β and IL-18, as well as to induce pyroptotic cell death in response to pathogens and endogenous danger signals. Recent discoveries, however, are beginning to unveil new components of the inflammasome machinery, and the full spectrum of inflammasome functions, extending their influence beyond canonical functions, to regulation of eicosanoid storm, autophagy and metabolism. In addition, the receptor components of the inflammasome can also regulate diverse biological processes, such as cellular proliferation, gene transcription and tumorigenesis, all of which are independent of their inflammasome complex-forming capabilities. Here, we review these recent advances that are shaping our understanding of the complex biology of the inflammasome and its constituents. PMID:27153493

The Science of Eliminating Health Disparities: Summary and Analysis of the NIH Summit Recommendations

PubMed Central

Rhee, Kyu B.; Williams, Kester; Sanchez, Idalia; Sy, Francisco S.; Stinson, Nathaniel; Ruffin, John

2010-01-01

In December 2008, the National Institutes of Health (NIH) sponsored the first NIH Summit showcasing its investment and contribution to health disparities research and unveiling a framework for moving this important field forward. The Summit, titled “The Science of Eliminating Health Disparities,” drew on extensive experience of experts leading health disparities research transformation in diverse fields. The Summit also provided a historic educational opportunity to contribute to health care reform. The theme, addressing disparities through integration of science, practice, and policy, introduced a paradigm for advancing research through transformational, translational, and transdisciplinary research. Engaging active participation throughout the Summit generated recommendations bridging science, practice, and policy, including action on social determinants of health, community engagement, broad partnerships, capacity-building, and media outreach. PMID:20147660

Anticipatory Water Management in Phoenix using Advanced Scenario Planning and Analyses: WaterSim 5

NASA Astrophysics Data System (ADS)

Sampson, D. A.; Quay, R.; White, D. D.; Gober, P.; Kirkwood, C.

2013-12-01

Complexity, uncertainty, and variability are inherent properties of linked social and natural processes; sustainable resource management must somehow consider all three. Typically, a decision support tool (using scenario analyses) is used to examine management alternatives under suspected trajectories in driver variables (i.e., climate forcing's, growth or economic projections, etc.). This traditional planning focuses on a small set of envisioned scenarios whose outputs are compared against one-another in order to evaluate their differing impacts on desired metrics. Human cognition typically limits this to three to five scenarios. However, complex and highly uncertain issues may require more, often much more, than five scenarios. In this case advanced scenario analysis provides quantitative or qualitative methods that can reveal patterns and associations among scenario metrics for a large ensemble of scenarios. From this analysis, then, a smaller set of heuristics that describe the complexity and uncertainty revealed provides a basis to guide planning in an anticipatory fashion. Our water policy and management model, termed WaterSim, permits advanced scenario planning and analysis for the Phoenix Metropolitan Area. In this contribution we examine the concepts of advanced scenario analysis on a large scale ensemble of scenarios using our work with WaterSim as a case study. For this case study we created a range of possible water futures by creating scenarios that encompasses differences in water supplies (our surrogates for climate change, drought, and inherent variability in riverine flows), population growth, and per capital water consumption. We used IPCC estimates of plausible, future, alterations in riverine runoff, locally produced and vetted estimates of population growth projections, and empirical trends in per capita water consumption for metropolitan cities. This ensemble consisted of ~ 30, 700 scenarios (~575 k observations). We compared and contrasted two metropolitan communities that exhibit differing growth projections and water portfolios; moderate growth with a diverse portfolio versus high growth for a more restrictive portfolio. Results illustrate that both communities exhibited an expanding envelope of possible, future water outcomes with rational water management trajectories. However, a more diverse portfolio resulted in a broad, time-insensitive decision space for management interventions. The reverse was true for the more restrictive water portfolio with high growth projections.

Circumplanetary discs around young giant planets: a comparison between core-accretion and disc instability

NASA Astrophysics Data System (ADS)

Szulágyi, J.; Mayer, L.; Quinn, T.

2017-01-01

Circumplanetary discs can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary discs for both formation scenarios, using as similar initial conditions as possible to unveil possible intrinsic differences in the circumplanetary disc mass and temperature between the two formation mechanisms. We found that the circumplanetary discs' mass linearly scales with the circumstellar disc mass. Therefore, in an equally massive protoplanetary disc, the circumplanetary discs formed in the disc instability model can be only a factor of 8 more massive than their core-accretion counterparts. On the other hand, the bulk circumplanetary disc temperature differs by more than an order of magnitude between the two cases. The subdiscs around planets formed by gravitational instability have a characteristic temperature below 100 K, while the core-accretion circumplanetary discs are hot, with temperatures even greater than 1000 K when embedded in massive, optically thick protoplanetary discs. We explain how this difference can be understood as the natural result of the different formation mechanisms. We argue that the different temperatures should persist up to the point when a full-fledged gas giant forms via disc instability; hence, our result provides a convenient criterion for observations to distinguish between the two main formation scenarios by measuring the bulk temperature in the planet vicinity.

Evidence for a Circum-Nuclear and Ionised Absorber in the X-ray Obscured Broad Line Radio Galaxy 3C 445

NASA Technical Reports Server (NTRS)

Braito, V.; Reeves, J. N.; Sambruna, R. M.; Gofford, J.

2012-01-01

Here we present the results of a Suzaku observation of the Broad Line Radio Galaxy 3C 445. We confirm the results obtained with the previous X-ray observations which unveiled the presence of several soft X-ray emission lines and an overall X-ray emission which strongly resembles a typical Seyfert 2 despite of the optical classification as an unobscured AGN. The broad band spectrum allowed us to measure for the first time the amount of reflection (R approximately 0.9) which together with the relatively strong neutral Fe Ka emission line (EW approximately 100 eV) strongly supports a scenario where a Compton-thick mirror is present. The primary X ray continuum is strongly obscured by an absorber with a column density of NH = 2 - 3 x 10(exp 23) per square centimeter. Two possible scenarios are proposed for the absorber: a neutral partial covering or a mildly ionised absorber with an ionisation parameter log xi approximately 1.0 erg centimeter per second. A comparison with the past and more recent X-ray observations of 3C 445 performed with XMM-Newton and Chandra is presented, which provided tentative evidence that the ionised and outflowing absorber varied. We argue that the absorber is probably associated with an equatorial diskwind located within the parsec scale molecular torus.

Useful global-change scenarios: current issues and challenges

NASA Astrophysics Data System (ADS)

Parson, E. A.

2008-10-01

Scenarios are increasingly used to inform global-change debates, but their connection to decisions has been weak and indirect. This reflects the greater number and variety of potential users and scenario needs, relative to other decision domains where scenario use is more established. Global-change scenario needs include common elements, e.g., model-generated projections of emissions and climate change, needed by many users but in different ways and with different assumptions. For these common elements, the limited ability to engage diverse global-change users in scenario development requires extreme transparency in communicating underlying reasoning and assumptions, including probability judgments. Other scenario needs are specific to users, requiring a decentralized network of scenario and assessment organizations to disseminate and interpret common elements and add elements requiring local context or expertise. Such an approach will make global-change scenarios more useful for decisions, but not less controversial. Despite predictable attacks, scenario-based reasoning is necessary for responsible global-change decisions because decision-relevant uncertainties cannot be specified scientifically. The purpose of scenarios is not to avoid speculation, but to make the required speculation more disciplined, more anchored in relevant scientific knowledge when available, and more transparent.

Projected trends in forest habitat classes under climate and land-use change scenarios

Treesearch

Brian G. Tavernia; Mark D. Nelson; Brian F. Walters; Chris Toney

2012-01-01

Wildlife species have diverse and sometimes conflicting habitat requirements. To support diverse wildlife communities, natural resource managers need to manage for a variety of habitats across a large area and to create long-term management plans to ensure this variety is maintained. In these efforts, managers would benefit from assessments of potential climate and...

2016 Standard Scenarios Report: A U.S. Electricity Sector Outlook

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

Cole, Wesley; Mai, Trieu; Logan, Jeffrey

The National Renewable Energy Laboratory is conducting a study sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) that aims to document and implement an annual process designed to identify a realistic and timely set of input assumptions (e.g., technology cost and performance, fuel costs), and a diverse set of potential futures (standard scenarios), initially for electric sector analysis.

Book review: Unveiling the Whale: Discourses on Whales and Whaling

Treesearch

John Schelhas

2012-01-01

Whaling represents one of the most internationally controversial and highly polarized environmental issues of recent times. Arne Kalland, in Unveiling the Whale: Discourses on Whales and Whaling, examines the whaling issue from the perspective of a pro-whaling country with an emphasis on analysis of discourse in international arenas, primarily the International Whaling...

A White Paper on Global Wheat Health Based on Scenario Development and Analysis.

PubMed

Savary, S; Djurle, A; Yuen, J; Ficke, A; Rossi, V; Esker, P D; Fernandes, J M C; Del Ponte, E M; Kumar, J; Madden, L V; Paul, P; McRoberts, N; Singh, P K; Huber, L; Pope de Vallavielle, C; Saint-Jean, S; Willocquet, L

2017-10-01

Scenario analysis constitutes a useful approach to synthesize knowledge and derive hypotheses in the case of complex systems that are documented with mainly qualitative or very diverse information. In this article, a framework for scenario analysis is designed and then, applied to global wheat health within a timeframe from today to 2050. Scenario analysis entails the choice of settings, the definition of scenarios of change, and the analysis of outcomes of these scenarios in the chosen settings. Three idealized agrosystems, representing a large fraction of the global diversity of wheat-based agrosystems, are considered, which represent the settings of the analysis. Several components of global changes are considered in their consequences on global wheat health: climate change and climate variability, nitrogen fertilizer use, tillage, crop rotation, pesticide use, and the deployment of host plant resistances. Each idealized agrosystem is associated with a scenario of change that considers first, a production situation and its dynamics, and second, the impacts of the evolving production situation on the evolution of crop health. Crop health is represented by six functional groups of wheat pathogens: the pathogens associated with Fusarium head blight; biotrophic fungi, Septoria-like fungi, necrotrophic fungi, soilborne pathogens, and insect-transmitted viruses. The analysis of scenario outcomes is conducted along a risk-analytical pattern, which involves risk probabilities represented by categorized probability levels of disease epidemics, and risk magnitudes represented by categorized levels of crop losses resulting from these levels of epidemics within each production situation. The results from this scenario analysis suggest an overall increase of risk probabilities and magnitudes in the three idealized agrosystems. Changes in risk probability or magnitude however vary with the agrosystem and the functional groups of pathogens. We discuss the effects of global changes on the six functional groups, in terms of their epidemiology and of the crop losses they cause. Scenario analysis enables qualitative analysis of complex systems, such as plant pathosystems that are evolving in response to global changes, including climate change and technology shifts. It also provides a useful framework for quantitative simulation modeling analysis for plant disease epidemiology.

Assessing the influence of climate change and inter-basin water diversion on Haihe River basin, eastern China: a coupled model approach

NASA Astrophysics Data System (ADS)

Xia, Jun; Wang, Qiang; Zhang, Xiang; Wang, Rui; She, Dunxian

2018-04-01

The modeling of changes in surface water and groundwater in the areas of inter-basin water diversion projects is quite difficult because surface water and groundwater models are run separately most of the time and the lack of sufficient data limits the application of complex surface-water/groundwater coupling models based on physical laws, especially for developing countries. In this study, a distributed surface-water and groundwater coupling model, named the distributed time variant gain model-groundwater model (DTVGM-GWM), was used to assess the influence of climate change and inter-basin water diversion on a watershed hydrological cycle. The DTVGM-GWM model can reflect the interaction processes of surface water and groundwater at basin scale. The model was applied to the Haihe River Basin (HRB) in eastern China. The possible influences of climate change and the South-to-North Water Diversion Project (SNWDP) on surface water and groundwater in the HRB were analyzed under various scenarios. The results showed that the newly constructed model DTVGM-GWM can reasonably simulate the surface and river runoff, and describe the spatiotemporal distribution characteristics of groundwater level, groundwater storage and phreatic recharge. The prediction results under different scenarios showed a decline in annual groundwater exploitation and also runoff in the HRB, while an increase of groundwater storage and groundwater level after the SNWDP's operation. Additionally, as the project also addresses future scenarios, a slight increase is predicted in the actual evapotranspiration, soil water content and phreatic recharge. This study provides valuable insights for developing sustainable groundwater management options for the HRB.

Co-management of domestic wastewater and food waste: A life cycle comparison of alternative food waste diversion strategies.

PubMed

Becker, Adilson M; Yu, Kevin; Stadler, Lauren B; Smith, Adam L

2017-01-01

Food waste is increasingly viewed as a resource that should be diverted from landfills. This study used life cycle assessment to compare co-management of food waste and domestic wastewater using anaerobic membrane bioreactor (AnMBR) against conventional activated sludge (CAS) and high rate activated sludge (HRAS) with three disposal options for food waste: landfilling (LF), anaerobic digestion (AD), and composting (CP). Based on the net energy balance (NEB), AnMBR and HRAS/AD were the most attractive scenarios due to cogeneration of produced biogas. However, cogeneration negatively impacted carcinogenics, non-carcinogenics, and ozone depletion, illustrating unavoidable tradeoffs between energy recovery from biogas and environmental impacts. Fugitive emissions of methane severely increased global warming impacts of all scenarios except HRAS/AD with AnMBR particularly affected by effluent dissolved methane emissions. AnMBR was also most sensitive to food waste diversion participation, with 40% diversion necessary to achieve a positive NEB at the current state of development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Manipulating type-I and type-II Dirac polaritons in cavity-embedded honeycomb metasurfaces.

PubMed

Mann, Charlie-Ray; Sturges, Thomas J; Weick, Guillaume; Barnes, William L; Mariani, Eros

2018-06-06

Pseudorelativistic Dirac quasiparticles have emerged in a plethora of artificial graphene systems that mimic the underlying honeycomb symmetry of graphene. However, it is notoriously difficult to manipulate their properties without modifying the lattice structure. Here we theoretically investigate polaritons supported by honeycomb metasurfaces and, despite the trivial nature of the resonant elements, we unveil rich Dirac physics stemming from a non-trivial winding in the light-matter interaction. The metasurfaces simultaneously exhibit two distinct species of massless Dirac polaritons, namely type-I and type-II. By modifying only the photonic environment via an enclosing cavity, one can manipulate the location of the type-II Dirac points, leading to qualitatively different polariton phases. This enables one to alter the fundamental properties of the emergent Dirac polaritons while preserving the lattice structure-a unique scenario which has no analog in real or artificial graphene systems. Exploiting the photonic environment will thus give rise to unexplored Dirac physics at the subwavelength scale.

Anyonic self-induced disorder in a stabilizer code: Quasi many-body localization in a translational invariant model

NASA Astrophysics Data System (ADS)

Yarloo, H.; Langari, A.; Vaezi, A.

2018-02-01

We enquire into the quasi many-body localization in topologically ordered states of matter, revolving around the case of Kitaev toric code on the ladder geometry, where different types of anyonic defects carry different masses induced by environmental errors. Our study verifies that the presence of anyons generates a complex energy landscape solely through braiding statistics, which suffices to suppress the diffusion of defects in such clean, multicomponent anyonic liquid. This nonergodic dynamics suggests a promising scenario for investigation of quasi many-body localization. Computing standard diagnostics evidences that a typical initial inhomogeneity of anyons gives birth to a glassy dynamics with an exponentially diverging time scale of the full relaxation. Our results unveil how self-generated disorder ameliorates the vulnerability of topological order away from equilibrium. This setting provides a new platform which paves the way toward impeding logical errors by self-localization of anyons in a generic, high energy state, originated exclusively in their exotic statistics.

STM images of carbon-nanotube quantum dots: Seeing a Wigner molecule of correlated electrons

NASA Astrophysics Data System (ADS)

Secchi, Andrea; Rontani, Massimo

2011-03-01

The paradigm of few-electron complexes in quantum dots (QDs) relies on the idea that the lowest quantized levels are filled according to Pauli's exclusion principle. If Coulomb repulsion is sufficiently strong to overcome the kinetic energy cost of localization, a different scenario is predicted: a ``Wigner'' molecule (WM) forms, made of electrons frozen in space according to a geometrical pattern. Despite considerable experimental effort, evidence of the WM in semiconductor QDs has been elusive so far. Here we demonstrate theoretically that WMs occur in gate-defined QDs embedded in typical semiconducting carbon nanotubes (CNTs). The unambiguous signatures of the WM state must be searched in the scanning tunneling microscopy (STM) images of the electrons. Through exact diagonalisation (ED) calculations, we unveil the inherent features of the electron molecular states. We show that, like nuclei in a usual molecule, electrons have localized wave functions and hence negligible exchange interactions. ED results for single and double QDs provide a simple interpretation for transport experiments in ultraclean CNTs.

A Giant Warm Baryonic Halo for the Coma Cluster

NASA Technical Reports Server (NTRS)

Bonamente, Max; Lieu, Richard; Joy, Marshall K.; Six, N. Frank (Technical Monitor)

2002-01-01

Several deep PSPC observations of the Coma cluster unveil a very large-scale halo of soft X-ray emission, substantially in excess of the well know radiation from the hot intra-cluster medium. The excess emission, previously reported in the central cluster regions through lower-sensitivity EUVE and ROSAT data, is now evident out to a radius of 2.5 Mpc, demonstrating that the soft excess radiation from clusters is a phenomenon of cosmological significance. The spectrum at these large radii cannot be modeled non-thermally, but is consistent with the original scenario of thermal emission at warm temperatures. The mass of this plasma is at least on par with that of the hot X-ray emitting plasma, and significantly more massive if the plasma resides in low-density filamentary structures. Thus the data lend vital support to current theories of cosmic evolution, which predict greater than 50 percent by mass of today's baryons reside in warm-hot filaments converging at clusters of galaxies.

Mitochondrial D-loop analysis for uncovering the population structure and genetic diversity among the indigenous duck (Anas platyrhynchos) populations of India.

PubMed

Gaur, Uma; Tantia, Madhu Sudan; Mishra, Bina; Bharani Kumar, Settypalli Tirumala; Vijh, Ramesh Kumar; Chaudhury, Ashok

2018-03-01

The indigenous domestic duck (Anas platyrhynchos domestica) which is domesticated from Mallard (Anas platyrhynchos) contributes significantly to poor farming community in coastal and North Eastern regions of India. For conservation and maintenance of indigenous duck populations it is very important to know the existing genetic diversity and population structure. To unravel the population structure and genetic diversity among the five indigenous duck populations of India, the mitochondrial D-loop sequences of 120 ducks were analyzed. The sequence analysis by comparison of mtDNA D-loop region (470 bp) of five Indian duck populations revealed 25 mitochondrial haplotypes. Pairwise F ST value among populations was 0.4243 (p < .01) and the range of nucleotide substitution per site (Dxy) between the five Indian duck populations was 0.00034-0.00555, and the net divergence (Da) was 0-0.00355. The phylogenetic analysis in the present study unveiled three clades. The analysis revealed genetic continuity among ducks of coastal region of the country which formed a separate group from the ducks of the inland area. Both coastal as well as the land birds revealed introgression of the out group breed Khaki Campbell, which is used for breed improvement programs in India. The observations revealed very less selection and a single matrilineal lineage of indigenous domestic ducks.

The Landscape Documentary: Unveiling the Face of "Wasteland."

ERIC Educational Resources Information Center

Denton, Craig L.

This paper outlines the process of a photographic landscape documentary project which set out to unveil the face of Utah's West Desert (a 42,000 square-mile, sparsely-populated, broad, rugged land of salt bed "playas" and high mountain ranges) comprising one-third of the state and which hoped to make the West Desert, recently under…

Unveiling epimerization effects: a rotational study of α-D-galactose.

PubMed

Peña, Isabel; Cabezas, Carlos; Alonso, José L

2015-06-25

By studying its C4 epimer α-D-galactose, the effects of epimerization on the conformational behaviour of α-D-glucose have been unveiled. Using laser ablation of crystalline samples, four conformers of α-D-galactopyranose have been observed, for the first time, in a supersonic expansion by analyzing the Fourier transform rotational spectrum.

Unveiling EFL and Self-Contained Teachers' Discourses on Bilingualism within the Context of Professional Development

ERIC Educational Resources Information Center

Camargo Cely, Jennyfer Paola

2018-01-01

Throughout time, the predominant use of certain languages has allowed some nations to take control over others and assure for them a privileged position. This study unveiled how certain practices and ideologies in regard to bilingualism have influenced teachers' professional development. Data were collected through discussion group sessions,…

Building Civilian-Military Collaboration to Enhance Response Following an Anthrax Release

DTIC Science & Technology

2012-05-04

thought that rural communities are not considered ―high risk‖ for the anthrax scenario as their widely dispersed population may not be a likely a...terrorist target.27 The community planners’ perception of risk will impact the time and effort a rural community places towards planning for these...types of scenarios. The diversity of urban and rural populations and their differing healthcare systems and infrastructures present complexities when

Nervous systems and scenarios for the invertebrate-to-vertebrate transition.

PubMed

Holland, Nicholas D

2016-01-05

Older evolutionary scenarios for the origin of vertebrates often gave nervous systems top billing in accordance with the notion that a big-brained Homo sapiens crowned a tree of life shaped mainly by progressive evolution. Now, however, tree thinking positions all extant organisms equidistant from the tree's root, and molecular phylogenies indicate that regressive evolution is more common than previously suspected. Even so, contemporary theories of vertebrate origin still focus on the nervous system because of its functional importance, its richness in characters for comparative biology, and its central position in the two currently prominent scenarios for the invertebrate-to-vertebrate transition, which grew out of the markedly neurocentric annelid and enteropneust theories of the nineteenth century. Both these scenarios compare phyla with diverse overall body plans. This diversity, exacerbated by the scarcity of relevant fossil data, makes it challenging to establish plausible homologies between component parts (e.g. nervous system regions). In addition, our current understanding of the relation between genotype and phenotype is too preliminary to permit us to convert gene network data into structural features in any simple way. These issues are discussed here with special reference to the evolution of nervous systems during proposed transitions from invertebrates to vertebrates. © 2015 The Author(s).

Exploring current and projected tradeoffs between hydropower profitability and reliability of supply in the Alps

NASA Astrophysics Data System (ADS)

Anghileri, D.; Castelletti, A.; Burlando, P.

2015-12-01

The recent spreading of renewable energy across Europe and the associated production variability and uncertainty are emerging challenges for hydropower system operation. Widely distributed and highly intermittent solar and wind power generation systems, along with feed-in-tariffs, at which they are remunerated, are threating the operation of traditional hydropower systems. For instance, in countries where the transition to a larger production by means of renewable power systems is a novel process, e.g. Switzerland, many hydropower companies are operating their reservoirs with low or no profits, claiming for a revision of the entire energy market system. This situation goes along with the problem of ensuring energy supply both nowadays and in the future, with changing energy demand and available water resources. In this work, we focus on a hydropower system in the Swiss Alps to explore how different operating policies can cope with both adequate energy supply and profitable operation under current and future climate and socio-economic conditions. We investigate the operation of the Mattmark reservoir in South-West Switzerland. Mattmark is a pumped reservoir of 98 106 m3 fed by a natural catchment of 37 km2 and contributing catchments, summing up to 51 km2, connected by several diversion channels. The hydrological regime, snow- and ice-melt dominated, has already experienced changes in the last decades due to glacier retreat and is expected to be strongly impacted by climate change in the future. We use Multi-Objective optimization techniques to explore current tradeoffs between profitability and secure supply. We then investigate how tradeoffs may evolve in time under different climate change projections and energy market scenarios. Results inform on the co-evolution of climate- and socio-economic induced variations, thus unveiling potential co-benefit situations to hydropower generation and providing insights to future energy market design.

­Genomic data mining of the marine actinobacteria Streptomyces sp. H-KF8 unveils insights into multi-stress related genes and metabolic pathways involved in antimicrobial synthesis

PubMed Central

Undabarrena, Agustina; Ugalde, Juan A.; Seeger, Michael

2017-01-01

Streptomyces sp. H-KF8 is an actinobacterial strain isolated from marine sediments of a Chilean Patagonian fjord. Morphological characterization together with antibacterial activity was assessed in various culture media, revealing a carbon-source dependent activity mainly against Gram-positive bacteria (S. aureus and L. monocytogenes). Genome mining of this antibacterial-producing bacterium revealed the presence of 26 biosynthetic gene clusters (BGCs) for secondary metabolites, where among them, 81% have low similarities with known BGCs. In addition, a genomic search in Streptomyces sp. H-KF8 unveiled the presence of a wide variety of genetic determinants related to heavy metal resistance (49 genes), oxidative stress (69 genes) and antibiotic resistance (97 genes). This study revealed that the marine-derived Streptomyces sp. H-KF8 bacterium has the capability to tolerate a diverse set of heavy metals such as copper, cobalt, mercury, chromate and nickel; as well as the highly toxic tellurite, a feature first time described for Streptomyces. In addition, Streptomyces sp. H-KF8 possesses a major resistance towards oxidative stress, in comparison to the soil reference strain Streptomyces violaceoruber A3(2). Moreover, Streptomyces sp. H-KF8 showed resistance to 88% of the antibiotics tested, indicating overall, a strong response to several abiotic stressors. The combination of these biological traits confirms the metabolic versatility of Streptomyces sp. H-KF8, a genetically well-prepared microorganism with the ability to confront the dynamics of the fjord-unique marine environment. PMID:28229018

Operational modeling system with dynamic-wave routing

USGS Publications Warehouse

Ishii, A.L.; Charlton, T.J.; Ortel, T.W.; Vonnahme, C.C.; ,

1998-01-01

A near real-time streamflow-simulation system utilizing continuous-simulation rainfall-runoff generation with dynamic-wave routing is being developed by the U.S. Geological Survey in cooperation with the Du Page County Department of Environmental Concerns for a 24-kilometer reach of Salt Creek in Du Page County, Illinois. This system is needed in order to more effectively manage the Elmhurst Quarry Flood Control Facility, an off-line stormwater diversion reservoir located along Salt Creek. Near real time simulation capabilities will enable the testing and evaluation of potential rainfall, diversion, and return-flow scenarios on water-surface elevations along Salt Creek before implementing diversions or return-flows. The climatological inputs for the continuous-simulation rainfall-runoff model, Hydrologic Simulation Program - FORTRAN (HSPF) are obtained by Internet access and from a network of radio-telemetered precipitation gages reporting to a base-station computer. The unit area runoff time series generated from HSPF are the input for the dynamic-wave routing model. Full Equations (FEQ). The Generation and Analysis of Model Simulation Scenarios (GENSCN) interface is used as a pre- and post-processor for managing input data and displaying and managing simulation results. The GENSCN interface includes a variety of graphical and analytical tools for evaluation and quick visualization of the results of operational scenario simulations and thereby makes it possible to obtain the full benefit of the fully distributed dynamic routing results.

Unveiling Members of Colletotrichum acutatum Species Complex Causing Colletotrichum Leaf Disease of Hevea brasiliensis in Sri Lanka.

PubMed

Hunupolagama, D M; Chandrasekharan, N V; Wijesundera, W S S; Kathriarachchi, H S; Fernando, T H P S; Wijesundera, R L C

2017-06-01

Colletotrichum is an important fungal genus with great diversity, which causes anthracnose of a variety of crop plants including rubber trees. Colletotrichum acutatum and Colletotrichum gloeosporioides have been identified as the major causative agents of Colletotrichum leaf disease of rubber trees in Sri Lanka based on morphology, pathogenicity, and the analysis of internally transcribed spacer sequences of the nuclear ribosomal DNA. This study has been conducted to investigate the members of the C. acutatum species complex causing rubber leaf disease using a morphological and multi gene approach. For the first time in Sri Lanka, Colletotrichum simmondsii, Colletotrichum laticiphilum, Colletotrichum nymphaeae, and Colletotrichum citri have been identified as causative agents of Colletotrichum leaf disease in addition to C. acutatum s. str. Among them, C. simmondsii has been recognized as the major causative agent.

Regulation of gene transcription by Polycomb proteins

PubMed Central

Aranda, Sergi; Mas, Gloria; Di Croce, Luciano

2015-01-01

The Polycomb group (PcG) of proteins defines a subset of factors that physically associate and function to maintain the positional identity of cells from the embryo to adult stages. PcG has long been considered a paradigmatic model for epigenetic maintenance of gene transcription programs. Despite intensive research efforts to unveil the molecular mechanisms of action of PcG proteins, several fundamental questions remain unresolved: How many different PcG complexes exist in mammalian cells? How are PcG complexes targeted to specific loci? How does PcG regulate transcription? In this review, we discuss the diversity of PcG complexes in mammalian cells, examine newly identified modes of recruitment to chromatin, and highlight the latest insights into the molecular mechanisms underlying the function of PcGs in transcription regulation and three-dimensional chromatin conformation. PMID:26665172

Climate-driven range shifts explain the distribution of extant gene pools and predict future loss of unique lineages in a marine brown alga.

PubMed

Assis, J; Serrão, E A; Claro, B; Perrin, C; Pearson, G A

2014-06-01

The climate-driven dynamics of species ranges is a critical research question in evolutionary ecology. We ask whether present intraspecific diversity is determined by the imprint of past climate. This is an ongoing debate requiring interdisciplinary examination of population genetic pools and persistence patterns across global ranges. Previously, contrasting inferences and predictions have resulted from distinct genomic coverage and/or geographical information. We aim to describe and explain the causes of geographical contrasts in genetic diversity and their consequences for the future baseline of the global genetic pool, by comparing present geographical distribution of genetic diversity and differentiation with predictive species distribution modelling (SDM) during past extremes, present time and future climate scenarios for a brown alga, Fucus vesiculosus. SDM showed that both atmospheric and oceanic variables shape the global distribution of intertidal species, revealing regions of persistence, extinction and expansion during glacial and postglacial periods. These explained the distribution and structure of present genetic diversity, consisting of differentiated genetic pools with maximal diversity in areas of long-term persistence. Most of the present species range comprises postglacial expansion zones and, in contrast to highly dispersive marine organisms, expansions involved only local fronts, leaving distinct genetic pools at rear edges. Besides unravelling a complex phylogeographical history and showing congruence between genetic diversity and persistent distribution zones, supporting the hypothesis of niche conservatism, range shifts and loss of unique genetic diversity at the rear edge were predicted for future climate scenarios, impoverishing the global gene pool. © 2014 John Wiley & Sons Ltd.

Genetic diversities of cytochrome B in Xinjiang Uyghur unveiled its origin and migration history

PubMed Central

2013-01-01

Background Uyghurs are one of the many populations of Central Eurasia that is considered to be genetically related to Eastern and Western Eurasian populations. However, there are some different opinions on the relative importance of the degree of Eastern and Western Eurasian genetic influence. In addition, the genetic diversity of the Uyghur in different geographic locations has not been clearly studied. Results In this study, we are the first to report on the DNA polymorphism of cytochrome B in the Uyghur population located in Xinjiang in northwest China. We observed a total of 102 mutant sites in the 240 samples that were studied. The average number of mutated nucleotides in the samples was 5.126. A total of 93 different haplotypes were observed. The gene diversity and discrimination power were 0.9480 and 0.9440, respectively. There were founder and bottleneck haplotypes observed in Xinjiang Uyghurs. Xinjiang Uyghurs are more genetically related to Chinese population in genetics than to Caucasians. Moreover, there was genetic diversity between Uyghurs from the southern and northern regions. There was significance in genetic distance between the southern Xinjiang Uyghurs and Chinese population, but not between the northern Xinjiang Uyghurs and Chinese. The European vs. East Asian contribution to the ten regional Uyghur groups varies among the groups and the European contribution to the Uyghur increases from north to south geographically. Conclusion This study is the first report on DNA polymorphisms of cytochrome B in the Uyghur population. The study also further confirms that there are significant genetic differences among the Uyghurs in different geographical locations. PMID:24103151

Unveiling a phytoplankton hotspot at a narrow boundary between coastal and offshore waters

PubMed Central

Ribalet, Francois; Marchetti, Adrian; Hubbard, Katherine A.; Brown, Kristina; Durkin, Colleen A.; Morales, Rhonda; Robert, Marie; Swalwell, Jarred E.; Tortell, Philippe D.; Armbrust, E. Virginia

2010-01-01

In terrestrial ecosystems, transitional areas between different plant communities (ecotones) are formed by steep environmental gradients and are commonly characterized by high species diversity and primary productivity, which in turn influences the foodweb structure of these regions. Whether comparable zones of elevated diversity and productivity characterize ecotones in the oceans remains poorly understood. Here we describe a previously hidden hotspot of phytoplankton diversity and productivity in a narrow but seasonally persistent transition zone at the intersection of iron-poor, nitrate-rich offshore waters and iron-rich, nitrate-poor coastal waters of the Northeast Pacific Ocean. Novel continuous measurements of phytoplankton cell abundance and composition identified a complex succession of blooms of five distinct size classes of phytoplankton populations within a 100-km–wide transition zone. The blooms appear to be fueled by natural iron enrichment of offshore communities as they are transported toward the coast. The observed succession of phytoplankton populations is likely driven by spatial gradients in iron availability or time since iron enrichment. Regardless of the underlying mechanism, the resulting communities have a strong impact on the regional biogeochemistry as evidenced by the low partial pressure of CO2 and the nearly complete depletion of nutrients. Enhanced phytoplankton productivity and diversity associated with steep environmental gradients are expected wherever water masses with complementary nutrient compositions mix to create a region more favorable for phytoplankton growth. The ability to detect and track these important but poorly characterized marine ecotones is critical for understanding their impact on productivity and ecosystem structure in the oceans. PMID:20823224

Unveiling a phytoplankton hotspot at a narrow boundary between coastal and offshore waters.

PubMed

Ribalet, Francois; Marchetti, Adrian; Hubbard, Katherine A; Brown, Kristina; Durkin, Colleen A; Morales, Rhonda; Robert, Marie; Swalwell, Jarred E; Tortell, Philippe D; Armbrust, E Virginia

2010-09-21

In terrestrial ecosystems, transitional areas between different plant communities (ecotones) are formed by steep environmental gradients and are commonly characterized by high species diversity and primary productivity, which in turn influences the foodweb structure of these regions. Whether comparable zones of elevated diversity and productivity characterize ecotones in the oceans remains poorly understood. Here we describe a previously hidden hotspot of phytoplankton diversity and productivity in a narrow but seasonally persistent transition zone at the intersection of iron-poor, nitrate-rich offshore waters and iron-rich, nitrate-poor coastal waters of the Northeast Pacific Ocean. Novel continuous measurements of phytoplankton cell abundance and composition identified a complex succession of blooms of five distinct size classes of phytoplankton populations within a 100-km-wide transition zone. The blooms appear to be fueled by natural iron enrichment of offshore communities as they are transported toward the coast. The observed succession of phytoplankton populations is likely driven by spatial gradients in iron availability or time since iron enrichment. Regardless of the underlying mechanism, the resulting communities have a strong impact on the regional biogeochemistry as evidenced by the low partial pressure of CO(2) and the nearly complete depletion of nutrients. Enhanced phytoplankton productivity and diversity associated with steep environmental gradients are expected wherever water masses with complementary nutrient compositions mix to create a region more favorable for phytoplankton growth. The ability to detect and track these important but poorly characterized marine ecotones is critical for understanding their impact on productivity and ecosystem structure in the oceans.

Microfungal oasis in an oligotrophic desert: diversity patterns and community structure in three freshwater systems of Cuatro Ciénegas, Mexico

PubMed Central

Gasca-Pineda, Jaime; Rosique-Gil, Edmundo; Eguiarte, Luis E.; Espinosa-Asuar, Laura

2016-01-01

The Cuatro Ciénegas Basin (CCB) comprises several oligotrophic aquatic ecosystems limited by phosphorus. These aquatic systems are dominated by a high prokaryotic diversity, shaped by the stress of low nutrient supplies and interspecific competition. Although fungi constitute a diverse and important component of microbial diversity, the microfungal diversity in the CCB remains to be unveiled. With the aim to explore microfungal diversity and ecological patterns in this area, we present the first investigation analyzing cultivable taxa from sediment and water, as well as lignocellulolytic taxa obtained from incubated submerged plant debris, and wood panels in three contrasting freshwater systems in the CCB: Churince, Becerra and Pozas Rojas. We chose a culture-based approach to analyze sediment and water samples in order to obtain fungal cultures, providing opportunities for a posteriori studies, and the possibility of ex situ preservation of the diversity. We evaluated sequence data from the nuclear ribosomal internal transcribed spacer including the 5.8 rDNA region for 126 isolates, revealing 37 OTUs. These OTUs were phylogenetically affiliated to several genera in the fungal phyla: Zygomycota, Basidiomycota, and Ascomycota. We recorded two OTUs with saline affinity, agreeing with previous findings on the prokaryotic communities with ancestral marine resemblances. All the studied systems showed moderate diversity levels, however discrepancies among the diversity indexes were observed, due to the occurrence of abundant taxa in the samples. Our results indicated that lignocellulolytic microfungal communities are dominated by transient fungal taxa, as resident species were not recorded perhaps as a result of the long-term strong competition with the highly adapted prokaryotic community. Moreover, the obtained microfungal taxa occurred mostly on the resident plant debris, rather than submerged wood panels, perhaps as a result of the high adaptation to specific environmental conditions. In conclusion, the CCB possess a moderate taxonomical diversity compared to other arid environments, probably as a result of high selective pressures. Nonetheless, due to high spatial and temporal heterogeneity, the functional fungal diversity was considerable as predicted by the intermediate disturbance hypothesis. Decisively, the assessment of microfungal diversity freshwater systems is relevant, since this ecological group of microorganisms represents an important indicator of trophic complexity and biotic interactions among microbial communities, having important implications for understanding eukaryotic survival at the oligotrophic limit for life. PMID:27280070

Defining conservation priorities for freshwater fishes according to taxonomic, functional, and phylogenetic diversity

USGS Publications Warehouse

Strecker, A.L.; Olden, J.D.; Whittier, Joanna B.; Paukert, C.P.

2011-01-01

To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential tradeoffs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity;contemporary threats to biodiversity (including interactions with nonnative species);and future climate change and human population growth. There was 75% congruence between areas of highest conservation priority for different aspects of biodiversity, suggesting that conservation efforts can concurrently achieve strong complementarity among all types of diversity. However, sizable fractions of the landscape were incongruent across conservation priorities for different diversity scenarios, underscoring the importance of considering multiple dimensions of biodiversity and highlighting catchments that contribute disproportionately to taxonomic, functional, and phylogenetic diversity in the region. Regions of projected human population growth were not concordant with conservation priorities;however, higher human population abundance will likely have indirect effects on native biodiversity by increasing demand for water. This will come in direct conflict with projected reductions in precipitation and warmer temperatures, which have substantial overlap with regions of high contemporary diversity. Native and endemic fishes in arid ecosystems are critically endangered by both current and future threats, but our results highlight the use of systematic conservation planning for the optimal allocation of limited resources that incorporates multiple and complementary conservation values describing taxonomic, functional, and phylogenetic diversity. ??2011 by the Ecological Society of America.

Defining conservation priorities for freshwater fishes according to taxonomic, functional, and phylogenetic diversity

USGS Publications Warehouse

Strecker, Angela L.; Olden, Julian D.; Whittier, Joanna B.; Paukert, Craig P.

2011-01-01

To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. There was 75% congruence between areas of highest conservation priority for different aspects of biodiversity, suggesting that conservation efforts can concurrently achieve strong complementarity among all types of diversity. However, sizable fractions of the landscape were incongruent across conservation priorities for different diversity scenarios, underscoring the importance of considering multiple dimensions of biodiversity and highlighting catchments that contribute disproportionately to taxonomic, functional, and phylogenetic diversity in the region. Regions of projected human population growth were not concordant with conservation priorities; however, higher human population abundance will likely have indirect effects on native biodiversity by increasing demand for water. This will come in direct conflict with projected reductions in precipitation and warmer temperatures, which have substantial overlap with regions of high contemporary diversity. Native and endemic fishes in arid ecosystems are critically endangered by both current and future threats, but our results highlight the use of systematic conservation planning for the optimal allocation of limited resources that incorporates multiple and complementary conservation values describing taxonomic, functional, and phylogenetic diversity.

Combined morphological and molecular data unveils relationships of Pseudobranchiomma (Sabellidae, Annelida) and reveals higher diversity of this intriguing group of fan worms in Australia, including potentially introduced species

PubMed Central

Capa, María; Murray, Anna

2016-01-01

Abstract Pseudobranchiomma (Sabellidae, Annelida) is a small and heterogeneous group of fan worms found in shallow marine environments and is generally associated with hard substrates. The delineation and composition of this genus is problematic since it has been defined only by plesiomorphic characters that are widely distributed among other sabellids. In this study we have combined morphological and molecular (mitochondrial and nuclear DNA sequences) data to evaluate species diversity in Australia and assess the phylogenetic relationships of these and other related sabellids. Unlike morphological data alone, molecular data and combined datasets suggest monophyly of Pseudobranchiomma. In this study, a new species of Pseudobranchiomma is described and three others are considered as potential unintentional introductions to Australian waters, one of them reported for the first time for the continent. Pseudobranchiomma pallida sp. n. bears 4–6 serrations along the radiolar flanges, lacks radiolar eyes and has uncini with three transverse rows of teeth over the main fang. In the new species the colour pattern as well is characteristic and species specific. PMID:27843378

White House Unveils America's College Promise Proposal: Tuition-Free Community College for Responsible Students. Fact Sheet

ERIC Educational Resources Information Center

The White House, 2015

2015-01-01

In January, 2015, the President unveiled the America's College Promise proposal, which would make two years of community college free for responsible students, letting students earn the first half of a bachelor's degree and earn skills needed in the workforce at no cost. This proposal will require everyone to do their part: community colleges must…

First National Picture of Trends in the Humanities Is Unveiled

ERIC Educational Resources Information Center

Howard, Jennifer

2009-01-01

When it comes to hard data about what they do, policy makers and educators in the humanities have been mostly left out in the cold, forced to rely on isolated statistics that do not give an overview of the field. That changed this month, as the American Academy of Arts and Sciences unveiled the prototype of its long-awaited Humanities Indicators…

Germany unveils €18bn research plan

NASA Astrophysics Data System (ADS)

Banks, Michael

2009-07-01

The German government has unveiled an ambitious plan to inject a total of €18bn into teaching and research over the next decade. The German chancellor Angela Merkel, who has a degree in physics, announced that she was releasing the funds despite concerns from her social-democrat coalition partners that financing the package could be difficult in the economic downturn.

Unveiling Reality of the Mind: Cultural Arbitrary of Consumerism

ERIC Educational Resources Information Center

Choi, Su-Jin

2012-01-01

This paper discusses the cultural arbitrary of consumerism by focusing on a personal realm. That is, I discuss what consumerism appeals to and how it flourishes in relation to our minds. I argue that we need to unveil reality of the mind, be aware of ourselves in relation to the perpetuation of consumerism, in order to critically intervene in the…

Photographer: NASA Ames On 20 December 1989, Ames buried a time capsule and unveiled a sculpture at

NASA Technical Reports Server (NTRS)

1989-01-01

Photographer: NASA Ames On 20 December 1989, Ames buried a time capsule and unveiled a sculpture at the spot where, fifty years earlier, Russel Robinson had turned the first spade of dirt for the Ames construction shack: Robinson (left) Ames Director Dale Compton (center) and Ames Deputy Director Sy Syvertson (right)

Open area 2 × 2 MIMO channel model for 2 GHz low-elevation links with diversity and capacity applications

NASA Astrophysics Data System (ADS)

Zelený, J.; Pérez-Fontán, F.; Pechac, P.; Mariño-Espiñeira, P.

2017-05-01

In civil surveillance applications, unmanned aerial vehicles (UAV) are being increasingly used in floods, fires, and law enforcement scenarios. In order to transfer large amounts of information from UAV-mounted cameras, relays, or sensors, large bandwidths are needed in comparison to those required for remotely commanding the UAV. This demands the use of higher-frequency bands, in all probability in the vicinity of 2 or 5 GHz. Novel hardware developments need propagation channel models for the ample range of operational scenarios envisaged, including multiple-input, multiple-output (MIMO) deployments. These configurations may enable a more robust transmission by increasing either the carrier-to-noise ratio statistics or the achievable capacity. In this paper, a 2 × 2 MIMO propagation channel model for an open-field environment capable of synthesizing a narrowband time series at 2 GHz is described. Maximal ratio combining diversity and capacity improvements are also evaluated through synthetic series and compared with measurement results. A simple flat, open scenario was evaluated based on which other, more complex environments can be modeled.

Projected shifts in copepod surface communities in the Mediterranean Sea under several climate change scenarios

NASA Astrophysics Data System (ADS)

Benedetti, F.; Guilhaumon, F.; Adloff, F.; Irisson, J. O.; Ayata, S. D.

2016-02-01

Although future increases in water temperature and future changes in regional circulation are expected to have great impacts on the pelagic food-web, estimates focusing on community-level shifts are still lacking for the planktonic compartment. By combining statistical niche models (or species distribution models) with projections from a regional circulation model, the impact of climate change on copepod epipelagic communities is assessed for the Mediterranean Sea. Habitat suitability maps are generated for 106 of the most abundant copepod species to analyze emerging patterns of diversity at the community level. Using variance analysis, we also quantified the uncertainties associated to our modeling strategy (niche model choice, CO2 emission scenario, boundary forcings of the circulation model). Comparing present and future projections, changes in species richness (alpha diversity) and in community composition (beta diversity, decomposed into turnover and nestedness component) are calculated. Average projections show that copepod communities will mainly experience turn-over processes, with little changes in species richness. Species gains are mainly located in the Gulf of Lions, the Northern Adriatic and the Northern Aegean seas. However, projections are highly variable, especially in the Eastern Mediterranean basin. We show that such variability is mainly driven by the choice of the niche model, through interactions with the CO2 emission scenario or the boundary forcing of the circulation model can be locally important. Finally, the possible impact of the estimated community changes on zooplanktonic functional and phylogenetic diversity is also assessed. We encourage the enlargement of this type of study to other components of the pelagic food-web, and argue that niche models' outputs should always be given along with a measure of uncertainty, and explained in light of a strong theoretical background.

Integrating science, policy and stakeholder perspectives for water resource management

NASA Astrophysics Data System (ADS)

Barbour, Emily; Allan, Andrew; Whitehead, Paul; Salehin, Mashfiqus; Lazzar, Attila; Lim, Michelle; Munsur Rahman, Md.

2015-04-01

Successful management of water resources requires an integrated approach considering the complex relationships between different biophysical processes, governance frameworks and socio-economic factors. The Ecosystem Services for Poverty Alleviation (ESPA) Deltas project has developed a range of socio-economic scenarios using a participatory approach, and applied these across different biophysical models as well as an integrated environmental, socio-economic model of the Ganges-Brahmaputra-Meghna (GBM) Delta. This work demonstrates a novel approach through the consideration of multiple ecosystem services and related socio-economic factors in the development of scenarios; the application of these to multiple models at multiple scales; and the participatory approach to improve project outcomes and engage national level stakeholders and policy makers. Scenarios can assist in planning for an uncertain future through exploring plausible alternatives. To adequately assess the potential impacts of future changes and management strategies on water resources, the wider biophysical, socio-economic and governance context needs to be considered. A series of stakeholder workshops have been held in Bangladesh to identify issues of main concern relating to the GBM Delta; to iteratively develop scenario narratives for business as usual, less sustainable, and more sustainable development pathways; and to translate these qualitative scenarios into a quantitative form suitable for analysis. The combined impact of these scenarios and climate change on water quantity and quality within the GBM Basin are demonstrated. Results suggest that climate change is likely to impact on both peak and low flows to a greater extent than most socio-economic changes. However, the diversion of water from the Ganges and Brahmaputra has the potential to significantly impact on water availability in Bangladesh depending on the timing and quantity of diversions. Both climate change and socio-economic scenarios are likely to impact on water quality. This work provides the foundation for investigating the effects of different policy and management interventions in coastal Bangladesh, and exploring trade-offs between different water resource objectives, and other ecosystem, social or economic objectives.

Unexpected High Diversity of Galling Insects in the Amazonian Upper Canopy: The Savanna Out There

PubMed Central

Julião, Genimar R.; Venticinque, Eduardo M.; Fernandes, G. Wilson; Price, Peter W.

2014-01-01

A relatively large number of studies reassert the strong relationship between galling insect diversity and extreme hydric and thermal status in some habitats, and an overall pattern of a greater number of galling species in the understory of scleromorphic vegetation. We compared galling insect diversity in the forest canopy and its relationship with tree richness among upland terra firme, várzea, and igapó floodplains in Amazonia, Brazil. The soils of these forest types have highly different hydric and nutritional status. Overall, we examined the upper layer of 1,091 tree crowns. Galling species richness and abundance were higher in terra firme forests compared to várzea and igapó forests. GLM-ANCOVA models revealed that the number of tree species sampled in each forest type was determinant in the gall-forming insect diversity. The ratio between galling insect richness and number of tree species sampled (GIR/TSS ratio) was higher in the terra firme forest and in seasonally flooded igapó, while the várzea presented the lowest GIR/TSS ratio. In this study, we recorded unprecedented values of galling species diversity and abundance per sampling point. The GIR/TSS ratio from várzea was approximately 2.5 times higher than the highest value of this ratio ever reported in the literature. Based on this fact, we ascertained that várzea and igapó floodplain forests (with lower GIA and GIR), together with the speciose terra firme galling community emerge as the gall diversity apex landscape among all biogeographic regions already investigated. Contrary to expectation, our results also support the “harsh environment hypothesis”, and unveil the Amazonian upper canopy as similar to Mediterranean vegetation habitats, hygrothermically stressed environments with leaf temperature at lethal limits and high levels of leaf sclerophylly. PMID:25551769

Demographic Histories, Isolation and Social Factors as Determinants of the Genetic Structure of Alpine Linguistic Groups

PubMed Central

Coia, Valentina; Capocasa, Marco; Anagnostou, Paolo; Pascali, Vincenzo; Scarnicci, Francesca; Boschi, Ilaria; Battaggia, Cinzia; Crivellaro, Federica; Ferri, Gianmarco; Alù, Milena; Brisighelli, Francesca; Busby, George B. J.; Capelli, Cristian; Maixner, Frank; Cipollini, Giovanna; Viazzo, Pier Paolo; Zink, Albert; Destro Bisol, Giovanni

2013-01-01

Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of “local ethnicity” on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet to be understood aspects of the genetic structure of European populations. PMID:24312576

Demographic histories, isolation and social factors as determinants of the genetic structure of Alpine linguistic groups.

PubMed

Coia, Valentina; Capocasa, Marco; Anagnostou, Paolo; Pascali, Vincenzo; Scarnicci, Francesca; Boschi, Ilaria; Battaggia, Cinzia; Crivellaro, Federica; Ferri, Gianmarco; Alù, Milena; Brisighelli, Francesca; Busby, George B J; Capelli, Cristian; Maixner, Frank; Cipollini, Giovanna; Viazzo, Pier Paolo; Zink, Albert; Destro Bisol, Giovanni

2013-01-01

Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of "local ethnicity" on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet to be understood aspects of the genetic structure of European populations.

“He Enjoys Giving her Pleasure”: Diversity and Complexity in Young Men’s Sexual Scripts

PubMed Central

Morrison, Diane M.; Masters, N. Tatiana; Wells, Elizabeth A.; Casey, Erin; Beadnell, Blair; Hoppe, Marilyn J.

2014-01-01

Research on heterosexual men’s sexual expectations has focused on self-described personal traits and culturally dominant models of masculinity. In a pair of studies, we used a sexual scripts perspective to explore the range and diversity of young men’s thoughts about sex and relationships with women and to develop measures for assessing these scripts. In the first study, we conducted semi-structured interviews to elicit young men’s accounts of their sexual relationships. We used these narratives to produce brief sexual script scenarios describing typical sexual situations, as well as conventional survey items assessing sexual behavior themes. In the second study, we administered the scenarios and theme items to an ethnically diverse, national sample of 648 heterosexually-active young men in an online survey. Using exploratory factor analysis, we delineated sets of sexual scripts and sexual behavior themes. In the scenarios, we found both a traditional masculine “player” script and a script that emphasized mutual sexual pleasure. Analysis of theme items produced scales of Drinking and Courtship, Monogamy and Emotion, and Sexual Focus and Variety. We discuss the implications of these findings for understanding heterosexual men’s thinking about sexuality and how cultural change in sexual thinking may arise. We also discuss the need for measures of sexual thinking that better integrate perceptions and expectations about the partner as well as the self in relation to the partner, rather than solely self-assessed traits. PMID:25287971

Integrated Modeling and Participatory Scenario Planning for Climate Adaptation: the Maui Groundwater Project

NASA Astrophysics Data System (ADS)

Keener, V. W.; Finucane, M.; Brewington, L.

2014-12-01

For the last century, the island of Maui, Hawaii, has been the center of environmental, agricultural, and legal conflict with respect to surface and groundwater allocation. Planning for adequate future freshwater resources requires flexible and adaptive policies that emphasize partnerships and knowledge transfer between scientists and non-scientists. In 2012 the Hawai'i state legislature passed the Climate Change Adaptation Priority Guidelines (Act 286) law requiring county and state policy makers to include island-wide climate change scenarios in their planning processes. This research details the ongoing work by researchers in the NOAA funded Pacific RISA to support the development of Hawaii's first island-wide water use plan under the new climate adaptation directive. This integrated project combines several models with participatory future scenario planning. The dynamically downscaled triply nested Hawaii Regional Climate Model (HRCM) was modified from the WRF community model and calibrated to simulate the many microclimates on the Hawaiian archipelago. For the island of Maui, the HRCM was validated using 20 years of hindcast data, and daily projections were created at a 1 km scale to capture the steep topography and diverse rainfall regimes. Downscaled climate data are input into a USGS hydrological model to quantify groundwater recharge. This model was previously used for groundwater management, and is being expanded utilizing future climate projections, current land use maps and future scenario maps informed by stakeholder input. Participatory scenario planning began in 2012 to bring together a diverse group of over 50 decision-makers in government, conservation, and agriculture to 1) determine the type of information they would find helpful in planning for climate change, and 2) develop a set of scenarios that represent alternative climate/management futures. This is an iterative process, resulting in flexible and transparent narratives at multiple scales. The resulting climate, land use, and groundwater recharge maps give stakeholders a common set of future scenarios that they understand through the participatory scenario process, and identify the vulnerabilities, trade-offs, and adaptive priorities for different groundwater management and land uses in an uncertain future.

China’s War by Other Means: Unveiling China’s Quest for Information Dominance

DTIC Science & Technology

2017-06-09

CHINA’S WAR BY OTHER MEANS: UNVEILING CHINA’S QUEST FOR INFORMATION DOMINANCE A thesis presented to the Faculty of the U.S...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...gathering and maintaining the data needed, and completing and reviewing this collection of information . Send comments regarding this burden estimate

Unveiling the Veiled and Veiling the Unveiled: Revealing the Underlying Linguistic Ideologies and Their Impact on Persian Language Loss and Maintenance among Second-Generation Iranian-American College Students

ERIC Educational Resources Information Center

Ramezanzadeh, Farah S.

2010-01-01

This study adopted an interpretive/qualitative methodology to explore the issues and challenges of developing and maintaining Persian/Farsi as a heritage language in homes and neighborhoods for second-generation Iranian-American youth living in a major US metropolitan area with a sizable concentration of Iranian immigrants. The purpose of the…

Unveiling Their Worlds: The Use of Dialogue as a Health-Promotion Tool for HIV/AIDS Education in a Poor Community in Kenya

ERIC Educational Resources Information Center

Kiragu, Susan; McLaughlin, Colleen

2011-01-01

Three decades since the onset of HIV/AIDS, 33.2 million people worldwide are infected and prevalence in Kenya is on the rise. This paper contributes to discussions about HIV/AIDS education and draws on the health promotion approach and the emancipatory theory of Paulo Freire. Freire argued that through dialogue people unveil their world. The…

Limited communication capacity unveils strategies for human interaction

NASA Astrophysics Data System (ADS)

Miritello, Giovanna; Lara, Rubén; Cebrian, Manuel; Moro, Esteban

2013-06-01

Connectivity is the key process that characterizes the structural and functional properties of social networks. However, the bursty activity of dyadic interactions may hinder the discrimination of inactive ties from large interevent times in active ones. We develop a principled method to detect tie de-activation and apply it to a large longitudinal, cross-sectional communication dataset (~19 months, ~20 million people). Contrary to the perception of ever-growing connectivity, we observe that individuals exhibit a finite communication capacity, which limits the number of ties they can maintain active in time. On average men display higher capacity than women, and this capacity decreases for both genders over their lifespan. Separating communication capacity from activity reveals a diverse range of tie activation strategies, from stable to exploratory. This allows us to draw novel relationships between individual strategies for human interaction and the evolution of social networks at global scale.

Limited communication capacity unveils strategies for human interaction

PubMed Central

Miritello, Giovanna; Lara, Rubén; Cebrian, Manuel; Moro, Esteban

2013-01-01

Connectivity is the key process that characterizes the structural and functional properties of social networks. However, the bursty activity of dyadic interactions may hinder the discrimination of inactive ties from large interevent times in active ones. We develop a principled method to detect tie de-activation and apply it to a large longitudinal, cross-sectional communication dataset (≈19 months, ≈20 million people). Contrary to the perception of ever-growing connectivity, we observe that individuals exhibit a finite communication capacity, which limits the number of ties they can maintain active in time. On average men display higher capacity than women, and this capacity decreases for both genders over their lifespan. Separating communication capacity from activity reveals a diverse range of tie activation strategies, from stable to exploratory. This allows us to draw novel relationships between individual strategies for human interaction and the evolution of social networks at global scale. PMID:23739519

Novel Genetic Resources in the Genus Vigna Unveiled from Gene Bank Accessions

PubMed Central

Takahashi, Yu; Somta, Prakit; Muto, Chiaki; Iseki, Kohtaro; Naito, Ken; Pandiyan, Muthaiyan; Natesan, Senthil; Tomooka, Norihiko

2016-01-01

The genus Vigna (Fabaceae) consists of five subgenera, and includes more than 100 wild species. In Vigna, 10 crops have been domesticated from three subgenera, Vigna, Plectrotropis, and Ceratotropis. The habitats of wild Vigna species are so diverse that their genomes could harbor various genes responsible for environmental stress adaptation, which could lead to innovations in agriculture. Since some of the gene bank Vigna accessions were unidentified and they seemed to be novel genetic resources, these accessions were identified based on morphological traits. The phylogenetic positions were estimated based on the DNA sequences of nuclear rDNA-ITS and chloroplast atpB-rbcL spacer regions. Based on the results, the potential usefulness of the recently described species V. indica and V. sahyadriana, and some wild Vigna species, i.e., V. aconitifolia, V. dalzelliana, V. khandalensis, V. marina var. oblonga, and V. vexillata, was discussed. PMID:26800459

Social wasps are a Saccharomyces mating nest.

PubMed

Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

2016-02-23

The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

Dynamic nigrostriatal dopamine biases action selection

PubMed Central

Howard, Christopher D.; Li, Hao; Geddes, Claire E.; Jin, Xin

2017-01-01

Summary Dopamine is thought to play a critical role in reinforcement learning and goal-directed behavior, but its function in action selection remains largely unknown. Here, we demonstrate that nigrostriatal dopamine biases ongoing action selection. When mice were trained to dynamically switch the action selected at different time points, changes in firing rate of nigrostriatal dopamine neurons, as well as dopamine signaling in the dorsal striatum, were found to be associated with action selection. This dopamine profile is specific to behavioral choice, scalable with interval duration, and doesn’t reflect reward prediction error, timing, or value as single factors alone. Genetic deletion of NMDA receptors on dopamine or striatal neurons, or optogenetic manipulation of dopamine concentration, alters dopamine signaling and biases action selection. These results unveil a crucial role of nigrostriatal dopamine in integrating diverse information for regulating upcoming actions and have important implications for neurological disorders including Parkinson’s disease and substance dependence. PMID:28285820

Dynamic Nigrostriatal Dopamine Biases Action Selection.

PubMed

Howard, Christopher D; Li, Hao; Geddes, Claire E; Jin, Xin

2017-03-22

Dopamine is thought to play a critical role in reinforcement learning and goal-directed behavior, but its function in action selection remains largely unknown. Here we demonstrate that nigrostriatal dopamine biases ongoing action selection. When mice were trained to dynamically switch the action selected at different time points, changes in firing rate of nigrostriatal dopamine neurons, as well as dopamine signaling in the dorsal striatum, were found to be associated with action selection. This dopamine profile is specific to behavioral choice, scalable with interval duration, and doesn't reflect reward prediction error, timing, or value as single factors alone. Genetic deletion of NMDA receptors on dopamine or striatal neurons or optogenetic manipulation of dopamine concentration alters dopamine signaling and biases action selection. These results unveil a crucial role of nigrostriatal dopamine in integrating diverse information for regulating upcoming actions, and they have important implications for neurological disorders, including Parkinson's disease and substance dependence. Copyright © 2017 Elsevier Inc. All rights reserved.

La tecnología y las monjitas: constellations of authoritative knowledge at a religious birthing center in south Texas.

PubMed

Fleuriet, K Jill

2009-09-01

In this article, I contrast conceptualizations of authoritative knowledge in pregnancy and birth between U.S. midwives and their Mexican immigrant clients at a religious birthing center in south Texas. Although the two groups share certain orientations to pregnancy management, essential differences in prenatal care and birth epistemologies underscore distinct social and economic positions. I use narrative data to document and explain these differences, which throw into relief the hierarchies of identity and need that structure immigrant women's reproductive experiences. Unveiling the different epistemologies can also help to explain sometimes radically divergent ideas that have impacted the very survivability of the birthing center. By focusing on Mexican immigrant women's reproductive decision making in an alternative birthing center, this analysis responds to feminists' call to look to the margins to understand the diversity of women's responses to what Rapp and Ginsburg have called "stratified reproduction".

Homeodomains, Hedgehogs, and Happiness.

PubMed

Scott, Matthew P

2016-01-01

Developmental biologists have had a spectacular quarter century of discoveries, building on many decades of work earlier, discovering molecular, cellular, and genetic mechanisms that underlie the magical process by which an egg becomes a plant or animal. Among the discoveries were homeodomains, DNA-binding domains that allow transcription factors to recognize their target genes, and the Hedgehog signaling pathway, which is used in many organs and tissues for communication among cells. The experience of unveiling the mechanisms and molecules connected to both of these findings has been remarkable, joyful, difficult, and a time of great teamwork and collaboration within and between laboratory groups. More than ever it is possible to discern the evolutionary processes, and their mechanisms, that led to the diversity of life on earth. A huge amount of work remains to be done to obtain a broad understanding of what happened and how development works. © 2016 Elsevier Inc. All rights reserved.

The cutaneous ecosystem: the roles of the skin microbiome in health and its association with inflammatory skin conditions in humans and animals.

PubMed

Rodrigues Hoffmann, Aline

2017-02-01

Inhabiting a sterile world is no longer an acceptable or desirable concept. Recent studies developed in the microbiome field have unveiled complex microbial populations inhabiting the skin, digestive, respiratory and reproductive tracts. Microbiome studies have opened new venues to explore the human and animal second genome, its functions and its importance in maintaining health. The composition of the skin microbiome varies across different body sites and across individuals, being influenced by different host habits, including for instance age, sex, diet, hygiene and lifestyle. Exposure to a diverse skin microbiome is now considered to be a key component in immune regulation, and imbalances in these microbial populations are being associated with human and animal skin inflammatory disorders. We have learned that in several skin conditions, there is a significant alteration in the diversity and composition of the microbiota colonizing the skin. For instance, in human and animal patients with atopic dermatitis, dysbiosis of the skin microbiota results in lower diversity of microbial populations. Whether these altered microbial populations are the cause or the effect of inflammatory skin conditions seen in humans and animals are still under investigation, but there is no doubt that the microbiome has an important role in maintaining skin health. This review focuses on the most current studies describing the skin microbiome in humans and animals, its role in modulating the immune system, and its association with human and animal skin diseases. © 2017 ESVD and ACVD.

Discovery and characterization of natural products that act as pheromones in fish.

PubMed

Li, Ke; Buchinger, Tyler J; Li, Weiming

2018-06-20

Covering: up to 2018 Fish use a diverse collection of molecules to communicate with conspecifics. Since Karlson and Lüscher termed these molecules 'pheromones', chemists and biologists have joined efforts to characterize their structures and functions. In particular, the understanding of insect pheromones developed at a rapid pace, set, in part, by the use of bioassay-guided fractionation and natural product chemistry. Research on vertebrate pheromones, however, has progressed more slowly. Initially, biologists characterized fish pheromones by screening commercially available compounds suspected to act as pheromones based upon their physiological function. Such biology-driven screening has proven a productive approach to studying pheromones in fish. However, the many functions of fish pheromones and diverse metabolites that fish release make predicting pheromone identity difficult and necessitate approaches led by chemistry. Indeed, the few cases in which pheromone identification was led by natural product chemistry indicated novel or otherwise unpredicted compounds act as pheromones. Here, we provide a brief review of the approaches to identifying pheromones, placing particular emphasis on the promise of using natural product chemistry together with assays of biological activity. Several case studies illustrate bioassay-guided fractionation as an approach to pheromone identification in fish and the unexpected diversity of pheromone structures discovered by natural product chemistry. With recent advances in natural product chemistry, bioassay-guided fractionation is likely to unveil an even broader collection of pheromone structures and enable research that spans across disciplines.

Application of an Environmental Decision Support System to a Water Quality Trading Program Affected by Surface Water Diversions

NASA Astrophysics Data System (ADS)

Obropta, Christopher C.; Niazi, Mehran; Kardos, Josef S.

2008-12-01

Environmental decision support systems (EDSSs) are an emerging tool used to integrate the evaluation of highly complex and interrelated physicochemical, biological, hydrological, social, and economic aspects of environmental problems. An EDSS approach is developed to address hot-spot concerns for a water quality trading program intended to implement the total maximum daily load (TMDL) for phosphorus in the Non-Tidal Passaic River Basin of New Jersey. Twenty-two wastewater treatment plants (WWTPs) spread throughout the watershed are considered the major sources of phosphorus loading to the river system. Periodic surface water diversions to a major reservoir from the confluence of two key tributaries alter the natural hydrology of the watershed and must be considered in the development of a trading framework that ensures protection of water quality. An EDSS is applied that enables the selection of a water quality trading framework that protects the watershed from phosphorus-induced hot spots. The EDSS employs Simon’s (1960) three stages of the decision-making process: intelligence, design, and choice. The identification of two potential hot spots and three diversion scenarios enables the delineation of three management areas for buying and selling of phosphorus credits among WWTPs. The result shows that the most conservative option entails consideration of two possible diversion scenarios, and trading between management areas is restricted accordingly. The method described here is believed to be the first application of an EDSS to a water quality trading program that explicitly accounts for surface water diversions.

Economics of Employer-Sponsored Workplace Vaccination to Prevent Pandemic and Seasonal Influenza

PubMed Central

Lee, Bruce Y.; Bailey, Rachel R.; Wiringa, Ann E.; Afriyie, Abena; Wateska, Angela R.; Smith, Kenneth J.; Zimmerman, Richard K.

2010-01-01

Employers may be loath to fund vaccination programs without understanding the economic consequences. We developed a decision analytic computational simulation model including dynamic transmission elements that determined the cost-benefit of employer-sponsored workplace vaccination from the employer's perspective. Implementing such programs was relatively inexpensive (<$35/vaccinated employee) and, in many cases, cost saving across diverse occupational groups in all seasonal influenza scenarios. Such programs were cost-saving for a 20% serologic attack rate pandemic scenario (−$15 to −$995) per vaccinated employee) and a 30% serologic attack rate pandemic scenario (range −$39 to −$1,494 per vaccinated employee) across all age and major occupational groups. PMID:20620168

Comparative genomics of wild type yeast strains unveils important genome diversity

PubMed Central

Carreto, Laura; Eiriz, Maria F; Gomes, Ana C; Pereira, Patrícia M; Schuller, Dorit; Santos, Manuel AS

2008-01-01

Background Genome variability generates phenotypic heterogeneity and is of relevance for adaptation to environmental change, but the extent of such variability in natural populations is still poorly understood. For example, selected Saccharomyces cerevisiae strains are variable at the ploidy level, have gene amplifications, changes in chromosome copy number, and gross chromosomal rearrangements. This suggests that genome plasticity provides important genetic diversity upon which natural selection mechanisms can operate. Results In this study, we have used wild-type S. cerevisiae (yeast) strains to investigate genome variation in natural and artificial environments. We have used comparative genome hybridization on array (aCGH) to characterize the genome variability of 16 yeast strains, of laboratory and commercial origin, isolated from vineyards and wine cellars, and from opportunistic human infections. Interestingly, sub-telomeric instability was associated with the clinical phenotype, while Ty element insertion regions determined genomic differences of natural wine fermentation strains. Copy number depletion of ASP3 and YRF1 genes was found in all wild-type strains. Other gene families involved in transmembrane transport, sugar and alcohol metabolism or drug resistance had copy number changes, which also distinguished wine from clinical isolates. Conclusion We have isolated and genotyped more than 1000 yeast strains from natural environments and carried out an aCGH analysis of 16 strains representative of distinct genotype clusters. Important genomic variability was identified between these strains, in particular in sub-telomeric regions and in Ty-element insertion sites, suggesting that this type of genome variability is the main source of genetic diversity in natural populations of yeast. The data highlights the usefulness of yeast as a model system to unravel intraspecific natural genome diversity and to elucidate how natural selection shapes the yeast genome. PMID:18983662

Upgraded Hubble Space Telescope Images

NASA Image and Video Library

2009-09-08

U.S. Senator Barbara A. Mikulski, D-Md., left foreground, NASA Administrator Charles F. Bolden, center, and NASA Deputy Administrator Lori Garver, right, along with members of the STS-125 and STS-31 space shuttle crews listen during a press conference where NASA unveiled new images from the Hubble Space Telescope Wednesday, Sept. 9, 2009 at NASA Headquarters in Washington. The unveiled images were from four of the telescopes' six operating science instruments. Photo Credit: (NASA/Bill Ingalls)

The universe unveiled : instruments and images through history

NASA Astrophysics Data System (ADS)

Stephenson, Bruce; Bolt, Marvin; Friedman, Anna Felicity

2000-11-01

The search for understanding creates more than answers; it also produces instruments, books, maps, and other tools made and used by those seeking knowledge. The Universe Unveiled uniquely focuses on these artifacts and devices resulting from the attempts to decipher the Universe from the late fifteenth to the early twentieth century. Beautiful, full-color photographs capture these extremely rare and sometimes unusual curios. Beginning with the discovery of ways to keep time, The Universe Unveiled depicts the shift from an Earth-centered understanding of the Universe to a Sun-centered view, the mapping of the stars, and the ever-expanding knowledge of the heavens using telescopes. It also examines the developing technologies of navigation and of the measuring and mapping of the Earth. In addition to rare European curios, the book is illustrated with non-Western and American works. With more than 250 full-color images, this unique volume will delight the inventive as well as the curious.

Large Ensemble Analytic Framework for Consequence-Driven Discovery of Climate Change Scenarios

NASA Astrophysics Data System (ADS)

Lamontagne, Jonathan R.; Reed, Patrick M.; Link, Robert; Calvin, Katherine V.; Clarke, Leon E.; Edmonds, James A.

2018-03-01

An analytic scenario generation framework is developed based on the idea that the same climate outcome can result from very different socioeconomic and policy drivers. The framework builds on the Scenario Matrix Framework's abstraction of "challenges to mitigation" and "challenges to adaptation" to facilitate the flexible discovery of diverse and consequential scenarios. We combine visual and statistical techniques for interrogating a large factorial data set of 33,750 scenarios generated using the Global Change Assessment Model. We demonstrate how the analytic framework can aid in identifying which scenario assumptions are most tied to user-specified measures for policy relevant outcomes of interest, specifically for our example high or low mitigation costs. We show that the current approach for selecting reference scenarios can miss policy relevant scenario narratives that often emerge as hybrids of optimistic and pessimistic scenario assumptions. We also show that the same scenario assumption can be associated with both high and low mitigation costs depending on the climate outcome of interest and the mitigation policy context. In the illustrative example, we show how agricultural productivity, population growth, and economic growth are most predictive of the level of mitigation costs. Formulating policy relevant scenarios of deeply and broadly uncertain futures benefits from large ensemble-based exploration of quantitative measures of consequences. To this end, we have contributed a large database of climate change futures that can support "bottom-up" scenario generation techniques that capture a broader array of consequences than those that emerge from limited sampling of a few reference scenarios.

Warming increases plant biomass and reduces diversity across continents, latitudes, and species migration scenarios in experimental wetland communities.

PubMed

Baldwin, Andrew H; Jensen, Kai; Schönfeldt, Marisa

2014-03-01

Atmospheric warming may influence plant productivity and diversity and induce poleward migration of species, altering communities across latitudes. Complicating the picture is that communities from different continents deviate in evolutionary histories, which may modify responses to warming and migration. We used experimental wetland plant communities grown from seed banks as model systems to determine whether effects of warming on biomass production and species richness are consistent across continents, latitudes, and migration scenarios. We collected soil samples from each of three tidal freshwater marshes in estuaries at three latitudes (north, middle, south) on the Atlantic coasts of Europe and North America. In one experiment, we exposed soil seed bank communities from each latitude and continent to ambient and elevated (+2.8 °C) temperatures in the greenhouse. In a second experiment, soil samples were mixed either within each estuary (limited migration) or among estuaries from different latitudes in each continent (complete migration). Seed bank communities of these migration scenarios were also exposed to ambient and elevated temperatures and contrasted with a no-migration treatment. In the first experiment, warming overall increased biomass (+16%) and decreased species richness (-14%) across latitudes in Europe and North America. Species richness and evenness of south-latitude communities were less affected by warming than those of middle and north latitudes. In the second experiment, warming also stimulated biomass and lowered species richness. In addition, complete migration led to increased species richness (+60% in North America, + 100% in Europe), but this higher diversity did not translate into increased biomass. Species responded idiosyncratically to warming, but Lythrum salicaria and Bidens sp. increased significantly in response to warming in both continents. These results reveal for the first time consistent impacts of warming on biomass and species richness for temperate wetland plant communities across continents, latitudes, and migration scenarios. © 2013 John Wiley & Sons Ltd.

Assessing global fossil fuel availability in a scenario framework

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

Bauer, Nico; Hilaire, Jérôme; Brecha, Robert J.

This study assesses global, long-term economic availability of coal, oil and gas within the Shared Socio-economic Pathway (SSP) scenario framework considering alternative assumptions as to highly uncertain future developments of technology, policy and the economy. Diverse sets of trajectories are formulated varying the challenges to mitigation and adaptation of climate change. The potential CO2 emissions from fossil fuels make it a crucial element subject to deep uncertainties. The analysis is based on a well-established data set of cost-quantity combinations that assumes favorable techno-economic developments, but ignores additional constraints on the extraction sector. This study significantly extends that analysis to includemore » alternative assumptions for the fossil fuel sector consistent with the SSP scenario families and applies these filters to the original data set, thus resulting in alternative cumulative fossil fuel availability curves. In a Middle-of-the-Road scenario, low cost fossil fuels embody carbon consistent with a RCP6.0 emission profile, if all the CO2 were emitted freely during the 21st century. In scenarios with high challenges to mitigation, the assumed embodied carbon in low-cost fossil fuels can trigger a RCP8.5 scenario; low mitigation challenges scenarios are still consistent with a RCP4.5 scenario.« less

Combining destination diversion decisions and critical in-flight event diagnosis in computer aided testing of pilots

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.; Romer, D. J.

1984-01-01

Rockwell and Giffin (1982) and Giffin and Rockwell (1983) have discussed the use of computer aided testing (CAT) in the study of pilot response to critical in-flight events. The present investigation represents an extension of these earlier studies. In testing pilot responses to critical in-flight events, use is made of a Plato-touch CRT system operating on a menu based format. In connection with the typical diagnostic problem, the pilot was presented with symptoms within a flight scenario. In one problem, the pilot has four minutes for obtaining the information which is needed to make a diagnosis of the problem. In the reported research, the attempt has been made to combine both diagnosis and diversion scenario into a single computer aided test. Tests with nine subjects were conducted. The obtained results and their significance are discussed.

Modeling impacts of sea-level rise, oil price, and management strategy on the costs of sustaining Mississippi delta marshes with hydraulic dredging.

PubMed

Wiegman, Adrian R H; Day, John W; D'Elia, Christopher F; Rutherford, Jeffrey S; Morris, James T; Roy, Eric D; Lane, Robert R; Dismukes, David E; Snyder, Brian F

2018-03-15

Over 25% of Mississippi River delta plain (MRDP) wetlands were lost over the past century. There is currently a major effort to restore the MRDP focused on a 50-year time horizon, a period during which the energy system and climate will change dramatically. We used a calibrated MRDP marsh elevation model to assess the costs of hydraulic dredging to sustain wetlands from 2016 to 2066 and 2016 to 2100 under a range of scenarios for sea level rise, energy price, and management regimes. We developed a subroutine to simulate dredging costs based on the price of crude oil and a project efficiency factor. Crude oil prices were projected using forecasts from global energy models. The costs to sustain marsh between 2016 and 2100 changed from $128,000/ha in the no change scenario to ~$1,010,000/ha in the worst-case scenario for sea level rise and energy price, an ~8-fold increase. Increasing suspended sediment concentrations, which is possible using managed river diversions, raised created marsh lifespan and decreased long term dredging costs. Created marsh lifespan changed nonlinearly with dredging fill elevation and suspended sediment level. Cost effectiveness of marsh creation and nourishment can be optimized by adjusting dredging fill elevation to the local sediment regime. Regardless of management scenario, sustaining the MRDP with hydraulic dredging suffered declining returns on investment due to the convergence of energy and climate trends. Marsh creation will likely become unaffordable in the mid to late 21st century, especially if river sediment diversions are not constructed before 2030. We recommend that environmental managers take into consideration coupled energy and climate scenarios for long-term risk assessments and adjust restoration goals accordingly. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamics in a one-dimensional ferrogel model: relaxation, pairing, shock-wave propagation.

PubMed

Goh, Segun; Menzel, Andreas M; Löwen, Hartmut

2018-05-23

Ferrogels are smart soft materials, consisting of a polymeric network and embedded magnetic particles. Novel phenomena, such as the variation of the overall mechanical properties by external magnetic fields, emerge consequently. However, the dynamic behavior of ferrogels remains largely unveiled. In this paper, we consider a one-dimensional chain consisting of magnetic dipoles and elastic springs between them as a simple model for ferrogels. The model is evaluated by corresponding simulations. To probe the dynamics theoretically, we investigate a continuum limit of the energy governing the system and the corresponding equation of motion. We provide general classification scenarios for the dynamics, elucidating the touching/detachment dynamics of the magnetic particles along the chain. In particular, it is verified in certain cases that the long-time relaxation corresponds to solutions of shock-wave propagation, while formations of particle pairs underlie the initial stage of the dynamics. We expect that these results will provide insight into the understanding of the dynamics of more realistic models with randomness in parameters and time-dependent magnetic fields.

The role of the airline transportation network in the prediction and predictability of global epidemics.

PubMed

Colizza, Vittoria; Barrat, Alain; Barthélemy, Marc; Vespignani, Alessandro

2006-02-14

The systematic study of large-scale networks has unveiled the ubiquitous presence of connectivity patterns characterized by large-scale heterogeneities and unbounded statistical fluctuations. These features affect dramatically the behavior of the diffusion processes occurring on networks, determining the ensuing statistical properties of their evolution pattern and dynamics. In this article, we present a stochastic computational framework for the forecast of global epidemics that considers the complete worldwide air travel infrastructure complemented with census population data. We address two basic issues in global epidemic modeling: (i) we study the role of the large scale properties of the airline transportation network in determining the global diffusion pattern of emerging diseases; and (ii) we evaluate the reliability of forecasts and outbreak scenarios with respect to the intrinsic stochasticity of disease transmission and traffic flows. To address these issues we define a set of quantitative measures able to characterize the level of heterogeneity and predictability of the epidemic pattern. These measures may be used for the analysis of containment policies and epidemic risk assessment.

The effect of aging on the (mis)perception of intentionality - an ERP study.

PubMed

Pasion, R; Fernandes, C; Gonçalves, A R; Ferreira-Santos, F; Páscoa, R; Barbosa, F; Marques-Teixeira, J

2018-01-23

Despite the accumulated knowledge on moral decision-making in the early stages of development, empirical evidence is still limited in the old-aged adults. The current study contributes to unveil the neural correlates of judgments of moral transgressions as a function of aging, by examining the temporal dynamics of neural activation elicited by intentional and accidental harmful actions in three groups of healthy participants: young adults (18-35), adults (40-55), and older adults (60-75). Older adults were slower and less accurate in rating intentionality, compared to the younger groups. In ERP analysis, the older group showed increased P2 amplitude, which was predicted by poorer performance on neuropsychological tests. Reduced amplitudes were found on critical ERP components to moral cognition (N2 and LPP), namely while processing intentional harmful scenarios. Older adults seem to allocate more attentional resources (P2) to the task, probably to compensate the age-related decline in executive functioning, while younger groups show a pronounced negativity while detecting harm (N2) and increased neural activation to encode the intentions behind the acts (LPP).

Conformational co-dependence between Plasmodium berghei LCCL proteins promotes complex formation and stability.

PubMed

Saeed, Sadia; Tremp, Annie Z; Dessens, Johannes T

2012-10-01

Malaria parasites express a conserved family of LCCL-lectin adhesive-like domain proteins (LAPs) that have essential functions in sporozoite transmission. In Plasmodium falciparum all six family members are expressed in gametocytes and form a multi-protein complex. Intriguingly, knockout of P. falciparum LCCL proteins adversely affects expression of other family members at protein, but not at mRNA level, a phenomenon termed co-dependent expression. Here, we investigate this in Plasmodium berghei by crossing a PbLAP1 null mutant parasite with a parasite line expressing GFP-tagged PbLAP3 that displays strong fluorescence in gametocytes. Selected and validated double mutants show normal synthesis and subcellular localization of PbLAP3::GFP. However, GFP-based fluorescence is dramatically reduced without PbLAP1 present, indicating that PbLAP1 and PbLAP3 interact. Moreover, absence of PbLAP1 markedly reduces the half-life of PbLAP3, consistent with a scenario of misfolding. These findings unveil a potential mechanism of conformational interdependence that facilitates assembly and stability of the functional LCCL protein complex. Copyright © 2012 Elsevier B.V. All rights reserved.

Impact of small groups with heterogeneous preference on behavioral evolution in population evacuation.

PubMed

Wang, Tao; Huang, Keke; Wang, Zhen; Zheng, Xiaoping

2015-01-01

Up to now, there have been a great number of mechanisms to explain the individual behavior and population traits, which seem of particular significance in evolutionary biology and social behavior analysis. Among them, small groups and heterogeneity are two useful frameworks to the above issue. However, vast majority of existing works separately consider both scenarios, which is inconsistent with realistic cases in our life. Here we propose the evolutionary games of heterogeneous small groups (namely, different small groups possess different preferences to dilemma) to study the collective behavior in population evacuation. Importantly, players usually face completely different dilemmas inside and outside the small groups. By means of numerous computation simulations, it is unveiled that the ratio of players in one certain small group directly decides the final behavior of the whole population. Moreover, it can also be concluded that heterogeneous degree of preference for different small groups plays a key role in the behavior traits of the system, which may validate some realistic social observations. The proposed framework is thus universally applicable and may shed new light into the solution of social dilemmas.

[Productive restructuring and the reallocation of work and employment: a survey of the "new" forms of social inequality].

PubMed

Marques, Ana Paula Pereira

2013-06-01

The scope of this paper is to question the inevitability of the processes of segmentation and increased precariousness of the relations of labor and employment, which are responsible for the introduction of "new" forms of social inequality that underpin the current model of development of economies and societies. It seeks to criticize the limits of global financial and economic logic, which constitute a "new spirit of capitalism," namely a kind of reverence for the natural order of things. It is therefore necessary to conduct an analytical survey of the ongoing changes in the labor market, accompanied by epistemological vigilance which makes it possible to see neoliberal (di)visions and dominant techno-deterministic theses in context. The enunciation of scenarios on the future of work will conclude this survey and will make it possible to draw attention to both the historical and temporal constraints and to the urgent need to unveil what is ideological and political in the prevailing logic of rationalization and processes to reinstate work and employment as a "central social experience" in contemporary times.

Wigner molecules in carbon-nanotube quantum dots

NASA Astrophysics Data System (ADS)

Rontani, Massimo; Secchi, Andrea

2010-03-01

The paradigm of few-electron complexes in quantum dots (QDs) relies on the ``particle-in-a-box'' idea that lowest-energy orbitals are filled according to Pauli's exclusion principle. If Coulomb repulsion is sufficiently strong to overcome the kinetic energy cost of localization, a different scenario is predicted: a ``Wigner'' molecule (WM) forms, made of electrons frozen in space according to a geometrical pattern. Despite considerable experimental effort, evidence of the WM in semiconductor QDs has been elusive so far. Here we demonstrate theoretically that WMs occur in gate-defined QDs embedded in typical semiconducting carbon nanotubes (CNTs). Their signatures must be searched ---and indeed have already been observed [Deshpande and Bockrath, Nature Phys. 4, 314 (2008)] --- in tunneling spectra. Through exact diagonalisation (ED) calculations, we unveil the inherent features of the electron molecular states. We show that, like nuclei in a usual molecule, electrons have localized wave functions and hence negligible exchange interactions. The molecular excitations are vibrations around the equilibrium positions of electrons. ED results are well reproduced by an ansatz vibrational wave function, which provides a simple theoretical model for transport experiments in ultraclean CNTs.

Topic Model for Graph Mining.

PubMed

Xuan, Junyu; Lu, Jie; Zhang, Guangquan; Luo, Xiangfeng

2015-12-01

Graph mining has been a popular research area because of its numerous application scenarios. Many unstructured and structured data can be represented as graphs, such as, documents, chemical molecular structures, and images. However, an issue in relation to current research on graphs is that they cannot adequately discover the topics hidden in graph-structured data which can be beneficial for both the unsupervised learning and supervised learning of the graphs. Although topic models have proved to be very successful in discovering latent topics, the standard topic models cannot be directly applied to graph-structured data due to the "bag-of-word" assumption. In this paper, an innovative graph topic model (GTM) is proposed to address this issue, which uses Bernoulli distributions to model the edges between nodes in a graph. It can, therefore, make the edges in a graph contribute to latent topic discovery and further improve the accuracy of the supervised and unsupervised learning of graphs. The experimental results on two different types of graph datasets show that the proposed GTM outperforms the latent Dirichlet allocation on classification by using the unveiled topics of these two models to represent graphs.

A New Scaling Relation for H II Regions in Spiral Galaxies: Unveiling the True Nature of the Mass-Metallicity Relation

NASA Astrophysics Data System (ADS)

Rosales-Ortega, F. F.; Sánchez, S. F.; Iglesias-Páramo, J.; Díaz, A. I.; Vílchez, J. M.; Bland-Hawthorn, J.; Husemann, B.; Mast, D.

2012-09-01

We demonstrate the existence of a local mass, metallicity, star formation relation using spatially resolved optical spectroscopy of H II regions in the local universe. One of the projections of this distribution—the local mass-metallicity relation—extends over a wide range in this parameter space: three orders of magnitude in mass and a factor of eight in metallicity. We explain the new relation as the combined effect of the differential distributions of mass and metallicity in the disks of galaxies, and a selective star formation efficiency. We use this local relation to reproduce—with a noticeable agreement—the mass-metallicity relation seen in galaxies, and conclude that the latter is a scale-up integrated effect of a local relation, supporting the inside-out growth and downsizing scenarios of galaxy evolution. Based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).

Engaging Stakeholders through Participatory Mapping and Spatial Analysis in a Scenarios Process for Alaska's North Slope

NASA Astrophysics Data System (ADS)

Fradkin, B.; Vargas, J. C.; Lee, O. A.; Emperador, S.

2016-12-01

A scenarios process was conducted for Alaska's North Slope to consider the wide range of drivers of change and uncertainties that could contribute to shifts in research and monitoring needs over the next 25 years. The project team, consisting of specialists in participatory scenarios and academic researchers, developed an interactive approach that helped facilitate the exploration of a range of plausible changes in the region. Over two years, the team designed and executed a series of workshops to capitalize on the collective expertise of researchers, resource managers, industry representatives, and traditional and local knowledge holders on the North Slope. The goal of this process was to evaluate three energy and resource development scenarios, which incorporated biophysical and socioeconomic drivers, to assess the implications of development on high-priority biophysical resources and the subsistence lifestyle and well-being of its Inupiat residents. Due to the diversity of the stakeholders engaged in the process, the workshop materials and activities had to be carefully designed and executed, in order to provide an adequate platform for discussion of each scenario component, as well as generating products that would provide management-relevant information to the NSSI and its member entities. Each workshop implemented a participatory mapping component, which relied on the best available geospatial datasets to generate informational maps that enabled participants to effectively consider a wide range of variables and outcomes for each of the selected scenarios. In addition, the map sketches produced in each workshop were digitized and incorporated into a spatial analysis that evaluated the level of agreement between stakeholder groups, as well as evaluating the geographic overlap of development features and anticipated implications with terrestrial and marine habitats, subsistence hunting zones, and sensitive landscape elements such as permafrost. This presentation will focus on how participatory mapping and analysis aided in eliciting stakeholder input and working towards consensus through a process that engaged a diverse group of parties concerned with the region's future research and monitoring needs.

Erik Lindbergh unveils a plaque commemorating his grandfather to dedicate the 747 Clipper Lindbergh, a NASA airborne infrared observatory known as SOFIA

NASA Image and Video Library

2007-05-21

Erik Lindbergh, grandson of aviator Charles Lindbergh, unveiled a plaque commemorating his grandfather on the 80th anniversary of Charles Lindbergh's transatlantic flight. The event was a dedication of the 747 Clipper Lindbergh, a NASA airborne infrared observatory that is beginning test flights in preparation for conducting world-class airborne astronomy. The project is known as the Stratospheric Observatory for Infrared Astronomy, or SOFIA.

Massive Infrared-Quiet Dense Cores: Unveiling the Initial Conditions of High-Mass Star Formation

NASA Astrophysics Data System (ADS)

Motte, F.; Bontemps, S.; Schneider, N.; Schilke, P.; Menten, K. M.

2008-05-01

As Th. Henning said at the conference, cold precursors of high-mass stars are now ``hot topics''. We here propose some observational criteria to identify massive infrared-quiet dense cores which can host the high-mass analogs of Class~0 protostars and pre-stellar condensations. We also show how far-infrared to millimeter imaging surveys of entire complexes forming OB stars are starting to unveil the initial conditions of high-mass star formation.

Unveiling the Hidden Bat Diversity of a Neotropical Montane Forest

PubMed Central

Chaverri, Gloriana; Garin, Inazio; Alberdi, Antton; Jimenez, Lide; Castillo-Salazar, Cristian; Aihartza, Joxerra

2016-01-01

Mountain environments, characterized by high levels of endemism, are at risk of experiencing significant biodiversity loss due to current trends in global warming. While many acknowledge their importance and vulnerability, these ecosystems still remain poorly studied, particularly for taxa that are difficult to sample such as bats. Aiming to estimate the amount of cryptic diversity among bats of a Neotropical montane cloud forest in Talamanca Range—south-east Central America—, we performed a 15-night sampling campaign, which resulted in 90 captured bats belonging to 8 species. We sequenced their mitochondrial cytochrome c oxidase subunit I (COI) and screened their inter- and intraspecific genetic variation. Phylogenetic relations with conspecifics and closely related species from other geographic regions were established using Maximum Likelihood and Bayesian inference methods, as well as median-joining haplotype networks. Mitochondrial lineages highly divergent from hitherto characterized populations (> 9% COI dissimilarity) were found in Myotis oxyotus and Hylonycteris underwoodi. Sturnira burtonlimi and M. keaysi also showed distinct mitochondrial structure with sibling species and/or populations. These results suggest that mountains in the region hold a high degree of endemicity potential that has previously been ignored in bats. They also warn of the high extinction risk montane bats may be facing due to climatic change, particularly in isolated mountain systems like Talamanca Range. PMID:27706168

A combined chloroplast atpB-rbcL and trnL-F phylogeny unveils the ancestry of balsams (Impatiens spp.) in the Western Ghats of India.

PubMed

Shajitha, P P; Dhanesh, N R; Ebin, P J; Laly, Joseph; Aneesha, Devassy; Reshma, John; Augustine, Jomy; Linu, Mathew

2016-12-01

Only a few Impatiens spp. from South India (one of the five centers of diversity for Impatiens species) were included in the published datum of molecular phylogeny of the family Balsaminaceae. The present investigation is a novel attempt to reveal the phylogenetic association of Impatiens species of South India, by placing them in the global phylogeny of Impatiens based on a combined analysis of two chloroplast genes. Thirty species of genus Impatiens were collected from different locations of South India. Total genomic DNA was extracted from fresh plant leaf, and polymerase chain reaction was carried out using atpB-rbcL and trnL-F intergenic spacer-specific forward and reverse primers. Thirteen sequences of Impatiens species from three centers of diversity were obtained from GenBank for reconstructing the evolutionary relationships within the genus Impatiens. Bayesian inference analysis was carried out in MrBayes v.3.2.2. This analysis supported Southeast Asia as the ancestral place of origin of extant Impatiens species. Molecular phylogeny of South Indian Impatiens spp. based on combined chloroplast sequences showed the same association as that of morphological taxonomy. Sections Scapigerae, Tomentosae, Sub-Umbellatae, and Racemosae showed Southeast Asian relationship, while sections Annuae and Microsepalae showed African affinity.

Methanol oxidation by temperate soils and environmental determinants of associated methylotrophs

PubMed Central

Stacheter, Astrid; Noll, Matthias; Lee, Charles K; Selzer, Mirjam; Glowik, Beate; Ebertsch, Linda; Mertel, Ralf; Schulz, Daria; Lampert, Niclas; Drake, Harold L; Kolb, Steffen

2013-01-01

The role of soil methylotrophs in methanol exchange with the atmosphere has been widely overlooked. Methanol can be derived from plant polymers and be consumed by soil microbial communities. In the current study, methanol-utilizing methylotrophs of 14 aerated soils were examined to resolve their comparative diversities and capacities to utilize ambient concentrations of methanol. Abundances of cultivable methylotrophs ranged from 106–108 gsoilDW−1. Methanol dissimilation was measured based on conversion of supplemented 14C-methanol, and occurred at concentrations down to 0.002 μmol methanol gsoilDW−1. Tested soils exhibited specific affinities to methanol (a0s=0.01 d−1) that were similar to those of other environments suggesting that methylotrophs with similar affinities were present. Two deep-branching alphaproteobacterial genotypes of mch responded to the addition of ambient concentrations of methanol (⩽0.6 μmol methanol gsoilDW−1) in one of these soils. Methylotroph community structures were assessed by amplicon pyrosequencing of genes of mono carbon metabolism (mxaF, mch and fae). Alphaproteobacteria-affiliated genotypes were predominant in all investigated soils, and the occurrence of novel genotypes indicated a hitherto unveiled diversity of methylotrophs. Correlations between vegetation type, soil pH and methylotroph community structure suggested that plant–methylotroph interactions were determinative for soil methylotrophs. PMID:23254514

Toward a Metagenomic Understanding on the Bacterial Composition and Resistome in Hong Kong Banknotes

PubMed Central

Heshiki, Yoshitaro; Dissanayake, Thrimendra; Zheng, Tingting; Kang, Kang; Yueqiong, Ni; Xu, Zeling; Sarkar, Chinmoy; Woo, Patrick C. Y.; Chow, Billy K. C.; Baker, David; Yan, Aixin; Webster, Christopher J.; Panagiotou, Gianni; Li, Jun

2017-01-01

Currency is possibly one of the main media transmitting pathogens and drug resistance due to its wide circulation in daily life. In this study, we made a comprehensive characterization of the bacterial community present on banknotes collected from different geographical regions of Hong Kong (HK) by performing in vitro characterization of the bacterial presence and resistome profile, as well as metagenomic analysis including microbial diversity, the prevalence of potential pathogens, the dissemination potential of antibiotic-resistance genes (ARGs), among others. When comparing the bacterial community of HK banknotes with other HK environmental samples, including water and marine sediment, we revealed that HK banknotes cover nearly 50% of total genera found in all the environmental samples, implying that banknotes harbor diverse bacteria originated from a variety of environments. Furthermore, the banknotes have higher abundance of potential pathogenic species (~5 times more) and ARGs (~5 times more) with higher dissemination potential (~48 times more) compared with other environmental samples. These findings unveiled the capabilities of this common medium of exchange to accommodate various bacteria, and transmit pathogens and antibiotic resistance. Furthermore, the observed independence of microbiome profile from the city's topological indices led us to formulate a hypothesis that due to their high circulation banknotes may harbor a homogenized microbiome. PMID:28450856

Rice Varieties in Archaic East Asia: Reduction of Its Diversity from Past to Present Times.

PubMed

Kumagai, Masahiko; Kanehara, Masaaki; Shoda, Shin'ya; Fujita, Saburo; Onuki, Shizuo; Ueda, Shintaroh; Wang, Li

2016-10-01

The Asian cultivated rice, Oryza sativa, is one of the most important crops feeding more than a third of global population. In spite of the studies for several decades, the origin and domestication history of rice varietal groups, japonica and indica, have not been fully unveiled. Genetic information of ancient rice remains is essential for direct and exclusive insight into the domestication history of rice. We performed ancient DNA analysis of 950- to 2,800-year-old rice remains excavated from Japan and Korea. We found the presence of both japonica- and indica-type varieties in the Yayoi period and the middle ages of Japan and the middle part of Korea Peninsula 2,000 years ago. It is popularly considered that japonica has been exclusively cultivated in northern part of East Asia including Japan and Korea. Our result disclosed unexpectedly wide diversity of rice varieties in archaic East Asia. The present results from ancient rice DNA reveal an exclusive insight for the domestication history of rice which is not provided as far as contemporary rice. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Toward a Metagenomic Understanding on the Bacterial Composition and Resistome in Hong Kong Banknotes.

PubMed

Heshiki, Yoshitaro; Dissanayake, Thrimendra; Zheng, Tingting; Kang, Kang; Yueqiong, Ni; Xu, Zeling; Sarkar, Chinmoy; Woo, Patrick C Y; Chow, Billy K C; Baker, David; Yan, Aixin; Webster, Christopher J; Panagiotou, Gianni; Li, Jun

2017-01-01

Currency is possibly one of the main media transmitting pathogens and drug resistance due to its wide circulation in daily life. In this study, we made a comprehensive characterization of the bacterial community present on banknotes collected from different geographical regions of Hong Kong (HK) by performing in vitro characterization of the bacterial presence and resistome profile, as well as metagenomic analysis including microbial diversity, the prevalence of potential pathogens, the dissemination potential of antibiotic-resistance genes (ARGs), among others. When comparing the bacterial community of HK banknotes with other HK environmental samples, including water and marine sediment, we revealed that HK banknotes cover nearly 50% of total genera found in all the environmental samples, implying that banknotes harbor diverse bacteria originated from a variety of environments. Furthermore, the banknotes have higher abundance of potential pathogenic species (~5 times more) and ARGs (~5 times more) with higher dissemination potential (~48 times more) compared with other environmental samples. These findings unveiled the capabilities of this common medium of exchange to accommodate various bacteria, and transmit pathogens and antibiotic resistance. Furthermore, the observed independence of microbiome profile from the city's topological indices led us to formulate a hypothesis that due to their high circulation banknotes may harbor a homogenized microbiome.

Using scenarios to assess possible future impacts of invasive species in the Laurentian Great Lakes

USGS Publications Warehouse

Lauber, T. Bruce; Stedman, Richard C.; Connelly, Nancy A; Rudstam, Lars G.; Ready, Richard C; Poe, Gregory L; Bunnell, David B.; Hook, Tomas O.; Koops, Marten A.; Ludsin, Stuart A.; Rutherford, Edward S; Wittmann, Marion E.

2016-01-01

The expected impacts of invasive species are key considerations in selecting policy responses to potential invasions. But predicting the impacts of invasive species is daunting, particularly in large systems threatened by multiple invasive species, such as North America’s Laurentian Great Lakes. We developed and evaluated a scenario-building process that relied on an expert panel to assess possible future impacts of aquatic invasive species on recreational fishing in the Great Lakes. To maximize its usefulness to policy makers, this process was designed to be implemented relatively rapidly and consider a range of species. The expert panel developed plausible, internally-consistent invasion scenarios for 5 aquatic invasive species, along with subjective probabilities of those scenarios. We describe these scenarios and evaluate this approach for assessing future invasive species impacts. The panel held diverse opinions about the likelihood of the scenarios, and only one scenario with impacts on sportfish species was considered likely by most of the experts. These outcomes are consistent with the literature on scenario building, which advocates for developing a range of plausible scenarios in decision making because the uncertainty of future conditions makes the likelihood of any particular scenario low. We believe that this scenario-building approach could contribute to policy decisions about whether and how to address the possible impacts of invasive species. In this case, scenarios could allow policy makers to narrow the range of possible impacts on Great Lakes fisheries they consider and help set a research agenda for further refining invasive species predictions.

Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia

PubMed Central

Alves, Isabel; Arenas, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Sousa, Vitor C.; Ray, Nicolas; Excoffier, Laurent

2016-01-01

Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the last glacial maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite data set genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion or due to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations. PMID:26637555

Forest species diversity reduces disease risk in a generalist plant pathogen invasion

USGS Publications Warehouse

Haas, Sarah E.; Hooten, Mevin B.; Rizzo, David M.; Meentemeyer, Ross K.

2011-01-01

Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the 'diversity-disease hypothesis' for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum across a broad, heterogeneous ecoregion: (1) an amplification effect exists where disease risk is greater in areas with higher plant diversity due to the pathogen's wide host range, or (2) a dilution effect where risk is reduced with increasing diversity due to lower competency of alternative hosts. We found evidence for pathogen dilution, whereby disease risk was lower in sites with higher species diversity, after accounting for potentially confounding effects of host density and landscape heterogeneity. Our results suggest that although nearly all plants in the ecosystem are hosts, alternative hosts may dilute disease transmission by competent hosts, thereby buffering forest health from infectious disease.

Genes Left Behind: Climate Change Threatens Cryptic Genetic Diversity in the Canopy-Forming Seaweed Bifurcaria bifurcata.

PubMed

Neiva, João; Assis, Jorge; Coelho, Nelson C; Fernandes, Francisco; Pearson, Gareth A; Serrão, Ester A

2015-01-01

The global redistribution of biodiversity will intensify in the coming decades of climate change, making projections of species range shifts and of associated genetic losses important components of conservation planning. Highly-structured marine species, notably brown seaweeds, often harbor unique genetic variation at warmer low-latitude rear edges and thus are of particular concern. Here, a combination of Ecological Niche Models (ENMs) and molecular data is used to forecast the potential near-future impacts of climate change for a warm-temperate, canopy forming seaweed, Bifurcaria bifurcata. ENMs for B. bifurcata were developed using marine and terrestrial climatic variables, and its range projected for 2040-50 and 2090-2100 under two greenhouse emission scenarios. Geographical patterns of genetic diversity were assessed by screening 18 populations spawning the entire distribution for two organelle genes and 6 microsatellite markers. The southern limit of B. bifurcata was predicted to shift northwards to central Morocco by the mid-century. By 2090-2100, depending on the emission scenario, it could either retreat further north to western Iberia or be relocated back to Western Sahara. At the opposing margin, B. bifurcata was predicted to expand its range to Scotland or even Norway. Microsatellite diversity and endemism were highest in Morocco, where a unique and very restricted lineage was also identified. Our results imply that B. bifurcata will maintain a relatively broad latitudinal distribution. Although its persistence is not threatened, the predicted extirpation of a unique southern lineage or even the entire Moroccan diversity hotspot will erase a rich evolutionary legacy and shrink global diversity to current (low) European levels. NW Africa and similarly understudied southern regions should receive added attention if expected range changes and diversity loss of warm-temperate species is not to occur unnoticed.

Population Structure, Genetic Diversity, and Evolutionary History of Kleinia neriifolia (Asteraceae) on the Canary Islands.

PubMed

Sun, Ye; Vargas-Mendoza, Carlos F

2017-01-01

Kleinia neriifolia Haw. is an endemic species on the Canarian archipelago, this species is widespread in the coastal thicket of all the Canarian islands. In the present study, genetic diversity and population structure of K. neriifolia were investigated using chloroplast gene sequences and nuclear SSR (simple sequence repeat). The differentiation among island populations, the historical demography, and the underlying evolutionary scenarios of this species are further tested based on the genetic data. Chloroplast diversity reveals a strong genetic divergence between eastern islands (Gran Canaria, Fuerteventura, and Lanzarote) and western islands (EI Hierro, La Palma, La Gomera, Tenerife), this west-east genetic divergence may reflect a very beginning of speciation. The evolutionary scenario with highest posterior probabilities suggests Gran Canaria as oldest population with a westward colonization path to Tenerife, La Gomera, La Palma, and EI Hierro, and eastward dispersal path to Lanzarote through Fuerteventura. In the western islands, there is a slight decrease in the effective population size toward areas of recent colonization. However, in the eastern islands, the effective population size increase in Lanzarote relative to Gran Canaria and Fuerteventura. These results further our understanding of the evolution of widespread endemic plants within Canarian archipelago.

Population Structure, Genetic Diversity, and Evolutionary History of Kleinia neriifolia (Asteraceae) on the Canary Islands

PubMed Central

Sun, Ye; Vargas-Mendoza, Carlos F.

2017-01-01

Kleinia neriifolia Haw. is an endemic species on the Canarian archipelago, this species is widespread in the coastal thicket of all the Canarian islands. In the present study, genetic diversity and population structure of K. neriifolia were investigated using chloroplast gene sequences and nuclear SSR (simple sequence repeat). The differentiation among island populations, the historical demography, and the underlying evolutionary scenarios of this species are further tested based on the genetic data. Chloroplast diversity reveals a strong genetic divergence between eastern islands (Gran Canaria, Fuerteventura, and Lanzarote) and western islands (EI Hierro, La Palma, La Gomera, Tenerife), this west–east genetic divergence may reflect a very beginning of speciation. The evolutionary scenario with highest posterior probabilities suggests Gran Canaria as oldest population with a westward colonization path to Tenerife, La Gomera, La Palma, and EI Hierro, and eastward dispersal path to Lanzarote through Fuerteventura. In the western islands, there is a slight decrease in the effective population size toward areas of recent colonization. However, in the eastern islands, the effective population size increase in Lanzarote relative to Gran Canaria and Fuerteventura. These results further our understanding of the evolution of widespread endemic plants within Canarian archipelago. PMID:28713419

AirSAR 2004 plaque unveiling by NASA Administrator Sean O'Keefe and Fernando Gutierrez, Costa Rican Minister of Science and Technology(MICIT)

NASA Image and Video Library

2004-03-03

AirSAR 2004 Mesoamerica plaque unveiling by NASA Administrator Sean O'Keefe and Fernando Gutierrez, Costa Rican Minister of Science and Technology(MICIT). AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), in a mission ranging from the tropical rain forests of Central America to frigid Antarctica.

A quantitative visual dashboard to explore exposures to consumer product ingredients

EPA Science Inventory

The Exposure Prioritization (Ex Priori) model features a simplified, quantitative visual dashboard to explore exposures across chemical space. Diverse data streams are integrated within the interface such that different exposure scenarios for “individual,” “pop...

Arctic shipping emissions inventories and future scenarios

NASA Astrophysics Data System (ADS)

Corbett, J. J.; Lack, D. A.; Winebrake, J. J.; Harder, S.; Silberman, J. A.; Gold, M.

2010-10-01

This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow), aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO2 emissions (~42 000 gigagrams) by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

The influence of the hijab (Islamic head-cover) on perceptions of women's attractiveness and intelligence.

PubMed

Mahmud, Yusr; Swami, Viren

2010-01-01

This study examined the effects of wearing the hijab, or Islamic headwear, on men's perceptions of women's attractiveness and intelligence. A total of 57 non-Muslim men and 41 Muslim men rated a series of images of women, half of whom were unveiled and half of whom wore the hijab. For attractiveness and intelligence ratings, a mixed analysis of variance showed a significant effect of hijab status, with women wearing the hijab being rated more negatively than unveiled women. For attractiveness ratings, there was no significant effect of participant religion, although non-Muslim men rated unveiled women significantly higher than veiled women. For intelligence ratings, non-Muslim men provided significantly higher ratings than Muslim men for both conditions. In addition, Muslim men's ratings of the attractiveness and intelligence of women wearing the hijab was positively correlated with self-reported religiosity. These results are discussed in relation to religious stereotyping within increasingly multi-cultural societies. Copyright 2009 Elsevier Ltd. All rights reserved.

Effective population size and the genetic consequences of commercial whaling on the humpback whales (Megaptera novaeangliae) from Southwestern Atlantic Ocean

PubMed Central

Cypriano-Souza, Ana Lúcia; da Silva, Tiago Ferraz; Engel, Márcia H.; Bonatto, Sandro L.

2018-01-01

Abstract Genotypes of 10 microsatellite loci of 420 humpback whales from the Southwestern Atlantic Ocean population were used to estimate for the first time its contemporary effective (N e) and census (N c) population sizes and to test the genetic effect of commercial whaling. The results are in agreement with our previous studies that found high genetic diversity for this breeding population. Using an approximate Bayesian computation approach, the scenario of constant N e was significantly supported over scenarios with moderate to strong size changes during the commercial whaling period. The previous generation N c (N e multiplied by 3.6), which should corresponds to the years between around 1980 and 1990, was estimated between ~2,600 and 6,800 whales (point estimate ~4,000), and is broadly compatible with the recent abundance surveys extrapolated to the past using a growth rate of 7.4% per annum. The long-term N c in the constant scenario (point estimate ~15,000) was broadly compatible (considering the confidence interval) with pre-whaling catch records estimates (point estimate ~25,000). Overall, our results shown that the Southwestern Atlantic Ocean humpback whale population is genetically very diverse and resisted well to the strong population reduction during commercial whaling. PMID:29668011

Effective population size and the genetic consequences of commercial whaling on the humpback whales (Megaptera novaeangliae) from Southwestern Atlantic Ocean.

PubMed

Cypriano-Souza, Ana Lúcia; da Silva, Tiago Ferraz; Engel, Márcia H; Bonatto, Sandro L

2018-01-01

Genotypes of 10 microsatellite loci of 420 humpback whales from the Southwestern Atlantic Ocean population were used to estimate for the first time its contemporary effective (Ne) and census (Nc) population sizes and to test the genetic effect of commercial whaling. The results are in agreement with our previous studies that found high genetic diversity for this breeding population. Using an approximate Bayesian computation approach, the scenario of constant Ne was significantly supported over scenarios with moderate to strong size changes during the commercial whaling period. The previous generation Nc (Ne multiplied by 3.6), which should corresponds to the years between around 1980 and 1990, was estimated between ~2,600 and 6,800 whales (point estimate ~4,000), and is broadly compatible with the recent abundance surveys extrapolated to the past using a growth rate of 7.4% per annum. The long-term Nc in the constant scenario (point estimate ~15,000) was broadly compatible (considering the confidence interval) with pre-whaling catch records estimates (point estimate ~25,000). Overall, our results shown that the Southwestern Atlantic Ocean humpback whale population is genetically very diverse and resisted well to the strong population reduction during commercial whaling.

Delineating ecologically significant taxonomic units from global patterns of marine picocyanobacteria

PubMed Central

Farrant, Gregory K.; Doré, Hugo; Cornejo-Castillo, Francisco M.; Partensky, Frédéric; Ratin, Morgane; Ostrowski, Martin; Pitt, Frances D.; Wincker, Patrick; Scanlan, David J.; Iudicone, Daniele; Acinas, Silvia G.; Garczarek, Laurence

2016-01-01

Prochlorococcus and Synechococcus are the two most abundant and widespread phytoplankton in the global ocean. To better understand the factors controlling their biogeography, a reference database of the high-resolution taxonomic marker petB, encoding cytochrome b6, was used to recruit reads out of 109 metagenomes from the Tara Oceans expedition. An unsuspected novel genetic diversity was unveiled within both genera, even for the most abundant and well-characterized clades, and 136 divergent petB sequences were successfully assembled from metagenomic reads, significantly enriching the reference database. We then defined Ecologically Significant Taxonomic Units (ESTUs)—that is, organisms belonging to the same clade and occupying a common oceanic niche. Three major ESTU assemblages were identified along the cruise transect for Prochlorococcus and eight for Synechococcus. Although Prochlorococcus HLIIIA and HLIVA ESTUs codominated in iron-depleted areas of the Pacific Ocean, CRD1 and the yet-to-be cultured EnvB were the prevalent Synechococcus clades in this area, with three different CRD1 and EnvB ESTUs occupying distinct ecological niches with regard to iron availability and temperature. Sharp community shifts were also observed over short geographic distances—for example, around the Marquesas Islands or between southern Indian and Atlantic Oceans—pointing to a tight correlation between ESTU assemblages and specific physico-chemical parameters. Together, this study demonstrates that there is a previously overlooked, ecologically meaningful, fine-scale diversity within some currently defined picocyanobacterial ecotypes, bringing novel insights into the ecology, diversity, and biology of the two most abundant phototrophs on Earth. PMID:27302952

Novel lineages of Prochlorococcus and Synechococcus in the global oceans.

PubMed

Huang, Sijun; Wilhelm, Steven W; Harvey, H Rodger; Taylor, Karen; Jiao, Nianzhi; Chen, Feng

2012-02-01

Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and HLV, detected in the Equatorial Pacific samples, could be related to the HNLC clades recently found in the high-nutrient, low-chlorophyll (HNLC), iron-depleted tropical oceans. At least four novel Synechococcus clades (out of six clades in total) in subcluster 5.3 were found in subtropical open oceans and the South China Sea. A niche partitioning with depth was observed in the Synechococcus subcluster 5.3. Members of Synechococcus subcluster 5.2 were dominant in the high-latitude waters (northern Bering Sea and Chukchi Sea), suggesting a possible cold-adaptation of some marine Synechococcus in this subcluster. A distinct shift of the picocyanobacterial community was observed from the Bering Sea to the Chukchi Sea, which reflected the change of water temperature. Our study demonstrates that oceanic systems contain a large pool of diverse picocyanobacteria, and further suggest that new genotypes or ecotypes of picocyanobacteria will continue to emerge, as microbial consortia are explored with advanced sequencing technology.

Development of DArT markers and assessment of diversity in Fusarium oxysporum f. sp. ciceris, wilt pathogen of chickpea (Cicer arietinum L.).

PubMed

Sharma, Mamta; Nagavardhini, Avuthu; Thudi, Mahendar; Ghosh, Raju; Pande, Suresh; Varshney, Rajeev K

2014-06-10

Fusarium oxysporum f. sp. ciceris (Foc), the causal agent of Fusarium wilt of chickpea is highly variable and frequent recurrence of virulent forms have affected chickpea production and exhausted valuable genetic resources. The severity and yield losses of Fusarium wilt differ from place to place owing to existence of physiological races among isolates. Diversity study of fungal population associated with a disease plays a major role in understanding and devising better disease control strategies. The advantages of using molecular markers to understand the distribution of genetic diversity in Foc populations is well understood. The recent development of Diversity Arrays Technology (DArT) offers new possibilities to study the diversity in pathogen population. In this study, we developed DArT markers for Foc population, analysed the genetic diversity existing within and among Foc isolates, compared the genotypic and phenotypic diversity and infer the race scenario of Foc in India. We report the successful development of DArT markers for Foc and their utility in genotyping of Foc collections representing five chickpea growing agro-ecological zones of India. The DArT arrays revealed a total 1,813 polymorphic markers with an average genotyping call rate of 91.16% and a scoring reproducibility of 100%. Cluster analysis, principal coordinate analysis and population structure indicated that the different isolates of Foc were partially classified based on geographical source. Diversity in Foc population was compared with the phenotypic variability and it was found that DArT markers were able to group the isolates consistent with its virulence group. A number of race-specific unique and rare alleles were also detected. The present study generated significant information in terms of pathogenic and genetic diversity of Foc which could be used further for development and deployment of region-specific resistant cultivars of chickpea. The DArT markers were proved to be a powerful diagnostic tool to study the genotypic diversity in Foc. The high number of DArT markers allowed a greater resolution of genetic differences among isolates and enabled us to examine the extent of diversity in the Foc population present in India, as well as provided support to know the changing race scenario in Foc population.

Foreword to farming with grass: Achieving sustainable mixed agricultural landscapes

USDA-ARS?s Scientific Manuscript database

The Farming with Grass conference was developed to bring together diverse stakeholders in grassland environments to (a) help assess the current condition of agriculture, (b) consider alternative production scenarios for grassland agricultural ecosystems, (c) identify key issues hindering the develop...

Reconciliation of Gene and Species Trees

PubMed Central

Rusin, L. Y.; Lyubetskaya, E. V.; Gorbunov, K. Y.; Lyubetsky, V. A.

2014-01-01

The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i) inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii) trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii) can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree. PMID:24800245

Colorful Twisted Top Partners and Partnerium at the LHC

NASA Astrophysics Data System (ADS)

Kats, Yevgeny; McCullough, Matthew; Perez, Gilad; Soreq, Yotam; Thaler, Jesse

2017-06-01

In scenarios that stabilize the electroweak scale, the top quark is typically accompanied by partner particles. In this work, we demonstrate how extended stabilizing symmetries can yield scalar or fermionic top partners that transform as ordinary color triplets but carry exotic electric charges. We refer to these scenarios as "hypertwisted" since they involve modifications to hypercharge in the top sector. As proofs of principle, we construct two hypertwisted scenarios: a supersymmetric construction with spin-0 top partners, and a composite Higgs construction with spin-1/2 top partners. In both cases, the top partners are still phenomenologically compatible with the mass range motivated by weak-scale naturalness. The phenomenology of hypertwisted scenarios is diverse, since the lifetimes and decay modes of the top partners are model dependent. The novel coupling structure opens up search channels that do not typically arise in top-partner scenarios, such as pair production of top-plus-jet resonances. Furthermore, hypertwisted top partners are typically sufficiently long lived to form "top-partnerium" bound states that decay predominantly via annihilation, motivating searches for rare narrow resonances with diboson decay modes.

Adaptive grid based multi-objective Cauchy differential evolution for stochastic dynamic economic emission dispatch with wind power uncertainty

PubMed Central

Lei, Xiaohui; Wang, Chao; Yue, Dong; Xie, Xiangpeng

2017-01-01

Since wind power is integrated into the thermal power operation system, dynamic economic emission dispatch (DEED) has become a new challenge due to its uncertain characteristics. This paper proposes an adaptive grid based multi-objective Cauchy differential evolution (AGB-MOCDE) for solving stochastic DEED with wind power uncertainty. To properly deal with wind power uncertainty, some scenarios are generated to simulate those possible situations by dividing the uncertainty domain into different intervals, the probability of each interval can be calculated using the cumulative distribution function, and a stochastic DEED model can be formulated under different scenarios. For enhancing the optimization efficiency, Cauchy mutation operation is utilized to improve differential evolution by adjusting the population diversity during the population evolution process, and an adaptive grid is constructed for retaining diversity distribution of Pareto front. With consideration of large number of generated scenarios, the reduction mechanism is carried out to decrease the scenarios number with covariance relationships, which can greatly decrease the computational complexity. Moreover, the constraint-handling technique is also utilized to deal with the system load balance while considering transmission loss among thermal units and wind farms, all the constraint limits can be satisfied under the permitted accuracy. After the proposed method is simulated on three test systems, the obtained results reveal that in comparison with other alternatives, the proposed AGB-MOCDE can optimize the DEED problem while handling all constraint limits, and the optimal scheme of stochastic DEED can decrease the conservation of interval optimization, which can provide a more valuable optimal scheme for real-world applications. PMID:28961262

Toward zero waste: composting and recycling for sustainable venue based events.

PubMed

Hottle, Troy A; Bilec, Melissa M; Brown, Nicholas R; Landis, Amy E

2015-04-01

This study evaluated seven different waste management strategies for venue-based events and characterized the impacts of event waste management via waste audits and the Waste Reduction Model (WARM). The seven waste management scenarios included traditional waste handling methods (e.g. recycle and landfill) and management of the waste stream via composting, including purchasing where only compostable food service items were used during the events. Waste audits were conducted at four Arizona State University (ASU) baseball games, including a three game series. The findings demonstrate a tradeoff among CO2 equivalent emissions, energy use, and landfill diversion rates. Of the seven waste management scenarios assessed, the recycling scenarios provide the greatest reductions in CO2 eq. emissions and energy use because of the retention of high value materials but are compounded by the difficulty in managing a two or three bin collection system. The compost only scenario achieves complete landfill diversion but does not perform as well with respect to CO2 eq. emissions or energy. The three game series was used to test the impact of staffed bins on contamination rates; the first game served as a baseline, the second game employed staffed bins, and the third game had non staffed bins to determine the effect of staffing on contamination rates. Contamination rates in both the recycling and compost bins were tracked throughout the series. Contamination rates were reduced from 34% in the first game to 11% on the second night (with the staffed bins) and 23% contamination rates at the third game. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genetic Diversity and Societally Important Disparities

PubMed Central

Rosenberg, Noah A.; Kang, Jonathan T. L.

2015-01-01

The magnitude of genetic diversity within human populations varies in a way that reflects the sequence of migrations by which people spread throughout the world. Beyond its use in human evolutionary genetics, worldwide variation in genetic diversity sometimes can interact with social processes to produce differences among populations in their relationship to modern societal problems. We review the consequences of genetic diversity differences in the settings of familial identification in forensic genetic testing, match probabilities in bone marrow transplantation, and representation in genome-wide association studies of disease. In each of these three cases, the contribution of genetic diversity to social differences follows from population-genetic principles. For a fourth setting that is not similarly grounded, we reanalyze with expanded genetic data a report that genetic diversity differences influence global patterns of human economic development, finding no support for the claim. The four examples describe a limit to the importance of genetic diversity for explaining societal differences while illustrating a distinction that certain biologically based scenarios do require consideration of genetic diversity for solving problems to which populations have been differentially predisposed by the unique history of human migrations. PMID:26354973

Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia.

PubMed

Alves, Isabel; Arenas, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Sousa, Vitor C; Ray, Nicolas; Excoffier, Laurent

2016-04-01

Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the last glacial maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite data set genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion or due to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Modeling the Gila-San Francisco Basin using system dynamics in support of the 2004 Arizona Water Settlement Act.

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

Tidwell, Vincent Carroll; Sun, Amy Cha-Tien; Peplinski, William J.

2012-04-01

Water resource management requires collaborative solutions that cross institutional and political boundaries. This work describes the development and use of a computer-based tool for assessing the impact of additional water allocation from the Gila River and the San Francisco River prescribed in the 2004 Arizona Water Settlements Act. Between 2005 and 2010, Sandia National Laboratories engaged concerned citizens, local water stakeholders, and key federal and state agencies to collaboratively create the Gila-San Francisco Decision Support Tool. Based on principles of system dynamics, the tool is founded on a hydrologic balance of surface water, groundwater, and their associated coupling between watermore » resources and demands. The tool is fitted with a user interface to facilitate sensitivity studies of various water supply and demand scenarios. The model also projects the consumptive use of water in the region as well as the potential CUFA (Consumptive Use and Forbearance Agreement which stipulates when and where Arizona Water Settlements Act diversions can be made) diversion over a 26-year horizon. Scenarios are selected to enhance our understanding of the potential human impacts on the rivers ecological health in New Mexico; in particular, different case studies thematic to water conservation, water rights, and minimum flow are tested using the model. The impact on potential CUFA diversions, agricultural consumptive use, and surface water availability are assessed relative to the changes imposed in the scenarios. While it has been difficult to gage the acceptance level from the stakeholders, the technical information that the model provides are valuable for facilitating dialogues in the context of the new settlement.« less

Diversity of deep-water cetaceans in relation to temperature: implications for ocean warming.

PubMed

Whitehead, Hal; McGill, Brian; Worm, Boris

2008-11-01

Understanding the effects of natural environmental variation on biodiversity can help predict response to future anthropogenic change. Here we analyse a large, long-term data set of sightings of deep-water cetaceans from the Atlantic, Pacific and Indian Oceans. Seasonal and geographic changes in the diversity of these genera are well predicted by a convex function of sea-surface temperature peaking at c. 21 degrees C. Thus, diversity is highest at intermediate latitudes - an emerging general pattern for the pelagic ocean. When applied to a range of Intergovernmental Panel on Climate Change global change scenarios, the predicted response is a decline of cetacean diversity across the tropics and increases at higher latitudes. This suggests that deep-water oceanic communities that dominate > 60% of the planet's surface may reorganize in response to ocean warming, with low-latitude losses of diversity and resilience.

The influence of contextual diversity on eye movements in reading.

PubMed

Plummer, Patrick; Perea, Manuel; Rayner, Keith

2014-01-01

Recent research has shown contextual diversity (i.e., the number of passages in which a given word appears) to be a reliable predictor of word processing difficulty. It has also been demonstrated that word-frequency has little or no effect on word recognition speed when accounting for contextual diversity in isolated word processing tasks. An eye-movement experiment was conducted wherein the effects of word-frequency and contextual diversity were directly contrasted in a normal sentence reading scenario. Subjects read sentences with embedded target words that varied in word-frequency and contextual diversity. All 1st-pass and later reading times were significantly longer for words with lower contextual diversity compared to words with higher contextual diversity when controlling for word-frequency and other important lexical properties. Furthermore, there was no difference in reading times for higher frequency and lower frequency words when controlling for contextual diversity. The results confirm prior findings regarding contextual diversity and word-frequency effects and demonstrate that contextual diversity is a more accurate predictor of word processing speed than word-frequency within a normal reading task. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Accretion of chemically fractionated material on a wide binary with a blue straggler

NASA Astrophysics Data System (ADS)

Desidera, S.; Gratton, R. G.; Lucatello, S.; Endl, M.; Udry, S.

2007-02-01

Context: The components of the wide binary HIP 64030 = HD 113984 show a large (about 0.25 dex) iron content difference (Desidera et al. 2006). The positions of the components on the color magnitude diagram suggest that the primary is a blue straggler. Aims: We studied the abundance difference of several elements besides iron, and we searched for stellar and substellar companions around the components to unveil the origin of the observed iron difference. Methods: A line-by-line differential abundance analysis for several elements was performed for iron, while suitable spectral synthesis was performed for C, N, and Li. High precision radial velocities obtained with the iodine cell were combined with available literature data. Results: The analysis of additional elements shows that the abundance difference for the elements studied increases with increasing condensation temperature, suggesting that accretion of chemically fractionated material might have occurred in the system. Alteration of C and N likely due to CNO processing is also observed. We also show that the primary is a spectroscopic binary with a period of 445 days and moderate eccentricity. The minimum mass of the companion is 0.17~M⊙. Conclusions: .Two scenarios were explored to explain the observed abundance pattern. In the first, all abundance anomalies arise on the blue straggler. If this is the case, the dust-gas separation may have been occurred in a circumbinary disk around the blue straggler and its expected white dwarf companion, as observed in several RV Tauri and post AGB binaries. In the second scenario, accretion of dust-rich material occurred on the secondary. This would also explain the anomalous carbon isotopic ratio of the secondary. Such a scenario requires that a substantial amount of mass lost by the central binary has been accreted by the wide component. Further studies to compare the two scenarios are proposed. Based on observations collected at the European Southern Observatory, Chile, using FEROS spectrograph (proposal ID: 70.D-0081), on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, and on observations made at McDonald Observatory.

Genetic structure along an altitudinal gradient in Lippia origanoides, a promising aromatic plant species restricted to semiarid areas in northern South America.

PubMed

Vega-Vela, Nelson Enrique; Sánchez, María Isabel Chacón

2012-11-01

The genetic diversity and population structure of Lippia origanoides, a species of the Verbenaceae family that shows promise as a crop plant, was investigated along an altitudinal gradient in the basin of the Chicamocha River in northeastern Colombia. The economic importance of the species, quality of its essential oils, and the fact that it is restricted to some few semiarid areas in northern South America may put the species at risk in a scenario of uncontrolled harvest of natural populations. Lippia origanoides was sampled along an altitudinal gradient from 365 to 2595 m.a.s.l. throughout Chicamocha River Canyon, a semiarid area in northeastern Colombia. Genetic diversity was assessed by means of AFLP markers. The number of AFLP loci (355) and the number of individuals sampled (173) were sufficient to reliably identify four populations at contrasting altitudes (F(ST) = 0.18, P-value < 0.0000), two populations in the lower basin, one population in the medium basin, and one population in the upper basin, with a low level of admixture between them. In average, genetic diversity within populations was relatively high (Ht = 0.32; I = 0.48); nevertheless, diversity was significantly reduced at higher altitude, a pattern that may be consistent with a scenario of range expansion toward higher elevations in an environment with more extreme conditions. The differences in altitude among the basins in the Chicamocha River seem to be relevant in determining the genetic structure of this species.

Using scenarios of North Slope energy and resource development to assess research and monitoring needs

NASA Astrophysics Data System (ADS)

Payne, J. F.

2016-12-01

Significant Arctic environmental and socio-economic change has been observed on the North Slope of Alaska, presenting challenges for resident communities and management agencies that need to adapt to future changes that are difficult to model or predict. Continued climate change coupled with new or modified energy development could substantially alter the landscape and ecosystem in the future. The North Slope Science Initiative (NSSI) recognized the value of using a participatory scenarios process to consider plausible future energy and resource development scenarios through the year 2040 to help identify and prioritize research and monitoring needs on the North Slope. The scenarios process engaged diverse stakeholders, including subject matter experts and local knowledge holders. Through identification and ranking of key drivers and uncertainties relevant to the focus of the study, a series of spatially explicit scenarios was developed, analyzed in terms of low, medium and high development activities. Climate change and economic factors were key drivers affecting plausible energy development scenarios. The implications from each of the scenarios were then used to identify important research and monitoring activities and their relevant spatial scales. The scenarios project identified over 40 research and monitoring needs. The top five research needs addressed data gaps and key concerns related to how the scenarios could affect: hunting and trapping on land, health and community well-being, permafrost and hydrology, marine mammal subsistence and potential marine oil spills. The use of a participatory scenarios process was essential for identifying a range of plausible energy and resource development scenarios using a framework that involved a systematic assessment of complex interacting drivers of change, consideration of key uncertainties, and transparency throughout the project.

Productive Struggle for All: Differentiated Instruction

ERIC Educational Resources Information Center

Lynch, Sararose D.; Hunt, Jessica H.; Lewis, Katherine E.

2018-01-01

This article demonstrates how to consider differentiating instruction for diverse learners while maintaining the cognitive demand of a mathematics task. The authors present scenarios involving hypothetical cases of students in inclusive classrooms who engaged in productive struggle within the differentiated task. The authors specifically focus on…

Optimizing emissions targets for residential recycling programmes: Why 'more' is not necessarily better with respect to diversion.

PubMed

Lakhan, Calvin

2016-11-01

This study highlights the economic and environmental challenges of recycling in Ontario, specifically examining the effect of attempting to increase the emissions target for the province's household recycling programme. The findings from the cost model analysis found that Ontario's Blue Box programme reduces overall carbon emissions by approximately 1.8 million tonnes every year. This study also found that targeting specific materials for recovery could result in a scenario where the province could improve both overall diversion and emissions offsets while reducing material management costs. Under our modelled scenario, as the tonnes of greenhouse gases (GHGs) avoided increases, the system cost per tonne of GHG avoided initial declines. However, after avoiding 2.05 million tonnes of GHGs, the system cost/tonne GHG avoided increases. To achieve an emissions target in excess of 2.05 million tonnes, the province will have to start recycling higher cost non-core materials (composite materials, other plastics, etc.). © The Author(s) 2016.

Plant-Pollinator Coextinctions and the Loss of Plant Functional and Phylogenetic Diversity

PubMed Central

Vieira, Marcos Costa; Cianciaruso, Marcus Vinicius; Almeida-Neto, Mário

2013-01-01

Plant-pollinator coextinctions are likely to become more frequent as habitat alteration and climate change continue to threaten pollinators. The consequences of the resulting collapse of plant communities will depend partly on how quickly plant functional and phylogenetic diversity decline following pollinator extinctions. We investigated the functional and phylogenetic consequences of pollinator extinctions by simulating coextinctions in seven plant-pollinator networks coupled with independent data on plant phylogeny and functional traits. Declines in plant functional diversity were slower than expected under a scenario of random extinctions, while phylogenetic diversity often decreased faster than expected by chance. Our results show that plant functional diversity was relatively robust to plant-pollinator coextinctions, despite the underlying rapid loss of evolutionary history. Thus, our study suggests the possibility of uncoupled responses of functional and phylogenetic diversity to species coextinctions, highlighting the importance of considering both dimensions of biodiversity explicitly in ecological studies and when planning for the conservation of species and interactions. PMID:24312281

Ecosystem Services in Agricultural Landscapes: A Spatially Explicit Approach to Support Sustainable Soil Management

PubMed Central

Crossman, Neville D.; MacEwan, Richard J.; Wallace, D. Dugal; Bennett, Lauren T.

2014-01-01

Soil degradation has been associated with a lack of adequate consideration of soil ecosystem services. We demonstrate a broadly applicable method for mapping changes in the supply of two priority soil ecosystem services to support decisions about sustainable land-use configurations. We used a landscape-scale study area of 302 km2 in northern Victoria, south-eastern Australia, which has been cleared for intensive agriculture. Indicators representing priority soil services (soil carbon sequestration and soil water storage) were quantified and mapped under both a current and a future 25-year land-use scenario (the latter including a greater diversity of land uses and increased perennial crops and irrigation). We combined diverse methods, including soil analysis using mid-infrared spectroscopy, soil biophysical modelling, and geostatistical interpolation. Our analysis suggests that the future land-use scenario would increase the landscape-level supply of both services over 25 years. Soil organic carbon content and water storage to 30 cm depth were predicted to increase by about 11% and 22%, respectively. Our service maps revealed the locations of hotspots, as well as potential trade-offs in service supply under new land-use configurations. The study highlights the need to consider diverse land uses in sustainable management of soil services in changing agricultural landscapes. PMID:24616632

Ecosystem services in agricultural landscapes: a spatially explicit approach to support sustainable soil management.

PubMed

Forouzangohar, Mohsen; Crossman, Neville D; MacEwan, Richard J; Wallace, D Dugal; Bennett, Lauren T

2014-01-01

Soil degradation has been associated with a lack of adequate consideration of soil ecosystem services. We demonstrate a broadly applicable method for mapping changes in the supply of two priority soil ecosystem services to support decisions about sustainable land-use configurations. We used a landscape-scale study area of 302 km(2) in northern Victoria, south-eastern Australia, which has been cleared for intensive agriculture. Indicators representing priority soil services (soil carbon sequestration and soil water storage) were quantified and mapped under both a current and a future 25-year land-use scenario (the latter including a greater diversity of land uses and increased perennial crops and irrigation). We combined diverse methods, including soil analysis using mid-infrared spectroscopy, soil biophysical modelling, and geostatistical interpolation. Our analysis suggests that the future land-use scenario would increase the landscape-level supply of both services over 25 years. Soil organic carbon content and water storage to 30 cm depth were predicted to increase by about 11% and 22%, respectively. Our service maps revealed the locations of hotspots, as well as potential trade-offs in service supply under new land-use configurations. The study highlights the need to consider diverse land uses in sustainable management of soil services in changing agricultural landscapes.

Investigating the timing of origin and evolutionary processes shaping regional species diversity: Insights from simulated data and neotropical butterfly diversification rates.

PubMed

Matos-Maraví, Pável

2016-07-01

Different diversification scenarios have been proposed to explain the origin of extant biodiversity. However, most existing meta-analyses of time-calibrated phylogenies rely on approaches that do not quantitatively test alternative diversification processes. Here, I highlight the shortcomings of using species divergence ranks, which is a method widely used in meta-analyses. Divergence ranks consist of categorizing cladogenetic events to certain periods of time, typically to either Pleistocene or to pre-Pleistocene ages. This approach has been claimed to shed light on the origin of most extant species and the timing and dynamics of diversification in any biogeographical region. However, interpretations drawn from such method often confound two fundamental questions in macroevolutionary studies, tempo (timing of evolutionary rate shifts) and mode ("how" and "why" of speciation). By using simulated phylogenies under four diversification scenarios, constant-rate, diversity-dependence, high extinction, and high speciation rates in the Pleistocene, I showed that interpretations based on species divergence ranks might have been seriously misleading. Future meta-analyses of dated phylogenies need to be aware of the impacts of incomplete taxonomic sampling, tree topology, and divergence time uncertainties, as well as they might be benefited by including quantitative tests of alternative diversification models that acknowledge extinction and diversity dependence. © 2016 The Author(s).

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

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

Husko, Chad; Wulf, Matthias; Lefrancois, Simon

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing themore » free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrodinger equation model. Finally, these results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.« less

Radical-Mediated Enzymatic Carbon Chain Fragmentation-Recombination

PubMed Central

Zhang, Qi; Li, Yuxue; Chen, Dandan; Yu, Yi; Duan, Lian; Shen, Ben; Liu, Wen

2010-01-01

The radical S-adenosylmethionine (S-AdoMet) superfamily contains thousands of proteins that catalyze highly diverse conversions, most of which are poorly understood due to a lack of information regarding chemical products and radical-dependent transformations. We here report that NosL, involved in forming the indole side ring of the thiopeptide nosiheptide (NOS), is a radical S-AdoMet 3-methyl-2-indolic acid (MIA) synthase. NosL catalyzed an unprecedented carbon chain reconstitution of L-Trp to give MIA, showing removal of the Cα-N unit and shift of the carboxylate to the indole ring. Dissection of the enzymatic process upon the identification of products and a putative glycyl intermediate uncovered a radical-mediated, unusual fragmentation-recombination reaction. This finding unveiled a key step in radical S-AdoMet enzyme-catalyzed structural rearrangements during complex biotransformations. Additionally, NosL tolerated fluorinated L-Trps as the substrates, allowing for production of a regiospecifically halogenated thiopeptide that has not been found in over 80 entity-containing, naturally occurring thiopeptide family. PMID:21240261

Single-Cell Transcriptomics Reveals a Population of Dormant Neural Stem Cells that Become Activated upon Brain Injury.

PubMed

Llorens-Bobadilla, Enric; Zhao, Sheng; Baser, Avni; Saiz-Castro, Gonzalo; Zwadlo, Klara; Martin-Villalba, Ana

2015-09-03

Heterogeneous pools of adult neural stem cells (NSCs) contribute to brain maintenance and regeneration after injury. The balance of NSC activation and quiescence, as well as the induction of lineage-specific transcription factors, may contribute to diversity of neuronal and glial fates. To identify molecular hallmarks governing these characteristics, we performed single-cell sequencing of an unbiased pool of adult subventricular zone NSCs. This analysis identified a discrete, dormant NSC subpopulation that already expresses distinct combinations of lineage-specific transcription factors during homeostasis. Dormant NSCs enter a primed-quiescent state before activation, which is accompanied by downregulation of glycolytic metabolism, Notch, and BMP signaling and a concomitant upregulation of lineage-specific transcription factors and protein synthesis. In response to brain ischemia, interferon gamma signaling induces dormant NSC subpopulations to enter the primed-quiescent state. This study unveils general principles underlying NSC activation and lineage priming and opens potential avenues for regenerative medicine in the brain. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure-based drug design targeting the cell membrane receptor GPBAR1: exploiting the bile acid scaffold towards selective agonism

NASA Astrophysics Data System (ADS)

di Leva, Francesco Saverio; Festa, Carmen; Renga, Barbara; Sepe, Valentina; Novellino, Ettore; Fiorucci, Stefano; Zampella, Angela; Limongelli, Vittorio

2015-11-01

Bile acids can regulate nutrient metabolism through the activation of the cell membrane receptor GPBAR1 and the nuclear receptor FXR. Developing an exogenous control over these receptors represents an attractive strategy for the treatment of enterohepatic and metabolic disorders. A number of dual GPBAR1/FXR agonists are known, however their therapeutic use is limited by multiple unwanted effects due to activation of the diverse downstream signals controlled by the two receptors. On the other hand, designing selective GPBAR1 and FXR agonists is challenging since the two proteins share similar structural requisites for ligand binding. Here, taking advantage of our knowledge of the two targets, we have identified through a rational drug design study a series of amine lithocholic acid derivatives as selective GPBAR1 agonists. The presence of the 3α-NH2 group on the steroidal scaffold is responsible for the selectivity over FXR unveiling unprecedented structural insights into bile acid receptors activity modulation.

[Therapeutical itineraries in poverty situations: diversity and plurality].

PubMed

Gerhardt, Tatiana Engel

2006-11-01

The low-income population's practices and strategies for coping with daily problems, especially in relation to the search for health care, are analyzed by means of therapeutic itineraries. To unveil this population's coping strategies in relation to their health-disease process means identifying the individual and collective strategies and the meaning of these social dynamics related directly or indirectly to health. The search for treatment is described and analyzed here in relation to socio-cultural practices in terms of the paths chosen by individuals in the attempt to solve their health problems. The study thus indicates an interdisciplinary and multi-methodological and conceptual approach relating concepts of practices, strategies, and health and life situations. The point of departure is that ways of coping with health problems require an understanding of the strategies developed in a process of (re)appropriation and (re)construction of knowledge. It is equally important to identify social support networks and individual capacity to mobilize such resources. The recognition of these practices allows (re)directing actions in collective health.

An excited state underlies gene regulation of a transcriptional riboswitch

PubMed Central

Zhao, Bo; Guffy, Sharon L.; Williams, Benfeard; Zhang, Qi

2017-01-01

Riboswitches control gene expression through ligand-dependent structural rearrangements of the sensing aptamer domain. However, we found that the Bacillus cereus fluoride riboswitch aptamer adopts identical tertiary structures in solution with and without ligand. Using chemical exchange saturation transfer (CEST) NMR spectroscopy, we revealed that the structured ligand-free aptamer transiently accesses a low-populated (~1%) and short-lived (~3 ms) excited conformational state that unravels a conserved ‘linchpin’ base pair to signal transcription termination. Upon fluoride binding, this highly localized fleeting process is allosterically suppressed to activate transcription. We demonstrated that this mechanism confers effective fluoride-dependent gene activation over a wide range of transcription rates, which is essential for robust toxicity response across diverse cellular conditions. These results unveil a novel switching mechanism that employs ligand-dependent suppression of an aptamer excited state to coordinate regulatory conformational transitions rather than adopting distinct aptamer ground-state tertiary architectures, exemplifying a new mode of ligand-dependent RNA regulation. PMID:28719589

From Molecular Docking to 3D-Quantitative Structure-Activity Relationships (3D-QSAR): Insights into the Binding Mode of 5-Lipoxygenase Inhibitors.

PubMed

Eren, Gokcen; Macchiarulo, Antonio; Banoglu, Erden

2012-02-01

Pharmacological intervention with 5-Lipoxygenase (5-LO) is a promising strategy for treatment of inflammatory and allergic ailments, including asthma. With the aim of developing predictive models of 5-LO affinity and gaining insights into the molecular basis of ligand-target interaction, we herein describe QSAR studies of 59 diverse nonredox-competitive 5-LO inhibitors based on the use of molecular shape descriptors and docking experiments. These studies have successfully yielded a predictive model able to explain much of the variance in the activity of the training set compounds while predicting satisfactorily the 5-LO inhibitory activity of an external test set of compounds. The inspection of the selected variables in the QSAR equation unveils the importance of specific interactions which are observed from docking experiments. Collectively, these results may be used to design novel potent and selective nonredox 5-LO inhibitors. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rap G protein signal in normal and disordered lymphohematopoiesis

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

Minato, Nagahiro, E-mail: minato@imm.med.kyoto-u.ac.jp

2013-09-10

Rap proteins (Rap1, Rap2a, b, c) are small molecular weight GTPases of the Ras family. Rap G proteins mediate diverse cellular events such as cell adhesion, proliferation, and gene activation through various signaling pathways. Activation of Rap signal is regulated tightly by several specific regulatory proteins including guanine nucleotide exchange factors and GTPase-activating proteins. Beyond cell biological studies, increasing attempts have been made in the past decade to define the roles of Rap signal in specific functions of normal tissue systems as well as in cancer. In the immune and hematopoietic systems, Rap signal plays crucial roles in the developmentmore » and function of essentially all lineages of lymphocytes and hematopoietic cells, and importantly, deregulated Rap signal may lead to unique pathological conditions depending on the affected cell types, including various types of leukemia and autoimmunity. The phenotypical studies have unveiled novel, even unexpected functional aspects of Rap signal in cells from a variety of tissues, providing potentially important clues for controlling human diseases, including malignancy.« less

Super-Resolution Microscopy Unveils Dynamic Heterogeneities in Nanoparticle Protein Corona.

PubMed

Feiner-Gracia, Natalia; Beck, Michaela; Pujals, Sílvia; Tosi, Sébastien; Mandal, Tamoghna; Buske, Christian; Linden, Mika; Albertazzi, Lorenzo

2017-11-01

The adsorption of serum proteins, leading to the formation of a biomolecular corona, is a key determinant of the biological identity of nanoparticles in vivo. Therefore, gaining knowledge on the formation, composition, and temporal evolution of the corona is of utmost importance for the development of nanoparticle-based therapies. Here, it is shown that the use of super-resolution optical microscopy enables the imaging of the protein corona on mesoporous silica nanoparticles with single protein sensitivity. Particle-by-particle quantification reveals a significant heterogeneity in protein absorption under native conditions. Moreover, the diversity of the corona evolves over time depending on the surface chemistry and degradability of the particles. This paper investigates the consequences of protein adsorption for specific cell targeting by antibody-functionalized nanoparticles providing a detailed understanding of corona-activity relations. The methodology is widely applicable to a variety of nanostructures and complements the existing ensemble approaches for protein corona study. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rotational Spectroscopy of Reactive Species at the Center for Astrochemical Studies.

NASA Astrophysics Data System (ADS)

Lattanzi, Valerio; Spezzano, Silvia; Caselli, Paola

2017-06-01

The Center for Astrochemical Studies at the Max Planck Institute for Extraterrestrial Physics in Garching, is a recently established group which collects scientists with very diverse backgrounds. In the same group observers, theoreticians, chemists and molecular astrophysicists join their efforts with the ultimate goal of properly interpreting observations with the new generation telescopes and unveiling our astrochemical/physical heritage. Among these tasks, the gas-phase spectroscopic characterisation of molecular species of astrophysical relevance is one of the main goals of the laboratory sub-group. This talk will mainly focus on the first experiment built in our center, the CASAC (CAS Absorption Cell) spectrometer: this experiment has been optimised on the production and probe of small molecular ions and radicals. The main laboratory techniques along with the more prominent outcomes of recent studies will be presented. Finally, a brief update on the status of the other instruments available in our center will be given, including their planned upgrades.

Free-carrier-induced soliton fission unveiled by in situ measurements in nanophotonic waveguides

DOE PAGES

Husko, Chad; Wulf, Matthias; Lefrancois, Simon; ...

2016-04-15

Solitons are localized waves formed by a balance of focusing and defocusing effects. These nonlinear waves exist in diverse forms of matter yet exhibit similar properties including stability, periodic recurrence and particle-like trajectories. One important property is soliton fission, a process by which an energetic higher-order soliton breaks apart due to dispersive or nonlinear perturbations. Here we demonstrate through both experiment and theory that nonlinear photocarrier generation can induce soliton fission. Using near-field measurements, we directly observe the nonlinear spatial and temporal evolution of optical pulses in situ in a nanophotonic semiconductor waveguide. We develop an analytic formalism describing themore » free-carrier dispersion (FCD) perturbation and show the experiment exceeds the minimum threshold by an order of magnitude. We confirm these observations with a numerical nonlinear Schrodinger equation model. Finally, these results provide a fundamental explanation and physical scaling of optical pulse evolution in free-carrier media and could enable improved supercontinuum sources in gas based and integrated semiconductor waveguides.« less

Cryptic indole hydroxylation by a non-canonical terpenoid cyclase parallels bacterial xenobiotic detoxification

NASA Astrophysics Data System (ADS)

Kugel, Susann; Baunach, Martin; Baer, Philipp; Ishida-Ito, Mie; Sundaram, Srividhya; Xu, Zhongli; Groll, Michael; Hertweck, Christian

2017-06-01

Terpenoid natural products comprise a wide range of molecular architectures that typically result from C-C bond formations catalysed by classical type I/II terpene cyclases. However, the molecular diversity of biologically active terpenoids is substantially increased by fully unrelated, non-canonical terpenoid cyclases. Their evolutionary origin has remained enigmatic. Here we report the in vitro reconstitution of an unusual flavin-dependent bacterial indoloterpenoid cyclase, XiaF, together with a designated flavoenzyme-reductase (XiaP) that mediates a key step in xiamycin biosynthesis. The crystal structure of XiaF with bound FADH2 (at 2.4 Å resolution) and phylogenetic analyses reveal that XiaF is, surprisingly, most closely related to xenobiotic-degrading enzymes. Biotransformation assays show that XiaF is a designated indole hydroxylase that can be used for the production of indigo and indirubin. We unveil a cryptic hydroxylation step that sets the basis for terpenoid cyclization and suggest that the cyclase has evolved from xenobiotics detoxification enzymes.

High-throughput search of ternary chalcogenides for p-type transparent electrodes

PubMed Central

Shi, Jingming; Cerqueira, Tiago F. T.; Cui, Wenwen; Nogueira, Fernando; Botti, Silvana; Marques, Miguel A. L.

2017-01-01

Delafossite crystals are fascinating ternary oxides that have demonstrated transparent conductivity and ambipolar doping. Here we use a high-throughput approach based on density functional theory to find delafossite and related layered phases of composition ABX2, where A and B are elements of the periodic table, and X is a chalcogen (O, S, Se, and Te). From the 15 624 compounds studied in the trigonal delafossite prototype structure, 285 are within 50 meV/atom from the convex hull of stability. These compounds are further investigated using global structural prediction methods to obtain their lowest-energy crystal structure. We find 79 systems not present in the materials project database that are thermodynamically stable and crystallize in the delafossite or in closely related structures. These novel phases are then characterized by calculating their band gaps and hole effective masses. This characterization unveils a large diversity of properties, ranging from normal metals, magnetic metals, and some candidate compounds for p-type transparent electrodes. PMID:28266587

An ubiquitin-binding molecule can work as an inhibitor of ubiquitin processing enzymes and ubiquitin receptors.

PubMed

Nguyen, Thanh; Ho, Minh; Ghosh, Ambarnil; Kim, Truc; Yun, Sun Il; Lee, Seung Seo; Kim, Kyeong Kyu

2016-10-07

The ubiquitin pathway plays a critical role in regulating diverse biological processes, and its dysregulation is associated with various diseases. Therefore, it is important to have a tool that can control the ubiquitin pathway in order to improve understanding of this pathway and to develop therapeutics against relevant diseases. We found that Chicago Sky Blue 6B binds directly to the β-groove, a major interacting surface of ubiquitin. Hence, it could successfully inhibit the enzymatic activity of ubiquitin processing enzymes and the binding of ubiquitin to the CXCR4, a cell surface ubiquitin receptor. Furthermore, we demonstrated that this ubiquitin binding chemical could effectively suppress the ubiquitin induced cancer cell migration by blocking ubiquitin-CXCR4 interaction. Current results suggest that ubiquitin binding molecules can be developed as inhibitors of ubiquitin-protein interactions, which will have the value not only in unveiling the biological role of ubiquitin but also in treating related diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Responding to home maintenance challenge scenarios: the role of selection, optimization, and compensation in aging-in-place.

PubMed

Kelly, Andrew John; Fausset, Cara Bailey; Rogers, Wendy; Fisk, Arthur D

2014-12-01

This study examined potential issues faced by older adults in managing their homes and their proposed solutions for overcoming hypothetical difficulties. Forty-four diverse, independently living older adults (66-85) participated in structured group interviews in which they discussed potential solutions to manage difficulties presented in four scenarios: perceptual, mobility, physical, and cognitive difficulties. The proposed solutions were classified using the Selection, Optimization, and Compensation (SOC) model. Participants indicated they would continue performing most tasks and reported a range of strategies to manage home maintenance challenges. Most participants reported that they would manage home maintenance challenges using compensation; the most frequently mentioned compensation strategy was using tools and technologies. There were also differences across the scenarios: Optimization was discussed most frequently with perceptual and cognitive difficulty scenarios. These results provide insights into supporting older adults' potential needs for aging-in-place and provide evidence of the value of the SOC model in applied research. © The Author(s) 2012.

Is story-based blended learning a promising avenue for skin and sexual health education? Results from the PAEDIMED project.

PubMed

Apfelbacher, Christian J; Deimling, Erika; Wulfhorst, Britta; Adler, Frederic; Diepgen, Thomas L; Linder, Dennis; Blenk, Holger; Stosiek, Nikolaus; Reinmann, Gabi

2010-03-01

The PAEDIMED study group developed a learning and teaching scenario for school health education in the area of skin and sexual health in Italy, Romania and Germany, combining web-based and traditional learning ("blended learning"). A questionnaire-based needs assessment and context analysis were conducted, based on which an education scenario was designed. Particular emphasis was put on emotional and motivational aspects, using narrative components in the didactic concept. The design process occupied a central role in the project (design-based research). Evaluation was both formative and summative. Continuous feedback was obtained from relevant stakeholders. Following a prototypical implementation, the scenario was evaluated using questionnaires. The results revealed a high level of acceptance of the education scenario as well as an increase in students' knowledge concerning skin and sexual health. Evaluation also suggested that health education is highly influenced by cultural background and habits as well as diverse contextual and personal conditions.

Phylogeographic patterns of genetic diversity in eastern Mediterranean water frogs have been determined by geological processes and climate change in the Late Cenozoic.

PubMed

Akın, Ciğdem; Bilgin, C Can; Beerli, Peter; Westaway, Rob; Ohst, Torsten; Litvinchuk, Spartak N; Uzzell, Thomas; Bilgin, Metin; Hotz, Hansjürg; Guex, Gaston-Denis; Plötner, Jörg

2010-11-01

AIM: Our aims were to assess the phylogeographic patterns of genetic diversity in eastern Mediterranean water frogs and to estimate divergence times using different geological scenarios. We related divergence times to past geological events and discuss the relevance of our data for the systematics of eastern Mediterranean water frogs. LOCATION: The eastern Mediterranean region. METHODS: Genetic diversity and divergence were calculated using sequences of two protein-coding mitochondrial (mt) genes: ND2 (1038 bp, 119 sequences) and ND3 (340 bp, 612 sequences). Divergence times were estimated in a Bayesian framework under four geological scenarios representing alternative possible geological histories for the eastern Mediterranean. We then compared the different scenarios using Bayes factors and additional geological data. RESULTS: Extensive genetic diversity in mtDNA divides eastern Mediterranean water frogs into six main haplogroups (MHG). Three MHGs were identified on the Anatolian mainland; the most widespread MHG with the highest diversity is distributed from western Anatolia to the northern shore of the Caspian Sea, including the type locality of Pelophylax ridibundus. The other two Anatolian MHGs are restricted to south-eastern Turkey, occupying localities west and east of the Amanos mountain range. One of the remaining three MHGs is restricted to Cyprus; a second to the Levant; the third was found in the distribution area of European lake frogs (P. ridibundus group), including the Balkans. MAIN CONCLUSIONS: Based on geological evidence and estimates of genetic divergence we hypothesize that the water frogs of Cyprus have been isolated from the Anatolian mainland populations since the end of the Messinian salinity crisis (MSC), i.e. since c. 5.5-5.3 Ma, while our divergence time estimates indicate that the isolation of Crete from the mainland populations (Peloponnese, Anatolia) most likely pre-dates the MSC. The observed rates of divergence imply a time window of c. 1.6-1.1 million years for diversification of the largest Anatolian MHG; divergence between the two other Anatolian MHGs may have begun about 3.0 Ma, apparently as a result of uplift of the Amanos Mountains. Our mtDNA data suggest that the Anatolian water frogs and frogs from Cyprus represent several undescribed species.

Response to selection while maximizing genetic variance in small populations.

PubMed

Cervantes, Isabel; Gutiérrez, Juan Pablo; Meuwissen, Theo H E

2016-09-20

Rare breeds represent a valuable resource for future market demands. These populations are usually well-adapted, but their low census compromises the genetic diversity and future of these breeds. Since improvement of a breed for commercial traits may also confer higher probabilities of survival for the breed, it is important to achieve good responses to artificial selection. Therefore, efficient genetic management of these populations is essential to ensure that they respond adequately to genetic selection in possible future artificial selection scenarios. Scenarios that maximize the maximum genetic variance in a unique population could be a valuable option. The aim of this work was to study the effect of the maximization of genetic variance to increase selection response and improve the capacity of a population to adapt to a new environment/production system. We simulated a random scenario (A), a full-sib scenario (B), a scenario applying the maximum variance total (MVT) method (C), a MVT scenario with a restriction on increases in average inbreeding (D), a MVT scenario with a restriction on average individual increases in inbreeding (E), and a minimum coancestry scenario (F). Twenty replicates of each scenario were simulated for 100 generations, followed by 10 generations of selection. Effective population size was used to monitor the outcomes of these scenarios. Although the best response to selection was achieved in scenarios B and C, they were discarded because they are unpractical. Scenario A was also discarded because of its low response to selection. Scenario D yielded less response to selection and a smaller effective population size than scenario E, for which response to selection was higher during early generations because of the moderately structured population. In scenario F, response to selection was slightly higher than in Scenario E in the last generations. Application of MVT with a restriction on individual increases in inbreeding resulted in the largest response to selection during early generations, but if inbreeding depression is a concern, a minimum coancestry scenario is then a valuable alternative, in particular for a long-term response to selection.

Toward zero waste: Composting and recycling for sustainable venue based events

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

Hottle, Troy A., E-mail: troy.hottle@asu.edu; Bilec, Melissa M., E-mail: mbilec@pitt.edu; Brown, Nicholas R., E-mail: nick.brown@asu.edu

Highlights: • Venues have billions of customers per year contributing to waste generation. • Waste audits of four university baseball games were conducted to assess venue waste. • Seven scenarios including composting were modeled using EPA’s WARM. • Findings demonstrate tradeoffs between emissions, energy, and landfill avoidance. • Sustainability of handling depends on efficacy of collection and treatment impacts. - Abstract: This study evaluated seven different waste management strategies for venue-based events and characterized the impacts of event waste management via waste audits and the Waste Reduction Model (WARM). The seven waste management scenarios included traditional waste handling methods (e.g.more » recycle and landfill) and management of the waste stream via composting, including purchasing where only compostable food service items were used during the events. Waste audits were conducted at four Arizona State University (ASU) baseball games, including a three game series. The findings demonstrate a tradeoff among CO{sub 2} equivalent emissions, energy use, and landfill diversion rates. Of the seven waste management scenarios assessed, the recycling scenarios provide the greatest reductions in CO{sub 2} eq. emissions and energy use because of the retention of high value materials but are compounded by the difficulty in managing a two or three bin collection system. The compost only scenario achieves complete landfill diversion but does not perform as well with respect to CO{sub 2} eq. emissions or energy. The three game series was used to test the impact of staffed bins on contamination rates; the first game served as a baseline, the second game employed staffed bins, and the third game had non staffed bins to determine the effect of staffing on contamination rates. Contamination rates in both the recycling and compost bins were tracked throughout the series. Contamination rates were reduced from 34% in the first game to 11% on the second night (with the staffed bins) and 23% contamination rates at the third game.« less

Scenario driven data modelling: a method for integrating diverse sources of data and data streams

PubMed Central

2011-01-01

Background Biology is rapidly becoming a data intensive, data-driven science. It is essential that data is represented and connected in ways that best represent its full conceptual content and allows both automated integration and data driven decision-making. Recent advancements in distributed multi-relational directed graphs, implemented in the form of the Semantic Web make it possible to deal with complicated heterogeneous data in new and interesting ways. Results This paper presents a new approach, scenario driven data modelling (SDDM), that integrates multi-relational directed graphs with data streams. SDDM can be applied to virtually any data integration challenge with widely divergent types of data and data streams. In this work, we explored integrating genetics data with reports from traditional media. SDDM was applied to the New Delhi metallo-beta-lactamase gene (NDM-1), an emerging global health threat. The SDDM process constructed a scenario, created a RDF multi-relational directed graph that linked diverse types of data to the Semantic Web, implemented RDF conversion tools (RDFizers) to bring content into the Sematic Web, identified data streams and analytical routines to analyse those streams, and identified user requirements and graph traversals to meet end-user requirements. Conclusions We provided an example where SDDM was applied to a complex data integration challenge. The process created a model of the emerging NDM-1 health threat, identified and filled gaps in that model, and constructed reliable software that monitored data streams based on the scenario derived multi-relational directed graph. The SDDM process significantly reduced the software requirements phase by letting the scenario and resulting multi-relational directed graph define what is possible and then set the scope of the user requirements. Approaches like SDDM will be critical to the future of data intensive, data-driven science because they automate the process of converting massive data streams into usable knowledge. PMID:22165854

Projected loss of a salamander diversity hotspot as a consequence of projected global climate change.

PubMed

Milanovich, Joseph R; Peterman, William E; Nibbelink, Nathan P; Maerz, John C

2010-08-16

Significant shifts in climate are considered a threat to plants and animals with significant physiological limitations and limited dispersal abilities. The southern Appalachian Mountains are a global hotspot for plethodontid salamander diversity. Plethodontids are lungless ectotherms, so their ecology is strongly governed by temperature and precipitation. Many plethodontid species in southern Appalachia exist in high elevation habitats that may be at or near their thermal maxima, and may also have limited dispersal abilities across warmer valley bottoms. We used a maximum-entropy approach (program Maxent) to model the suitable climatic habitat of 41 plethodontid salamander species inhabiting the Appalachian Highlands region (33 individual species and eight species included within two species complexes). We evaluated the relative change in suitable climatic habitat for these species in the Appalachian Highlands from the current climate to the years 2020, 2050, and 2080, using both the HADCM3 and the CGCM3 models, each under low and high CO(2) scenarios, and using two-model thresholds levels (relative suitability thresholds for determining suitable/unsuitable range), for a total of 8 scenarios per species. While models differed slightly, every scenario projected significant declines in suitable habitat within the Appalachian Highlands as early as 2020. Species with more southern ranges and with smaller ranges had larger projected habitat loss. Despite significant differences in projected precipitation changes to the region, projections did not differ significantly between global circulation models. CO(2) emissions scenario and model threshold had small effects on projected habitat loss by 2020, but did not affect longer-term projections. Results of this study indicate that choice of model threshold and CO(2) emissions scenario affect short-term projected shifts in climatic distributions of species; however, these factors and choice of global circulation model have relatively small affects on what is significant projected loss of habitat for many salamander species that currently occupy the Appalachian Highlands.

A fine structure genetic analysis evaluating ecoregional adaptability of a Bos taurus breed (Hereford)

USDA-ARS?s Scientific Manuscript database

Ecoregional differences contribute to genetic environmental interactions and impact animal performance. These differences may become more important under climate change scenarios. Utilizing genetic diversity within a species to address such problems has not been fully explored. In this study Herefor...

Taming the Technology.

ERIC Educational Resources Information Center

Clinton, Janeen S.

This document reports on efforts to find technology-based solutions for the diverse challenges faced by students with disabling conditions. Twenty-three case studies describe actual scenarios experienced in the school district of Palm Beach County, Florida. For each case study, a situation is described, a challenge is identified, solutions are…

The Origins of Tropical Rainforest Hyperdiversity.

PubMed

Pennington, R Toby; Hughes, Mark; Moonlight, Peter W

2015-11-01

Traditional models for tropical species richness contrast rainforests as "museums" of old species or "cradles" of recent speciation. High plant species diversity in rainforests may be more likely to reflect high episodic evolutionary turnover of species--a scenario implicating high rates of both speciation and extinction through geological time.

Effects of Transparency on Pilot Trust and Agreement in the Autonomous Constrained Flight Planner

NASA Technical Reports Server (NTRS)

Sadler, Garrett; Battiste, Henri; Ho, Nhut; Hoffmann, Lauren; Lyons, Joseph; Johnson, Walter; Shively, Robert; Smith, David

2016-01-01

We performed a human-in-the-loop study to explore the role of transparency in engendering trust and reliance within highly automated systems. Specifically, we examined how transparency impacts trust in and reliance upon the Autonomous Constrained Flight Planner (ACFP), a critical automated system being developed as part of NASA's Reduced Crew Operations (RCO) Concept. The ACFP is designed to provide an enhanced ground operator, termed a super dispatcher, with recommended diversions for aircraft when their primary destinations are unavailable. In the current study, 12 commercial transport rated pilots who played the role of super dispatchers were given six time-pressured all land scenarios where they needed to use the ACFP to determine diversions for multiple aircraft. Two factors were manipulated. The primary factor was level of transparency. In low transparency scenarios the pilots were given a recommended airport and runway, plus basic information about the weather conditions, the aircraft types, and the airport and runway characteristics at that and other airports. In moderate transparency scenarios the pilots were also given a risk evaluation for the recommended airport, and for the other airports if they requested it. In the high transparency scenario additional information including the reasoning for the risk evaluations was made available to the pilots. The secondary factor was level of risk, either high or low. For high-risk aircraft, all potential diversions were rated as highly risky, with the ACFP giving the best option for a bad situation. For low-risk aircraft the ACFP found only low-risk options for the pilot. Both subjective and objective measures were collected, including rated trust, whether the pilots checked the validity of the automation recommendation, and whether the pilots eventually flew to the recommended diversion airport. Key results show that: 1) Pilots trust increased with higher levels of transparency, 2) Pilots were more likely to verify ACFPs recommendations with low levels of transparency and when risk was high, 3) Pilots were more likely to explore other options from the ACFP in low transparency conditions and when risk was high, and 4) Pilots decision to accept or reject ACFPs recommendations increased as a function of the transparency in the explanation. The finding that higher levels of transparency was coupled with higher levels of trust, a lower need to verify other options, and higher levels of agreement with ACFP recommendations, confirms the importance of transparency in aiding reliance on automated recommendations. Additional analyses of qualitative data gathered from subjects through surveys and during debriefing interviews also provided the basis for new design recommendations for the ACFP.

The Jena Diversity Model: Towards a Richer Representation of the Terrestrial Biosphere for Earth System Modelling

NASA Astrophysics Data System (ADS)

Pavlick, R.; Reu, B.; Bohn, K.; Dyke, J.; Kleidon, A.

2010-12-01

The terrestrial biosphere is a complex, self-organizing system which is continually both adapting to and altering its global environment. It also exhibits a vast diversity of vegetation forms and functioning. However, the terrestrial biosphere components within current state-of-the-art Earth System Models abstract this diversity in to a handful of relatively static plant functional types. These coarse and static representations of functional diversity might contribute to overly pessimistic projections regarding terrestrial ecosystem responses to scenarios of global change (e.g. Amazonian and boreal forest diebacks). In the Jena Diversity (JeDi) model, we introduce a new approach to vegetation modelling with a richer representation of functional diversity, based not on plant functional types, but on unavoidable plant ecophysiological trade-offs, which we hypothesize should be more stable in time. The JeDi model tests a large number of plant growth strategies. Each growth strategy is simulated using a set of randomly generated parameter values, which characterize its functioning in terms of carbon allocation, ecophysiology, and phenology, which are then linked to the growing conditions at the land surface. The model is constructed in such a way that these parameters inherently lead to ecophysiological trade-offs, which determine whether a growth strategy is able to survive and reproduce under the prevalent climatic conditions. Kleidon and Mooney (2000) demonstrated that this approach is capable of reproducing the geographic distribution of species richness. More recently, we have shown the JeDi model can explain other biogeographical phenomena including the present-day global pattern of biomes (Reu et al., accepted), ecosystem evenness (Kleidon et al. 2009), and possible mechanisms for biome shifts and biodiversity changes under scenarios of global warming (Reu et al., submitted). We have also evaluated the simulated biogeochemical fluxes from JeDi against a variety of site, field, and satellite observations (Pavlick et al., submitted) following a protocol established by the Carbon-Land Model Intercomparison Project (Randerson et al. 2009). We found that the global patterns of biogeochemical fluxes and land surface properties are reasonably well simulated using this bottom-up trade-off approach and compare favorably with other state of the art terrestrial biosphere models. Here, we present some results from JeDi simulations, wherein we varied the modelled functional diversity to quantify its impact on terrestrial biogeochemical fluxes under both present-day conditions and projected scenarios of global change. We also present results from a set of simulations wherein we vary the ability of the modelled ecosystems to adapt through changes in functional composition, leading to different projection responses of the carbon cycle to global warming. This plant functional tradeoff approach sets the foundation for many applications, including exploring the emergence and climatic impacts of major vegetation transitions throughout the last 400 million years as well as quantifying the significance of preserving functional diversity to hedge against uncertain climates in the future.

Differential staining of Western blots of human secreted glycoproteins from serum, milk, saliva, and seminal fluid using lectins displaying diverse sugar specificities.

PubMed

Gilboa-Garber, Nechama; Lerrer, Batya; Lesman-Movshovich, Efrat; Dgani, Orly

2005-12-01

Human milk, serum, saliva, and seminal fluid glycoproteins (gps) nourish and protect newborn and adult tissues. Their saccharides, which resemble cell membrane components, may block pathogen adhesion and infection. In the present study, they were examined by a battery of lectins from plants, animals, and bacteria, using hemagglutination inhibition and Western blot analyses. The lectins included galactophilic ones from Aplysia gonad, Erythrina corallodendron, Maclura pomifera (MPL), peanut, and Pseudomonas aeruginosa (PA-IL); fucose-binding lectins from Pseudomonas aeruginosa (PA-IIL), Ralstonia solanacearum (RSL), and Ulex europaeus (UEA-I), and mannose/glucose-binding Con A. The results demonstrated the chosen lectin efficiency for differential analysis of human secreted gps as compared to CBB staining. They unveiled the diversity of these body fluid gp glycans (those of the milk and seminal fluid being highest): the milk gps interacted most strongly with PA-IIL, followed by RSL; the saliva gps with RSL, followed by PA-IIL and MPL; the serum gps with Con A and MPL, followed by PA-IIL and RSL, and the seminal plasma gps with RSL and MPL, followed by UEA-I and PA-IIL. The potential usage of these lectins as probes for scientific, industrial, and medical purposes, and for quality control of the desired gps is clearly indicated.

Subsurface metagenomes uncover a vast repertoire of hypervariable proteins encoded by genetic elements in uncultivated organisms and viruses

NASA Astrophysics Data System (ADS)

Paul, B. G.; Burstein, D.; Castelle, C. J.; Banfield, J. F.; Valentine, D. L.; Miller, J. F.; Ghosh, P.; Handa, S.; Arambula, D.; Czornyj, E.; Thomas, B. C.

2016-12-01

Uncultivated microorganisms primarily account for the remarkable diversity harbored in subsurface environments and represent an expansive subset of the current Tree of Life. Recent metagenomic efforts to investigate subsurface biomes have unveiled an array of bacterial and archaeal candidate phyla, whose members have minimal genomes and an apparent host-dependent existence. Still, little is known about the adaptive strategies that mediate host interactions in these organisms or their viruses. Genomic features known as diversity-generating retroelements (DGRs), which guide variability into targeted genes, were recently discovered in two single-cell genomes of uncultivated nanoarchaea, and independently in the genome of a marine virus from methane seep sediments. These prodigious drivers of protein hypervariability were first identified as the key force behind phage tail fiber diversification for binding different host receptors. Since their discovery, approximately 500 new DGRs have been found across a wide range of bacterial genomes representing various niches. We identified an unexpected 1136 distinct diversifiers from a single groundwater environment in reconstructed microbial genomes and genome fragments. The newly detected DGRs - predominantly linked to members of the candidate phyla radiation (CPR) - appear to target genes associated with cell-cell attachment, signaling, and transcription regulation. These findings suggest that targeted protein diversification may have an important role in regulating symbiotic or parasitic associations in groundwater microbiomes.

Multi-criteria decision analysis of concentrated solar power with thermal energy storage and dry cooling.

PubMed

Klein, Sharon J W

2013-12-17

Decisions about energy backup and cooling options for parabolic trough (PT) concentrated solar power have technical, economic, and environmental implications. Although PT development has increased rapidly in recent years, energy policies do not address backup or cooling option requirements, and very few studies directly compare the diverse implications of these options. This is the first study to compare the annual capacity factor, levelized cost of energy (LCOE), water consumption, land use, and life cycle greenhouse gas (GHG) emissions of PT with different backup options (minimal backup (MB), thermal energy storage (TES), and fossil fuel backup (FF)) and different cooling options (wet (WC) and dry (DC). Multicriteria decision analysis was used with five preference scenarios to identify the highest-scoring energy backup-cooling combination for each preference scenario. MB-WC had the highest score in the Economic and Climate Change-Economy scenarios, while FF-DC and FF-WC had the highest scores in the Equal and Availability scenarios, respectively. TES-DC had the highest score for the Environmental scenario. DC was ranked 1-3 in all preference scenarios. Direct comparisons between GHG emissions and LCOE and between GHG emissions and land use suggest a preference for TES if backup is require for PT plants to compete with baseload generators.

Hypothetical scenario exercises to improve planning and readiness for drinking water quality management during extreme weather events.

PubMed

Deere, Daniel; Leusch, Frederic D L; Humpage, Andrew; Cunliffe, David; Khan, Stuart J

2017-03-15

Two hypothetical scenario exercises were designed and conducted to reflect the increasingly extreme weather-related challenges faced by water utilities as the global climate changes. The first event was based on an extreme flood scenario. The second scenario involved a combination of weather events, including a wild forest fire ('bushfire') followed by runoff due to significant rainfall. For each scenario, a panel of diverse personnel from water utilities and relevant agencies (e.g. health departments) formed a hypothetical water utility and associated regulatory body to manage water quality following the simulated extreme weather event. A larger audience participated by asking questions and contributing key insights. Participants were confronted with unanticipated developments as the simulated scenarios unfolded, introduced by a facilitator. Participants were presented with information that may have challenged their conventional experiences regarding operational procedures in order to identify limitations in current procedures, assumptions, and readily available information. The process worked toward the identification of a list of specific key lessons for each event. At the conclusion of each simulation a facilitated discussion was used to establish key lessons of value to water utilities in preparing them for similar future extreme events. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expectations and satisfaction of pregnant women: unveiling prenatal care in primary care.

PubMed

Aparecida Maciel Cardelli, Alexandrina; Li Marrero, Tai; Aparecida Pimenta Ferrari, Rosângela; Trevisan Martins, Júlia; Serafim, Deise

2016-06-01

To analyze the perception of primiparous women about prenatal care in Basic Health Units in a municipality in southern Brazil. This is a qualitative research from the perspective of Social Representation Theory, from the following question: How has been the pre-natal care for you? Eighteen pregnant women were interviewed. The analysis resulted in three categories: Expectation representation about prenatal care; Rescuing the care offered in prenatal consultation; Unveiling the (dis) satisfaction with prenatal consultation. The prenatal care was apprehended as an essential moment for safe pregnancy, although centered on the doctor's figure and guarantee access to early laboratory and imaging tests. On the other hand, dissatisfaction was revealed from the reception at the entrance to the health unit to the consultations access, although some statements suggest timely satisfaction. Prenatal care did not meet the specific expectations of the study group and unveiled that the nurse did not supply it, as a member of the multidisciplinary team. The organization of the nursing work process in primary care, related to prenatal care, needs to be revisited to promote the effectiveness of its actions.

Geoscience Diversity Experiential Simulations (GeoDES) Workshop Report

NASA Astrophysics Data System (ADS)

Houlton, H. R.; Chen, J.; Brown, B.; Samuels, D.; Brinkworth, C.

2017-12-01

The geosciences have to solve increasingly complex problems relating to earth and society, as resources become limited, natural hazards and changes in climate impact larger communities, and as people interacting with Earth become more interconnected. However, the profession has dismally low representation from geoscientists who are from diverse racial, ethnic, or socioeconomic backgrounds, as well as women in leadership roles. This underrepresentation also includes individuals whose gender identity/expression is non-binary or gender-conforming, or those who have physical, cognitive, or emotional disabilities. This lack of diversity ultimately impacts our profession's ability to produce our best science and work with the communities that we strive to protect and serve as stewards of the earth. As part of the NSF GOLD solicitation, we developed a project (Geoscience Diversity Experiential Simulations) to train 30 faculty and administrators to be "champions for diversity" and combat the hostile climates in geoscience departments. We hosted a 3-day workshop in November that used virtual simulations to give participants experience in building the skills to react to situations regarding bias, discrimination, microaggressions, or bullying often cited in geoscience culture. Participants interacted with avatars on screen, who responded to participants' actions and choices, given certain scenarios. The scenarios are framed within a geoscience perspective; we integrated qualitative interview data from informants who experienced inequitable judgement, bias, discrimination, or harassment during their geoscience careers. The simulations gave learners a safe environment to practice and build self-efficacy in how to professionally and productively engage peers in difficult conversations. In addition, we obtained pre-workshop survey data about participants' understanding regarding Diversity, Equity, and Inclusion practices, as well as observation data of participants' responses during the simulations. Follow-up activities include monthly online meetings to engage problem solving and strategy-building skills for catalyzing institutional culture change within departments. This talk will specifically focus on workshop observations and preliminary reactions to the training.

Roles of Fe-S proteins: from cofactor synthesis to iron homeostasis to protein synthesis.

PubMed

Pain, Debkumar; Dancis, Andrew

2016-06-01

Fe-S cluster assembly is an essential process for all cells. Impairment of Fe-S cluster assembly creates diseases in diverse and surprising ways. In one scenario, the loss of function of lipoic acid synthase, an enzyme with Fe-S cluster cofactor in mitochondria, impairs activity of various lipoamide-dependent enzymes with drastic consequences for metabolism. In a second scenario, the heme biosynthetic pathway in red cell precursors is specifically targeted, and iron homeostasis is perturbed, but lipoic acid synthesis is unaffected. In a third scenario, tRNA modifications arising from action of the cysteine desulfurase and/or Fe-S cluster proteins are lost, which may lead to impaired protein synthesis. These defects can then result in cancer, neurologic dysfunction or type 2 diabetes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fossil resource and energy security dynamics in conventional and carbon-constrained worlds

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

McCollum, David; Bauer, Nico; Calvin, Katherine V.

Fossil resource endowments and the future development of fossil fuel prices are important factors that will critically influence the nature and direction of the global energy system. In this paper we analyze a multi-model ensemble of long-term energy and emissions scenarios that were developed within the framework of the EMF27 integrated assessment model inter-comparison exercise. The diverse nature of these models highlights large uncertainties in the likely development of fossil resource (coal, oil, and natural gas) consumption, trade, and prices over the course of the twenty-first century and under different climate policy frameworks. We explore and explain some of themore » differences across scenarios and models and compare the scenario results with fossil resource estimates from the literature. A robust finding across the suite of IAMs is that the cumulative fossil fuel consumption foreseen by the models is well within the bounds of estimated recoverable reserves and resources. Hence, fossil resource constraints are, in and of themselves, unlikely to limit future GHG emissions. Our analysis also shows that climate mitigation policies could lead to a major reallocation of financial flows between regions, in terms of expenditures on fossil fuels and carbon, and can help to alleviate near-term energy security concerns via the reductions in oil imports and increases in energy system diversity they will help to motivate.« less

[Women, health, and labor in Brazil: challenges for new action].

PubMed

Aquino, E M; Menezes, G M; Marinho, L F

1995-01-01

Despite the remarkable rise in women's participation in the labor market in Brazil, its consequences on health are still virtually unknown. This study aims to identify theoretical and methodological problems in the relationship between labor and women's health from a gender perspective. Characteristics of women's occupational placement are described and analyzed as resulting from their role in social reproduction. The study examines the development of several conciliatory strategies between paid work and housework which are discussed as potential determinants of health problems and support the need for a critical reappraisal of theoretical and methodological strategies to reach a better understanding of the complexity and specificities of women's living and working conditions. The author also stresses the role of women's recent participation in the trade union movements in defense of health, body rights, and women's issues in the workplace, as well as the need for a new framework embodied in the women's social movement. The study thus points to the challenge to produce knowledge on this subject in order to unveil the uniqueness of the national scenario marked by unemployment, informal jobs, low salaries, weak trade unions and other civil organizations, and traditional domestic and marriage relationships.

A mathematical model of sentimental dynamics accounting for marital dissolution.

PubMed

Rey, José-Manuel

2010-03-31

Marital dissolution is ubiquitous in western societies. It poses major scientific and sociological problems both in theoretical and therapeutic terms. Scholars and therapists agree on the existence of a sort of second law of thermodynamics for sentimental relationships. Effort is required to sustain them. Love is not enough. Building on a simple version of the second law we use optimal control theory as a novel approach to model sentimental dynamics. Our analysis is consistent with sociological data. We show that, when both partners have similar emotional attributes, there is an optimal effort policy yielding a durable happy union. This policy is prey to structural destabilization resulting from a combination of two factors: there is an effort gap because the optimal policy always entails discomfort and there is a tendency to lower effort to non-sustaining levels due to the instability of the dynamics. These mathematical facts implied by the model unveil an underlying mechanism that may explain couple disruption in real scenarios. Within this framework the apparent paradox that a union consistently planned to last forever will probably break up is explained as a mechanistic consequence of the second law.

Unveiling the decoherence effect of noise on the entropic uncertainty relation and its control by partially collapsed operations

NASA Astrophysics Data System (ADS)

Chen, Min-Nan; Sun, Wen-Yang; Huang, Ai-Jun; Ming, Fei; Wang, Dong; Ye, Liu

2018-01-01

In this work, we investigate the dynamics of quantum-memory-assisted entropic uncertainty relations under open systems, and how to steer the uncertainty under different types of decoherence. Specifically, we develop the dynamical behaviors of the uncertainty of interest under two typical categories of noise; bit flipping and depolarizing channels. It has been shown that the measurement uncertainty firstly increases and then decreases with the growth of the decoherence strength in bit flipping channels. In contrast, the uncertainty monotonically increases with the increase of the decoherence strength in depolarizing channels. Notably, and to a large degree, it is shown that the uncertainty depends on both the systematic quantum correlation and the minimal conditional entropy of the observed subsystem. Moreover, we present a possible physical interpretation for these distinctive behaviors of the uncertainty within such scenarios. Furthermore, we propose a simple and effective strategy to reduce the entropic uncertainty by means of a partially collapsed operation—quantum weak measurement. Therefore, our investigations might offer an insight into the dynamics of the measurment uncertainty under decoherence, and be of importance to quantum precision measurement in open systems.

A Mathematical Model of Sentimental Dynamics Accounting for Marital Dissolution

PubMed Central

Rey, José-Manuel

2010-01-01

Background Marital dissolution is ubiquitous in western societies. It poses major scientific and sociological problems both in theoretical and therapeutic terms. Scholars and therapists agree on the existence of a sort of second law of thermodynamics for sentimental relationships. Effort is required to sustain them. Love is not enough. Methodology/Principal Findings Building on a simple version of the second law we use optimal control theory as a novel approach to model sentimental dynamics. Our analysis is consistent with sociological data. We show that, when both partners have similar emotional attributes, there is an optimal effort policy yielding a durable happy union. This policy is prey to structural destabilization resulting from a combination of two factors: there is an effort gap because the optimal policy always entails discomfort and there is a tendency to lower effort to non-sustaining levels due to the instability of the dynamics. Conclusions/Significance These mathematical facts implied by the model unveil an underlying mechanism that may explain couple disruption in real scenarios. Within this framework the apparent paradox that a union consistently planned to last forever will probably break up is explained as a mechanistic consequence of the second law. PMID:20360987

Perceptions of Intercultural Social Challenges: Towards Culturally Competent Counselling Practice

ERIC Educational Resources Information Center

Mak, Anita S.; Shaw, Tamara L.

2015-01-01

Increasing ethnic and cultural diversity worldwide and especially in Australia requires that psychologists and counsellors cultivate the know-how to interact and work effectively with clients and stakeholders in cross-cultural contexts. This study aimed to identify and compare themes regarding challenging intercultural social scenarios experienced…

A pharmacokinetic model of cis- and trans-permethrin disposition in rats and humans with aggregate exposure application

EPA Science Inventory

Permethrin is a broad-spectrum pyrethroid insecticide and among the most widely used insecticides in homes and crops. Managing the risks for pesticides such as permethrin depends on the ability to consider diverse exposure scenarios and their relative risks. Physiologically-base...

Managing Information Technology in Academic Medical Centers: A "Multicultural" Experience.

ERIC Educational Resources Information Center

Friedman, Charles P.; Corn, Milton; Krumrey, Arthur; Perry, David R.; Stevens, Ronald H.

1998-01-01

Examines how beliefs and concerns of academic medicine's diverse professional cultures affect management of information technology. Two scenarios, one dealing with standardization of desktop personal computers and the other with publication of syllabi on an institutional intranet, form the basis for an exercise in which four prototypical members…

The Function of Phenomenal States: Supramodular Interaction Theory

ERIC Educational Resources Information Center

Morsella, Ezequiel

2005-01-01

Discovering the function of phenomenal states remains a formidable scientific challenge. Research on consciously penetrable conflicts (e.g., "pain-for-gain" scenarios) and impenetrable conflicts (as in the pupillary reflex, ventriloquism, and the McGurk effect [H. McGurk & J. MacDonald, 1976]) reveals that these states integrate diverse kinds of…

Breeding black walnuts in the age of genomics

Treesearch

Mark V. Coggeshall; Jeanne Romero-Severson

2013-01-01

Molecular markers have been used in several walnut species to help reconstruct breeding program pedigrees, to characterize genetic structure in natural Juglans populations, to determine the impact of different timber harvest scenarios on residual levels of genetic diversity, and to quantify the effects of interspecific hybridization on subsequent...

Six Easy and Beneficial Strategies for an Interculturally Responsive (IR) Classroom

ERIC Educational Resources Information Center

Jones, Kathryn; Mixon, Jason R.

2015-01-01

This scenario is a reflection of many classrooms throughout the United States. This heterogeneous population of students is Linguistically, Culturally, and Educationally Diverse. Some are Native Born, and others have immigrated for various reasons. These reasons include new Employment Opportunities, a United States Education, Political Refuge, and…

Consequences of the genetic threshold model for observing partial migration under climate change scenarios.

PubMed

Cobben, Marleen M P; van Noordwijk, Arie J

2017-10-01

Migration is a widespread phenomenon across the animal kingdom as a response to seasonality in environmental conditions. Partially migratory populations are populations that consist of both migratory and residential individuals. Such populations are very common, yet their stability has long been debated. The inheritance of migratory activity is currently best described by the threshold model of quantitative genetics. The inclusion of such a genetic threshold model for migratory behavior leads to a stable zone in time and space of partially migratory populations under a wide range of demographic parameter values, when assuming stable environmental conditions and unlimited genetic diversity. Migratory species are expected to be particularly sensitive to global warming, as arrival at the breeding grounds might be increasingly mistimed as a result of the uncoupling of long-used cues and actual environmental conditions, with decreasing reproduction as a consequence. Here, we investigate the consequences for migratory behavior and the stability of partially migratory populations under five climate change scenarios and the assumption of a genetic threshold value for migratory behavior in an individual-based model. The results show a spatially and temporally stable zone of partially migratory populations after different lengths of time in all scenarios. In the scenarios in which the species expands its range from a particular set of starting populations, the genetic diversity and location at initialization determine the species' colonization speed across the zone of partial migration and therefore across the entire landscape. Abruptly changing environmental conditions after model initialization never caused a qualitative change in phenotype distributions, or complete extinction. This suggests that climate change-induced shifts in species' ranges as well as changes in survival probabilities and reproductive success can be met with flexibility in migratory behavior at the species level, which will reduce the risk of extinction.

Managing uncertainty: a review of food system scenario analysis and modelling

PubMed Central

Reilly, Michael; Willenbockel, Dirk

2010-01-01

Complex socio-ecological systems like the food system are unpredictable, especially to long-term horizons such as 2050. In order to manage this uncertainty, scenario analysis has been used in conjunction with food system models to explore plausible future outcomes. Food system scenarios use a diversity of scenario types and modelling approaches determined by the purpose of the exercise and by technical, methodological and epistemological constraints. Our case studies do not suggest Malthusian futures for a projected global population of 9 billion in 2050; but international trade will be a crucial determinant of outcomes; and the concept of sustainability across the dimensions of the food system has been inadequately explored so far. The impact of scenario analysis at a global scale could be strengthened with participatory processes involving key actors at other geographical scales. Food system models are valuable in managing existing knowledge on system behaviour and ensuring the credibility of qualitative stories but they are limited by current datasets for global crop production and trade, land use and hydrology. Climate change is likely to challenge the adaptive capacity of agricultural production and there are important knowledge gaps for modelling research to address. PMID:20713402

From Structure to Function: A Comprehensive Compendium of Tools to Unveil Protein Domains and Understand Their Role in Cytokinesis.

PubMed

Rincon, Sergio A; Paoletti, Anne

2016-01-01

Unveiling the function of a novel protein is a challenging task that requires careful experimental design. Yeast cytokinesis is a conserved process that involves modular structural and regulatory proteins. For such proteins, an important step is to identify their domains and structural organization. Here we briefly discuss a collection of methods commonly used for sequence alignment and prediction of protein structure that represent powerful tools for the identification homologous domains and design of structure-function approaches to test experimentally the function of multi-domain proteins such as those implicated in yeast cytokinesis.

News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

NASA Astrophysics Data System (ADS)

2011-01-01

Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

Microevolution Analysis of Bacillus coahuilensis Unveils Differences in Phosphorus Acquisition Strategies and Their Regulation.

PubMed

Gómez-Lunar, Zulema; Hernández-González, Ismael; Rodríguez-Torres, María-Dolores; Souza, Valeria; Olmedo-Álvarez, Gabriela

2016-01-01

Bacterial genomes undergo numerous events of gene losses and gains that generate genome variability among strains of the same species (microevolution). Our aim was to compare the genomes and relevant phenotypes of three Bacillus coahuilensis strains from two oligotrophic hydrological systems in the Cuatro Ciénegas Basin (México), to unveil the environmental challenges that this species cope with, and the microevolutionary differences in these genotypes. Since the strains were isolated from a low P environment, we placed emphasis on the search of different phosphorus acquisition strategies. The three B. coahuilensis strains exhibited similar numbers of coding DNA sequences, of which 82% (2,893) constituted the core genome, and 18% corresponded to accessory genes. Most of the genes in this last group were associated with mobile genetic elements (MGEs) or were annotated as hypothetical proteins. Ten percent of the pangenome consisted of strain-specific genes. Alignment of the three B. coahuilensis genomes indicated a high level of synteny and revealed the presence of several genomic islands. Unexpectedly, one of these islands contained genes that encode the 2-keto-3-deoxymannooctulosonic acid (Kdo) biosynthesis enzymes, a feature associated to cell walls of Gram-negative bacteria. Some microevolutionary changes were clearly associated with MGEs. Our analysis revealed inconsistencies between phenotype and genotype, which we suggest result from the impossibility to map regulatory features to genome analysis. Experimental results revealed variability in the types and numbers of auxotrophies between the strains that could not consistently be explained by in silico metabolic models. Several intraspecific differences in preferences for carbohydrate and phosphorus utilization were observed. Regarding phosphorus recycling, scavenging, and storage, variations were found between the three genomes. The three strains exhibited differences regarding alkaline phosphatase that revealed that in addition to gene gain and loss, regulation adjustment of gene expression also has contributed to the intraspecific diversity of B. coahuilensis.

Finding a needle in the virus metagenome haystack--micro-metagenome analysis captures a snapshot of the diversity of a bacteriophage armoire.

PubMed

Ray, Jessica; Dondrup, Michael; Modha, Sejal; Steen, Ida Helene; Sandaa, Ruth-Anne; Clokie, Martha

2012-01-01

Viruses are ubiquitous in the oceans and critical components of marine microbial communities, regulating nutrient transfer to higher trophic levels or to the dissolved organic pool through lysis of host cells. Hydrothermal vent systems are oases of biological activity in the deep oceans, for which knowledge of biodiversity and its impact on global ocean biogeochemical cycling is still in its infancy. In order to gain biological insight into viral communities present in hydrothermal vent systems, we developed a method based on deep-sequencing of pulsed field gel electrophoretic bands representing key viral fractions present in seawater within and surrounding a hydrothermal plume derived from Loki's Castle vent field at the Arctic Mid-Ocean Ridge. The reduction in virus community complexity afforded by this novel approach enabled the near-complete reconstruction of a lambda-like phage genome from the virus fraction of the plume. Phylogenetic examination of distinct gene regions in this lambdoid phage genome unveiled diversity at loci encoding superinfection exclusion- and integrase-like proteins. This suggests the importance of fine-tuning lyosgenic conversion as a viral survival strategy, and provides insights into the nature of host-virus and virus-virus interactions, within hydrothermal plumes. By reducing the complexity of the viral community through targeted sequencing of prominent dsDNA viral fractions, this method has selectively mimicked virus dominance approaching that hitherto achieved only through culturing, thus enabling bioinformatic analysis to locate a lambdoid viral "needle" within the greater viral community "haystack". Such targeted analyses have great potential for accelerating the extraction of biological knowledge from diverse and poorly understood environmental viral communities.

Trends in genome dynamics among major orders of insects revealed through variations in protein families.

PubMed

Rappoport, Nadav; Linial, Michal

2015-08-07

Insects belong to a class that accounts for the majority of animals on earth. With over one million identified species, insects display a huge diversity and occupy extreme environments. At present, there are dozens of fully sequenced insect genomes that cover a range of habitats, social behavior and morphologies. In view of such diverse collection of genomes, revealing evolutionary trends and charting functional relationships of proteins remain challenging. We analyzed the relatedness of 17 complete proteomes representative of proteomes from insects including louse, bee, beetle, ants, flies and mosquitoes, as well as an out-group from the crustaceans. The analyzed proteomes mostly represented the orders of Hymenoptera and Diptera. The 287,405 protein sequences from the 18 proteomes were automatically clustered into 20,933 families, including 799 singletons. A comprehensive analysis based on statistical considerations identified the families that were significantly expanded or reduced in any of the studied organisms. Among all the tested species, ants are characterized by an exceptionally high rate of family gain and loss. By assigning annotations to hundreds of species-specific families, the functional diversity among species and between the major clades (Diptera and Hymenoptera) is revealed. We found that many species-specific families are associated with receptor signaling, stress-related functions and proteases. The highest variability among insects associates with the function of transposition and nucleic acids processes (collectively coined TNAP). Specifically, the wasp and ants have an order of magnitude more TNAP families and proteins relative to species that belong to Diptera (mosquitoes and flies). An unsupervised clustering methodology combined with a comparative functional analysis unveiled proteomic signatures in the major clades of winged insects. We propose that the expansion of TNAP families in Hymenoptera potentially contributes to the accelerated genome dynamics that characterize the wasp and ants.

Telling better stories: strengthening the story in story and simulation

NASA Astrophysics Data System (ADS)

Kemp-Benedict, Eric

2012-12-01

The scenarios of the IPCC Special Report on Emissions Scenarios (SRES) (Nakicenovic and Swart 2000) are both widely cited and widely criticized. This combination of censure and regard reflects their importance, as they provide both a point of reference and a point of departure for those wishing to understand the long-term implications of policies and human activities for the climate and adaptive capacity. The paper by Schweizer and Kriegler in this issue (Schweizer and Kriegler 2012) reports a unique and interesting critique of the SRES scenarios. The authors find several results, including that the path the world may now be on (labeled by them 'coal-powered growth') is under-represented in the SRES scenarios. While such post-hoc critiques are easy to dismiss, Schweizer and Kriegler were careful to use only the information available to the SRES authors, and they applied a technique that (if it had been available) could have been carried out at that time. In this way they demonstrate that not only was coal-powered growth a clearly discernible possible future at the time of the SRES, but variants on the theme dominate the handful of highly consistent and robust scenarios as identified by their method. Their paper is well-timed because a new round of climate scenarios is now under development (Kriegler et al 2012, van Vuuren et al 2012), and it could learn from evaluations of the SRES process and scenarios. Schweizer and Kriegler (2012) construct a consistent scenario logic using a relatively new foresight technique, cross-impact balances (CIB) (Weimer-Jehle 2006). As explained above, to sharpen their critique and properly evaluate the method, they apply CIB to the information that the authors of the SRES had at their disposal at the time they constructed their scenarios. Their study is therefore anachronistic, in that the CIB method was not published when the SRES was released, but historically faithful in that Schweizer and Kriegler limit themselves to the information available at that time, based on statements that appear in the SRES itself. The CIB method is a technique for constructing internally consistent qualitative scenarios. Global-scale scenario exercises, in particular climate scenarios, typically include both qualitative (narrative) and quantitative (model) elements. As noted by Schweizer and Kriegler, the dominant method for such studies, which Alcamo (2001, 2008) formalized and named the 'story and simulation' (SAS) approach, relies at least in part on quantitative modeling to ensure consistency. Schweizer and Kriegler rightly criticize the idea that models alone can ensure consistency of a scenario narrative. By itself, this critique is not new. Indeed, if asked, both Alcamo and Raskin et al (Raskin et al 2005), whom Schweizer and Kriegler (2012) cite, would probably agree with them; both sources emphasize the need for qualitative storylines that go beyond what models can provide. However, Schweizer and Kriegler correctly point out that these sources provide little or no guidance to those responsible for the narratives beyond a dialog with the model outputs. The CIB method addresses this problem, and Schweizer and Kriegler's application of the method shows that even the best narrative-writing teams can benefit from this guidance. While the paper of Schweizer and Kriegler makes a compelling argument for using CIB in global scenarios, it should be used in combination with other methods. A scenario exercise has several aims, of which consistency is one. Another important goal is diversity: given a set of internally consistent scenarios, a diverse set covers the space of possibilities, and thereby helps users of the scenarios avoid underestimating or overestimating the potential for change in one or another key factor (e.g., see (Carlsen 2009)). From this point of view, the SRES authors could legitimately respond to Schweizer and Kriegler's finding that the SRES scenarios excluded interesting variants on coal-fueled growth by arguing that they did include some variants, and to include more would have conflicted with a legitimate goal of breadth. In this imagined dialog, Schweizer and Kriegler could concede the point, but then point out that several of the SRES scenarios were revealed to be either marginally or very inconsistent by their exercise. Thus, CIB and a technique that helps ensure breadth can usefully complement one another. The CIB method is also liable to a form of specification error, in that the worldviews of the people filling in the cross-impact table influence the results. This is a problem with many foresight techniques, but it is masked by the formalism of CIB, and there is a danger it will go unnoticed. For example, Schweizer and Kriegler's paper suggests that the A1T2 scenario is (marginally) internally consistent. It has relatively low carbon emissions, low rates of population growth, very high GDP per capita growth rates, low primary energy intensity, very low carbon intensity, high fossil-fuel availability, global economic policy focus, and mixed global and regional energy policy focus. It has been argued by Jackson (2009) and Victor (2008), among others, that the evidence is slim that we ever will decouple carbon emissions from GDP to any meaningful extent. Thus, they would presumably argue that this is an inconsistent scenario, and might very well have done so at the time the SRES was written. That is not by itself a reason to reject the scenario, but it suggests that a CIB exercise could be run assuming the qualitative models implied by different worldviews, and the results contrasted. Such an exercise would go beyond the sensitivity analysis that Schweizer and Kriegler report in their paper. The cross-impact balance method should be a useful tool for constructing the next round of climate scenarios. It will be even more useful if combined with techniques that ensure a diversity of scenarios. This could include formal techniques such as 'scenario diversity analysis', which maximizes a quantitative measure of the spread of a set of qualitative scenarios defined by states of driving forces (Carlsen 2009). It could also include a survey of different worldviews, and the qualitative models that they imply, such as that carried out by Sunderlin (Sunderlin 2003). Futures studies has moved forward from the time the SRES was published, and new techniques are now available that can help us to tell better stories of the future. References Alcamo J 2001 Scenarios as Tools for International Environmental Assessments (Cophenhagen: European Environment Agency) Alcamo J 2008 The SAS approach: combining qualitative and quantitative knowledge in environmental scenarios Environmental Futures—The Practice of Environmental Scenario Analysis vol 2, ed J Alcamo (Amsterdam: Elsevier) pp 123-50 Carlsen H 2009 Climate change and the construction of scenario sets that span the range of societal uncertainties Paper for International Studies Association Annual Convention 2009 (New York City, February) Jackson T 2009 Prosperity Without Growth: Economics for a Finite Planet (London: Earthscan) Kriegler E, O'Neill B C, Hallegatte S, Kram T, Lempert R J, Moss R H and Wilbanks T 2012 The need for and use of socio-economic scenarios for climate change analysis: a new approach based on shared socio-economic pathways Glob. Environ. Change 22 807-22 Nakicenovic N and Swart R (eds) 2000 Special Report on Emissions Scenarios (Cambridge: Cambridge University Press) Raskin P, Monks F, Ribeiro T, van Vuuren D and Zurek M 2005 Global scenarios in historical perspective Ecosystems and Human Well-Being: Scenarios: Findings of the Scenarios Working Group vol 2, ed S R Carpenter et al (Washington, DC: Island) pp 35-44 Schweizer V J and Kriegler E 2012 Improving environmental change research with systematic techniques for qualitative scenarios Environ. Res. Lett. 7 044011 Sunderlin W D 2003 Ideology, Social Theory, and the Environment (Lanham, MD: Rowman & Littlefield) van Vuuren D P et al 2012 A proposal for a new scenario framework to support research and assessment in different climate research communities Glob. Environ. Change 22 21-35 Victor P A 2008 Managing Without Growth: Slower by Design, Not Disaster (Advances in Ecological Economics Series) (Cheltenham: Edward Elgar) Weimer-Jehle W 2006 Cross-impact balances: a system—theoretical approach to cross-impact analysis Technol. Forecast. Social Change 73 334-61

Comparisons of Simulated Hydrodynamics and Water Quality for Projected Demands in 2046, Pueblo Reservoir, Southeastern Colorado

USGS Publications Warehouse

Ortiz, Roderick F.; Galloway, Joel M.; Miller, Lisa D.; Mau, David P.

2008-01-01

Pueblo Reservoir is one of southeastern Colorado's most valuable water resources. The reservoir provides irrigation, municipal, and industrial water to various entities throughout the region. The reservoir also provides flood control, recreational activities, sport fishing, and wildlife enhancement to the region. The Bureau of Reclamation is working to meet its goal to issue a Final Environmental Impact Statement (EIS) on the Southern Delivery System project (SDS). SDS is a regional water-delivery project that has been proposed to provide a safe, reliable, and sustainable water supply through the foreseeable future (2046) for Colorado Springs, Fountain, Security, and Pueblo West. Discussions with the Bureau of Reclamation and the U.S. Geological Survey led to a cooperative agreement to simulate the hydrodynamics and water quality of Pueblo Reservoir. This work has been completed and described in a previously published report, U.S. Geological Survey Scientific Investigations Report 2008-5056. Additionally, there was a need to make comparisons of simulated hydrodynamics and water quality for projected demands associated with the various EIS alternatives and plans by Pueblo West to discharge treated water into the reservoir. Plans by Pueblo West are fully independent of the SDS project. This report compares simulated hydrodynamics and water quality for projected demands in Pueblo Reservoir resulting from changes in inflow and water quality entering the reservoir, and from changes to withdrawals from the reservoir as projected for the year 2046. Four of the seven EIS alternatives were selected for scenario simulations. The four U.S. Geological Survey simulation scenarios were the No Action scenario (EIS Alternative 1), the Downstream Diversion scenario (EIS Alternative 2), the Upstream Return-Flow scenario (EIS Alternative 4), and the Upstream Diversion scenario (EIS Alternative 7). Additionally, the results of an Existing Conditions scenario (water years 2000 through 2002) were compared to the No Action scenario (projected demands in 2046) to assess changes in water quality over time. All scenario modeling used an external nutrient-decay model to simulate degradation and assimilation of nutrients along the riverine reach upstream from Pueblo Reservoir. Reservoir modeling was conducted using the U.S. Army Corps of Engineers CE-QUAL-W2 two-dimensional water-quality model. Lake hydrodynamics, water temperature, dissolved oxygen, dissolved solids, dissolved ammonia, dissolved nitrate, total phosphorus, algal biomass, and total iron were simulated. Two reservoir site locations were selected for comparison. Results of simulations at site 3B were characteristic of a riverine environment in the reservoir while results at site 7B (near the dam) were characteristic of the main body of the reservoir. Simulation results for the epilimnion and hypolimnion at these two sites also were evaluated and compared. The simulation results in the hypolimnion at site 7B were indicative of the water quality leaving the reservoir. Comparisons of the different scenario results were conducted to assess if substantial differences were observed between selected scenarios. Each of the scenarios was simulated for three contiguous years representing a wet, average, and dry annual hydrologic cycle (water years 2000 through 2002). Additionally, each selected simulation scenario was evaluated for differences in direct- and cumulative-effects on a particular scenario. Direct effects are intended to isolate the future effects of the scenarios. Cumulative effects are intended to evaluate the effects of the scenarios in conjunction with all reasonably foreseeable future activities in the study area. Comparisons between the direct- and cumulative-effects analyses indicated that there were not large differences in the results between most of the simulation scenarios and, as such, the focus of this report was on results for the direct-effects analysis. Addi

Revised Comparisons of Simulated Hydrodynamics and Water Quality for Projected Demands in 2046, Pueblo Reservoir, Southeastern Colorado

USGS Publications Warehouse

Ortiz, Roderick F.; Miller, Lisa D.

2009-01-01

Pueblo Reservoir is one of southeastern Colorado's most valuable water resources. The reservoir provides irrigation, municipal, and industrial water to various entities throughout the region. The reservoir also provides flood control, recreational activities, sport fishing, and wildlife enhancement to the region. The Southern Delivery System (SDS) project is a regional water-delivery project that has been proposed to provide a safe, reliable, and sustainable water supply through the foreseeable future (2046) for Colorado Springs, Fountain, Security, and Pueblo West. Discussions with the Bureau of Reclamation and the U.S. Geological Survey led to a cooperative agreement to simulate the hydrodynamics and water quality of Pueblo Reservoir. This work has been completed and described in a previously published report, U.S. Geological Survey Scientific Investigations Report 2008-5056. Additionally, there was a need to make comparisons of simulated hydrodynamics and water quality for projected demands associated with the various Environmental Impact Statements (EIS) alternatives and plans by Pueblo West to discharge treated wastewater into the reservoir. Wastewater plans by Pueblo West are fully independent of the SDS project. This report compares simulated hydrodynamics and water quality for projected demands in Pueblo Reservoir resulting from changes in inflow and water quality entering the reservoir, and from changes to withdrawals from the reservoir as projected for the year 2046. Four of the seven EIS alternatives were selected for scenario simulations. The four U.S. Geological Survey simulation scenarios were the No Action scenario (EIS Alternative 1), the Downstream Diversion scenario (EIS Alternative 2), the Upstream Return-Flow scenario (EIS Alternative 4), and the Upstream Diversion scenario (EIS Alternative 7). Additionally, the results of an Existing Conditions scenario (year 2006 demand conditions) were compared to the No Action scenario (projected demands in 2046) to assess changes in water quality over time. All scenario modeling used an external nutrient-decay model to simulate degradation and assimilation of nutrients along the riverine reach upstream from Pueblo Reservoir. Reservoir modeling was conducted using the U.S. Army Corps of Engineers CE-QUAL-W2 two-dimensional water-quality model. Lake hydrodynamics, water temperature, dissolved oxygen, dissolved solids, dissolved ammonia, dissolved nitrate, total phosphorus, algal biomass, and total iron were simulated. Two reservoir site locations were selected for comparison. Results of simulations at site 3B were characteristic of a riverine environment in the reservoir, whereas results at site 7B (near the dam) were characteristic of the main body of the reservoir. Simulation results for the epilimnion and hypolimnion at these two sites also were evaluated and compared. The simulation results in the hypolimnion at site 7B were indicative of the water quality leaving the reservoir. Comparisons of the different scenario results were conducted to assess if substantial differences were observed between selected scenarios. Each of the scenarios was simulated for three contiguous years representing a wet, average, and dry annual hydrologic cycle (water years 2000 through 2002). Additionally, each selected simulation scenario was evaluated for differences in direct and cumulative effects on a particular scenario. Direct effects are intended to isolate the future effects of the scenarios. Cumulative effects are intended to evaluate the effects of the scenarios in conjunction with all reasonably foreseeable future activities in the study area. Comparisons between the direct- and cumulative-effects analyses indicated that there were not large differences in the results between most of the simulation scenarios, and, as such, the focus of this report was on results for the direct-effects analysis. Additionally, the differences between simulation results generally were

Assessment of climate change impact on water diversion strategies of Melamchi Water Supply Project in Nepal

NASA Astrophysics Data System (ADS)

Shrestha, Sangam; Shrestha, Manish; Babel, Mukand S.

2017-04-01

This paper analyzes the climate change impact on water diversion plan of Melamchi Water Supply Project (MWSP) in Nepal. The MWSP is an interbasin water transfer project aimed at diverting water from the Melamchi River of the Indrawati River basin to Kathmandu Valley for drinking water purpose. Future temperature and precipitation of the basin were predicted using the outputs of two regional climate models (RCMs) and two general circulation models (GCMs) under two representative concentration pathway (RCP) scenarios which were then used as inputs to Soil and Water Assessment Tool (SWAT) to predict the water availability and evaluate the water diversion strategies in the future. The average temperature of the basin is projected to increase by 2.35 to 4.25 °C under RCP 4.5 and RCP 8.5, respectively, by 2085s. The average precipitation in the basin is projected to increase by 6-18 % in the future. The annual water availability is projected to increase in the future; however, the variability is observed in monthly water availability in the basin. The water supply and demand scenarios of Kathmandu Valley was also examined by considering the population increase, unaccounted for water and water diversion from MWSP in the future. It is observed that even with the additional supply of water from MWSP and reduction of unaccounted for water, the Kathmandu Valley will be still under water scarcity in the future. The findings of this study can be helpful to formulate water supply and demand management strategies in Kathmandu Valley in the context of climate change in the future.

Drastic changes in aquatic bacterial populations from the Cuatro Cienegas Basin (Mexico) in response to long-term environmental stress.

PubMed

Pajares, Silvia; Eguiarte, Luis E; Bonilla-Rosso, German; Souza, Valeria

2013-12-01

Understanding the changes of aquatic microbial community composition in response to changes in temperature and ultraviolet irradiation is relevant for predicting biogeochemical modifications in the functioning of natural microbial communities under global climate change scenarios. Herein we investigate shifts in the bacterioplankton composition in response to long-term changes in temperature and UV radiation. For this purpose, 15 mesocosms were seeded with composite aquatic microbial communities from natural pools within the Cuatro Cienegas Basin (Mexican Chihuahuan desert) and were subject to different temperatures and UV conditions. 16S rRNA gene clone libraries were obtained from water samples at the mid-point (4 months) and the end of the experiment (8 months). An increase in bacterial diversity over time was found in the treatment of constant temperature and UV protection, which suggests that stable environments promote the establishment of complex and diverse bacterial community. Drastic changes in the phylogenetic bacterioplankton composition and structure were observed in response to fluctuating temperature and increasing UV radiation and temperature. Fluctuating temperature induced the largest decrease of bacterial richness during the experiment, indicating that frequent temperature changes drive the reduction in abundance of several species, most notably autotrophs. The long-term impact of these environmental stresses reduced diversity and selected for generalist aquatic bacterial populations, such as Porphyrobacter. These changes at the community level occur at an ecological time scale, suggesting that under global warming scenarios cascade effects on the food web are possible if the microbial diversity is modified.

Genetic structure along an altitudinal gradient in Lippia origanoides, a promising aromatic plant species restricted to semiarid areas in northern South America

PubMed Central

Vega-Vela, Nelson Enrique; Sánchez, María Isabel Chacón

2012-01-01

The genetic diversity and population structure of Lippia origanoides, a species of the Verbenaceae family that shows promise as a crop plant, was investigated along an altitudinal gradient in the basin of the Chicamocha River in northeastern Colombia. The economic importance of the species, quality of its essential oils, and the fact that it is restricted to some few semiarid areas in northern South America may put the species at risk in a scenario of uncontrolled harvest of natural populations. Lippia origanoides was sampled along an altitudinal gradient from 365 to 2595 m.a.s.l. throughout Chicamocha River Canyon, a semiarid area in northeastern Colombia. Genetic diversity was assessed by means of AFLP markers. The number of AFLP loci (355) and the number of individuals sampled (173) were sufficient to reliably identify four populations at contrasting altitudes (FST = 0.18, P-value < 0.0000), two populations in the lower basin, one population in the medium basin, and one population in the upper basin, with a low level of admixture between them. In average, genetic diversity within populations was relatively high (Ht = 0.32; I = 0.48); nevertheless, diversity was significantly reduced at higher altitude, a pattern that may be consistent with a scenario of range expansion toward higher elevations in an environment with more extreme conditions. The differences in altitude among the basins in the Chicamocha River seem to be relevant in determining the genetic structure of this species. PMID:23170204

Change of niche in guanaco (Lama guanicoe): the effects of climate change on habitat suitability and lineage conservatism in Chile.

PubMed

Castillo, Andrea G; Alò, Dominique; González, Benito A; Samaniego, Horacio

2018-01-01

The main goal of this contribution was to define the ecological niche of the guanaco ( Lama guanicoe ), to describe potential distributional changes, and to assess the relative importance of niche conservatism and divergence processes between the two lineages described for the species ( L.g. cacsilensis and L.g. guanicoe ). We used maximum entropy to model lineage's climate niche from 3,321 locations throughout continental Chile, and developed future niche models under climate change for two extreme greenhouse gas emission scenarios (RCP2.6 and RCP8.5). We evaluated changes of the environmental niche and future distribution of the largest mammal in the Southern Cone of South America. Evaluation of niche conservatism and divergence were based on identity and background similarity tests. We show that: (a) the current geographic distribution of lineages is associated with different climatic requirements that are related to the geographic areas where these lineages are located; (b) future distribution models predict a decrease in the distribution surface under both scenarios; (c) a 3% decrease of areal protection is expected if the current distribution of protected areas is maintained, and this is expected to occur at the expense of a large reduction of high quality habitats under the best scenario; (d) current and future distribution ranges of guanaco mostly adhere to phylogenetic niche divergence hypotheses between lineages. Associating environmental variables with species ecological niche seems to be an important aspect of unveiling the particularities of, both evolutionary patterns and ecological features that species face in a changing environment. We report specific descriptions of how these patterns may play out under the most extreme climate change predictions and provide a grim outlook of the future potential distribution of guanaco in Chile. From an ecological perspective, while a slightly smaller distribution area is expected, this may come with an important reduction of available quality habitats. From the evolutionary perspective, we describe the limitations of this taxon as it experiences forces imposed by climate change dynamics.

Change of niche in guanaco (Lama guanicoe): the effects of climate change on habitat suitability and lineage conservatism in Chile

PubMed Central

Castillo, Andrea G.; González, Benito A.

2018-01-01

Background The main goal of this contribution was to define the ecological niche of the guanaco (Lama guanicoe), to describe potential distributional changes, and to assess the relative importance of niche conservatism and divergence processes between the two lineages described for the species (L.g. cacsilensis and L.g. guanicoe). Methods We used maximum entropy to model lineage’s climate niche from 3,321 locations throughout continental Chile, and developed future niche models under climate change for two extreme greenhouse gas emission scenarios (RCP2.6 and RCP8.5). We evaluated changes of the environmental niche and future distribution of the largest mammal in the Southern Cone of South America. Evaluation of niche conservatism and divergence were based on identity and background similarity tests. Results We show that: (a) the current geographic distribution of lineages is associated with different climatic requirements that are related to the geographic areas where these lineages are located; (b) future distribution models predict a decrease in the distribution surface under both scenarios; (c) a 3% decrease of areal protection is expected if the current distribution of protected areas is maintained, and this is expected to occur at the expense of a large reduction of high quality habitats under the best scenario; (d) current and future distribution ranges of guanaco mostly adhere to phylogenetic niche divergence hypotheses between lineages. Discussion Associating environmental variables with species ecological niche seems to be an important aspect of unveiling the particularities of, both evolutionary patterns and ecological features that species face in a changing environment. We report specific descriptions of how these patterns may play out under the most extreme climate change predictions and provide a grim outlook of the future potential distribution of guanaco in Chile. From an ecological perspective, while a slightly smaller distribution area is expected, this may come with an important reduction of available quality habitats. From the evolutionary perspective, we describe the limitations of this taxon as it experiences forces imposed by climate change dynamics. PMID:29868293

Targeting climate diversity in conservation planning to build resilience to climate change

USGS Publications Warehouse

Heller, Nicole E.; Kreitler, Jason R.; Ackerly, David; Weiss, Stuart; Recinos, Amanda; Branciforte, Ryan; Flint, Lorraine E.; Flint, Alan L.; Micheli, Elisabeth

2015-01-01

Climate change is raising challenging concerns for systematic conservation planning. Are methods based on the current spatial patterns of biodiversity effective given long-term climate change? Some conservation scientists argue that planning should focus on protecting the abiotic diversity in the landscape, which drives patterns of biological diversity, rather than focusing on the distribution of focal species, which shift in response to climate change. Climate is one important abiotic driver of biodiversity patterns, as different climates host different biological communities and genetic pools. We propose conservation networks that capture the full range of climatic diversity in a region will improve the resilience of biotic communities to climate change compared to networks that do not. In this study we used historical and future hydro-climate projections from the high resolution Basin Characterization Model to explore the utility of directly targeting climatic diversity in planning. Using the spatial planning tool, Marxan, we designed conservation networks to capture the diversity of climate types, at the regional and sub-regional scale, and compared them to networks we designed to capture the diversity of vegetation types. By focusing on the Conservation Lands Network (CLN) of the San Francisco Bay Area as a real-world case study, we compared the potential resilience of networks by examining two factors: the range of climate space captured, and climatic stability to 18 future climates, reflecting different emission scenarios and global climate models. We found that the climate-based network planned at the sub-regional scale captured a greater range of climate space and showed higher climatic stability than the vegetation and regional based-networks. At the same time, differences among network scenarios are small relative to the variance in climate stability across global climate models. Across different projected futures, topographically heterogeneous areas consistently show greater climate stability than homogenous areas. The analysis suggests that utilizing high-resolution climate and hydrological data in conservation planning improves the likely resilience of biodiversity to climate change. We used these analyses to suggest new conservation priorities for the San Francisco Bay Area.

On the performance of energy detection-based CR with SC diversity over IG channel

NASA Astrophysics Data System (ADS)

Verma, Pappu Kumar; Soni, Sanjay Kumar; Jain, Priyanka

2017-12-01

Cognitive radio (CR) is a viable 5G technology to address the scarcity of the spectrum. Energy detection-based sensing is known to be the simplest method as far as hardware complexity is concerned. In this paper, the performance of spectrum sensing-based energy detection technique in CR networks over inverse Gaussian channel for selection combining diversity technique is analysed. More specifically, accurate analytical expressions for the average detection probability under different detection scenarios such as single channel (no diversity) and with diversity reception are derived and evaluated. Further, the detection threshold parameter is optimised by minimising the probability of error over several diversity branches. The results clearly show the significant improvement in the probability of detection when optimised threshold parameter is applied. The impact of shadowing parameters on the performance of energy detector is studied in terms of complimentary receiver operating characteristic curve. To verify the correctness of our analysis, the derived analytical expressions are corroborated via exact result and Monte Carlo simulations.

An interactive ontology-driven information system for simulating background radiation and generating scenarios for testing special nuclear materials detection algorithms

DOE PAGES

Sorokine, Alexandre; Schlicher, Bob G.; Ward, Richard C.; ...

2015-05-22

This paper describes an original approach to generating scenarios for the purpose of testing the algorithms used to detect special nuclear materials (SNM) that incorporates the use of ontologies. Separating the signal of SNM from the background requires sophisticated algorithms. To assist in developing such algorithms, there is a need for scenarios that capture a very wide range of variables affecting the detection process, depending on the type of detector being used. To provide such a cpability, we developed an ontology-driven information system (ODIS) for generating scenarios that can be used in creating scenarios for testing of algorithms for SNMmore » detection. The ontology-driven scenario generator (ODSG) is an ODIS based on information supplied by subject matter experts and other documentation. The details of the creation of the ontology, the development of the ontology-driven information system, and the design of the web user interface (UI) are presented along with specific examples of scenarios generated using the ODSG. We demonstrate that the paradigm behind the ODSG is capable of addressing the problem of semantic complexity at both the user and developer levels. Compared to traditional approaches, an ODIS provides benefits such as faithful representation of the users' domain conceptualization, simplified management of very large and semantically diverse datasets, and the ability to handle frequent changes to the application and the UI. Furthermore, the approach makes possible the generation of a much larger number of specific scenarios based on limited user-supplied information« less

Objective comparison of particle tracking methods.

PubMed

Chenouard, Nicolas; Smal, Ihor; de Chaumont, Fabrice; Maška, Martin; Sbalzarini, Ivo F; Gong, Yuanhao; Cardinale, Janick; Carthel, Craig; Coraluppi, Stefano; Winter, Mark; Cohen, Andrew R; Godinez, William J; Rohr, Karl; Kalaidzidis, Yannis; Liang, Liang; Duncan, James; Shen, Hongying; Xu, Yingke; Magnusson, Klas E G; Jaldén, Joakim; Blau, Helen M; Paul-Gilloteaux, Perrine; Roudot, Philippe; Kervrann, Charles; Waharte, François; Tinevez, Jean-Yves; Shorte, Spencer L; Willemse, Joost; Celler, Katherine; van Wezel, Gilles P; Dan, Han-Wei; Tsai, Yuh-Show; Ortiz de Solórzano, Carlos; Olivo-Marin, Jean-Christophe; Meijering, Erik

2014-03-01

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Because manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized an open competition in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to notable practical conclusions for users and developers.

Non-duplicate polarization-diversity 8 × 8 Si-wire PILOSS switch integrated with polarization splitter-rotators.

PubMed

Tanizawa, Ken; Suzuki, Keijiro; Ikeda, Kazuhiro; Namiki, Shu; Kawashima, Hitoshi

2017-05-15

We demonstrate a fully integrated polarization-diversity 8 × 8 thermo-optic Si-wire switch that uses only a single path-independent insertion loss (PILOSS) switch matrix. All input/output ports of the PILOSS switch matrix are uniquely assigned for polarization diversity without switch duplication. To integrate polarization splitter-rotators on a chip, we propose a compact path-length-equalized polarization-diversity switch configuration. Polarization-dependent loss (PDL) and differential group delay (DGD) are minimized. The 8 × 8 switch is fabricated by the CMOS-compatible fabrication process on 300-mm diameter wafer and additional etching of upper cladding after dicing. The chip size is 7 × 10.5 mm 2 . A PDL of 2 dB and a DGD of 1.5 ps are achieved. The crosstalk in the worst-case scenario is -20 dB in the full C-band.

Targeting Critical Thinking Skills in a First-Year Undergraduate Research Course †

PubMed Central

Carson, Susan

2015-01-01

TH!NK is a new initiative at NC State University focused on enhancing students’ higher-order cognitive skills. As part of this initiative, I explicitly emphasized critical and creative thinking in an existing bacteriophage discovery first-year research course. In addition to the typical activities associated with undergraduate research such as review of primary literature and writing research papers, another strategy employed to enhance students’ critical thinking skills was the use of discipline-specific, real-world scenarios. This paper outlines a general “formula” for writing scenarios, as well as several specific scenarios created for the described course. I also present how embedding aspects of the scenarios in reviews of the primary literature enriched the activity. I assessed student gains in critical thinking skills using a pre-/posttest model of the Critical Thinking Assessment Test (CAT), developed by Tennessee Technological University. I observed a positive gain trend in most of the individual skills assessed in the CAT, with a statistically significant large effect on critical thinking skills overall in students in the test group. I also show that a higher level of critical thinking skills was demonstrated in research papers written by students who participated in the scenarios compared with similar students who did not participate in the scenario activities. The scenario strategy described here can be modified for use in biology and other STEM disciplines, as well as in diverse disciplines in the social sciences and humanities. PMID:26753022

Targeting Critical Thinking Skills in a First-Year Undergraduate Research Course.

PubMed

Carson, Susan

2015-12-01

TH!NK is a new initiative at NC State University focused on enhancing students' higher-order cognitive skills. As part of this initiative, I explicitly emphasized critical and creative thinking in an existing bacteriophage discovery first-year research course. In addition to the typical activities associated with undergraduate research such as review of primary literature and writing research papers, another strategy employed to enhance students' critical thinking skills was the use of discipline-specific, real-world scenarios. This paper outlines a general "formula" for writing scenarios, as well as several specific scenarios created for the described course. I also present how embedding aspects of the scenarios in reviews of the primary literature enriched the activity. I assessed student gains in critical thinking skills using a pre-/posttest model of the Critical Thinking Assessment Test (CAT), developed by Tennessee Technological University. I observed a positive gain trend in most of the individual skills assessed in the CAT, with a statistically significant large effect on critical thinking skills overall in students in the test group. I also show that a higher level of critical thinking skills was demonstrated in research papers written by students who participated in the scenarios compared with similar students who did not participate in the scenario activities. The scenario strategy described here can be modified for use in biology and other STEM disciplines, as well as in diverse disciplines in the social sciences and humanities.

Contextual diversity facilitates learning new words in the classroom.

PubMed

Rosa, Eva; Tapia, José Luis; Perea, Manuel

2017-01-01

In the field of word recognition and reading, it is commonly assumed that frequently repeated words create more accessible memory traces than infrequently repeated words, thus capturing the word-frequency effect. Nevertheless, recent research has shown that a seemingly related factor, contextual diversity (defined as the number of different contexts [e.g., films] in which a word appears), is a better predictor than word-frequency in word recognition and sentence reading experiments. Recent research has shown that contextual diversity plays an important role when learning new words in a laboratory setting with adult readers. In the current experiment, we directly manipulated contextual diversity in a very ecological scenario: at school, when Grade 3 children were learning words in the classroom. The new words appeared in different contexts/topics (high-contextual diversity) or only in one of them (low-contextual diversity). Results showed that words encountered in different contexts were learned and remembered more effectively than those presented in redundant contexts. We discuss the practical (educational [e.g., curriculum design]) and theoretical (models of word recognition) implications of these findings.

Contextual diversity facilitates learning new words in the classroom

PubMed Central

Tapia, José Luis; Perea, Manuel

2017-01-01

In the field of word recognition and reading, it is commonly assumed that frequently repeated words create more accessible memory traces than infrequently repeated words, thus capturing the word-frequency effect. Nevertheless, recent research has shown that a seemingly related factor, contextual diversity (defined as the number of different contexts [e.g., films] in which a word appears), is a better predictor than word-frequency in word recognition and sentence reading experiments. Recent research has shown that contextual diversity plays an important role when learning new words in a laboratory setting with adult readers. In the current experiment, we directly manipulated contextual diversity in a very ecological scenario: at school, when Grade 3 children were learning words in the classroom. The new words appeared in different contexts/topics (high-contextual diversity) or only in one of them (low-contextual diversity). Results showed that words encountered in different contexts were learned and remembered more effectively than those presented in redundant contexts. We discuss the practical (educational [e.g., curriculum design]) and theoretical (models of word recognition) implications of these findings. PMID:28586354

The impact of using old germplasm on genetic merit and diversity-A cattle breed case study.

PubMed

Eynard, Sonia E; Windig, Jack J; Hulsegge, Ina; Hiemstra, Sipke-Joost; Calus, Mario P L

2018-05-29

Artificial selection and high genetic gains in livestock breeds led to a loss of genetic diversity. Current genetic diversity conservation actions focus on long-term maintenance of breeds under selection. Gene banks play a role in such actions by storing genetic materials for future use and the recent development of genomic information is facilitating characterization of gene bank material for better use. Using the Meuse-Rhine-Issel Dutch cattle breed as a case study, we inferred the potential role of germplasm of old individuals for genetic diversity conservation of the current population. First, we described the evolution of genetic merit and diversity over time and then we applied the optimal contribution (OC) strategy to select individuals for maximizing genetic diversity, or maximizing genetic merit while constraining loss of genetic diversity. In the past decades, genetic merit increased while genetic diversity decreased. Genetic merit and diversity were both higher in an OC scenario restricting the rate of inbreeding when old individuals were considered for selection, compared to considering only animals from the current population. Thus, our study shows that gene bank material, in the form of old individuals, has the potential to support long-term maintenance and selection of breeds. © 2018 The Authors. Journal of Animal Breeding and Genetics Published by Blackwell Verlag GmbH.

How much can we save? Impact of different emission scenarios on future snow cover in the Alps

NASA Astrophysics Data System (ADS)

Marty, Christoph; Schlögl, Sebastian; Bavay, Mathias; Lehning, Michael

2017-02-01

This study focuses on an assessment of the future snow depth for two larger Alpine catchments. Automatic weather station data from two diverse regions in the Swiss Alps have been used as input for the Alpine3D surface process model to compute the snow cover at a 200 m horizontal resolution for the reference period (1999-2012). Future temperature and precipitation changes have been computed from 20 downscaled GCM-RCM chains for three different emission scenarios, including one intervention scenario (2 °C target) and for three future time periods (2020-2049, 2045-2074, 2070-2099). By applying simple daily change values to measured time series of temperature and precipitation, small-scale climate scenarios have been calculated for the median estimate and extreme changes. The projections reveal a decrease in snow depth for all elevations, time periods and emission scenarios. The non-intervention scenarios demonstrate a decrease of about 50 % even for elevations above 3000 m. The most affected elevation zone for climate change is located below 1200 m, where the simulations show almost no snow towards the end of the century. Depending on the emission scenario and elevation zone the winter season starts half a month to 1 month later and ends 1 to 3 months earlier in this last scenario period. The resulting snow cover changes may be roughly equivalent to an elevation shift of 500-800 or 700-1000 m for the two non-intervention emission scenarios. At the end of the century the number of snow days may be more than halved at an elevation of around 1500 m and only 0-2 snow days are predicted in the lowlands. The results for the intervention scenario reveal no differences for the first scenario period but clearly demonstrate a stabilization thereafter, comprising much lower snow cover reductions towards the end of the century (ca. 30 % instead of 70 %).

Patterns of Nucleotide Diversity at Photoperiod Related Genes in Norway Spruce [Picea abies (L.) Karst.

PubMed Central

Källman, Thomas; De Mita, Stéphane; Larsson, Hanna; Gyllenstrand, Niclas; Heuertz, Myriam; Parducci, Laura; Suyama, Yoshihisa; Lagercrantz, Ulf; Lascoux, Martin

2014-01-01

The ability of plants to track seasonal changes is largely dependent on genes assigned to the photoperiod pathway, and variation in those genes is thereby important for adaptation to local day length conditions. Extensive physiological data in several temperate conifer species suggest that populations are adapted to local light conditions, but data on the genes underlying this adaptation are more limited. Here we present nucleotide diversity data from 19 genes putatively involved in photoperiodic response in Norway spruce (Picea abies). Based on similarity to model plants the genes were grouped into three categories according to their presumed position in the photoperiod pathway: photoreceptors, circadian clock genes, and downstream targets. An HKA (Hudson, Kreitman and Aquade) test showed a significant excess of diversity at photoreceptor genes, but no departure from neutrality at circadian genes and downstream targets. Departures from neutrality were also tested with Tajima's D and Fay and Wu's H statistics under three demographic scenarios: the standard neutral model, a population expansion model, and a more complex population split model. Only one gene, the circadian clock gene PaPRR3 with a highly positive Tajima's D value, deviates significantly from all tested demographic scenarios. As the PaPRR3 gene harbours multiple non-synonymous variants it appears as an excellent candidate gene for control of photoperiod response in Norway spruce. PMID:24810273

Patterns of nucleotide diversity at photoperiod related genes in Norway spruce [Picea abies (L.) Karst].

PubMed

Källman, Thomas; De Mita, Stéphane; Larsson, Hanna; Gyllenstrand, Niclas; Heuertz, Myriam; Parducci, Laura; Suyama, Yoshihisa; Lagercrantz, Ulf; Lascoux, Martin

2014-01-01

The ability of plants to track seasonal changes is largely dependent on genes assigned to the photoperiod pathway, and variation in those genes is thereby important for adaptation to local day length conditions. Extensive physiological data in several temperate conifer species suggest that populations are adapted to local light conditions, but data on the genes underlying this adaptation are more limited. Here we present nucleotide diversity data from 19 genes putatively involved in photoperiodic response in Norway spruce (Picea abies). Based on similarity to model plants the genes were grouped into three categories according to their presumed position in the photoperiod pathway: photoreceptors, circadian clock genes, and downstream targets. An HKA (Hudson, Kreitman and Aquade) test showed a significant excess of diversity at photoreceptor genes, but no departure from neutrality at circadian genes and downstream targets. Departures from neutrality were also tested with Tajima's D and Fay and Wu's H statistics under three demographic scenarios: the standard neutral model, a population expansion model, and a more complex population split model. Only one gene, the circadian clock gene PaPRR3 with a highly positive Tajima's D value, deviates significantly from all tested demographic scenarios. As the PaPRR3 gene harbours multiple non-synonymous variants it appears as an excellent candidate gene for control of photoperiod response in Norway spruce.

Modeling urban storm rainfall runoff from diverse underlying surfaces and application for control design in Beijing.

PubMed

Ouyang, Wei; Guo, Bobo; Hao, Fanghua; Huang, Haobo; Li, Junqi; Gong, Yongwei

2012-12-30

Managing storm rainfall runoff is paramount in semi-arid regions with urban development. In Beijing, pollution prevention in urban storm runoff and storm water utilization has been identified as the primary strategy for urban water management. In this paper, we sampled runoff during storm rainfall events and analyzed the concentration of chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus (TP) in the runoff. Furthermore, the first flush effect of storm rainfall from diverse underlying surfaces was also analyzed. With the Storm Water Management Model (SWMM), the different impervious rates of underlying surfaces during the storm runoff process were expressed. The removal rates of three typical pollutants and their interactions with precipitation and underlying surfaces were identified. From these rates, the scenarios regarding the urban storm runoff pollution loading from different designs of underlying previous rates were assessed with the SWMM. First flush effect analysis showed that the first 20% of the storm runoff should be discarded, which can help in utilizing the storm water resource. The results of this study suggest that the SWMM can express in detail the storm water pollution patterns from diverse underlying surfaces in Beijing, which significantly affected water quality. The scenario analysis demonstrated that impervious rate adjustment has the potential to reduce runoff peak and decrease pollution loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Research on soil bacteria under the impact of sealed CO2 leakage by high-throughput sequencing technology].

PubMed

Tian, Di; Ma, Xin; Li, Yu-E; Zha, Liang-Song; Wu, Yang; Zou, Xiao-Xia; Liu, Shuang

2013-10-01

Carbon dioxide Capture and Storage has provided a new option for mitigating global anthropogenic CO2 emission with its unique advantages. However, there is a risk of the sealed CO2 leakage, bringing a serious threat to the ecology system. It is widely known that soil microorganisms are closely related to soil health, while the study on the impact of sequestered CO2 leakage on soil microorganisms is quite deficient. In this study, the leakage scenarios of sealed CO2 were constructed and the 16S rRNA genes of soil bacteria were sequenced by Illumina high-throughput sequencing technology on Miseq platform, and related biological analysis was conducted to explore the changes of soil bacterial abundance, diversity and structure. There were 486,645 reads for 43,017 OTUs of 15 soil samples and the results of biological analysis showed that there were differences in the abundance, diversity and community structure of soil bacterial community under different CO, leakage scenarios while the abundance and diversity of the bacterial community declined with the amplification of CO2 leakage quantity and leakage time, and some bacteria species became the dominant bacteria species in the bacteria community, therefore the increase of Acidobacteria species would be a biological indicator for the impact of sealed CO2 leakage on soil ecology system.

Learning to deal with crisis in the home: Part 2 - preparing preregistration students.

PubMed

Gibson, Caroline E; Dickson, Caroline; Lawson, Bill; McMillan, Ailsa; Kelly, Helena

2015-12-01

The global shift of health care is from acute services to community and primary care. Therefore, registrants must be prepared to work effectively within diverse settings. This article is the second in a series discussing the preparation of nurses for contemporary health-care challenges in the community. In it, we outline the design, implementation, and evaluation of simulated emergency scenarios within an honours degree-level, pre-registration nursing curriculum in Scotland. Over 3 years, 99 final-year students participated in interactive sessions focusing on recognition and management of the deteriorating patient and emergency care. Clinical scenarios were designed and delivered collaboratively with community practitioners. Debriefing challenged the students to reflect on learning and transferability of skills of clinical reasoning and care management to the community context. Students considered the scenarios to be realistic and perceived that their confidence had increased. Development of such simulation exercises is worthy of further debate in education and practice.

In the slammer: the myth of the prison in American gay pornographic video.

PubMed

Mercer, John

2004-01-01

The purpose of this paper is to discuss the significance of the prison scenario and its various permutations in the texts of American commercial pornographic video. The paper will identify the prison as a highly eroticised all male environment, an arena where the active/passive dichotomy of gay pornography is staged and re-staged. The significances of the prison are multiple. The prison draws on a gay mythology of homosexual desire that has its origins in sources as diverse as the literature of the Marquis de Sade and Jean Genet and the erotic illustrations of Tom of Finland and Etienne. Prison scenarios take many shapes in gay pornography such as the American penitentiary, the military brig, and the fantasised dungeon of the leatherman. I see these scenarios as performing an important function within gay porn by offering idealised spaces for the acts of pornography: voyeurism, narcissistic display and active/ passive role-play.

Assessment of national biomass in complex forests and technical capacity scenarios

Treesearch

Matieu Henry; Javier G. P. Gamarra; Gael Sola; Luca Birigazzi; Emily Donegan; Julian Murillo; Tommaso Chiti; Nicolas Picard; Miguel Cifuentes-Jara; S Sandeep; Laurent Saint-André

2015-01-01

Understanding forest ecosystems is paramount for their sustainable management and for the livelihoods and ecosystem services which depend on them. However, the complexity and diversity of these systems poses a challenge to interpreting data patterns. The availability and accessibility of data and tools often determine the method selected for forest assessment. Capacity...

Adaptive Multimedia Content Delivery for Context-Aware U-Learning

ERIC Educational Resources Information Center

Zhao, Xinyou; Okamoto, Toshio

2011-01-01

Empowered by mobile computing, teachers and students can benefit from computing in more scenarios beyond the traditional computer classroom. But because of the much diversity of device specification, learning contents and mobile context existing today, the learners get a bad learning experience (e.g. rich contents cannot be displayed correctly)…

Gamification: A Systematic Review of Design Frameworks

ERIC Educational Resources Information Center

Mora, Alberto; Riera, Daniel; González, Carina; Arnedo-Moreno, Joan

2017-01-01

Learner's motivation difficulties are recognized as a problem in diverse educational scenarios, reaching up to university degrees. Among other techniques that are often applied by instructors to counteract this issue, those related to the use of gaming elements seem to very promising. In this context, considering the use of game-like properties in…

78 FR 26807 - Vista Grande Drainage Basin Improvement Project, Fort Funston, Golden Gate National Recreation...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

... Village, in northwestern San Mateo County. This watershed is approximately 2.5 square miles in area and is... diversion and discharge structures to route some stormwater (and authorized non-storm water) flows from the... water detention structures, lake level scenarios, and groundwater recharge facilities. The Project would...

Translation and Its Discontents: Key Concepts in English and German History Education

ERIC Educational Resources Information Center

Seixas, Peter

2016-01-01

Key terms and concepts are crucial tools in teaching and learning in the disciplines. Different linguistic traditions approach such tools in diverse ways. This paper offers an initial contribution by a monolingual Anglophone history educator in dialogue with German history educators. It presents three different scenarios for the potential of…

Content and Language Integrated Learning by Interaction. Fremdsprachendidaktik inhalts-und lernerorientiert. Volume 26

ERIC Educational Resources Information Center

Kupetz, Rita, Ed.; Becker, Carmen, Ed.

2014-01-01

Content and Language Integrated Learning (CLIL) is an established approach to support multilingualism in Europe by teaching various school subjects in an additional language. The practices used, however, vary considerably. Our book considers this diversity by looking at CLIL scenarios, defined as learning environments supporting content learning,…

Exploring the Perceived Effectiveness of the School Administration: Studying the Enhancement of Organizational Practices

ERIC Educational Resources Information Center

Urrutia-Campos, Carlos Lenin

2016-01-01

Principals are facing complex educational scenarios such as an increasing diversity of minority groups in schools, adjustments in regulations, and higher academic standards that press school leaders to update or obtain professional skills. Administrators should be aware that current professional skills may not be sufficient to comply with new…

Lifelines: An Ethnographic Study of an IEP Student

ERIC Educational Resources Information Center

Bro, Elsa C.

2004-01-01

River guides and teachers share important characteristics, like having a rescue plan or a teaching plan for every imaginable scenario. A raft guide describes her modified teaching plan that will help the students with diverse learning needs and also describes the similarities between a teacher and a raft guide as she studies a high school…

The effects of built environment attributes on physical activity-related health and health care costs outcomes in Australia.

PubMed

Zapata-Diomedi, Belen; Herrera, Ana Maria Mantilla; Veerman, J Lennert

2016-11-01

Attributes of the built environment can positively influence physical activity of urban populations, which results in health and economic benefits. In this study, we derived scenarios from the literature for the association built environment-physical activity and used a mathematical model to translate improvements in physical activity to health-adjusted life years and health care costs. We modelled 28 scenarios representing a diverse range of built environment attributes including density, diversity of land use, availability of destinations, distance to transit, design and neighbourhood walkability. Our results indicated potential health gains in 24 of the 28 modelled built environment attributes. Health care cost savings due to prevented physical activity-related diseases ranged between A$1300 to A$105,355 per 100,000 adults per year. On the other hand, additional health care costs of prolonged life years attributable to improvements in physical activity were nearly 50% higher than the estimated health care costs savings. Our results give an indication of the potential health benefits of investing in physical activity-friendly built environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Unveiling the signals from extremely noisy microseismic data for high-resolution hydraulic fracturing monitoring.

PubMed

Huang, Weilin; Wang, Runqiu; Li, Huijian; Chen, Yangkang

2017-09-20

Microseismic method is an essential technique for monitoring the dynamic status of hydraulic fracturing during the development of unconventional reservoirs. However, one of the challenges in microseismic monitoring is that those seismic signals generated from micro seismicity have extremely low amplitude. We develop a methodology to unveil the signals that are smeared in the strong ambient noise and thus facilitate a more accurate arrival-time picking that will ultimately improve the localization accuracy. In the proposed technique, we decompose the recorded data into several morphological multi-scale components. In order to unveil weak signal, we propose an orthogonalization operator which acts as a time-varying weighting in the morphological reconstruction. The orthogonalization operator is obtained using an inversion process. This orthogonalized morphological reconstruction can be interpreted as a projection of the higher-dimensional vector. We first test the proposed technique using a synthetic dataset. Then the proposed technique is applied to a field dataset recorded in a project in China, in which the signals induced from hydraulic fracturing are recorded by twelve three-component (3-C) geophones in a monitoring well. The result demonstrates that the orthogonalized morphological reconstruction can make the extremely weak microseismic signals detectable.

Hotspots of uncertainty in land-use and land-cover change projections: A global-scale model comparison

DOE PAGES

Prestele, Reinhard; Alexander, Peter; Rounsevell, Mark D. A.; ...

2016-05-02

Model-based global projections of future land use and land cover (LULC) change are frequently used in environmental assessments to study the impact of LULC change on environmental services and to provide decision support for policy. These projections are characterized by a high uncertainty in terms of quantity and allocation of projected changes, which can severely impact the results of environmental assessments. In this study, we identify hotspots of uncertainty, based on 43 simulations from 11 global-scale LULC change models representing a wide range of assumptions of future biophysical and socio-economic conditions. We attribute components of uncertainty to input data, modelmore » structure, scenario storyline and a residual term, based on a regression analysis and analysis of variance. From this diverse set of models and scenarios we find that the uncertainty varies, depending on the region and the LULC type under consideration. Hotspots of uncertainty appear mainly at the edges of globally important biomes (e.g. boreal and tropical forests). Our results indicate that an important source of uncertainty in forest and pasture areas originates from different input data applied in the models. Cropland, in contrast, is more consistent among the starting conditions, while variation in the projections gradually increases over time due to diverse scenario assumptions and different modeling approaches. Comparisons at the grid cell level indicate that disagreement is mainly related to LULC type definitions and the individual model allocation schemes. We conclude that improving the quality and consistency of observational data utilized in the modeling process as well as improving the allocation mechanisms of LULC change models remain important challenges. Furthermore, current LULC representation in environmental assessments might miss the uncertainty arising from the diversity of LULC change modeling approaches and many studies ignore the uncertainty in LULC projections in assessments of LULC change impacts on climate, water resources or biodiversity.« less

Simulation of streamflow temperatures in the Yakima River basin, Washington, April-October 1981

USGS Publications Warehouse

Vaccaro, J.J.

1986-01-01

The effects of storage, diversion, return flow, and meteorological variables on water temperature in the Yakima River, in Washington State, were simulated, and the changes in water temperature that could be expected under four alternative-management scenarios were examined for improvement in anadromous fish environment. A streamflow routing model and Lagrangian streamflow temperature model were used to simulate water discharge and temperature in the river. The estimated model errors were 12% for daily discharge and 1.7 C for daily temperature. Sensitivity analysis of the simulation of water temperatures showed that the effect of reservoir outflow temperatures diminishes in a downstream direction. A 4 C increase in outflow temperatures results in a 1.0 C increase in mean irrigation season water temperature at Umtanum in the upper Yakima River basin, but only a 0.01C increase at Prosser in the lower basin. The influence of air temperature on water temperature increases in a downstream direction and is the dominant influence in the lower basin. A 4 C increase in air temperature over the entire basin resulted in a 2.34 C increase in river temperatures at Prosser in the lower basin and 1.46 C at Umtanum in the upper basin. Changes in wind speed and model wind-function parameters had little effect on the model predicted water temperature. Of four alternative management scenarios suggested by the U.S. Bureau of Indian Affairs and the Yakima Indian Nation, the 1981 reservoir releases maintained without diversions or return flow in the river basin produced water temperatures nearest those considered as preferable for salmon and steelhead trout habitat. The alternative management scenario for no reservoir storage and no diversions or return flows in the river basin (estimate of natural conditions) produced conditions that were the least like those considered as preferable for salmon and steelhead trout habitat. (Author 's abstract)

Hotspots of uncertainty in land-use and land-cover change projections: a global-scale model comparison.

PubMed

Prestele, Reinhard; Alexander, Peter; Rounsevell, Mark D A; Arneth, Almut; Calvin, Katherine; Doelman, Jonathan; Eitelberg, David A; Engström, Kerstin; Fujimori, Shinichiro; Hasegawa, Tomoko; Havlik, Petr; Humpenöder, Florian; Jain, Atul K; Krisztin, Tamás; Kyle, Page; Meiyappan, Prasanth; Popp, Alexander; Sands, Ronald D; Schaldach, Rüdiger; Schüngel, Jan; Stehfest, Elke; Tabeau, Andrzej; Van Meijl, Hans; Van Vliet, Jasper; Verburg, Peter H

2016-12-01

Model-based global projections of future land-use and land-cover (LULC) change are frequently used in environmental assessments to study the impact of LULC change on environmental services and to provide decision support for policy. These projections are characterized by a high uncertainty in terms of quantity and allocation of projected changes, which can severely impact the results of environmental assessments. In this study, we identify hotspots of uncertainty, based on 43 simulations from 11 global-scale LULC change models representing a wide range of assumptions of future biophysical and socioeconomic conditions. We attribute components of uncertainty to input data, model structure, scenario storyline and a residual term, based on a regression analysis and analysis of variance. From this diverse set of models and scenarios, we find that the uncertainty varies, depending on the region and the LULC type under consideration. Hotspots of uncertainty appear mainly at the edges of globally important biomes (e.g., boreal and tropical forests). Our results indicate that an important source of uncertainty in forest and pasture areas originates from different input data applied in the models. Cropland, in contrast, is more consistent among the starting conditions, while variation in the projections gradually increases over time due to diverse scenario assumptions and different modeling approaches. Comparisons at the grid cell level indicate that disagreement is mainly related to LULC type definitions and the individual model allocation schemes. We conclude that improving the quality and consistency of observational data utilized in the modeling process and improving the allocation mechanisms of LULC change models remain important challenges. Current LULC representation in environmental assessments might miss the uncertainty arising from the diversity of LULC change modeling approaches, and many studies ignore the uncertainty in LULC projections in assessments of LULC change impacts on climate, water resources or biodiversity. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Predicted extinction of unique genetic diversity in marine forests of Cystoseira spp.

PubMed

Buonomo, Roberto; Chefaoui, Rosa M; Lacida, Ricardo Bermejo; Engelen, Aschwin H; Serrão, Ester A; Airoldi, Laura

2018-07-01

Climate change is inducing shifts in species ranges across the globe. These can affect the genetic pools of species, including loss of genetic variability and evolutionary potential. In particular, geographically enclosed ecosystems, like the Mediterranean Sea, have a higher risk of suffering species loss and genetic erosion due to barriers to further range shifts and to dispersal. In this study, we address these questions for three habitat-forming seaweed species, Cystoseira tamariscifolia, C. amentacea and C. compressa, throughout their entire ranges in the Atlantic and Mediterranean regions. We aim to 1) describe their population genetic structure and diversity, 2) model the present and predict the future distribution and 3) assess the consequences of predicted future range shifts for their population genetic structure, according to two contrasting future climate change scenarios. A net loss of suitable areas was predicted in both climatic scenarios across the range of distribution of the three species. This loss was particularly severe for C. amentacea in the Mediterranean Sea (less 90% in the most extreme climatic scenario), suggesting that the species could become potentially at extinction risk. For all species, genetic data showed very differentiated populations, indicating low inter-population connectivity, and high and distinct genetic diversity in areas that were predicted to become lost, causing erosion of unique evolutionary lineages. Our results indicated that the Mediterranean Sea is the most threatened region, where future suitable Cystoseira habitats will become more limited. This is likely to have wider ecosystem impacts as there is a lack of species with the same ecological niche and functional role in the Mediterranean. The projected accelerated loss of already fragmented and disturbed populations and the long-term genetic effects highlight the urge for local scale management strategies that sustain the capacity of these habitat-forming species to persist despite climatic impacts while waiting for global emission reductions. Copyright © 2018 Elsevier Ltd. All rights reserved.

How does variation in rainfall affect simulated tropical tree mortality, functional diversity and coexistence?

NASA Astrophysics Data System (ADS)

Powell, T.; Kueppers, L. M.; Koven, C.; Johnson, D. J.; Faybishenko, B.; McDowell, N. G.; Chambers, J. Q.

2016-12-01

Land surface models that include demographic and plant hydrodynamic processes are promising tools for characterizing how different drought scenarios may affect carbon cycling of tropical forests. The Ecosystem Demography (ED2) model, now formulated with such features, was used to evaluate how different drought scenarios affect mortality patterns, functional diversity and coexistence of four plant functional types (PFTs) of tropical trees at Barro Colorado Island (BCI), Panama. The four PFTs simulated were early- versus late-successional groups subdivided into drought-tolerant versus -intolerant groups. The hydrodynamic formulation enables the four PFTs to compete mechanistically along two largely orthogonal resource gradients of water and light. The model simulations produced considerable differences in the aboveground biomass response to contrasting drying scenarios that included longer dry seasons, El Nino related droughts, and drier dry seasons. The emergent mortality dynamics reflect the physiological trade-off between water-use and carbon fixation formulated by the hydrodynamic regulation over stomatal conductance. During dry periods, the model predicts increased mortality rates of pioneer trees compared to generalists and drought-intolerant trees compared to -tolerant trees. The model also predicts that surviving cohorts in the smallest size classes of drought-intolerant trees are occasionally primed for release from competition following acute droughts. Observations at BCI showed increased mortality rates for large trees (i.e. >30 cm dbh) during the 1982 El Nino drought, but not subsequent El Nino related droughts. The causes of the elevated mortality rates are explored with the model. Coexistence of four plant functional types in the model is highly sensitive to the parameterization of stem hydraulic conductivity; but, surprisingly not very sensitive to shifts in rainfall patterns. These results demonstrate (a) that plant hydrodynamics are critical for simulating dynamic mortality patterns between drought-tolerant and -intolerant PFTs in order to increase representation of functional diversity in land surface models, and (b) that more demographic, plant hydraulic and deeper soil moisture observations are required to constrain hydrodynamic parameter selection.

Hotspots of uncertainty in land-use and land-cover change projections: A global-scale model comparison

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

Prestele, Reinhard; Alexander, Peter; Rounsevell, Mark D. A.

Model-based global projections of future land use and land cover (LULC) change are frequently used in environmental assessments to study the impact of LULC change on environmental services and to provide decision support for policy. These projections are characterized by a high uncertainty in terms of quantity and allocation of projected changes, which can severely impact the results of environmental assessments. In this study, we identify hotspots of uncertainty, based on 43 simulations from 11 global-scale LULC change models representing a wide range of assumptions of future biophysical and socio-economic conditions. We attribute components of uncertainty to input data, modelmore » structure, scenario storyline and a residual term, based on a regression analysis and analysis of variance. From this diverse set of models and scenarios we find that the uncertainty varies, depending on the region and the LULC type under consideration. Hotspots of uncertainty appear mainly at the edges of globally important biomes (e.g. boreal and tropical forests). Our results indicate that an important source of uncertainty in forest and pasture areas originates from different input data applied in the models. Cropland, in contrast, is more consistent among the starting conditions, while variation in the projections gradually increases over time due to diverse scenario assumptions and different modeling approaches. Comparisons at the grid cell level indicate that disagreement is mainly related to LULC type definitions and the individual model allocation schemes. We conclude that improving the quality and consistency of observational data utilized in the modeling process as well as improving the allocation mechanisms of LULC change models remain important challenges. Furthermore, current LULC representation in environmental assessments might miss the uncertainty arising from the diversity of LULC change modeling approaches and many studies ignore the uncertainty in LULC projections in assessments of LULC change impacts on climate, water resources or biodiversity.« less

Disturbance History,Spatial Variability, and Patterns of Biodiversity

NASA Astrophysics Data System (ADS)

Bendix, J.; Wiley, J. J.; Commons, M.

2012-12-01

The intermediate disturbance hypothesis predicts that species diversity will be maximized in environments experiencing intermediate intensity disturbance, after an intermediate timespan. Because many landscapes comprise mosaics with complex disturbance histories, the theory implies that each patch in those mosaics should have a distinct level of diversity reflecting combined impact of the magnitude of disturbance and the time since it occurred. We modeled the changing patterns of species richness across a landscape experiencing varied scenarios of simulated disturbance. Model outputs show that individual landscape patches have highly variable species richness through time, with the details reflecting the timing, intensity and sequence of their disturbance history. When the results are mapped across the landscape, the resulting temporal and spatial complexity illustrates both the contingent nature of diversity and the danger of generalizing about the impacts of disturbance.

Evaluation and Testing of the ADVANTG Code on SNM Detection

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

Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.

2013-09-24

Pacific Northwest National Laboratory (PNNL) has been tasked with evaluating the effectiveness of ORNL’s new hybrid transport code, ADVANTG, on scenarios of interest to our NA-22 sponsor, specifically of detection of diversion of special nuclear material (SNM). PNNL staff have determined that acquisition and installation of ADVANTG was relatively straightforward for a code in its phase of development, but probably not yet sufficient for mass distribution to the general user. PNNL staff also determined that with little effort, ADVANTG generated weight windows that typically worked for the problems and generated results consistent with MCNP. With slightly greater effort of choosingmore » a finer mesh around detectors or sample reaction tally regions, the figure of merit (FOM) could be further improved in most cases. This does take some limited knowledge of deterministic transport methods. The FOM could also be increased by limiting the energy range for a tally to the energy region of greatest interest. It was then found that an MCNP run with the full energy range for the tally showed improved statistics in the region used for the ADVANTG run. The specific case of interest chosen by the sponsor is the CIPN project from Las Alamos National Laboratory (LANL), which is an active interrogation, non-destructive assay (NDA) technique to quantify the fissile content in a spent fuel assembly and is also sensitive to cases of material diversion. Unfortunately, weight windows for the CIPN problem cannot currently be properly generated with ADVANTG due to inadequate accommodations for source definition. ADVANTG requires that a fixed neutron source be defined within the problem and cannot account for neutron multiplication. As such, it is rendered useless in active interrogation scenarios. It is also interesting to note that this is a difficult problem to solve and that the automated weight windows generator in MCNP actually slowed down the problem. Therefore, PNNL had determined that there is not an effective tool available for speeding up MCNP for problems such as the CIPN scenario. With regard to the Benchmark scenarios, ADVANTG performed very well for most of the difficult, long-running, standard radiation detection scenarios. Specifically, run time speedups were observed for spatially large scenarios, or those having significant shielding or scattering geometries. ADVANTG performed on par with existing codes for moderate sized scenarios, or those with little to moderate shielding, or multiple paths to the detectors. ADVANTG ran slower than MCNP for very simply, spatially small cases with little to no shielding that run very quickly anyway. Lastly, ADVANTG could not solve problems that did not consist of fixed source to detector geometries. For example, it could not solve scenarios with multiple detectors or secondary particles, such as active interrogation, neutron induced gamma, or fission neutrons.« less

Global associations between terrestrial producer and vertebrate consumer diversity

PubMed Central

Jetz, Walter; Kreft, Holger; Ceballos, Gerardo; Mutke, Jens

2008-01-01

In both ecology and conservation, often a strong positive association is assumed between the diversity of plants as primary producers and that of animals, specifically primary consumers. Such a relationship has been observed at small spatial scales, and a begetting of diversity by diversity is expected under various scenarios of co-evolution and co-adaptation. But positive producer–consumer richness relationships may also arise from similar associations with past opportunities for diversification or contemporary environmental conditions, or from emerging properties of plant diversity such as vegetation complexity or productivity. Here we assess whether the producer–consumer richness relationship generalizes from plot to regional scale and provide a first global test of its strength for vascular plants and endothermic vertebrates. We find strong positive richness associations, but only limited congruence of the most diverse regions. The richness of both primary and higher-level consumers increases with plant richness at similar strength and rate. Environmental conditions emerge as much stronger predictors of consumer richness, and after accounting for environmental differences little variation is explained by plant diversity. We conclude that biotic interactions and strong local associations between plants and consumers only relatively weakly scale up to broad geographical scales and to functionally diverse taxa, for which environmental constraints on richness dominate. PMID:18832059

Scenario Planning to Identify Science Needs for the Management of Energy and Resource Development in the Arctic

NASA Astrophysics Data System (ADS)

Lassuy, D.

2013-12-01

The North Slope Science Initiative (NSSI) is an intergovernmental science collaboration forum in Arctic Alaska (USA). NSSI has initiated a 'Scenario Planning' effort with the focal question: 'What is the future of energy development, resource extraction, and associated support activities on the North Slope and adjacent seas through 2040?' With over 500 thousand square kilometers of land and sea, the area of the North Slope and adjacent seas is believed to have some of the largest oil, gas, and coal potential remaining in the United States, but it is also home to a diverse array of fish, wildlife, and plant resources that support a vibrant subsistence culture. Our scenario planning will involve a full and collaborative dialogue among a wide range of U.S. Arctic stakeholders, including Alaska Native subsistence users, local communities, academia, non-governmental organizations, and a variety of industries (oil and gas, mining, transportation, etc.) and government agencies (federal, state, local). The formulation of development scenarios and an understanding of their implications will provide a practical context for NSSI member agencies to make informed decisions about the research and monitoring that will be needed to sustain these resources and to plan for safe energy and resource development in the face of impending changes. The future of Arctic America is difficult to accurately predict, particularly in an era of intense pressures from both energy development and climate warming. However, it will almost surely be characterized by highly consequential and unprecedented changes. Complex and uncertain are appropriate descriptors of the Arctic and its future; and scenario planning has proven an effective tool to help engage diverse stakeholders in a focused dialogue and systematic thinking about plausible futures in complex and uncertain settings. The NSSI leadership recognized the critical need for this dialogue and has begun a scenario planning effort for the North Slope of Alaska and the adjacent Beaufort and Chukchi Seas. As currently designed, this NSSI scenario planning effort will encompass two broadly defined steps. We will engage local communities along with resource agencies, industry, non-governmental organizations, academia, and others with Arctic interests in exploring plausible future development activity (scenarios). Then we will undertake science- and traditional knowledge-informed explorations of the relevant research and monitoring that will be needed to detect, assess, and respond to the identified range of plausible development-driven changes on the North Slope and adjacent seas (strategies). The intent is for these strategies to then inform agency decisions about future investment in research and monitoring, and particularly to identify opportunities to collaborate in a manner that will benefit all involved parties. However, it is also important to note that the most important short- and long-term benefit of this scenario planning exercise may in fact be the strengthening of an involved and informed community of stakeholder participants, regardless of specific informational or strategic outcomes.

Scenario-Led Habitat Modelling of Land Use Change Impacts on Key Species

PubMed Central

Geary, Matthew; Fielding, Alan H.; McGowan, Philip J. K.; Marsden, Stuart J.

2015-01-01

Accurate predictions of the impacts of future land use change on species of conservation concern can help to inform policy-makers and improve conservation measures. If predictions are spatially explicit, predicted consequences of likely land use changes could be accessible to land managers at a scale relevant to their working landscape. We introduce a method, based on open source software, which integrates habitat suitability modelling with scenario-building, and illustrate its use by investigating the effects of alternative land use change scenarios on landscape suitability for black grouse Tetrao tetrix. Expert opinion was used to construct five near-future (twenty years) scenarios for the 800 km2 study site in upland Scotland. For each scenario, the cover of different land use types was altered by 5–30% from 20 random starting locations and changes in habitat suitability assessed by projecting a MaxEnt suitability model onto each simulated landscape. A scenario converting grazed land to moorland and open forestry was the most beneficial for black grouse, and ‘increased grazing’ (the opposite conversion) the most detrimental. Positioning of new landscape blocks was shown to be important in some situations. Increasing the area of open-canopy forestry caused a proportional decrease in suitability, but suitability gains for the ‘reduced grazing’ scenario were nonlinear. ‘Scenario-led’ landscape simulation models can be applied in assessments of the impacts of land use change both on individual species and also on diversity and community measures, or ecosystem services. A next step would be to include landscape configuration more explicitly in the simulation models, both to make them more realistic, and to examine the effects of habitat placement more thoroughly. In this example, the recommended policy would be incentives on grazing reduction to benefit black grouse. PMID:26569604

A fine-scale assessment of using barriers to conserve native stream salmonids: a case study in Akokala Creek, Glacier National Park, USA

USGS Publications Warehouse

Muhlfeld, Clint C.; D'Angelo, Vincent S.; S. T. Kalinowski,; Landguth, Erin L.; C. C. Downs,; J. Tohtz,; Kershner, Jeffrey L.

2012-01-01

Biologists are often faced with the difficult decision in managing native salmonids of where and when to install barriers as a conservation action to prevent upstream invasion of nonnative fishes. However, fine-scale approaches to assess long-term persistence of populations within streams and watersheds chosen for isolation management are often lacking. We employed a spatially-explicit approach to evaluate stream habitat conditions, relative abundance, and genetic diversity of native westslope cutthroat trout (Oncorhynchus clarkii lewisi) within the Akokala Creek watershed in Glacier National Park- a population threatened by introgressive hybridization with nonnative rainbow trout (O. mykiss) from nearby sources. The systematic survey of 24 stream reaches showed broad overlap in fish population and suitable habitat characteristics among reaches and no natural barriers to fish migration were found. Analysis of population structure using 16 microsatellite loci showed modest amounts of genetic diversity among reaches, and that fish from Long Bow Creek were the only moderately distinct genetic group. We then used this information to assess the potential impacts of three barrier placement scenarios on long-term population persistence and genetic diversity. The two barrier placement scenarios in headwater areas generally failed to meet general persistence criteria for minimum population size (2,500 individuals, Ne = 500), maintenance of long-term genetic diversity (He), and no population subdivision. Conversely, placing a barrier near the stream mouth and selectively passing non-hybridized, migratory spawners entering Akokala Creek met all persistence criteria and may offer the best option to conserve native trout populations and life history diversity. Systematic, fine-scale stream habitat, fish distribution, and genetic assessments in streams chosen for barrier installation are needed in conjunction with broader scale assessments to understand the potential impacts of using barriers for conservation of native salmonid populations threatened by nonnative fish invasions.

The response of tropical rainforests to drought-lessons from recent research and future prospects.

PubMed

Bonal, Damien; Burban, Benoit; Stahl, Clément; Wagner, Fabien; Hérault, Bruno

We review the recent findings on the influence of drought on tree mortality, growth or ecosystem functioning in tropical rainforests. Drought plays a major role in shaping tropical rainforests and the response mechanisms are highly diverse and complex. The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical rainforests on the three continents. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance. Tropical rainforest ecosystems are characterized by high annual rainfall. Nevertheless, rainfall regularly fluctuates during the year and seasonal soil droughts do occur. Over the past decades, a number of extreme droughts have hit tropical rainforests, not only in Amazonia but also in Asia and Africa. The influence of drought events on tree mortality and growth or on ecosystem functioning (carbon and water fluxes) in tropical rainforest ecosystems has been studied intensively, but the response mechanisms are complex. Herein, we review the recent findings related to the response of tropical forest ecosystems to seasonal and extreme droughts and the current knowledge about the future of these ecosystems. This review emphasizes the progress made over recent years and the importance of the studies conducted under extreme drought conditions or in through-fall exclusion experiments in understanding the response of these ecosystems. It also points to the great diversity and complexity of the response of tropical rainforest ecosystems to drought. The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical forest regions. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance.

Diversity and Hidden Host Specificity of Chytrids infecting Colonial Volvocacean Algae.

PubMed

Van den Wyngaert, Silke; Rojas-Jimenez, Keilor; Seto, Kensuke; Kagami, Maiko; Grossart, Hans-Peter

2018-05-12

Chytrids are zoosporic fungi that play an important, but yet understudied, ecological role in aquatic ecosystems. Many chytrid species have been morphologically described as parasites on phytoplankton. However, the majority of them have rarely been isolated and lack DNA sequence data. In this study we isolated and cultivated three parasitic chytrids, infecting a common volvocacean host species, Yamagishiella unicocca. In order to identify the chytrids, we characterized morphology and life cycle, and analyzed phylogenetic relationships based on 18S and 28S rDNA genes. Host range and specificity of the chytrids was determined by cross infection assays with host strains, characterized by rbcL and ITS markers. We were able to confirm the identity of two chytrid strains as Endocoenobium eudorinae Ingold and Dangeardia mamillata Schröder and described the third chytrid strain as Algomyces stechlinensis gen. et sp. nov. The three chytrids were assigned to novel and phylogenetically distant clades within the phylum Chytridiomycota, each exhibiting different host specificities. By integrating morphological and molecular data of both the parasitic chytrids and their respective host species, we unveiled cryptic host-parasite associations. This study highlights that a high prevalence of (pseudo)cryptic diversity requires molecular characterization of both phytoplankton host and parasitic chytrid to accurately identify and compare host range and specificity, and to study phytoplankton-chytrid interactions in general. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Diversity of peptidic and proteinaceous toxins from social Hymenoptera venoms.

PubMed

Dos Santos-Pinto, José Roberto Aparecido; Perez-Riverol, Amilcar; Lasa, Alexis Musacchio; Palma, Mario Sergio

2018-06-15

Among venomous animals, Hymenoptera have been suggested as a rich source of natural toxins. Due to their broad ecological diversity, venom from Hymenoptera insects (bees, wasps and ants) have evolved differentially thus widening the types and biological functions of their components. To date, insect toxinology analysis have scarcely uncovered the complex composition of bee, wasp and ant venoms which include low molecular weight compounds, highly abundant peptides and proteins, including several allergens. In Hymenoptera, these complex mixtures of toxins represent a potent arsenal of biological weapons that are used for self-defense, to repel intruders and to capture prey. Consequently, Hymenoptera venom components have a broad range of pharmacological targets and have been extensively studied, as promising sources of new drugs and biopesticides. In addition, the identification and molecular characterization of Hymenoptera venom allergens have allowed for the rational design of component-resolved diagnosis of allergy, finally improving the outcome of venom immunotherapy (VIT). Until recently, a limited number of Hymenoptera venoms had been unveiled due to the technical limitations of the approaches used to date. Nevertheless, the application of novel techniques with high dynamic range has significantly increased the number of identified peptidic and proteinaceous toxins. Considering this, the present review summarizes the current knowledge about the most representative Hymenoptera venom peptides and proteins which are under study for a better understanding of the insect-caused envenoming process and the development of new drugs and biopesticides. Copyright © 2018 Elsevier Ltd. All rights reserved.

RuBisCO large-subunit gene primers for assessing the CO2-assimilating planktonic community structure in Jiaozhou Bay, China.

PubMed

Chi, Xiang-Qun; Wang, Long; Guo, Ruoyu; Zhao, Dexi; Li, Jia; Zhang, Yongyu; Jiao, Nianzhi

2018-06-19

The protein coding genes (rbcL/cbbL/cbbM) for RuBisCO large subunit, the most abundant protein on earth that drives biological CO2 fixation, were considered as useful marker genes in characterizing CO2-assimilating plankton. However, their community specificity has hindered comprehensive screening of genetic diversity. In this study, six different rbcL/cbbL/cbbM primers were employed to screen clone libraries to identify CO2-assimilating plankton in Jiaozhou Bay. The following community compositions were observed: the community components in Form I A/B rbcL/cbbL clone library mainly comprised Chlorophyta and Proteobacteria, Form ID2 and ID3 libraries consisted of Bacillariophyta, Form II cbbM library consisted of Proteobacteria and Alveolata, and both Form I green and red libraries included Proteobacteria, respectively. At the genus taxonomic level, no overlaps among these clone libraries were observed, except for ID2 and ID3. Overall, the phytoplankton in Jiaozhou Bay mainly consists of Bacillariophyta, Chlorophyta, Cryptophyta, Haptophyceae, and Alveolata. The CO2-assimilating prokaryotes mainly consist of Proteobacteria. Considering the high sequence specificities of these marker genes, we propose that the joint use of multiple primers may be utilized in unveiling the diversity of CO2-assimilating organisms. In addition, designing novel RuBisCO gene primers that generate longer amplicons and have broader phylogenetic coverage may be necessary in the future.

Compositional Bias in Naïve and Chemically-modified Phage-Displayed Libraries uncovered by Paired-end Deep Sequencing.

PubMed

He, Bifang; Tjhung, Katrina F; Bennett, Nicholas J; Chou, Ying; Rau, Andrea; Huang, Jian; Derda, Ratmir

2018-01-19

Understanding the composition of a genetically-encoded (GE) library is instrumental to the success of ligand discovery. In this manuscript, we investigate the bias in GE-libraries of linear, macrocyclic and chemically post-translationally modified (cPTM) tetrapeptides displayed on the M13KE platform, which are produced via trinucleotide cassette synthesis (19 codons) and NNK-randomized codon. Differential enrichment of synthetic DNA {S}, ligated vector {L} (extension and ligation of synthetic DNA into the vector), naïve libraries {N} (transformation of the ligated vector into the bacteria followed by expression of the library for 4.5 hours to yield a "naïve" library), and libraries chemically modified by aldehyde ligation and cysteine macrocyclization {M} characterized by paired-end deep sequencing, detected a significant drop in diversity in {L} → {N}, but only a minor compositional difference in {S} → {L} and {N} → {M}. Libraries expressed at the N-terminus of phage protein pIII censored positively charged amino acids Arg and Lys; libraries expressed between pIII domains N1 and N2 overcame Arg/Lys-censorship but introduced new bias towards Gly and Ser. Interrogation of biases arising from cPTM by aldehyde ligation and cysteine macrocyclization unveiled censorship of sequences with Ser/Phe. Analogous analysis can be used to explore library diversity in new display platforms and optimize cPTM of these libraries.

Blind Source Separation for Unimodal and Multimodal Brain Networks: A Unifying Framework for Subspace Modeling

PubMed Central

Silva, Rogers F.; Plis, Sergey M.; Sui, Jing; Pattichis, Marios S.; Adalı, Tülay; Calhoun, Vince D.

2016-01-01

In the past decade, numerous advances in the study of the human brain were fostered by successful applications of blind source separation (BSS) methods to a wide range of imaging modalities. The main focus has been on extracting “networks” represented as the underlying latent sources. While the broad success in learning latent representations from multiple datasets has promoted the wide presence of BSS in modern neuroscience, it also introduced a wide variety of objective functions, underlying graphical structures, and parameter constraints for each method. Such diversity, combined with a host of datatype-specific know-how, can cause a sense of disorder and confusion, hampering a practitioner’s judgment and impeding further development. We organize the diverse landscape of BSS models by exposing its key features and combining them to establish a novel unifying view of the area. In the process, we unveil important connections among models according to their properties and subspace structures. Consequently, a high-level descriptive structure is exposed, ultimately helping practitioners select the right model for their applications. Equipped with that knowledge, we review the current state of BSS applications to neuroimaging. The gained insight into model connections elicits a broader sense of generalization, highlighting several directions for model development. In light of that, we discuss emerging multi-dataset multidimensional (MDM) models and summarize their benefits for the study of the healthy brain and disease-related changes. PMID:28461840

iDNA screening: Disease vectors as vertebrate samplers.

PubMed

Kocher, Arthur; de Thoisy, Benoit; Catzeflis, François; Valière, Sophie; Bañuls, Anne-Laure; Murienne, Jérôme

2017-11-01

In the current context of global change and human-induced biodiversity decline, there is an urgent need for developing sampling approaches able to accurately describe the state of biodiversity. Traditional surveys of vertebrate fauna involve time-consuming and skill-demanding field methods. Recently, the use of DNA derived from invertebrate parasites (leeches and blowflies) was suggested as a new tool for vertebrate diversity assessment. Bloodmeal analyses of arthropod disease vectors have long been performed to describe their feeding behaviour, for epidemiological purposes. On the other hand, this existing expertise has not yet been applied to investigate vertebrate fauna per se. Here, we evaluate the usefulness of hematophagous dipterans as vertebrate samplers. Blood-fed sand flies and mosquitoes were collected in Amazonian forest sites and analysed using high-throughput sequencing of short mitochondrial markers. Bloodmeal identifications highlighted contrasting ecological features and feeding behaviour among dipteran species, which allowed unveiling arboreal and terrestrial mammals of various body size, as well as birds, lizards and amphibians. Additionally, lower vertebrate diversity was found in sites undergoing higher levels of human-induced perturbation. These results suggest that, in addition to providing precious information on disease vector host use, dipteran bloodmeal analyses may represent a useful tool in the study of vertebrate communities. Although further effort is required to validate the approach and consider its application to large-scale studies, this first work opens up promising perspectives for biodiversity monitoring and eco-epidemiology. © 2017 John Wiley & Sons Ltd.

Predicting outcomes of restored Everglades high flow: A model system for scientifically managed floodplains

USGS Publications Warehouse

Choi, Jay; Harvey, Judson

2017-01-01

Restoration of higher flows through the Everglades is intended to reestablish sheetflow to rebuild a well-functioning ridge and slough landscape that supports a productive and diverse ecosystem. Our objective of the study was to use hydrologic simulations and biophysical analysis to predict restoration outcomes for five major subbasins of the Everglades. Five different scenarios of restoration were examined, and for each we predicted an outcome based on metrics describing the present-day condition of the landscape and additional metrics determined by modeling the hydrologic changes accompanying restoration. Restoration scenarios spanned from a baseline case with average annual flows of about 52% of the predrainage flow to the most aggressive scenario that permits 91% of the predrainage flow. Our predictions indicated that all restoration scenarios could benefit the functionality of the ridge-slough ecosystem. However, the difference between any single restoration scenario and the “no restoration” baseline was far greater than was the difference between any two levels of restoration. Interestingly, our analysis suggested that the most extensive (and highest cost) restoration scenarios are not likely to improve ridge and slough function more than less extensive restoration options. However, the value of more aggressive restoration may lie in factors not considered directly in our analysis. For example, an important reason to implement the more aggressive restoration scenarios could be additional flexibility that permitting greater flow allows for adaptively managing the ecosystem while also serving water needs for southeastern Florida in what could be a drier Everglades in the coming decades.

Investigating impact of waste reuse on the sustainability of municipal solid waste (MSW) incineration industry using emergy approach: A case study from Sichuan province, China.

PubMed

Wang, Yanqing; Zhang, Xiaohong; Liao, Wenjie; Wu, Jun; Yang, Xiangdong; Shui, Wei; Deng, Shihuai; Zhang, Yanzong; Lin, Lili; Xiao, Yinlong; Yu, Xiaoyu; Peng, Hong

2018-04-25

China has become the largest generator of municipal solid waste (MSW) in the world with its rapid urbanization, population growth and raising living standard. Among diverse solid waste disposal technologies, MSW incineration has been becoming an attractive choice. In terms of systematic point, an integrated MSW incineration system should include an incineration subsystem and a bottom ash (BA) disposal subsystem. This paper employed an extend emergy assessment method with several improved indicators, which considers the emissions' impact, to evaluate the comprehensive performances of an integrated MSW incineration system. One existing incineration plant in Yibin City, Sichuan Province, China, as a case study, is evaluated using the proposed method. Three alternative scenarios (scenario A: the incineration subsystem + the BA landfill subsystem; scenario B: the incineration subsystem + the concrete paving brick production subsystem using BA as raw material; scenario C: the incineration subsystem + the non-burnt wall brick production subsystem using BA as raw material) were compared. The study results reveal that the ratio of positive output is 1.225, 2.861 and 1.230, the improved environmental loading ratio is 2.715, 2.742 and 1.533, and the improved environmental sustainability index is 0.451, 1.043 and 0.803 for scenario A, B and C respectively. Therefore, reuse of BA can enhance the sustainability level of this integrated system greatly. Comparatively, scenario B has the best comprehensive performance among the three scenarios. Finally, some targeted recommendations are put forward for decision-making. Copyright © 2018. Published by Elsevier Ltd.

Breeding Bird Communities On Four Watersheds Under Different Forest Management Scenarios in the Ouachita Mountains Of Arkansas

Treesearch

Philip A. Tappe; Ronald E. Thill; M. Anthony Melchiors; T. Bently Wigley

2004-01-01

Abstract - Concern for many migratory landbird species has led to an increased emphasis on managing ecosystems at scales beyond the stand level. We characterized breeding bird numbers, species richness, diversity, and evenness on four watersheds in the Ouachita Mountains of west-central Arkansas. These four watersheds represented different ownerships...

Science Initial Teacher Education and Superdiversity: Educating Science Teachers for a Multi-Religious and Globalised Science Classroom

ERIC Educational Resources Information Center

De Carvalho, Roussel

2016-01-01

Steven Vertovec (2006, 2007) has recently offered a re-interpretation of population diversity in large urban centres due to a considerable increase in immigration patterns in the UK. This complex scenario called superdiversity has been conceptualised to help illuminate significant interactions of variables such as religion, language, gender, age,…

Twenty-First Century Police Training: Recruits' Problem-Solving Skills Following Scenario-Based Training

ERIC Educational Resources Information Center

Perry, Lee R.

2012-01-01

In response to the diverse requirements of 21st-century police work and the increasing emphasis on community-policing philosophy, the Los Angeles Police Department has implemented changes within its academy curricula and methods of instruction, including the use of adult-learning concepts, a community policing problem-solving model known as…

Cancelable biometrics realization with multispace random projections.

PubMed

Teoh, Andrew Beng Jin; Yuang, Chong Tze

2007-10-01

Biometric characteristics cannot be changed; therefore, the loss of privacy is permanent if they are ever compromised. This paper presents a two-factor cancelable formulation, where the biometric data are distorted in a revocable but non-reversible manner by first transforming the raw biometric data into a fixed-length feature vector and then projecting the feature vector onto a sequence of random subspaces that were derived from a user-specific pseudorandom number (PRN). This process is revocable and makes replacing biometrics as easy as replacing PRNs. The formulation has been verified under a number of scenarios (normal, stolen PRN, and compromised biometrics scenarios) using 2400 Facial Recognition Technology face images. The diversity property is also examined.

Objective comparison of particle tracking methods

PubMed Central

Chenouard, Nicolas; Smal, Ihor; de Chaumont, Fabrice; Maška, Martin; Sbalzarini, Ivo F.; Gong, Yuanhao; Cardinale, Janick; Carthel, Craig; Coraluppi, Stefano; Winter, Mark; Cohen, Andrew R.; Godinez, William J.; Rohr, Karl; Kalaidzidis, Yannis; Liang, Liang; Duncan, James; Shen, Hongying; Xu, Yingke; Magnusson, Klas E. G.; Jaldén, Joakim; Blau, Helen M.; Paul-Gilloteaux, Perrine; Roudot, Philippe; Kervrann, Charles; Waharte, François; Tinevez, Jean-Yves; Shorte, Spencer L.; Willemse, Joost; Celler, Katherine; van Wezel, Gilles P.; Dan, Han-Wei; Tsai, Yuh-Show; de Solórzano, Carlos Ortiz; Olivo-Marin, Jean-Christophe; Meijering, Erik

2014-01-01

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Since manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized, for the first time, an open competition, in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to important practical conclusions for users and developers. PMID:24441936

The diversity effect in diagnostic reasoning.

PubMed

Rebitschek, Felix G; Krems, Josef F; Jahn, Georg

2016-07-01

Diagnostic reasoning draws on knowledge about effects and their potential causes. The causal-diversity effect in diagnostic reasoning normatively depends on the distribution of effects in causal structures, and thus, a psychological diversity effect could indicate whether causally structured knowledge is used in evaluating the probability of a diagnosis, if the effect were to covary with manipulations of causal structures. In four experiments, participants dealt with a quasi-medical scenario presenting symptom sets (effects) that consistently suggested a specified diagnosis (cause). The probability that the diagnosis was correct had to be rated for two opposed symptom sets that differed with regard to the symptoms' positions (proximal or diverse) in the causal structure that was initially acquired. The causal structure linking the diagnosis to the symptoms and the base rate of the diagnosis were manipulated to explore whether the diagnosis was rated as more probable for diverse than for proximal symptoms when alternative causations were more plausible (e.g., because of a lower base rate of the diagnosis in question). The results replicated the causal diversity effect in diagnostic reasoning across these conditions, but no consistent effects of structure and base rate variations were observed. Diversity effects computed in causal Bayesian networks are presented, illustrating the consequences of the structure manipulations and corroborating that a diversity effect across the different experimental manipulations is normatively justified. The observed diversity effects presumably resulted from shortcut reasoning about the possibilities of alternative causation.

Functional characterization of piggyBat from the bat Myotis lucifugus unveils an active mammalian DNA transposon.

PubMed

Mitra, Rupak; Li, Xianghong; Kapusta, Aurélie; Mayhew, David; Mitra, Robi D; Feschotte, Cédric; Craig, Nancy L

2013-01-02

A revelation of the genomic age has been the contributions of the mobile DNA segments called transposable elements to chromosome structure, function, and evolution in virtually all organisms. Substantial fractions of vertebrate genomes derive from transposable elements, being dominated by retroelements that move via RNA intermediates. Although many of these elements have been inactivated by mutation, several active retroelements remain. Vertebrate genomes also contain substantial quantities and a high diversity of cut-and-paste DNA transposons, but no active representative of this class has been identified in mammals. Here we show that a cut-and-paste element called piggyBat, which has recently invaded the genome of the little brown bat (Myotis lucifugus) and is a member of the piggyBac superfamily, is active in its native form in transposition assays in bat and human cultured cells, as well as in the yeast Saccharomyces cerevisiae. Our study suggests that some DNA transposons are still actively shaping some mammalian genomes and reveals an unprecedented opportunity to study the mechanism, regulation, and genomic impact of cut-and-paste transposition in a natural mammalian host.

Synaptopodin Is a Coincidence Detector of Tyrosine versus Serine/Threonine Phosphorylation for the Modulation of Rho Protein Crosstalk in Podocytes

PubMed Central

Buvall, Lisa; Wallentin, Hanna; Sieber, Jonas; Andreeva, Svetlana; Choi, Hoon Young; Mundel, Peter

2017-01-01

Tyrosine and serine/threonine signal-transduction pathways influence many aspects of cell behavior, including the spatial and temporal regulation of the actin cytoskeleton. However, little is known about how input from diverse tyrosine and serine/threonine kinases is integrated to control Rho protein crosstalk and actin remodeling, which are critically important in podocyte health and disease. Here we unveil the proteolytically-regulated, actin organizing protein synaptopodin as a coincidence detector of tyrosine versus serine/threonine phosphorylation. We show that serine/threonine and tyrosine kinases duel for synaptopodin stability versus degradation. EGFR/Src-mediated tyrosine phosphorylation of synaptopodin in podocytes promotes binding to the serine/threonine phosphatase calcineurin. This leads to the loss of 14–3-3 binding, resulting in synaptopodin degradation, Vav2 activation, enhanced Rac1 signaling, and ultimate loss of stress fibers. Our studies reveal how synaptopodin, a single proteolytically-controlled protein, integrates antagonistic tyrosine versus serine/threonine phosphorylation events for the dynamic control of the actin cytoskeleton in podocytes. PMID:27628902

Advances in biomaterials for preventing tissue adhesion.

PubMed

Wu, Wei; Cheng, Ruoyu; das Neves, José; Tang, Jincheng; Xiao, Junyuan; Ni, Qing; Liu, Xinnong; Pan, Guoqing; Li, Dechun; Cui, Wenguo; Sarmento, Bruno

2017-09-10

Adhesion is one of the most common postsurgical complications, occurring simultaneously as the damaged tissue heals. Accompanied by symptoms such as inflammation, pain and even dyskinesia in particular circumstances, tissue adhesion has substantially compromised the quality of life of patients. Instead of passive treatment, which involves high cost and prolonged hospital stay, active intervention to prevent the adhesion from happening has been accepted as the optimized strategy against this complication. Herein, this paper will cover not only the mechanism of adhesion forming, but also the biomaterials and medicines used in its prevention. Apart from acting as a direct barrier, biomaterials also show promising anti-adhesive bioactivity though their intrinsic physical and chemical are still not completely unveiled. Considering the diversity of human tissue organization, it is imperative that various biomaterials in combination with specific medicine could be tuned to fit the microenvironment of targeted tissues. With the illustration of different adhesion mechanism and solutions, we hope this review can become a beacon and further inspires the development of anti-adhesion biomedicines. Copyright © 2017 Elsevier B.V. All rights reserved.

Bacterial communities and enzymatic activities in the vegetation-activated sludge process (V-ASP) and related advantages by comparison with conventional constructed wetland.

PubMed

Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Zhao, Ke; Du, Changhang; Shao, Yunxian

2016-11-01

A new-developed vegetation-activated sludge process (V-ASP) was implemented for decentralized domestic wastewater treatment, and studied in lab-scale and full-scale. The main purpose of this work was the investigation of biomass activities and microbial communities in V-ASP by comparison with conventional constructed wetland (CW), to unveil the causations of its consistently higher pollutants removal efficiencies. Compared with CWs, V-ASP has greater vegetation nitrogen and phosphorus uptake rates, higher biomass and enzymatic activities, and more bacteria community diversity. The microbial community structure was comprehensively analyzed by using high-throughput sequencing. It was observed that Proteobacteria was dominated in both CWs and V-ASPs, while their subdivisions distribution was rather different. V-ASPs contained a higher nitrite-oxidizing bacteria (Nitrospira) abundances that resulted in a consistently better nitrogen removal efficiency. Hence, a long-term experiment of full-scale V-ASP displayed stably excellent capability in resistance of influent loading shocks and seasonal temperature effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synaptopodin Is a Coincidence Detector of Tyrosine versus Serine/Threonine Phosphorylation for the Modulation of Rho Protein Crosstalk in Podocytes.

PubMed

Buvall, Lisa; Wallentin, Hanna; Sieber, Jonas; Andreeva, Svetlana; Choi, Hoon Young; Mundel, Peter; Greka, Anna

2017-03-01

Tyrosine and serine/threonine signal-transduction pathways influence many aspects of cell behavior, including the spatial and temporal regulation of the actin cytoskeleton. However, little is known about how input from diverse tyrosine and serine/threonine kinases is integrated to control Rho protein crosstalk and actin remodeling, which are critically important in podocyte health and disease. Here we unveil the proteolytically-regulated, actin organizing protein synaptopodin as a coincidence detector of tyrosine versus serine/threonine phosphorylation. We show that serine/threonine and tyrosine kinases duel for synaptopodin stability versus degradation. EGFR/Src-mediated tyrosine phosphorylation of synaptopodin in podocytes promotes binding to the serine/threonine phosphatase calcineurin. This leads to the loss of 14-3-3 binding, resulting in synaptopodin degradation, Vav2 activation, enhanced Rac1 signaling, and ultimate loss of stress fibers. Our studies reveal how synaptopodin, a single proteolytically-controlled protein, integrates antagonistic tyrosine versus serine/threonine phosphorylation events for the dynamic control of the actin cytoskeleton in podocytes. Copyright © 2017 by the American Society of Nephrology.

Communication, Reasoning, and Planned Behaviors: Unveiling the Effect of Interactive Communication in an Anti-Smoking Social Media Campaign.

PubMed

Namkoong, Kang; Nah, Seungahn; Record, Rachael A; Van Stee, Stephanie K

2017-01-01

This study examines direct and indirect effects of interactive communication in an antismoking social media campaign. To that end, we pose a multitheoretical framework that integrates communication mediation models and the Theory of Planned Behavior. To test the theorized model, we conducted an experiment using a two-group pretest-posttest design. Participants (N = 201) were randomly assigned into two experimental conditions: "campaign message reception only" as a control group and "message reception and social interaction" as a treatment group, in which the participants contributed to the antismoking campaign by posting their own campaign ideas and information they found through mediated and interpersonal communication. The findings show that interactive communication catalyzes the participants' information searching behaviors through diverse communication channels. In turn, increased media use plays a crucial role in changing their attitudes and perceived social norms about smoking behaviors, and eventually reducing smoking intention. This study affirms that the theory of planned behavior is effective in predicting behavioral intention and demonstrates the usefulness of a multitheoretical approach in interactive campaign research on social media.

Hydroxy fatty acids in fresh snow samples from northern Japan: long-range atmospheric transport of Gram-negative bacteria by Asian winter monsoon

NASA Astrophysics Data System (ADS)

Tyagi, P.; Yamamoto, S.; Kawamura, K.

2015-08-01

Hydroxy fatty acids (FAs) in fresh snow from Sapporo, one of the heaviest snowfall regions in the world, have been studied to ascertain the airborne bacterial endotoxin concentrations and their biomass. The presence of β-hydroxy FAs (C9-C28), constituents of Gram-negative bacteria (GNB), suggests long-range transport of soil microbes. Likewise, the occurrence of α- and ω-hydroxy FAs (C9-C30 and C9-C28, respectively) in snow reveals their contribution from epicuticular waxes and soil microorganisms. Estimated endotoxin and GNB mass can aid in assessing their possible impacts on the diversity and functioning of aquatic and terrestrial ecosystems, as well as lethal effects on pedestrians through dispersal of microbes. Air mass back trajectories together with hydroxy FAs unveil their sources from Siberia, Russian Far East and North China by the Asian monsoon. This study highlights the role of fresh snow that reduces the human health risk of GNB and endotoxin by scavenging from the air.

A non-canonical mechanism for Crm1-export cargo complex assembly.

PubMed

Fischer, Ute; Schäuble, Nico; Schütz, Sabina; Altvater, Martin; Chang, Yiming; Faza, Marius Boulos; Panse, Vikram Govind

2015-04-21

The transport receptor Crm1 mediates the export of diverse cargos containing leucine-rich nuclear export signals (NESs) through complex formation with RanGTP. To ensure efficient cargo release in the cytoplasm, NESs have evolved to display low affinity for Crm1. However, mechanisms that overcome low affinity to assemble Crm1-export complexes in the nucleus remain poorly understood. In this study, we reveal a new type of RanGTP-binding protein, Slx9, which facilitates Crm1 recruitment to the 40S pre-ribosome-associated NES-containing adaptor Rio2. In vitro, Slx9 binds Rio2 and RanGTP, forming a complex. This complex directly loads Crm1, unveiling a non-canonical stepwise mechanism to assemble a Crm1-export complex. A mutation in Slx9 that impairs Crm1-export complex assembly inhibits 40S pre-ribosome export. Thus, Slx9 functions as a scaffold to optimally present RanGTP and the NES to Crm1, therefore, triggering 40S pre-ribosome export. This mechanism could represent one solution to the paradox of weak binding events underlying rapid Crm1-mediated export.

Phenotypic engineering unveils the function of genital morphology.

PubMed

Hotzy, Cosima; Polak, Michal; Rönn, Johanna L; Arnqvist, Göran

2012-12-04

The rapidly evolving and often extraordinarily complex appearance of male genital morphology of internally fertilizing animals has been recognized for centuries. Postcopulatory sexual selection is regarded as the likely evolutionary engine of this diversity, but direct support for this hypothesis is limited. We used two complementary approaches, evolution through artificial selection and microscale laser surgery, to experimentally manipulate genital morphology in an insect model system. We then assessed the competitive fertilization success of these phenotypically manipulated males and studied the fate of their ejaculate in females using high-resolution radioisotopic labeling of ejaculates. Males with longer genital spines were more successful in gaining fertilizations, providing experimental evidence that male genital morphology influences success in postcopulatory reproductive competition. Furthermore, a larger proportion of the ejaculate moved from the reproductive tract into the female body following mating with males with longer spines, suggesting that genital spines increase the rate at which seminal fluid passes into the female hemolymph. Our results show that genital morphology affects male competitive fertilization success and imply that sexual selection on genital morphology may be mediated in part through seminal fluid. Copyright © 2012 Elsevier Ltd. All rights reserved.

Structural Insight into the Mechanism of c-di-GMP hydrolysis by EAL domain phosphodiesterases.

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

Tchigvintsev, A.; Xu, X.; Singer, A.

2010-08-01

Cyclic diguanylate (or bis-(3'-5') cyclic dimeric guanosine monophosphate; c-di-GMP) is a ubiquitous second messenger that regulates diverse cellular functions, including motility, biofilm formation, cell cycle progression, and virulence in bacteria. In the cell, degradation of c-di-GMP is catalyzed by highly specific EAL domain phosphodiesterases whose catalytic mechanism is still unclear. Here, we purified 13 EAL domain proteins from various organisms and demonstrated that their catalytic activity is associated with the presence of 10 conserved EAL domain residues. The crystal structure of the TBD1265 EAL domain was determined in free state (1.8 {angstrom}) and in complex with c-di-GMP (2.35 {angstrom}), andmore » unveiled the role of conserved residues in substrate binding and catalysis. The structure revealed the presence of two metal ions directly coordinated by six conserved residues, two oxygens of c-di-GMP phosphate, and potential catalytic water molecule. Our results support a two-metal-ion catalytic mechanism of c-di-GMP hydrolysis by EAL domain phosphodiesterases.« less

Yeasts isolated from Algerian infants's feces revealed a burden of Candida albicans species, non-albicans Candida species and Saccharomyces cerevisiae.

PubMed

Seddik, Hamza Ait; Ceugniez, Alexandre; Bendali, Farida; Cudennec, Benoit; Drider, Djamel

2016-01-01

This study aimed at showing the yeast diversity in feces of Algerian infants, aged between 1 and 24 months, hospitalized at Bejaia hospital (northeast side of the country). Thus, 20 colonies with yeast characteristics were isolated and identified using biochemical (ID32C Api system) and molecular (sequencing of ITS1-5.8S-ITS2 region) methods. Almost all colonies isolated (19 strains) were identified as Candida spp., with predominance of Candida albicans species, and one strain was identified as Saccharomyces cerevisiae. Screening of strains with inhibitory activities unveiled the potential of Candida parapsilosis P48L1 and Candida albicans P51L1 to inhibit the growth of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Further studies performed with these two Candida strains revealed their susceptibility to clinically used antifungal compounds and were then characterized for their cytotoxicity and hemolytic properties. On the other hand, Saccharomyces cerevisiae P9L1 isolated as well in this study was shown to be devoid of antagonism but resulted safe and overall usable as probiotic.

Graph processing platforms at scale: practices and experiences

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

Lim, Seung-Hwan; Lee, Sangkeun; Brown, Tyler C

2015-01-01

Graph analysis unveils hidden associations of data in many phenomena and artifacts, such as road network, social networks, genomic information, and scientific collaboration. Unfortunately, a wide diversity in the characteristics of graphs and graph operations make it challenging to find a right combination of tools and implementation of algorithms to discover desired knowledge from the target data set. This study presents an extensive empirical study of three representative graph processing platforms: Pegasus, GraphX, and Urika. Each system represents a combination of options in data model, processing paradigm, and infrastructure. We benchmarked each platform using three popular graph operations, degree distribution,more » connected components, and PageRank over a variety of real-world graphs. Our experiments show that each graph processing platform shows different strength, depending the type of graph operations. While Urika performs the best in non-iterative operations like degree distribution, GraphX outputforms iterative operations like connected components and PageRank. In addition, we discuss challenges to optimize the performance of each platform over large scale real world graphs.« less

Memory outcomes following cognitive interventions in children with neurological deficits: A review with a focus on under-studied populations.

PubMed

Schaffer, Yael; Geva, Ronny

2016-01-01

Given the primary role of memory in children's learning and well-being, the aim of this review was to examine the outcomes of memory remediation interventions in children with neurological deficits as a function of the affected memory system and intervention method. Fifty-seven studies that evaluated the outcome of memory interventions in children were identified. Thirty-four studies met the inclusion criteria, and were included in a systematic review. Diverse rehabilitation methods for improving explicit and implicit memory in children were reviewed. The analysis indicates that teaching restoration strategies may improve, and result in the generalisation of, semantic memory and working memory performance in children older than 7 years with mild to moderate memory deficits. Factors such as longer protocols, emotional support, and personal feedback contribute to intervention efficacy. In addition, the use of compensation aids seems to be highly effective in prospective memory tasks. Finally, the review unveiled a lack of studies with young children and the absence of group interventions. These findings point to the importance of future evidence-based intervention protocols in these areas.

Mercury MESSENGER Stamp Unveiling

NASA Image and Video Library

2011-05-03

United States Postal Service Vice President of Finance Steve Masse, left, and NASA Mercury Astronaut Scott Carpenter, unveil two USPS stamps to commemorate and celebrate 50 years of US Spaceflight and the MESSENGER program during an event, Wednesday, May 4, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. One stamp commemorates NASA’s Project Mercury, America’s first manned spaceflight program, and NASA astronaut Alan Shepard’s historic flight on May 5, 1961, aboard spacecraft Freedom 7. The other stamp draws attention to NASA’s unmanned MESSENGER mission, a scientific investigation of the planet Mercury. On March 17, 2011, MESSENGER became the first spacecraft to enter into orbit around Mercury. Photo Credit: (NASA/Bill Ingalls)

Unveiling causal activity of complex networks

NASA Astrophysics Data System (ADS)

Williams-García, Rashid V.; Beggs, John M.; Ortiz, Gerardo

2017-07-01

We introduce a novel tool for analyzing complex network dynamics, allowing for cascades of causally-related events, which we call causal webs (c-webs), to be separated from other non-causally-related events. This tool shows that traditionally-conceived avalanches may contain mixtures of spatially-distinct but temporally-overlapping cascades of events, and dynamical disorder or noise. In contrast, c-webs separate these components, unveiling previously hidden features of the network and dynamics. We apply our method to mouse cortical data with resulting statistics which demonstrate for the first time that neuronal avalanches are not merely composed of causally-related events. The original version of this article was uploaded to the arXiv on March 17th, 2016 [1].

Photonic integrated circuits unveil crisis-induced intermittency.

PubMed

Karsaklian Dal Bosco, Andreas; Akizawa, Yasuhiro; Kanno, Kazutaka; Uchida, Atsushi; Harayama, Takahisa; Yoshimura, Kazuyuki

2016-09-19

We experimentally investigate an intermittent route to chaos in a photonic integrated circuit consisting of a semiconductor laser with time-delayed optical feedback from a short external cavity. The transition from a period-doubling dynamics to a fully-developed chaos reveals a stage intermittently exhibiting these two dynamics. We unveil the bifurcation mechanism underlying this route to chaos by using the Lang-Kobayashi model and demonstrate that the process is based on a phenomenon of attractor expansion initiated by a particular distribution of the local Lyapunov exponents. We emphasize on the crucial importance of the distribution of the steady-state solutions introduced by the time-delayed feedback on the existence of this intermittent dynamics.

Mercury MESSENGER Stamp Unveiling

NASA Image and Video Library

2011-05-03

Daughters of NASA astronaut Alan Shepard, Laura Shepard Churchley, left, Alice Wackermann and Julie Jenkins, right, speak during an unveiling ceremony of two USPS stamps that commemorate and celebrate 50 years of US Spaceflight and the MESSENGER program during an event, Wednesday, May 4, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. One stamp commemorates NASA’s Project Mercury, America’s first manned spaceflight program, and NASA astronaut Alan Shepard’s historic flight on May 5, 1961, aboard spacecraft Freedom 7. The other stamp draws attention to NASA’s unmanned MESSENGER mission, a scientific investigation of the planet Mercury. On March 17, 2011, MESSENGER became the first spacecraft to enter into orbit around Mercury. Photo Credit: (NASA/Bill Ingalls)

Development of Hospital-Based Guidelines for Skeletal Survey in Young Children With Bruises

PubMed Central

Fakeye, Oludolapo; Mondestin, Valerie; Rubin, David M.; Localio, Russell; Feudtner, Chris

2015-01-01

OBJECTIVE: To develop guidelines for performing an initial skeletal survey (SS) for children <24 months of age presenting with bruising in the hospital setting, combining available evidence with expert opinion. METHODS: Applying the Rand/UCLA Appropriateness Method, a multispecialty panel of 10 experts relied on evidence from the literature and their own clinical expertise in rating the appropriateness of performing SS for 198 clinical scenarios characterizing children <24 months old with bruising. After a moderated discussion of initial ratings, the scenarios were revised. Panelists re-rated SS appropriateness for 219 revised scenarios. For the 136 clinical scenarios in which SS was deemed appropriate, the panel finally assessed the necessity of SS. RESULTS: Panelists agreed that SS is “appropriate” for 62% (136/219) of scenarios, and “inappropriate” for children ≥12 months old with nonpatterned bruising on bony prominences. Panelists agreed that SS is “necessary” for 95% (129/136) of the appropriate scenarios. SS was deemed necessary for infants <6 months old regardless of bruise location, with rare exceptions, but the necessity of SS in older children depends on bruise location. According to the panelists, bruising on the cheek, eye area, ear, neck, upper arm, upper leg, hand, foot, torso, buttock, or genital area necessitates SS in children <12 months. CONCLUSIONS: The appropriateness and necessity of SS in children presenting for care to the hospital setting with bruising, as determined by a diverse panel of experts, depends on age of the child and location of bruising. PMID:25601982

Evaluating water management scenarios to support habitat management for the Cape Sable seaside sparrow

USGS Publications Warehouse

Beerens, James M.; Romañach, Stephanie S.; McKelvy, Mark

2016-06-22

The endangered Cape Sable seaside sparrow (Ammodramus maritimus mirabilis) is endemic to south Florida and a key indicator species of marl prairie, a highly diverse freshwater community in the Florida Everglades. Maintenance and creation of suitable habitat is seen as the most important pathway to the persistence of the six existing sparrow subpopulations; however, major uncertainties remain in how to increase suitable habitat within and surrounding these subpopulations, which are vulnerable to environmental stochasticity. Currently, consistently suitable conditions for the Cape Sable seaside sparrow are only present in two of these subpopulations (B and E). The water management scenarios evaluated herein were intended to lower water levels and improve habitat conditions in subpopulation A and D, raise water levels to improve habitat conditions in subpopulations C and F, and minimize impacts to subpopulations B and E. Our objective in this analysis was to compare these scenarios utilizing a set of metrics (short- to long-time scales) that relate habitat suitability to hydrologic conditions. Although hydrologic outputs are similar across scenarios in subpopulation A, scenario R2H reaches the hydroperiod and depth suitability targets more than the other scenarios relative to ECB, while minimizing negative consequences to subpopulation E. However, although R2H hydroperiods are longer than those for ECB during the wet season in subpopulations C and F, depths during the breeding season are predicted to decrease in suitability (less than -50 cm) relative to existing conditions.

Low-carbon yak cheese: transition to biogas in a Himalayan socio-technical niche

PubMed Central

Campbell, Ben; Sallis, Paul

2013-01-01

This study looks at how potential for resilient low-carbon solutions can be understood and enhanced in the diverse environmental, economic and socio-political contexts in which actual scenarios of energy needs and diverse development pathways take shape. It discusses socio-technical transition approaches to assist implementation of a biogas digester system. This will replace fuelwood use in the high forests of Central Nepal, where yak cheese production provides livelihood income but is under threat from the Langtang National Park, which is concerned to protect biodiversity. Alternatives for digester design are discussed, and the consultative issues for deliberative processes among stakeholders’ varied agendas raised. PMID:24427516

Realistic diversity loss and variation in soil depth independently affect community-level plant nitrogen use.

PubMed

Selmants, Paul C; Zavaleta, Erika S; Wolf, Amelia A

2014-01-01

Numerous experiments have demonstrated that diverse plant communities use nitrogen (N) more completely and efficiently, with implications for how species conservation efforts might influence N cycling and retention in terrestrial ecosystems. However, most such experiments have randomly manipulated species richness and minimized environmental heterogeneity, two design aspects that may reduce applicability to real ecosystems. Here we present results from an experiment directly comparing how realistic and randomized plant species losses affect plant N use across a gradient of soil depth in a native-dominated serpentine grassland in California. We found that the strength of the species richness effect on plant N use did not increase with soil depth in either the realistic or randomized species loss scenarios, indicating that the increased vertical heterogeneity conferred by deeper soils did not lead to greater complementarity among species in this ecosystem. Realistic species losses significantly reduced plant N uptake and altered N-use efficiency, while randomized species losses had no effect on plant N use. Increasing soil depth positively affected plant N uptake in both loss order scenarios but had a weaker effect on plant N use than did realistic species losses. Our results illustrate that realistic species losses can have functional consequences that differ distinctly from randomized losses, and that species diversity effects can be independent of and outweigh those of environmental heterogeneity on ecosystem functioning. Our findings also support the value of conservation efforts aimed at maintaining biodiversity to help buffer ecosystems against increasing anthropogenic N loading.

Bird community conservation and carbon offsets in western North America.

PubMed

Schuster, Richard; Martin, Tara G; Arcese, Peter

2014-01-01

Conservation initiatives to protect and restore valued species and communities in human-dominated landscapes face huge challenges linked to the cost of acquiring habitat. We ask how the sale of forest carbon offsets could reduce land acquisition costs, and how the alternate goals of maximizing α or β-diversity in focal communities could affect the prioritization land parcels over a range of conservation targets. Maximizing total carbon storage and carbon sequestration potential reduced land acquisition costs by up to 48%. Maximizing β rather than α-diversity within forest and savannah bird communities reduced acquisition costs by up to 15%, and when these solutions included potential carbon credit revenues, acquisition cost reductions up to 32% were achieved. However, the total cost of conservation networks increased exponentially as area targets increased in all scenarios. Our results indicate that carbon credit sales have the potential to enhance conservation outcomes in human-dominated landscapes by reducing the net acquisition costs of land conservation in old and maturing forests essential for the persistence of old forest plant and animal communities. Maximizing β versus α-diversity may further reduce costs by reducing the total area required to meet conservation targets and enhancing landscape heterogeneity. Although the potential value of carbon credit sales declined as a fraction of total acquisition costs, even conservative scenarios using a carbon credit value of $12.5/T suggest reductions in acquisition cost of up to $235 M, indicating that carbon credit sales could substantially reduce the costs of conservation.

Bird Community Conservation and Carbon Offsets in Western North America

PubMed Central

Schuster, Richard; Martin, Tara G.; Arcese, Peter

2014-01-01

Conservation initiatives to protect and restore valued species and communities in human-dominated landscapes face huge challenges linked to the cost of acquiring habitat. We ask how the sale of forest carbon offsets could reduce land acquisition costs, and how the alternate goals of maximizing α or β-diversity in focal communities could affect the prioritization land parcels over a range of conservation targets. Maximizing total carbon storage and carbon sequestration potential reduced land acquisition costs by up to 48%. Maximizing β rather than α-diversity within forest and savannah bird communities reduced acquisition costs by up to 15%, and when these solutions included potential carbon credit revenues, acquisition cost reductions up to 32% were achieved. However, the total cost of conservation networks increased exponentially as area targets increased in all scenarios. Our results indicate that carbon credit sales have the potential to enhance conservation outcomes in human-dominated landscapes by reducing the net acquisition costs of land conservation in old and maturing forests essential for the persistence of old forest plant and animal communities. Maximizing β versus α-diversity may further reduce costs by reducing the total area required to meet conservation targets and enhancing landscape heterogeneity. Although the potential value of carbon credit sales declined as a fraction of total acquisition costs, even conservative scenarios using a carbon credit value of $12.5/T suggest reductions in acquisition cost of up to $235 M, indicating that carbon credit sales could substantially reduce the costs of conservation. PMID:24918621

Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity

PubMed Central

Hegyi, Barnabás; Levendovszky, János

2010-01-01

Battery-operated medical implants—such as pacemakers or cardioverter-defibrillators—have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading—hence to improve system performance—in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability. PMID:20379346

Ectomycorrhizal fungal diversity increases phosphorus uptake efficiency of European beech.

PubMed

Köhler, Julia; Yang, Nan; Pena, Rodica; Raghavan, Venket; Polle, Andrea; Meier, Ina C

2018-05-17

Increases in summer droughts and nitrogen (N) deposition have raised concerns of widespread biodiversity loss and nutrient imbalances, but our understanding of the ecological role of ectomycorrhizal fungal (ECMF) diversity in mediating root functions remains a major knowledge gap. We used different global change scenarios to experimentally alter the composition of ECMF communities colonizing European beech saplings and examined the consequences for phosphorus (P) uptake (H 3 33 PO 4 feeding experiment) and use efficiencies of trees. Specifically, we simulated increases in temperature and N deposition and decreases in soil moisture and P availability in a factorial experiment. Here, we show that ECMF α diversity is a major factor contributing to root functioning under global change. P uptake efficiency of beech significantly increased with increasing ECMF species richness and diversity, as well as with decreasing P availability. As a consequence of decreases in ECMF diversity, P uptake efficiency decreased when soil moisture was limiting. By contrast, P use efficiencies were a direct (negative) function of P availability and not of ECMF diversity. We conclude that increasing summer droughts may reduce ECMF diversity and the complementarity of P uptake by ECMF species, which will add to negative growth effects expected from nutrient imbalances under global change. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Dilemmas in the (un)veiling of the diagnosis of Alzheimer's disease: walking an ethical and professional tight rope.

PubMed

Karnieli-Miller, Orit; Werner, Perla; Aharon-Peretz, Judith; Eidelman, Shmuel

2007-08-01

To enhance the understanding and effect of physician's difficulties, attitudes and communication styles on the disclosure of the diagnosis of AD in practice. Qualitative, phenomenological study, combining pre-encounter interviews with physicians, observations of actual encounters of diagnosis disclosure of AD, and post-encounter interviews. There were various ways or tactics to (un)veil the bad news that may be perceived as different ways of dulling the impact and avoiding full and therefore problematic statements. In the actual encounters this was accomplished by keeping encounters short, avoiding elaboration, confirmation of comprehension and explicit terminology and using fractured sentences. The present study's findings highlight the difficulties encountered in breaking the news about AD, in the way it is actually done, and the problems that may arise from this way of un/veiling the news. The main problem is that the reluctance to make a candid disclosure of the diagnosis as was demonstrated in this study may violate basic moral and legal rights and may also deprive patients and caregivers of some of the benefits of early disclosure of diagnosis. There is a need for assisting physicians to cope with their personal difficulties, problems and pitfalls in breaking the news.

Data analysis unveils a new stylized fact in foreign currency markets

NASA Astrophysics Data System (ADS)

Nacher, J. C.; Ochiai, T.

2012-09-01

The search for stylized facts (i.e., simplified empirical facts) is of capital importance in econophysics because the stylized facts constitute the experimental empirical body on which theories and models should be tested. At the moment they are too few and this is an important limitation to the progress in the field. In this work, we unveil a new stylized fact, which consists of resistance effect and breaking-acceleration effect that implicitly requires a long memory feature in price movement. By analyzing a vast amount of historical data, we demonstrate that the financial market tends to exceed a past (historical) extreme price less often than expected by a classic short-memory model (e.g., Black-Scholes model). We call it resistance effect. However, when the market does it, we predict that the average volatility at that time point will be much higher (accelerates more). It means, in average, volatility accelerates more when the price breaks the highest (lowest) value. We refer to this as breaking-acceleration effect. These observed empirical facts are actually an effect which may arise from technical trading and psychological effects. Taken together, these results indicate that, beyond the predictive capability of this unveiled stylized fact, traditional short-memory models do not faithfully capture the market dynamics.

Hydrologic drivers of tree biodiversity: The impact of climate change (Invited)

NASA Astrophysics Data System (ADS)

Rodriguez-Iturbe, I.; Konar, M.; Muneepeerakul, R.; Azaele, S.; Bertuzzo, E.; Rinaldo, A.

2009-12-01

Biodiversity of forests is of major importance for society. The possible impact of climate change on the characteristics of tree diversity is a topic of crucial importance with relevant implications for conservation campaigns and resource management. Here we present the main results of the expected biodiversity changes in the Mississippi-Missouri River Basin (MMRS) and two of its subregions under different scenarios of possible climate change. A mechanistic neutral metapopulation model is developed to study the main drivers of large scale biodiversity signatures in the MMRS system. The region is divided into 824 Direct Tributary Areas (DTAs), each one characterized by its own habitat capacity. Data for the spatial occurrence of the 231 species present in the system is taken from the US Forest Service Inventory and Analysis Database. The model has permeable boundaries to account for immigration from the regions surrounding the MMRS. The model accounts for key aspects of ecological dynamics (e.g., birth, death, speciation, and migration) and is fundamentally driven by the mean annual precipitation characteristic of each of the DTAs in the system. It is found that such a simple model, with only four parameters, yields an excellent representation of the observed local species richness (LSR), between-community (β) diversity, and species rank-occupancy function. The mean annual rainfall of each DTA is then changed according to the climate scenarios and new habitat capacities are thus obtained throughout the MMRS and its subregions. The resulting large-scale biodiversity signatures are computed and compared with those of the present scenario, showing that there are very important changes arising from the climate change conditions. For the dry scenarios, it is shown that there is a considerable decrease of species richness, both at local and regional scales, and a contraction of species' geographic ranges. These findings link the hydrologic and ecological dynamics of the MMRS under climate change conditions and are important for a comprehensive evaluation of the climate change impacts over the United States.

Rapid topographic and bathymetric reconnaissance using airborne LiDAR

NASA Astrophysics Data System (ADS)

Axelsson, Andreas

2010-10-01

Today airborne LiDAR (Light Detection And Ranging) systems has gained acceptance as a powerful tool to rapidly collect invaluable information to assess the impact from either natural disasters, such as hurricanes, earthquakes and flooding, or human inflicted disasters such as terrorist/enemy activities. Where satellite based imagery provides an excellent tool to remotely detect changes in the environment, the LiDAR systems, being active remote sensors, provide an unsurpassed method to quantify these changes. The strength of the active laser based systems is especially evident in areas covered by occluding vegetation or in the shallow coastal zone as the laser can penetrate the vegetation or water body to unveil what is below. The purpose of this paper is to address the task to survey complex areas with help of the state-of-the-art airborne LiDAR systems and also discuss scenarios where the method is used today and where it may be used tomorrow. Regardless if it is a post-hurricane survey or a preparation stage for a landing operation in unchartered waters, it is today possible to collect, process and present a dense 3D model of the area of interest within just a few hours from deployment. By utilizing the advancement in processing power and wireless network capabilities real-time presentation would be feasible.

Exploring the Dynamics of Cell Processes through Simulations of Fluorescence Microscopy Experiments

PubMed Central

Angiolini, Juan; Plachta, Nicolas; Mocskos, Esteban; Levi, Valeria

2015-01-01

Fluorescence correlation spectroscopy (FCS) methods are powerful tools for unveiling the dynamical organization of cells. For simple cases, such as molecules passively moving in a homogeneous media, FCS analysis yields analytical functions that can be fitted to the experimental data to recover the phenomenological rate parameters. Unfortunately, many dynamical processes in cells do not follow these simple models, and in many instances it is not possible to obtain an analytical function through a theoretical analysis of a more complex model. In such cases, experimental analysis can be combined with Monte Carlo simulations to aid in interpretation of the data. In response to this need, we developed a method called FERNET (Fluorescence Emission Recipes and Numerical routines Toolkit) based on Monte Carlo simulations and the MCell-Blender platform, which was designed to treat the reaction-diffusion problem under realistic scenarios. This method enables us to set complex geometries of the simulation space, distribute molecules among different compartments, and define interspecies reactions with selected kinetic constants, diffusion coefficients, and species brightness. We apply this method to simulate single- and multiple-point FCS, photon-counting histogram analysis, raster image correlation spectroscopy, and two-color fluorescence cross-correlation spectroscopy. We believe that this new program could be very useful for predicting and understanding the output of fluorescence microscopy experiments. PMID:26039162

VLTI Imaging of a High-Mass Protobinary System: Unveiling the Dynamical Processes in High-Mass Star Formation

NASA Astrophysics Data System (ADS)

Kraus, S.; Kluska, J.; Kreplin, A.; Bate, M.; Harries, T.; Hofmann, K.-H.; Hone, E.; Monnier, J.; Weigelt, G.; Anugu, N.; de Wit, W.-J..; Wittkowski, M.

2017-12-01

High-mass stars exhibit a significantly higher multiplicity frequency than low-mass stars, likely reflecting differences in how they formed. Theory suggests that high-mass binaries may form by the fragmentation of self-gravitational discs or by alternative scenarios such as disc-assisted capture. Near-infrared interferometric observations reveal the high-mass young stellar object IRAS 17216-3801 to be a close high-mass protobinary with a separation of 0.058 arcseconds ( 170 au). This is the closest high-mass protobinary system imaged to date. We also resolve near- infrared excess emission around the individual stars, which is associated with hot dust in circumstellar discs. These discs are strongly misaligned with respect to the binary separation vector, indicating that tidal forces have not yet had time to realign. We measure a higher accretion rate towards the circumsecondary disc, confirming a hydrodynamic effect where the secondary star disrupts the primary star’s accretion stream and effectively limits the mass that the primary star can accrete. NACO L'-band imaging may also have resolved the circumbinary disc that feeds the accretion onto the circumstellar discs. This discovery demonstrates the unique capabilities of the VLTI, creating exciting new opportunities to study the dynamical processes that govern the architecture of close multiple systems.

Large Scale Variability Survey of Orion II: mapping the young, low-mass stellar populations

NASA Astrophysics Data System (ADS)

Briceño, C.; Calvet, N.; Hartmann, L. W.; Vivas, A. K.

2000-12-01

We present further results of our ongoing large scale variability survey of the Orion OB1 Association, carried out with the 8k x 8k CCD Mosaic Camera on the 1m Schmidt telescope at the Venezuela National Observatory. In an area of over 60 square degrees we have unveiled new populations of low-mass young stars over a range of environments, from the dense molecular clouds of the Orion belt region, Ori OB 1b, to areas devoid of gas in Orion OB 1a. These new young stars span ages from 1-2 Myr in Ori OB 1b to roughly 10 Myr in Ori OB 1a, a likely scenario of sequential star formation triggered by the first generation of massive stars. Proxy indicators like Hα emission and near-IR excesses show that accretion from circumstellar disks in the 10 Myr stars of Ori OB 1a has mostly stopped. This population is a numerous analog of groups like TW Hya, making it an excellent laboratory to look for debris disks and study the epoch of planet formation in sparse, non-clustered environments. Research reported herein funded by NSF grant No. 9987367, and by CONICIT and Ministerio de Ciencia y Tecnología, Venezuela.

Experimental study on ignition mechanisms of wet granulation sulfur caused by friction.

PubMed

Dai, Haoyuan; Fan, Jianchun; Wu, Shengnan; Yu, Yanqiu; Liu, Di; Hu, Zhibin

2018-02-15

It is common to see fire accidents caused by friction during the storage and transportation of wet granulation sulfur. To study the sulfur ignition mechanism under friction conditions, a new rotating test apparatus is developed to reproduce friction scenes at lab scale. A series of experiments are performed under different normal loads. The SEM-EDS and the XRD were utilized to examine the morphologies and compositions of the tested specimens and the friction products. Experimental results show that these two methods are mostly in agreement with each other. The iron-sulfide compounds are produced and the proportion of iron-sulfide compounds is reduced with normal loads increasing, compared to the total number of the friction products. The facts implied by the integration analysis of friction products with the temperature changes of the near friction surface unveil an underlying mechanism that may explain sulfur ignition by friction in real scenarios. The sulfur ignition may be mainly caused by the spontaneous combustion of iron sulfide compounds produced by friction under low normal load with 200N. With the increase of normal loads, the resulting iron-sulfide compounds are decreasing and the high temperature from friction heat begins to play a major role in causing fire. Copyright © 2017 Elsevier B.V. All rights reserved.

SWIM: a computational tool to unveiling crucial nodes in complex biological networks

PubMed Central

Paci, Paola; Colombo, Teresa; Fiscon, Giulia; Gurtner, Aymone; Pavesi, Giulio; Farina, Lorenzo

2017-01-01

SWItchMiner (SWIM) is a wizard-like software implementation of a procedure, previously described, able to extract information contained in complex networks. Specifically, SWIM allows unearthing the existence of a new class of hubs, called “fight-club hubs”, characterized by a marked negative correlation with their first nearest neighbors. Among them, a special subset of genes, called “switch genes”, appears to be characterized by an unusual pattern of intra- and inter-module connections that confers them a crucial topological role, interestingly mirrored by the evidence of their clinic-biological relevance. Here, we applied SWIM to a large panel of cancer datasets from The Cancer Genome Atlas, in order to highlight switch genes that could be critically associated with the drastic changes in the physiological state of cells or tissues induced by the cancer development. We discovered that switch genes are found in all cancers we studied and they encompass protein coding genes and non-coding RNAs, recovering many known key cancer players but also many new potential biomarkers not yet characterized in cancer context. Furthermore, SWIM is amenable to detect switch genes in different organisms and cell conditions, with the potential to uncover important players in biologically relevant scenarios, including but not limited to human cancer. PMID:28317894

SWIM: a computational tool to unveiling crucial nodes in complex biological networks.

PubMed

Paci, Paola; Colombo, Teresa; Fiscon, Giulia; Gurtner, Aymone; Pavesi, Giulio; Farina, Lorenzo

2017-03-20

SWItchMiner (SWIM) is a wizard-like software implementation of a procedure, previously described, able to extract information contained in complex networks. Specifically, SWIM allows unearthing the existence of a new class of hubs, called "fight-club hubs", characterized by a marked negative correlation with their first nearest neighbors. Among them, a special subset of genes, called "switch genes", appears to be characterized by an unusual pattern of intra- and inter-module connections that confers them a crucial topological role, interestingly mirrored by the evidence of their clinic-biological relevance. Here, we applied SWIM to a large panel of cancer datasets from The Cancer Genome Atlas, in order to highlight switch genes that could be critically associated with the drastic changes in the physiological state of cells or tissues induced by the cancer development. We discovered that switch genes are found in all cancers we studied and they encompass protein coding genes and non-coding RNAs, recovering many known key cancer players but also many new potential biomarkers not yet characterized in cancer context. Furthermore, SWIM is amenable to detect switch genes in different organisms and cell conditions, with the potential to uncover important players in biologically relevant scenarios, including but not limited to human cancer.

Multi-hazard risk analysis using the FP7 RASOR Platform

NASA Astrophysics Data System (ADS)

Koudogbo, Fifamè N.; Duro, Javier; Rossi, Lauro; Rudari, Roberto; Eddy, Andrew

2014-10-01

Climate change challenges our understanding of risk by modifying hazards and their interactions. Sudden increases in population and rapid urbanization are changing exposure to risk around the globe, making impacts harder to predict. Despite the availability of operational mapping products, there is no single tool to integrate diverse data and products across hazards, update exposure data quickly and make scenario-based predictions to support both short and long-term risk-related decisions. RASOR (Rapid Analysis and Spatialization Of Risk) will develop a platform to perform multi-hazard risk analysis for the full cycle of disaster management, including targeted support to critical infrastructure monitoring and climate change impact assessment. A scenario-driven query system simulates future scenarios based on existing or assumed conditions and compares them with historical scenarios. RASOR will thus offer a single work environment that generates new risk information across hazards, across data types (satellite EO, in-situ), across user communities (global, local, climate, civil protection, insurance, etc.) and across the world. Five case study areas are considered within the project, located in Haiti, Indonesia, Netherlands, Italy and Greece. Initially available over those demonstration areas, RASOR will ultimately offer global services to support in-depth risk assessment and full-cycle risk management.

Knowledge sharing within organizations: linking art, theory, scenarios and professional experience

NASA Technical Reports Server (NTRS)

Burton, Y. C.; Bailey, T.

2000-01-01

In this presentation, Burton and Bailey, discuss the challenges and opportunities in developing knowledge sharing systems in organizations. Bailey provides a tool using imagery and collage for identifying and utilizing the diverse values and beliefs of individuals and groups. Burton reveals findings from a business research study that examines how social construction influences knowledge sharing among task oriented groups.

Integrating natural disturbances and management activities to examine risks and opportunities in the central Oregon landscape analysis

Treesearch

Miles A. Hemstrom; James Merzenich; Theresa Burcsu; Janet Ohmann; Ryan Singleton

2010-01-01

We used state and transition models to integrate natural disturbances and management activities for a 275 000-ha landscape in the central Oregon Cascades. The landscape consists of a diverse mix of land ownerships, land use allocations, and environments. Three different management scenarios were developed from public input: (1) no management except wildfire suppression...

Streamflow Prediction in Ungauged, Irrigated Basins

NASA Astrophysics Data System (ADS)

Zhang, M.; Thompson, S. E.

2016-12-01

The international "predictions in ungauged basins" or "PUB" effort has broadened and improved the tools available to support water resources management in sparsely observed regions. These tools have, however, been primarily focused on regions with limited diversion of surface or shallow groundwater resources. Incorporating anthropogenic activity into PUB methods is essential given the high level of development of many basins. We extended an existing stochastic framework used to predict the flow duration curve to explore the effects of irrigation on streamflow dynamics. Four canonical scenarios were considered in which irrigation water was (i) primarily sourced from water imports, (ii) primarily sourced from direct in-channel diversions, (iii) sourced from shallow groundwater with direct connectivity to stream channels, or (iv) sourced from deep groundwater that is indirectly connected to surface flow via a shallow aquifer. By comparing the predicted flow duration curves to those predicted by accounting for climate and geomorphic factors in isolation, specific "fingerprints" of human water withdrawals could be identified for the different irrigation scenarios, and shown to be sensitive to irrigation volumes and scheduling. The results provide a first insight into PUB methodologies that could be employed in heavily managed basins.

DnaSAM: Software to perform neutrality testing for large datasets with complex null models.

PubMed

Eckert, Andrew J; Liechty, John D; Tearse, Brandon R; Pande, Barnaly; Neale, David B

2010-05-01

Patterns of DNA sequence polymorphisms can be used to understand the processes of demography and adaptation within natural populations. High-throughput generation of DNA sequence data has historically been the bottleneck with respect to data processing and experimental inference. Advances in marker technologies have largely solved this problem. Currently, the limiting step is computational, with most molecular population genetic software allowing a gene-by-gene analysis through a graphical user interface. An easy-to-use analysis program that allows both high-throughput processing of multiple sequence alignments along with the flexibility to simulate data under complex demographic scenarios is currently lacking. We introduce a new program, named DnaSAM, which allows high-throughput estimation of DNA sequence diversity and neutrality statistics from experimental data along with the ability to test those statistics via Monte Carlo coalescent simulations. These simulations are conducted using the ms program, which is able to incorporate several genetic parameters (e.g. recombination) and demographic scenarios (e.g. population bottlenecks). The output is a set of diversity and neutrality statistics with associated probability values under a user-specified null model that are stored in easy to manipulate text file. © 2009 Blackwell Publishing Ltd.

Trait-specific long-term consequences of genomic selection in beef cattle.

PubMed

de Rezende Neves, Haroldo Henrique; Carvalheiro, Roberto; de Queiroz, Sandra Aidar

2018-02-01

Simulation studies allow addressing consequences of selection schemes, helping to identify effective strategies to enable genetic gain and maintain genetic diversity. The aim of this study was to evaluate the long-term impact of genomic selection (GS) in genetic progress and genetic diversity of beef cattle. Forward-in-time simulation generated a population with pattern of linkage disequilibrium close to that previously reported for real beef cattle populations. Different scenarios of GS and traditional pedigree-based BLUP (PBLUP) selection were simulated for 15 generations, mimicking selection for female reproduction and meat quality. For GS scenarios, an alternative selection criterion was simulated (wGBLUP), intended to enhance long-term gains by attributing more weight to favorable alleles with low frequency. GS allowed genetic progress up to 40% greater than PBLUP, for female reproduction and meat quality. The alternative criterion wGBLUP did not increase long-term response, although allowed reducing inbreeding rates and loss of favorable alleles. The results suggest that GS outperforms PBLUP when the selected trait is under less polygenic background and that attributing more weight to low-frequency favorable alleles can reduce inbreeding rates and loss of favorable alleles in GS.

Survivial Strategies in Bacterial Range Expansions

NASA Astrophysics Data System (ADS)

Frey, Erwin

2014-03-01

Bacterial communities represent complex and dynamic ecological systems. Different environmental conditions as well as bacterial interactions determine the establishment and sustainability of bacterial diversity. In this talk we discuss the competition of three Escherichia coli strains during range expansions on agar plates. In this bacterial model system, a colicin E2 producing strain C competes with a colicin resistant strain R and with a colicin sensitive strain S for new territory. Genetic engineering allows us to tune the growth rates of the strains and to study distinct ecological scenarios. These scenarios may lead to either single-strain dominance, pairwise coexistence, or to the coexistence of all three strains. In order to elucidate the survival mechanisms of the individual strains, we also developed a stochastic agent-based model to capture the ecological scenarios in silico. In a combined theoretical and experimental approach we are able to show that the level of biodiversity depends crucially on the composition of the inoculum, on the relative growth rates of the three strains, and on the effective reach of colicin toxicity.

A triangular fuzzy TOPSIS-based approach for the application of water technologies in different emergency water supply scenarios.

PubMed

Qu, Jianhua; Meng, Xianlin; Yu, Huan; You, Hong

2016-09-01

Because of the increasing frequency and intensity of unexpected natural disasters, providing safe drinking water for the affected population following a disaster has become a global challenge of growing concern. An onsite water supply technology that is portable, mobile, or modular is a more suitable and sustainable solution for the victims than transporting bottled water. In recent years, various water techniques, such as membrane-assisted technologies, have been proposed and successfully implemented in many places. Given the diversity of techniques available, the current challenge is how to scientifically identify the optimum options for different disaster scenarios. Hence, a fuzzy triangular-based multi-criteria, group decision-making tool was developed in this research. The approach was then applied to the selection of the most appropriate water technologies corresponding to the different emergency water supply scenarios. The results show this tool capable of facilitating scientific analysis in the evaluation and selection of emergency water technologies for enduring security drinking water supply in disaster relief.

Evolutionary Algorithms for Boolean Functions in Diverse Domains of Cryptography.

PubMed

Picek, Stjepan; Carlet, Claude; Guilley, Sylvain; Miller, Julian F; Jakobovic, Domagoj

2016-01-01

The role of Boolean functions is prominent in several areas including cryptography, sequences, and coding theory. Therefore, various methods for the construction of Boolean functions with desired properties are of direct interest. New motivations on the role of Boolean functions in cryptography with attendant new properties have emerged over the years. There are still many combinations of design criteria left unexplored and in this matter evolutionary computation can play a distinct role. This article concentrates on two scenarios for the use of Boolean functions in cryptography. The first uses Boolean functions as the source of the nonlinearity in filter and combiner generators. Although relatively well explored using evolutionary algorithms, it still presents an interesting goal in terms of the practical sizes of Boolean functions. The second scenario appeared rather recently where the objective is to find Boolean functions that have various orders of the correlation immunity and minimal Hamming weight. In both these scenarios we see that evolutionary algorithms are able to find high-quality solutions where genetic programming performs the best.

Color-Space-Based Visual-MIMO for V2X Communication †

PubMed Central

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-01-01

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

Color-Space-Based Visual-MIMO for V2X Communication.

PubMed

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-04-23

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

Can diversity in root architecture explain plant water use efficiency? A modeling study

PubMed Central

Tron, Stefania; Bodner, Gernot; Laio, Francesco; Ridolfi, Luca; Leitner, Daniel

2015-01-01

Drought stress is a dominant constraint to crop production. Breeding crops with adapted root systems for effective uptake of water represents a novel strategy to increase crop drought resistance. Due to complex interaction between root traits and high diversity of hydrological conditions, modeling provides important information for trait based selection. In this work we use a root architecture model combined with a soil-hydrological model to analyze whether there is a root system ideotype of general adaptation to drought or water uptake efficiency of root systems is a function of specific hydrological conditions. This was done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soil textures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in water uptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep root systems are not superior in water uptake under all hydrological scenarios. Our results demonstrate that mere architectural description is insufficient to find root systems of optimum functionality. We find that in environments with sufficient rainfall before the growing season, root depth represents the key trait for the exploration of stored water, especially in fine soils. Root density, instead, especially near the soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supply is mainly provided by rainfall events during the root system development. We therefore concluded that trait based root breeding has to consider root systems with specific adaptation to the hydrology of the target environment. PMID:26412932

Can diversity in root architecture explain plant water use efficiency? A modeling study.

PubMed

Tron, Stefania; Bodner, Gernot; Laio, Francesco; Ridolfi, Luca; Leitner, Daniel

2015-09-24

Drought stress is a dominant constraint to crop production. Breeding crops with adapted root systems for effective uptake of water represents a novel strategy to increase crop drought resistance. Due to complex interaction between root traits and high diversity of hydrological conditions, modeling provides important information for trait based selection. In this work we use a root architecture model combined with a soil-hydrological model to analyze whether there is a root system ideotype of general adaptation to drought or water uptake efficiency of root systems is a function of specific hydrological conditions. This was done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soil textures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in water uptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep root systems are not superior in water uptake under all hydrological scenarios. Our results demonstrate that mere architectural description is insufficient to find root systems of optimum functionality. We find that in environments with sufficient rainfall before the growing season, root depth represents the key trait for the exploration of stored water, especially in fine soils. Root density, instead, especially near the soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supply is mainly provided by rainfall events during the root system development. We therefore concluded that trait based root breeding has to consider root systems with specific adaptation to the hydrology of the target environment.

Where, When, and How mmWave is Used in 5G and Beyond

NASA Astrophysics Data System (ADS)

Sakaguchi, Kei; Haustein, Thomas; Barbarossa, Sergio; Strinati, Emilio Calvanese; Clemente, Antonio; Destino, Giuseppe; Pärssinen, Aarno; Kim, Ilgyu; Chung, Heesang; Kim, Junhyeong; Keusgen, Wilhelm; Weiler, Richard J.; Takinami, Koji; Ceci, Elena; Sadri, Ali; Xian, Liang; Maltsev, Alexander; Tran, Gia Khanh; Ogawa, Hiroaki; Mahler, Kim; Heath, Robert W., Jr.

Wireless engineers and business planners commonly raise the question on where, when, and how millimeter-wave (mmWave) will be used in 5G and beyond. Since the next generation network is not just a new radio access standard, but instead an integration of networks for vertical markets with diverse applications, answers to the question depend on scenarios and use cases to be deployed. This paper gives four 5G mmWave deployment examples and describes in chronological order the scenarios and use cases of their probable deployment, including expected system architectures and hardware prototypes. The paper starts with 28 GHz outdoor backhauling for fixed wireless access and moving hotspots, which will be demonstrated at the PyeongChang winter Olympic games in 2018. The second deployment example is a 60 GHz unlicensed indoor access system at the Tokyo-Narita airport, which is combined with Mobile Edge Computing (MEC) to enable ultra-high speed content download with low latency. The third example is mmWave mesh network to be used as a micro Radio Access Network ({\\mu}-RAN), for cost-effective backhauling of small-cell Base Stations (BSs) in dense urban scenarios. The last example is mmWave based Vehicular-to-Vehicular (V2V) and Vehicular-to-Everything (V2X) communications system, which enables automated driving by exchanging High Definition (HD) dynamic map information between cars and Roadside Units (RSUs). For 5G and beyond, mmWave and MEC will play important roles for a diverse set of applications that require both ultra-high data rate and low latency communications.

Testing Domestication Scenarios of Lima Bean (Phaseolus lunatus L.) in Mesoamerica: Insights from Genome-Wide Genetic Markers

PubMed Central

Chacón-Sánchez, María I.; Martínez-Castillo, Jaime

2017-01-01

Plant domestication can be seen as a long-term process that involves a complex interplay among demographic processes and evolutionary forces. Previous studies have suggested two domestication scenarios for Lima bean in Mesoamerica: two separate domestication events, one from gene pool MI in central-western Mexico and another one from gene pool MII in the area Guatemala-Costa Rica, or a single domestication from gene pool MI in central-western Mexico followed by post-domestication gene flow with wild populations. In this study we evaluated the genetic structure of the wild gene pool and tested these two competing domestication scenarios of Lima bean in Mesoamerica by applying an ABC approach to a set of genome-wide SNP markers. The results confirm the existence of three gene pools in wild Lima bean, two Mesoamerican gene pools (MI and MII) and the Andean gene pool (AI), and suggest the existence of another gene pool in central Colombia. The results indicate that although both domestication scenarios may be supported by genetic data, higher statistical support was given to the single domestication scenario in central-western Mexico followed by admixture with wild populations. Domestication would have involved strong founder effects reflected in loss of genetic diversity and increased LD levels in landraces. Genomic regions affected by selection were detected and these may harbor candidate genes related to domestication. PMID:28955351

Evaluating hydrological response to forecasted land-use change—scenario testing with the automated geospatial watershed assessment (AGWA) tool

USGS Publications Warehouse

Kepner, William G.; Semmens, Darius J.; Hernandez, Mariano; Goodrich, David C.

2009-01-01

Envisioning and evaluating future scenarios has emerged as a critical component of both science and social decision-making. The ability to assess, report, map, and forecast the life support functions of ecosystems is absolutely critical to our capacity to make informed decisions to maintain the sustainable nature of our ecosystem services now and into the future. During the past two decades, important advances in the integration of remote imagery, computer processing, and spatial-analysis technologies have been used to develop landscape information that can be integrated with hydrologic models to determine long-term change and make predictive inferences about the future. Two diverse case studies in northwest Oregon (Willamette River basin) and southeastern Arizona (San Pedro River) were examined in regard to future land use scenarios relative to their impact on surface water conditions (e.g., sediment yield and surface runoff) using hydrologic models associated with the Automated Geospatial Watershed Assessment (AGWA) tool. The base reference grid for land cover was modified in both study locations to reflect stakeholder preferences 20 to 60 yrs into the future, and the consequences of landscape change were evaluated relative to the selected future scenarios. The two studies provide examples of integrating hydrologic modeling with a scenario analysis framework to evaluate plausible future forecasts and to understand the potential impact of landscape change on ecosystem services.

Future trends of global atmospheric antimony emissions from anthropogenic activities until 2050

NASA Astrophysics Data System (ADS)

Zhou, Junrui; Tian, Hezhong; Zhu, Chuanyong; Hao, Jiming; Gao, Jiajia; Wang, Yong; Xue, Yifeng; Hua, Shenbin; Wang, Kun

2015-11-01

This paper presents the scenario forecast of global atmospheric antimony (Sb) emissions from anthropogenic activities till 2050. The projection scenarios are built based on the comprehensive global antimony emission inventory for the period 1995-2010 which is reported in our previous study. Three scenarios are set up to investigate the future changes of global antimony emissions as well as their source and region contribution characteristics. Trends of activity levels specified as 5 primary source categories are projected by combining the historical trend extrapolation with EIA International energy outlook 2013, while the source-specific dynamic emission factors are determined by applying transformed normal distribution functions. If no major changes in the efficiency of emission control are introduced and keep current air quality legislations (Current Legislation scenario), global antimony emissions will increase by a factor of 2 between 2010 and 2050. The largest increase in Sb emissions is projected from Asia due to large volume of nonferrous metals production and waste incineration. In case of enforcing the pollutant emission standards (Strengthened Control scenario), global antimony emissions in 2050 will stabilize with that of 2010. Moreover, we can anticipate further declines in Sb emissions for all continents with the best emission control performances (Maximum Feasible Technological Reduction scenario). Future antimony emissions from the top 10 largest emitting countries have also been calculated and source category contributions of increasing emissions of these countries present significant diversity. Furthermore, global emission projections in 2050 are distributed within a 1° × 1°latitude/longitude grid. East Asia, Western Europe and North America present remarkable differences in emission intensity under the three scenarios, which implies that source-and-country specific control measures are necessary to be implemented for abating Sb emissions from varied continents and countries in the future.

Unity in defence: honeybee workers exhibit conserved molecular responses to diverse pathogens.

PubMed

Doublet, Vincent; Poeschl, Yvonne; Gogol-Döring, Andreas; Alaux, Cédric; Annoscia, Desiderato; Aurori, Christian; Barribeau, Seth M; Bedoya-Reina, Oscar C; Brown, Mark J F; Bull, James C; Flenniken, Michelle L; Galbraith, David A; Genersch, Elke; Gisder, Sebastian; Grosse, Ivo; Holt, Holly L; Hultmark, Dan; Lattorff, H Michael G; Le Conte, Yves; Manfredini, Fabio; McMahon, Dino P; Moritz, Robin F A; Nazzi, Francesco; Niño, Elina L; Nowick, Katja; van Rij, Ronald P; Paxton, Robert J; Grozinger, Christina M

2017-03-02

Organisms typically face infection by diverse pathogens, and hosts are thought to have developed specific responses to each type of pathogen they encounter. The advent of transcriptomics now makes it possible to test this hypothesis and compare host gene expression responses to multiple pathogens at a genome-wide scale. Here, we performed a meta-analysis of multiple published and new transcriptomes using a newly developed bioinformatics approach that filters genes based on their expression profile across datasets. Thereby, we identified common and unique molecular responses of a model host species, the honey bee (Apis mellifera), to its major pathogens and parasites: the Microsporidia Nosema apis and Nosema ceranae, RNA viruses, and the ectoparasitic mite Varroa destructor, which transmits viruses. We identified a common suite of genes and conserved molecular pathways that respond to all investigated pathogens, a result that suggests a commonality in response mechanisms to diverse pathogens. We found that genes differentially expressed after infection exhibit a higher evolutionary rate than non-differentially expressed genes. Using our new bioinformatics approach, we unveiled additional pathogen-specific responses of honey bees; we found that apoptosis appeared to be an important response following microsporidian infection, while genes from the immune signalling pathways, Toll and Imd, were differentially expressed after Varroa/virus infection. Finally, we applied our bioinformatics approach and generated a gene co-expression network to identify highly connected (hub) genes that may represent important mediators and regulators of anti-pathogen responses. Our meta-analysis generated a comprehensive overview of the host metabolic and other biological processes that mediate interactions between insects and their pathogens. We identified key host genes and pathways that respond to phylogenetically diverse pathogens, representing an important source for future functional studies as well as offering new routes to identify or generate pathogen resilient honey bee stocks. The statistical and bioinformatics approaches that were developed for this study are broadly applicable to synthesize information across transcriptomic datasets. These approaches will likely have utility in addressing a variety of biological questions.

Microbial Diversity and Cyanobacterial Production in Dziani Dzaha Crater Lake, a Unique Tropical Thalassohaline Environment

PubMed Central

Carré, Claire; Cellamare, Maria; Duval, Charlotte; Intertaglia, Laurent; Lavergne, Céline; Roques, Cécile

2017-01-01

This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.6–14.5 g L-1 eq. CO32-, i.e. 160–220 mM compare to around 2–2.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 μg chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the photosynthetic biomass was dominated (>97% of total biovolume) by the filamentous cyanobacteria Arthrospira sp. with a straight morphotype. In situ daily photosynthetic oxygen production ranged from 17.3 to 22.2 g O2 m-2 d-1, consistent with experimental production / irradiance measurements and modeling. Heterotrophic bacterioplankton was extremely abundant, with cell densities up to 1.5 108 cells mL-1 in the whole water column. Isolation and culture of 59 Eubacteria strains revealed the prevalence of alkaliphilic and halophilic organisms together with taxa unknown to date, based on 16S rRNA gene analysis. A single cloning-sequencing approach using archaeal 16S rDNA gene primers unveiled the presence of diverse extremophilic Euryarchaeota. The water chemistry of Dziani Dzaha Lake supports the hypothesis that it was derived from seawater and strongly modified by geological conditions and microbial activities that increased the alkalinity. Dziani Dzaha has a unique consortium of cyanobacteria, phytoplankton, heterotrophic Eubacteria and Archaea, with very few unicellular protozoa, that will deserve further deep analysis to unravel its uncommon diversity. A single taxon, belonging to the genus Arthrospira, was found responsible for almost all photosynthetic primary production. PMID:28045976

A metric for quantifying El Niño pattern diversity with implications for ENSO-mean state interaction

NASA Astrophysics Data System (ADS)

Lemmon, Danielle E.; Karnauskas, Kristopher B.

2018-04-01

Recent research on the El Niño-Southern Oscillation (ENSO) phenomenon increasingly reveals the highly complex and diverse nature of ENSO variability. A method of quantifying ENSO spatial pattern uniqueness and diversity is presented, which enables (1) formally distinguishing between unique and "canonical" El Niño events, (2) testing whether historical model simulations aptly capture ENSO diversity by comparing with instrumental observations, (3) projecting future ENSO diversity using future model simulations, (4) understanding the dynamics that give rise to ENSO diversity, and (5) analyzing the associated diversity of ENSO-related atmospheric teleconnection patterns. Here we develop a framework for measuring El Niño spatial SST pattern uniqueness and diversity for a given set of El Niño events using two indices, the El Niño Pattern Uniqueness (EPU) index and El Niño Pattern Diversity (EPD) index, respectively. By applying this framework to instrumental records, we independently confirm a recent regime shift in El Niño pattern diversity with an increase in unique El Niño event sea surface temperature patterns. However, the same regime shift is not observed in historical CMIP5 model simulations; moreover, a comparison between historical and future CMIP5 model scenarios shows no robust change in future ENSO diversity. Finally, we support recent work that asserts a link between the background cooling of the eastern tropical Pacific and changes in ENSO diversity. This robust link between an eastern Pacific cooling mode and ENSO diversity is observed not only in instrumental reconstructions and reanalysis, but also in historical and future CMIP5 model simulations.

Mercury MESSENGER Stamp Unveiling

NASA Image and Video Library

2011-05-03

Daughters of NASA astronaut Alan Shepard, Laura Shepard Churchley, standing left, Alice Wackermann and Julie Jenkins, standing right, speak during an unveiling ceremony of two USPS stamps that commemorate and celebrate 50 years of US Spaceflight and the MESSENGER program during an event, Wednesday, May 4, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. One stamp commemorates NASA’s Project Mercury, America’s first manned spaceflight program, and NASA astronaut Alan Shepard’s historic flight on May 5, 1961, aboard spacecraft Freedom 7. The other stamp draws attention to NASA’s unmanned MESSENGER mission, a scientific investigation of the planet Mercury. On March 17, 2011, MESSENGER became the first spacecraft to enter into orbit around Mercury. Photo Credit: (NASA/Bill Ingalls)

Quantification of non-coding RNA target localization diversity and its application in cancers.

PubMed

Cheng, Lixin; Leung, Kwong-Sak

2018-04-01

Subcellular localization is pivotal for RNAs and proteins to implement biological functions. The localization diversity of protein interactions has been studied as a crucial feature of proteins, considering that the protein-protein interactions take place in various subcellular locations. Nevertheless, the localization diversity of non-coding RNA (ncRNA) target proteins has not been systematically studied, especially its characteristics in cancers. In this study, we provide a new algorithm, non-coding RNA target localization coefficient (ncTALENT), to quantify the target localization diversity of ncRNAs based on the ncRNA-protein interaction and protein subcellular localization data. ncTALENT can be used to calculate the target localization coefficient of ncRNAs and measure how diversely their targets are distributed among the subcellular locations in various scenarios. We focus our study on long non-coding RNAs (lncRNAs), and our observations reveal that the target localization diversity is a primary characteristic of lncRNAs in different biotypes. Moreover, we found that lncRNAs in multiple cancers, differentially expressed cancer lncRNAs, and lncRNAs with multiple cancer target proteins are prone to have high target localization diversity. Furthermore, the analysis of gastric cancer helps us to obtain a better understanding that the target localization diversity of lncRNAs is an important feature closely related to clinical prognosis. Overall, we systematically studied the target localization diversity of the lncRNAs and uncovered its association with cancer.

Analysis of Present Day and Future OH and Methane Lifetime in the ACCMIP Simulations

NASA Technical Reports Server (NTRS)

Voulgarakis, A.; Naik, V.; Lamarque, J. -F.; Shindell, D. T.; Young, P. J.; Prather, M. J.; Wild, O.; Field, R. D.; Bergmann, D.; Cameron-Smith P.;

Diversity and origins of anaerobic metabolism in mitochondria and related organelles

PubMed Central

Stairs, Courtney W.; Leger, Michelle M.; Roger, Andrew J.

2015-01-01

Across the diversity of life, organisms have evolved different strategies to thrive in hypoxic environments, and microbial eukaryotes (protists) are no exception. Protists that experience hypoxia often possess metabolically distinct mitochondria called mitochondrion-related organelles (MROs). While there are some common metabolic features shared between the MROs of distantly related protists, these organelles have evolved independently multiple times across the breadth of eukaryotic diversity. Until recently, much of our knowledge regarding the metabolic potential of different MROs was limited to studies in parasitic lineages. Over the past decade, deep-sequencing studies of free-living anaerobic protists have revealed novel configurations of metabolic pathways that have been co-opted for life in low oxygen environments. Here, we provide recent examples of anaerobic metabolism in the MROs of free-living protists and their parasitic relatives. Additionally, we outline evolutionary scenarios to explain the origins of these anaerobic pathways in eukaryotes. PMID:26323757

Modelling the evolution and diversity of cumulative culture

PubMed Central

Enquist, Magnus; Ghirlanda, Stefano; Eriksson, Kimmo

2011-01-01

Previous work on mathematical models of cultural evolution has mainly focused on the diffusion of simple cultural elements. However, a characteristic feature of human cultural evolution is the seemingly limitless appearance of new and increasingly complex cultural elements. Here, we develop a general modelling framework to study such cumulative processes, in which we assume that the appearance and disappearance of cultural elements are stochastic events that depend on the current state of culture. Five scenarios are explored: evolution of independent cultural elements, stepwise modification of elements, differentiation or combination of elements and systems of cultural elements. As one application of our framework, we study the evolution of cultural diversity (in time as well as between groups). PMID:21199845

A Proposal To Improve Retention Rates of Culturally Diverse Students in the College and University Setting Using Interpreters, Go-Betweens, and Models.

ERIC Educational Resources Information Center

Fant, Hugh J.; And Others

Dropout rates at the college and university level are much higher for students of minority cultures than for their majority culture peers. This paper suggests that the "revolving door" scenario of minority-culture college students can be stemmed by the proper use of mentoring. A combination of successful peers (interpreters), university…

Warming climate may negatively affect native forest understory plant richness and composition by increasing invasions of non-native plants

NASA Astrophysics Data System (ADS)

Dovciak, M.; Wason, J. W., III; Frair, J.; Lesser, M.; Hurst, J.

2016-12-01

Warming climate is often expected to cause poleward and upslope migrations of native plant species and facilitate the spread of non-native plants, and thus affect the composition and diversity of forest understory plant communities. However, changing climate can often interact with other components of global environmental change, and especially so with land use, which often varies along extant climatic gradients making it more difficult to predict species and biodiversity responses to changing climate. We used large national databases (USDA FIA, NLCD, and PRISM) within GLM and NMDS analytical frameworks to study the effects of climate (temperature and precipitation), and land management (type, fragmentation, time since disturbance) on the diversity and composition of native and non-native plant species in forest understories across large geographical (environmental) gradients of the northeastern United States. We tested how non-native and native species diversity and composition responded to existing climate gradients and land-use drivers, and we approximated how changing climate may affect both native and non-native species composition and richness under different climate change scenarios (+1.5, 2, and 4.8 degrees C). Many understory forest plant communities already contain large proportions of non-native plants, particularly so in relatively warmer and drier areas, at lower elevations, and in areas with more substantial land-use histories. On the other hand, cooler and moister areas, higher elevations, and areas used predominantly for forestry or nature conservation (i.e., large contiguous forest cover) were characterized by a low proportion of non-native plant species in terms of both species cover and richness. In contrast to native plants, non-native plant richness was related positively to mean annual temperature and negatively to precipitation. Mountain areas appeared to serve as refugia for native forest understory species under the current climate, but considering various climate change scenarios (including IPCC) suggested that many of these climate refugia may considerably decline even under more moderate climate change scenarios as they may become increasingly invaded by non-native plant species.

Osteopathic Manipulative Treatment

MedlinePlus

... Library Osteopathic Manipulative Treatment Becoming a DO Video Library What is Osteopathic Medicine? Osteopathic Manipulative Treatment Page Content Nearly every day, medical science unveils new discoveries from brain scans to anti- ...

South-East Asia is the center of origin, diversity and dispersion of the rice blast fungus, Magnaporthe oryzae

PubMed Central

Saleh, Dounia; Milazzo, Joëlle; Adreit, Henri; Fournier, Elisabeth; Tharreau, Didier

2014-01-01

Inferring invasion routes and identifying reservoirs of diversity of plant pathogens are essential in proposing new strategies for their control. Magnaporthe oryzae, the fungus responsible for rice blast disease, has invaded all rice growing areas. Virulent genotypes regularly (re)emerge, causing rapid resistance breakdowns. However, the world-wide genetic subdivision of M. oryzae populations on rice and its past history of invasion have never been elucidated. In order to investigate the centers of diversity, origin and migration of M. oryzae on rice, we analyzed the genetic diversity of 55 populations from 15 countries. Three genetic clusters were identified world-wide. Asia was the center of diversity and the origin of most migrations to other continents. In Asia, two centers of diversity were revealed in the Himalayan foothills: South China–Laos–North Thailand, and western Nepal. Sexual reproduction persisted only in the South China–Laos–North Thailand region, which was identified as the putative center of origin of all M. oryzae populations on rice. Our results suggest a scenario of early evolution of M. oryzae on rice that matches the past history of rice domestication. This study confirms that crop domestication may have considerable influence on the pestification process of natural enemies. PMID:24320224

Comprehensive Census of Bacteria in Clean Rooms by Using DNA Microarray and Cloning Methods▿ †

PubMed Central

La Duc, Myron T.; Osman, Shariff; Vaishampayan, Parag; Piceno, Yvette; Andersen, Gary; Spry, J. A.; Venkateswaran, Kasthuri

2009-01-01

A census of clean room surface-associated bacterial populations was derived from the results of both the cloning and sequencing of 16S rRNA genes and DNA microarray (PhyloChip) analyses. Samples from the Lockheed Martin Aeronautics Multiple Testing Facility (LMA-MTF), the Kennedy Space Center Payload Hazard and Servicing Facility (KSC-PHSF), and the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) clean rooms were collected during the various assembly phases of the Phoenix and Mars Science Laboratory (MSL) spacecraft. Clone library-derived analyses detected a larger bacterial diversity prior to the arrival of spacecraft hardware in these clean room facilities. PhyloChip results were in agreement with this trend but also unveiled the presence of anywhere from 9- to 70-fold more bacterial taxa than cloning approaches. Among the facilities sampled, the JPL-SAF (MSL mission) housed a significantly less diverse bacterial population than either the LMA-MTF or KSC-PHSF (Phoenix mission). Bacterial taxa known to thrive in arid conditions were frequently detected in MSL-associated JPL-SAF samples, whereas proteobacterial lineages dominated Phoenix-associated KSC-PHSF samples. Comprehensive bacterial censuses, such as that reported here, will help space-faring nations preemptively identify contaminant biomatter that may compromise extraterrestrial life detection experiments. The robust nature and high sensitivity of DNA microarray technologies should prove beneficial to a wide range of scientific, electronic, homeland security, medical, and pharmaceutical applications and to any other ventures with a vested interest in monitoring and controlling contamination in exceptionally clean environments. PMID:19700540

Photophysical Diversity of Water-Soluble Fluorescent Conjugated Polymers Induced by Surfactant Stabilizers for Rapid and Highly Selective Determination of 2,4,6-Trinitrotoluene Traces.

PubMed

Alizadeh, Naader; Akbarinejad, Alireza; Ghoorchian, Arash

2016-09-21

The increasing application of fluorescence spectroscopy in development of reliable sensing platforms has triggered a lot of research interest for the synthesis of advanced fluorescent materials. Herein, we report a simple, low-cost strategy for the synthesis of a series of water-soluble conjugated polymer nanoparticles with diverse emission range using cationic (hexadecyltrimethylammonium bromide, CTAB), anionic (sodium dodecylbenzenesulfonate, SDBS), and nonionic (TX114) surfactants as the stabilizing agents. The role of surfactant type on the photophisical and sensing properties of resultant polymers has been investigated using dynamic light scattering (DLS), FT-IR, UV-vis, fluorescence, and energy dispersive X-ray (EDS) spectroscopies. The results show that the surface polarity, size, and spectroscopic and sensing properties of conjugated polymers could be well controlled by the proper selection of the stabilizer type. The fluorescent conjugated polymers exhibited fluorescence quenching toward nitroaromatic compounds. Further studies on the fluorescence properties of conjugated polymers revealed that the emission of the SDBS stabilized polymer, N-methylpolypyrrole-SDBS (NMPPY-SDBS), is strongly quenched by 2,4,6-trinitrotoluene molecule with a large Stern -Volmer constant of 59 526 M(-1) and an excellent detection limit of 100 nM. UV-vis and cyclic voltammetry measurements unveiled that fluorescence quenching occurs through a charge transfer mechanism between electron rich NMPPY-SDBS and electron deficient 2,4,6-trinitrotoluene molecules. Finally, the as-prepared conjugated polymer and approach were successfully applied to the determination of 2,4,6-trinitrotoluene in real water samples.

Early arrival and climatically-linked geographic expansion of New World monkeys from tiny African ancestors.

PubMed

Silvestro, Daniele; Tejedor, Marcelo F; Serrano-Serrano, Martha L; Loiseau, Oriane; Rossier, Victor; Rolland, Jonathan; Zizka, Alexander; Höhna, Sebastian; Antonelli, Alexandre; Salamin, Nicolas

2018-06-20

New World monkeys (platyrrhines) are one of the most diverse groups of primates, occupying today a wide range of ecosystems in the American tropics and exhibiting large variations in ecology, morphology, and behavior. Although the relationships among the almost 200 living species are relatively well understood, we lack robust estimates of the timing of origin, ancestral morphology, and geographic range evolution of the clade. Here we integrate paleontological and molecular evidence to assess the evolutionary dynamics of extinct and extant platyrrhines. We develop novel analytical frameworks to infer the evolution of body mass, changes in latitudinal ranges through time, and species diversification rates using a phylogenetic tree of living and fossil taxa. Our results show that platyrrhines originated 5-10 million years earlier than previously assumed, dating back to the Middle Eocene. The estimated ancestral platyrrhine was small - weighing 0.4 kg - and matched the size of their presumed African ancestors. As the three platyrrhine families diverged, we recover a rapid change in body mass range. During the Miocene Climatic Optimum, fossil diversity peaked and platyrrhines reached their widest latitudinal range, expanding as far South as Patagonia, favored by warm and humid climate and the lower elevation of the Andes. Finally, global cooling and aridification after the middle Miocene triggered a geographic contraction of New World monkeys and increased their extinction rates. These results unveil the full evolutionary trajectory of an iconic and ecologically important radiation of monkeys and showcase the necessity of integrating fossil and molecular data for reliably estimating evolutionary rates and trends.

Comprehensive census of bacteria in clean rooms by using DNA microarray and cloning methods.

PubMed

La Duc, Myron T; Osman, Shariff; Vaishampayan, Parag; Piceno, Yvette; Andersen, Gary; Spry, J A; Venkateswaran, Kasthuri

2009-10-01

A census of clean room surface-associated bacterial populations was derived from the results of both the cloning and sequencing of 16S rRNA genes and DNA microarray (PhyloChip) analyses. Samples from the Lockheed Martin Aeronautics Multiple Testing Facility (LMA-MTF), the Kennedy Space Center Payload Hazard and Servicing Facility (KSC-PHSF), and the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) clean rooms were collected during the various assembly phases of the Phoenix and Mars Science Laboratory (MSL) spacecraft. Clone library-derived analyses detected a larger bacterial diversity prior to the arrival of spacecraft hardware in these clean room facilities. PhyloChip results were in agreement with this trend but also unveiled the presence of anywhere from 9- to 70-fold more bacterial taxa than cloning approaches. Among the facilities sampled, the JPL-SAF (MSL mission) housed a significantly less diverse bacterial population than either the LMA-MTF or KSC-PHSF (Phoenix mission). Bacterial taxa known to thrive in arid conditions were frequently detected in MSL-associated JPL-SAF samples, whereas proteobacterial lineages dominated Phoenix-associated KSC-PHSF samples. Comprehensive bacterial censuses, such as that reported here, will help space-faring nations preemptively identify contaminant biomatter that may compromise extraterrestrial life detection experiments. The robust nature and high sensitivity of DNA microarray technologies should prove beneficial to a wide range of scientific, electronic, homeland security, medical, and pharmaceutical applications and to any other ventures with a vested interest in monitoring and controlling contamination in exceptionally clean environments.

Population cycles and species diversity in dynamic Kill-the-Winner model of microbial ecosystems

NASA Astrophysics Data System (ADS)

Maslov, Sergei; Sneppen, Kim

2017-01-01

Determinants of species diversity in microbial ecosystems remain poorly understood. Bacteriophages are believed to increase the diversity by the virtue of Kill-the-Winner infection bias preventing the fastest growing organism from taking over the community. Phage-bacterial ecosystems are traditionally described in terms of the static equilibrium state of Lotka-Volterra equations in which bacterial growth is exactly balanced by losses due to phage predation. Here we consider a more dynamic scenario in which phage infections give rise to abrupt and severe collapses of bacterial populations whenever they become sufficiently large. As a consequence, each bacterial population in our model follows cyclic dynamics of exponential growth interrupted by sudden declines. The total population of all species fluctuates around the carrying capacity of the environment, making these cycles cryptic. While a subset of the slowest growing species in our model is always driven towards extinction, in general the overall ecosystem diversity remains high. The number of surviving species is inversely proportional to the variation in their growth rates but increases with the frequency and severity of phage-induced collapses. Thus counter-intuitively we predict that microbial communities exposed to more violent perturbations should have higher diversity.

A two-stage mixed-integer fuzzy programming with interval-valued membership functions approach for flood-diversion planning.

PubMed

Wang, S; Huang, G H

2013-03-15

Flood disasters have been extremely severe in recent decades, and they account for about one third of all natural catastrophes throughout the world. In this study, a two-stage mixed-integer fuzzy programming with interval-valued membership functions (TMFP-IMF) approach is developed for flood-diversion planning under uncertainty. TMFP-IMF integrates the fuzzy flexible programming, two-stage stochastic programming, and integer programming within a general framework. A concept of interval-valued fuzzy membership function is introduced to address complexities of system uncertainties. TMFP-IMF can not only deal with uncertainties expressed as fuzzy sets and probability distributions, but also incorporate pre-regulated water-diversion policies directly into its optimization process. TMFP-IMF is applied to a hypothetical case study of flood-diversion planning for demonstrating its applicability. Results indicate that reasonable solutions can be generated for binary and continuous variables. A variety of flood-diversion and capacity-expansion schemes can be obtained under four scenarios, which enable decision makers (DMs) to identify the most desired one based on their perceptions and attitudes towards the objective-function value and constraints. Copyright © 2013 Elsevier Ltd. All rights reserved.

Coalescence and genetic diversity in sexual populations under selection.

PubMed

Neher, Richard A; Kessinger, Taylor A; Shraiman, Boris I

2013-09-24

In sexual populations, selection operates neither on the whole genome, which is repeatedly taken apart and reassembled by recombination, nor on individual alleles that are tightly linked to the chromosomal neighborhood. The resulting interference between linked alleles reduces the efficiency of selection and distorts patterns of genetic diversity. Inference of evolutionary history from diversity shaped by linked selection requires an understanding of these patterns. Here, we present a simple but powerful scaling analysis identifying the unit of selection as the genomic "linkage block" with a characteristic length, , determined in a self-consistent manner by the condition that the rate of recombination within the block is comparable to the fitness differences between different alleles of the block. We find that an asexual model with the strength of selection tuned to that of the linkage block provides an excellent description of genetic diversity and the site frequency spectra compared with computer simulations. This linkage block approximation is accurate for the entire spectrum of strength of selection and is particularly powerful in scenarios with many weakly selected loci. The latter limit allows us to characterize coalescence, genetic diversity, and the speed of adaptation in the infinitesimal model of quantitative genetics.

Genetic Diversity and Ecological Niche Modelling of Wild Barley: Refugia, Large-Scale Post-LGM Range Expansion and Limited Mid-Future Climate Threats?

PubMed Central

Russell, Joanne; van Zonneveld, Maarten; Dawson, Ian K.; Booth, Allan; Waugh, Robbie; Steffenson, Brian

2014-01-01

Describing genetic diversity in wild barley (Hordeum vulgare ssp. spontaneum) in geographic and environmental space in the context of current, past and potential future climates is important for conservation and for breeding the domesticated crop (Hordeum vulgare ssp. vulgare). Spatial genetic diversity in wild barley was revealed by both nuclear- (2,505 SNP, 24 nSSR) and chloroplast-derived (5 cpSSR) markers in 256 widely-sampled geo-referenced accessions. Results were compared with MaxEnt-modelled geographic distributions under current, past (Last Glacial Maximum, LGM) and mid-term future (anthropogenic scenario A2, the 2080s) climates. Comparisons suggest large-scale post-LGM range expansion in Central Asia and relatively small, but statistically significant, reductions in range-wide genetic diversity under future climate. Our analyses support the utility of ecological niche modelling for locating genetic diversity hotspots and determine priority geographic areas for wild barley conservation under anthropogenic climate change. Similar research on other cereal crop progenitors could play an important role in tailoring conservation and crop improvement strategies to support future human food security. PMID:24505252

Population cycles and species diversity in dynamic Kill-the-Winner model of microbial ecosystems

PubMed Central

Maslov, Sergei; Sneppen, Kim

2017-01-01

Determinants of species diversity in microbial ecosystems remain poorly understood. Bacteriophages are believed to increase the diversity by the virtue of Kill-the-Winner infection bias preventing the fastest growing organism from taking over the community. Phage-bacterial ecosystems are traditionally described in terms of the static equilibrium state of Lotka-Volterra equations in which bacterial growth is exactly balanced by losses due to phage predation. Here we consider a more dynamic scenario in which phage infections give rise to abrupt and severe collapses of bacterial populations whenever they become sufficiently large. As a consequence, each bacterial population in our model follows cyclic dynamics of exponential growth interrupted by sudden declines. The total population of all species fluctuates around the carrying capacity of the environment, making these cycles cryptic. While a subset of the slowest growing species in our model is always driven towards extinction, in general the overall ecosystem diversity remains high. The number of surviving species is inversely proportional to the variation in their growth rates but increases with the frequency and severity of phage-induced collapses. Thus counter-intuitively we predict that microbial communities exposed to more violent perturbations should have higher diversity. PMID:28051127

Consequences of harvesting for genetic diversity in American ginseng (Panax quinquefolius L.): A simulation study

USGS Publications Warehouse

Cruse-Sanders, J. M.; Hamrick, J.L.; Ahumada, J.A.

2005-01-01

American ginseng, Panax quinquefolius L., is one of the most heavily traded medicinal plants in North America. The effect of harvest on genetic diversity in ginseng was measured with a single generation culling simulation program. Culling scenarios included random harvest at varying levels, legal limit random harvest and legal limit mature plant harvest. The legal limit was determined by the proportion of legally harvestable plants per population (% mature plants per population). Random harvest at varying levels resulted in significant loss of genetic diversity, especially allelic richness. Relative to initial levels, average within-population genetic diversity (H e) was significantly lower when plants were culled randomly at the legal limit (Mann-Whitney U = 430, p < 0.001) or when only mature plants were culled (Mann-Whitney U = 394, p < 0.01). Within-population genetic diversity was significantly higher with legal limit mature plant harvest (H e = 0.068) than when plants were culled randomly at the legal limit (H e = 0.064; U = 202, p < 0.01). Based on these simulations of harvest over one generation, we recommend that harvesting fewer than the proportion of mature plants could reduce the negative genetic effects of harvest on ginseng populations. ?? Springer 2005.

[The visual perception of the elements of technical drawings among masking distractions in advanced and nonadvanced students in the building and architectural professions].

PubMed

Balichev, Iu

1997-01-01

To investigation were submitted the particularities of the process of visual perception of technical drawings and schemes in advanced and backward pupils, who were mastering the specialties of "building and architecture", "hydroconstruction", "transport construction", "geodesy". The time was registered, which was necessary to advanced and backward pupils for unveiling the different elements in the drawing, scheme, and such attributes of the drawing as: orientation, length, curves of the lined, the boundary between them; time for identification of the specific designations, symbols, group of symbols, elements of the sketch from the simple to the complex ones. The results of the investigations revealed that in the advanced pupils the perception (unveiling) of the different elements of the technical drawing proceeded very rapidly, almost automatically. In the backward pupils this process elapsed reliably more slowly. It was demonstrated that the growing up pupils, who were distinguished with more rapid perception of the different elements of the drawing (advanced ones) more rapidly and more exactly dealt with solution of the technical tasks as compared with these, who more slowly unveiled the looked for elements (backwardness). Some other individual particularities were also established with respect to the visual perception of the elements of the technical drawing and its properties in advanced and backward pupils who were mastering the investigated professions.

Spreading out and staying sharp - creating diverse rotation curves via baryonic and self-interaction effects

NASA Astrophysics Data System (ADS)

Creasey, Peter; Sameie, Omid; Sales, Laura V.; Yu, Hai-Bo; Vogelsberger, Mark; Zavala, Jesús

2017-06-01

Galactic rotation curves are a fundamental constraint for any cosmological model. We use controlled N-body simulations of galaxies to study the gravitational effect of baryons in a scenario with collisionless cold dark matter (CDM) versus one with a self-interacting dark matter (SIDM) component. In particular, we examine the inner profiles of the rotation curves in the velocity range Vmax = [30-250] km s-1, whose diversity has been found to be greater than predicted by the ΛCDM scenario. We find that the scatter in the observed rotation curves exceeds that predicted by dark matter only mass-concentration relations in either the CDM nor SIDM models. Allowing for realistic baryonic content and spatial distributions, however, helps create a large variety of rotation curve shapes, which is in a better agreement with observations in the case of self-interactions due to the characteristic cored profiles being more accommodating to the slowly rising rotation curves than CDM. We find individual fits to model two of the most remarkable outliers of similar Vmax, UGC 5721 and IC 2574 - the former a cusp-like rotation curve and the latter a seemingly 8-kpc-cored profile. This diversity in SIDM arises as permutations of overly concentrated haloes with compact baryonic distributions versus underdense haloes with extended baryonic discs. The SIDM solution is promising and its feasibility ultimately depends on the sampling of the halo mass-concentration relation and its interplay with the baryonic profiles, emphasizing the need for a better understanding of the frequency of extreme outliers present in current observational samples.

Evaluating taboo trade-offs in ecosystems services and human well-being.

PubMed

Daw, Tim M; Coulthard, Sarah; Cheung, William W L; Brown, Katrina; Abunge, Caroline; Galafassi, Diego; Peterson, Garry D; McClanahan, Tim R; Omukoto, Johnstone O; Munyi, Lydiah

2015-06-02

Managing ecosystems for multiple ecosystem services and balancing the well-being of diverse stakeholders involves different kinds of trade-offs. Often trade-offs involve noneconomic and difficult-to-evaluate values, such as cultural identity, employment, the well-being of poor people, or particular species or ecosystem structures. Although trade-offs need to be considered for successful environmental management, they are often overlooked in favor of win-wins. Management and policy decisions demand approaches that can explicitly acknowledge and evaluate diverse trade-offs. We identified a diversity of apparent trade-offs in a small-scale tropical fishery when ecological simulations were integrated with participatory assessments of social-ecological system structure and stakeholders' well-being. Despite an apparent win-win between conservation and profitability at the aggregate scale, food production, employment, and well-being of marginalized stakeholders were differentially influenced by management decisions leading to trade-offs. Some of these trade-offs were suggested to be "taboo" trade-offs between morally incommensurable values, such as between profits and the well-being of marginalized women. These were not previously recognized as management issues. Stakeholders explored and deliberated over trade-offs supported by an interactive "toy model" representing key system trade-offs, alongside qualitative narrative scenarios of the future. The concept of taboo trade-offs suggests that psychological bias and social sensitivity may exclude key issues from decision making, which can result in policies that are difficult to implement. Our participatory modeling and scenarios approach has the potential to increase awareness of such trade-offs, promote discussion of what is acceptable, and potentially identify and reduce obstacles to management compliance.

Simulated tri-trophic networks reveal complex relationships between species diversity and interaction diversity

PubMed Central

Lumpkin, Will; Hurtado, Paul J.; Dyer, Lee A.

2018-01-01

Most of earth’s biodiversity is comprised of interactions among species, yet it is unclear what causes variation in interaction diversity across space and time. We define interaction diversity as the richness and relative abundance of interactions linking species together at scales from localized, measurable webs to entire ecosystems. Large-scale patterns suggest that two basic components of interaction diversity differ substantially and predictably between different ecosystems: overall taxonomic diversity and host specificity of consumers. Understanding how these factors influence interaction diversity, and quantifying the causes and effects of variation in interaction diversity are important goals for community ecology. While previous studies have examined the effects of sampling bias and consumer specialization on determining patterns of ecological networks, these studies were restricted to two trophic levels and did not incorporate realistic variation in species diversity and consumer diet breadth. Here, we developed a food web model to generate tri-trophic ecological networks, and evaluated specific hypotheses about how the diversity of trophic interactions and species diversity are related under different scenarios of species richness, taxonomic abundance, and consumer diet breadth. We investigated the accumulation of species and interactions and found that interactions accumulate more quickly; thus, the accumulation of novel interactions may require less sampling effort than sampling species in order to get reliable estimates of either type of diversity. Mean consumer diet breadth influenced the correlation between species and interaction diversity significantly more than variation in both species richness and taxonomic abundance. However, this effect of diet breadth on interaction diversity is conditional on the number of observed interactions included in the models. The results presented here will help develop realistic predictions of the relationships between consumer diet breadth, interaction diversity, and species diversity within multi-trophic communities, which is critical for the conservation of biodiversity in this period of accelerated global change. PMID:29579077

Simulated tri-trophic networks reveal complex relationships between species diversity and interaction diversity.

PubMed

Pardikes, Nicholas A; Lumpkin, Will; Hurtado, Paul J; Dyer, Lee A

2018-01-01

Most of earth's biodiversity is comprised of interactions among species, yet it is unclear what causes variation in interaction diversity across space and time. We define interaction diversity as the richness and relative abundance of interactions linking species together at scales from localized, measurable webs to entire ecosystems. Large-scale patterns suggest that two basic components of interaction diversity differ substantially and predictably between different ecosystems: overall taxonomic diversity and host specificity of consumers. Understanding how these factors influence interaction diversity, and quantifying the causes and effects of variation in interaction diversity are important goals for community ecology. While previous studies have examined the effects of sampling bias and consumer specialization on determining patterns of ecological networks, these studies were restricted to two trophic levels and did not incorporate realistic variation in species diversity and consumer diet breadth. Here, we developed a food web model to generate tri-trophic ecological networks, and evaluated specific hypotheses about how the diversity of trophic interactions and species diversity are related under different scenarios of species richness, taxonomic abundance, and consumer diet breadth. We investigated the accumulation of species and interactions and found that interactions accumulate more quickly; thus, the accumulation of novel interactions may require less sampling effort than sampling species in order to get reliable estimates of either type of diversity. Mean consumer diet breadth influenced the correlation between species and interaction diversity significantly more than variation in both species richness and taxonomic abundance. However, this effect of diet breadth on interaction diversity is conditional on the number of observed interactions included in the models. The results presented here will help develop realistic predictions of the relationships between consumer diet breadth, interaction diversity, and species diversity within multi-trophic communities, which is critical for the conservation of biodiversity in this period of accelerated global change.

Novel optimum contribution selection methods accounting for conflicting objectives in breeding programs for livestock breeds with historical migration.

PubMed

Wang, Yu; Bennewitz, Jörn; Wellmann, Robin

2017-05-12

Optimum contribution selection (OCS) is effective for increasing genetic gain, controlling the rate of inbreeding and enables maintenance of genetic diversity. However, this diversity may be caused by high migrant contributions (MC) in the population due to introgression of genetic material from other breeds, which can threaten the conservation of small local populations. Therefore, breeding objectives should not only focus on increasing genetic gains but also on maintaining genetic originality and diversity of native alleles. This study aimed at investigating whether OCS was improved by including MC and modified kinships that account for breed origin of alleles. Three objective functions were considered for minimizing kinship, minimizing MC and maximizing genetic gain in the offspring generation, and we investigated their effects on German Angler and Vorderwald cattle. In most scenarios, the results were similar for Angler and Vorderwald cattle. A significant positive correlation between MC and estimated breeding values of the selection candidates was observed for both breeds, thus traditional OCS would increase MC. Optimization was performed under the condition that the rate of inbreeding did not exceed 1% and at least 30% of the maximum progress was achieved for all other criteria. Although traditional OCS provided the highest breeding values under restriction of classical kinship, the magnitude of MC in the progeny generation was not controlled. When MC were constrained or minimized, the kinship at native alleles increased compared to the reference scenario. Thus, in addition to constraining MC, constraining kinship at native alleles is required to ensure that native genetic diversity is maintained. When kinship at native alleles was constrained, the classical kinship was automatically lowered in most cases and more sires were selected. However, the average breeding value in the next generation was also lower than that obtained with traditional OCS. For local breeds with historical introgressions, current breeding programs should focus on increasing genetic gain and controlling inbreeding, as well as maintaining the genetic originality of the breeds and the diversity of native alleles via the inclusion of MC and kinship at native alleles in the OCS process.

Counting on β-Diversity to Safeguard the Resilience of Estuaries

PubMed Central

de Juan, Silvia; Thrush, Simon F.; Hewitt, Judi E.

2013-01-01

Coastal ecosystems are often stressed by non-point source and cumulative effects that can lead to local-scale community homogenisation and a concomitant loss of large-scale ecological connectivity. Here we investigate the use of β-diversity as a measure of both community heterogeneity and ecological connectivity. To understand the consequences of different environmental scenarios on heterogeneity and connectivity, it is necessary to understand the scale at which different environmental factors affect β-diversity. We sampled macrofauna from intertidal sites in nine estuaries from New Zealand’s North Island that represented different degrees of stress derived from land-use. We used multiple regression models to identify relationships between β-diversity and local sediment variables, factors related to the estuarine and catchment hydrodynamics and morphology and land-based stressors. At local scales, we found higher β-diversity at sites with a relatively high total richness. At larger scales, β-diversity was positively related to γ-diversity, suggesting that a large regional species pool was linked with large-scale heterogeneity in these systems. Local environmental heterogeneity influenced β-diversity at both local and regional scales, although variables at the estuarine and catchment scales were both needed to explain large scale connectivity. The estuaries expected a priori to be the most stressed exhibited higher variance in community dissimilarity between sites and connectivity to the estuary species pool. This suggests that connectivity and heterogeneity metrics could be used to generate early warning signals of cumulative stress. PMID:23755252

Mercury MESSENGER Stamp Unveiling

NASA Image and Video Library

2011-05-03

Patty Carpenter, wife of NASA Mercury Astronaut Scott Carpenter, left, Daughters of NASA astronaut Alan Shepard, Laura Shepard Churchley, and, Alice Wackermann, right, sing the National Anthem during an unveiling ceremony of two USPS stamps that commemorate and celebrate 50 years of US Spaceflight and the MESSENGER program during an event, Wednesday, May 4, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. One stamp commemorates NASA’s Project Mercury, America’s first manned spaceflight program, and NASA astronaut Alan Shepard’s historic flight on May 5, 1961, aboard spacecraft Freedom 7. The other stamp draws attention to NASA’s unmanned MESSENGER mission, a scientific investigation of the planet Mercury. On March 17, 2011, MESSENGER became the first spacecraft to enter into orbit around Mercury. Photo Credit: (NASA/Bill Ingalls)

Unveiling the molecular bipolar outflow of the peculiar red supergiant VY Canis Majoris

NASA Astrophysics Data System (ADS)

Shinnaga, Hiroko; Claussen, Mark J.; Lim, Jeremy; Dinh-van-Trung; Tsuboi, Masato

2003-04-01

We carried out polarimetric spectral-line imaging of the molecular outflow of the peculiar red supergiant VY Canis Majoris in SiO J=1-0 line in the ground vibrational state, which contains highly linearly-polarized velocity components, using the Very Large Array. We succeeded in unveiling the highly linearly polarized bipolar outflow for the first time at subarcsecond spatial resolution. The results clearly show that the direction of linear polarization of the brightest maser components is parallel to the outflow axis. The results strongly suggest that the linear polarization of the SiO maser is closely related to the outflow phenomena of the star. Furthermore, the results indicate that the linear polarization observed in the optical and infrared also occur due to the outflow phenomena.

NASA's Great Observatories Celebrate the International Year of Astronomy With a National Unveiling of Spectacular Images

NASA Astrophysics Data System (ADS)

2009-02-01

In 1609, Galileo first turned his telescope to the heavens and gave birth to modern astronomy. To commemorate four hundred years of exploring the universe, 2009 is designated the International Year of Astronomy. NASA's Great Observatories - the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory - are marking the occasion with the release of a suite of images at over 100 planetariums, museums, nature centers, and schools across the country in conjunction with Galileo's birthday on February 15. The selected sites will unveil a large 9-square-foot print of the spiral galaxy Messier 101 that combines the optical view of Hubble, the infrared view of Spitzer, and the X-ray view of Chandra into one multi-wavelength picture. "It's like using your eyes, night vision goggles, and X-ray vision all at the same time," says Dr. Hashima Hasan, lead scientist for the International Year of Astronomy at NASA Headquarters in Washington. Cas A animation Chandra X-ray Image of M101 Participating institutions also will display a matched trio of Hubble, Spitzer, and Chandra images of Messier 101. Each image shows a different wavelength view of the galaxy that illustrates not only the different science uncovered by each observatory, but also just how far astronomy has come since Galileo. Messier 101 is a face-on spiral galaxy about 22 million light-years away in the constellation Ursa Major. It is in many ways similar to, but larger than, our own Milky Way galaxy. Hubble's visible light view shows off the swirls of bright stars and glowing gas that give the galaxy its nickname the Pinwheel Galaxy. In contrast, Spitzer's infrared-light image sees into the spiral arms and reveals the glow of dust lanes where dense clouds can collapse to form new stars. Chandra's X-ray picture uncovers the high-energy features in the galaxy, such as remnants of exploded stars or matter zooming around black holes. The juxtaposition of observations from these three telescopes provides an in-depth view of the galaxy for both astronomers and the public. People Who Read This Also Read... Cosmic Heavyweights in Free-for-all Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago Chandra Data Reveal Rapidly Whirling Black Holes Jet Power and Black Hole Assortment Revealed in New Chandra Image "The amazing scientific discoveries made by Galileo four centuries ago are continued today by scientists using NASA's space observatories," says Dr. Denise Smith, the unveiling Project Manager at the Space Telescope Science Institute in Baltimore, Md. "NASA's Great Observatories are distributing huge prints of spectacular images so that the public can share in the exploration and wonder of the universe." The unveilings will take place between February 14 and 28 at 76 museums and 40 schools and universities in 39 states, reaching both big cities and small towns. Sites are planning celebrations involving the public, schools, and the local media. A complete listing of the national unveiling sites accompanies this press release. The International Year of Astronomy Great Observatories Image Unveiling is supported by the NASA Science Mission Directorate Astrophysics Division. The project is a collaboration between the Space Telescope Science Institute, the Spitzer Science Center, and the Chandra X-ray Center.

Economic consequences of earthquakes: bridging research and practice with HayWired

NASA Astrophysics Data System (ADS)

Wein, A. M.; Kroll, C.

2016-12-01

The U.S. Geological Survey partners with organizations and experts to develop multiple hazard scenarios. The HayWired earthquake scenario refers to a rupture of the Hayward fault in the Bay Area of California and addresses the potential chaos related to interconnectedness at many levels: the fault afterslip and aftershocks, interdependencies of lifelines, wired/wireless technology, communities at risk, and ripple effects throughout today's digital economy. The scenario is intended for diverse audiences. HayWired analyses translate earthquake hazards (surface rupture, ground shaking, liquefaction, landslides) into physical engineering and environmental health impacts, and into societal consequences. Damages to life and property and lifeline service disruptions are direct causes of business interruption. Economic models are used to estimate the economic impacts and resilience in the regional economy. The objective of the economic analysis is to inform policy discourse about economic resilience at all three levels of the economy: macro, meso, and micro. Stakeholders include businesses, economic development, and community leaders. Previous scenario analyses indicate the size of an event: large earthquakes and large winter storms are both "big ones" for California. They motivate actions to reduce the losses from fire following earthquake and water supply outages. They show the effect that resilience can have on reducing economic losses. Evaluators find that stakeholders learned the most about the economic consequences.

HCLS 2.0/3.0: health care and life sciences data mashup using Web 2.0/3.0.

PubMed

Cheung, Kei-Hoi; Yip, Kevin Y; Townsend, Jeffrey P; Scotch, Matthew

2008-10-01

We describe the potential of current Web 2.0 technologies to achieve data mashup in the health care and life sciences (HCLS) domains, and compare that potential to the nascent trend of performing semantic mashup. After providing an overview of Web 2.0, we demonstrate two scenarios of data mashup, facilitated by the following Web 2.0 tools and sites: Yahoo! Pipes, Dapper, Google Maps and GeoCommons. In the first scenario, we exploited Dapper and Yahoo! Pipes to implement a challenging data integration task in the context of DNA microarray research. In the second scenario, we exploited Yahoo! Pipes, Google Maps, and GeoCommons to create a geographic information system (GIS) interface that allows visualization and integration of diverse categories of public health data, including cancer incidence and pollution prevalence data. Based on these two scenarios, we discuss the strengths and weaknesses of these Web 2.0 mashup technologies. We then describe Semantic Web, the mainstream Web 3.0 technology that enables more powerful data integration over the Web. We discuss the areas of intersection of Web 2.0 and Semantic Web, and describe the potential benefits that can be brought to HCLS research by combining these two sets of technologies.

HCLS 2.0/3.0: Health Care and Life Sciences Data Mashup Using Web 2.0/3.0

PubMed Central

Cheung, Kei-Hoi; Yip, Kevin Y.; Townsend, Jeffrey P.; Scotch, Matthew

2010-01-01

We describe the potential of current Web 2.0 technologies to achieve data mashup in the health care and life sciences (HCLS) domains, and compare that potential to the nascent trend of performing semantic mashup. After providing an overview of Web 2.0, we demonstrate two scenarios of data mashup, facilitated by the following Web 2.0 tools and sites: Yahoo! Pipes, Dapper, Google Maps and GeoCommons. In the first scenario, we exploited Dapper and Yahoo! Pipes to implement a challenging data integration task in the context of DNA microarray research. In the second scenario, we exploited Yahoo! Pipes, Google Maps, and GeoCommons to create a geographic information system (GIS) interface that allows visualization and integration of diverse categories of public health data, including cancer incidence and pollution prevalence data. Based on these two scenarios, we discuss the strengths and weaknesses of these Web 2.0 mashup technologies. We then describe Semantic Web, the mainstream Web 3.0 technology that enables more powerful data integration over the Web. We discuss the areas of intersection of Web 2.0 and Semantic Web, and describe the potential benefits that can be brought to HCLS research by combining these two sets of technologies. PMID:18487092

Projected climate changes threaten ancient refugia of kelp forests in the North Atlantic.

PubMed

Assis, Jorge; Araújo, Miguel B; Serrão, Ester A

2018-01-01

Intraspecific genetic variability is critical for species adaptation and evolution and yet it is generally overlooked in projections of the biological consequences of climate change. We ask whether ongoing climate changes can cause the loss of important gene pools from North Atlantic relict kelp forests that persisted over glacial-interglacial cycles. We use ecological niche modelling to predict genetic diversity hotspots for eight species of large brown algae with different thermal tolerances (Arctic to warm temperate), estimated as regions of persistence throughout the Last Glacial Maximum (20,000 YBP), the warmer Mid-Holocene (6,000 YBP), and the present. Changes in the genetic diversity within ancient refugia were projected for the future (year 2100) under two contrasting climate change scenarios (RCP2.6 and RCP8.5). Models predicted distributions that matched empirical distributions in cross-validation, and identified distinct refugia at the low latitude ranges, which largely coincide among species with similar ecological niches. Transferred models into the future projected polewards expansions and substantial range losses in lower latitudes, where richer gene pools are expected (in Nova Scotia and Iberia for cold affinity species and Gibraltar, Alboran, and Morocco for warm-temperate species). These effects were projected for both scenarios but were intensified under the extreme RCP8.5 scenario, with the complete borealization (circum-Arctic colonization) of kelp forests, the redistribution of the biogeographical transitional zones of the North Atlantic, and the erosion of global gene pools across all species. As the geographic distribution of genetic variability is unknown for most marine species, our results represent a baseline for identification of locations potentially rich in unique phylogeographic lineages that are also climatic relics in threat of disappearing. © 2017 John Wiley & Sons Ltd.

Quantifying Forest Ecosystem Services Tradeoff—Coupled Ecological and Economic Models

NASA Astrophysics Data System (ADS)

Haff, P. K.; Ling, P. Y.

2015-12-01

Quantification of the effect of carbon-related forestland management activities on ecosystem services is difficult, because knowledge about the dynamics of coupled social-ecological systems is lacking. Different forestland management activities, such as various amount, timing, and methods of harvesting, and natural disturbances events, such as wind and fires, create shocks and uncertainties to the forest carbon dynamics. A spatially explicit model, Landis-ii, was used to model the forest succession for different harvest management scenarios at the Grandfather District, North Carolina. In addition to harvest, the model takes into account of the impact of natural disturbances, such as fire and insects, and species competition. The result shows the storage of carbon in standing biomass and in wood product for each species for each scenario. In this study, optimization is used to analyze the maximum profit and the number of tree species that each forest landowner can gain at different prices of carbon, roundwood, and interest rates for different harvest management scenarios. Time series of roundwood production of different types were estimated using remote sensing data. Econometric analysis is done to understand the possible interaction and relations between the production of different types of roundwood and roundwood prices, which can indicate the possible planting scheme that a forest owner may make. This study quantifies the tradeoffs between carbon sequestration, roundwood production, and forest species diversity not only from an economic perspective, but also takes into account of the forest succession mechanism in a species-diverse region. The resulting economic impact on the forest landowners is likely to influence their future planting decision, which in turn, will influence the species composition and future revenue of the landowners.

Mitochondrial DNA Analyses Indicate High Diversity, Expansive Population Growth and High Genetic Connectivity of Vent Copepods (Dirivultidae) across Different Oceans

PubMed Central

Kihara, Terue C.; Laurent, Stefan; Kodami, Sahar; Martinez Arbizu, Pedro

2016-01-01

Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima’s D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid populations are generally large and continuously undergoing population growth. Benthic and pelagic species abundance data support these findings. PMID:27732624

Can captive populations function as sources of genetic variation for reintroductions into the wild? A case study of the Arabian oryx from the Phoenix Zoo and the Shaumari Wildlife Reserve, Jordan

USGS Publications Warehouse

Ochoa, Alexander; Wells, Stuart A.; West, Gary; Al-Smadi, Ma’en; Redondo, Sergio A.; Sexton, Sydnee R.; Culver, Melanie

2016-01-01

The Arabian oryx (Oryx leucoryx) historically ranged across the Arabian Peninsula and neighboring countries until its extirpation in 1972. In 1963–1964 a captive breeding program for this species was started at the Phoenix Zoo (PHX); it ultimately consisted of 11 animals that became known as the ‘World Herd’. In 1978–1979 a wild population was established at the Shaumari Wildlife Reserve (SWR), Jordan, with eight descendants from the World Herd and three individuals from Qatar. We described the mtDNA and nuclear genetic diversity and structure of PHX and SWR. We also determined the long-term demographic and genetic viability of these populations under different reciprocal translocation scenarios. PHX displayed a greater number of mtDNA haplotypes (n = 4) than SWR (n = 2). Additionally, PHX and SWR presented nuclear genetic diversities of N¯AN¯A = 2.88 vs. 2.75, H¯OH¯O = 0.469 vs. 0.387, and H¯EH¯E = 0.501 vs. 0.421, respectively. Although these populations showed no signs of inbreeding (F¯ISF¯IS ≈ 0), they were highly differentiated (G′′STGST′′ = 0.580; P < 0.001). Migration between PHX and SWR (Nm = 1, 4, and 8 individuals/generation) increased their genetic diversity in the short-term and substantially reduced the probability of extinction in PHX during 25 generations. Under such scenarios, maximum genetic diversities were achieved in the first generations before the effects of genetic drift became predominant. Although captive populations can function as sources of genetic variation for reintroduction programs, we recommend promoting mutual and continuous gene flow with wild populations to ensure the long-term survival of this species.

Predicting the effects of climate change on population connectivity and genetic diversity of an imperiled freshwater mussel, Cumberlandia monodonta (Bivalvia: Margaritiferidae), in riverine systems.

PubMed

Inoue, Kentaro; Berg, David J

2017-01-01

In the face of global climate change, organisms may respond to temperature increases by shifting their ranges poleward or to higher altitudes. However, the direction of range shifts in riverine systems is less clear. Because rivers are dendritic networks, there is only one dispersal route from any given location to another. Thus, range shifts are only possible if branches are connected by suitable habitat, and stream-dwelling organisms can disperse through these branches. We used Cumberlandia monodonta (Bivalvia: Unionoida: Margaritiferidae) as a model species to investigate the effects of climate change on population connectivity because a majority of contemporary populations are panmictic. We combined ecological niche models (ENMs) with population genetic simulations to investigate the effects of climate change on population connectivity and genetic diversity of C. monodonta. The ENMs were constructed using bioclimatic and landscape data to project shifts in suitable habitat under future climate scenarios. We then used forward-time simulations to project potential changes in genetic diversity and population connectivity based on these range shifts. ENM results under current conditions indicated long stretches of highly suitable habitat in rivers where C. monodonta persists; populations in the upper Mississippi River remain connected by suitable habitat that does not impede gene flow. Future climate scenarios projected northward and headwater-ward range contraction and drastic declines in habitat suitability for most extant populations throughout the Mississippi River Basin. Simulations indicated that climate change would greatly reduce genetic diversity and connectivity across populations. Results suggest that a single, large population of C. monodonta will become further fragmented into smaller populations, each of which will be isolated and begin to differentiate genetically. Because C. monodonta is a widely distributed species and purely aquatic, our results suggest that persistence and connectivity of stream-dwelling organisms will be significantly altered in response to future climate change. © 2016 John Wiley & Sons Ltd.

Mitochondrial DNA Analyses Indicate High Diversity, Expansive Population Growth and High Genetic Connectivity of Vent Copepods (Dirivultidae) across Different Oceans.

PubMed

Gollner, Sabine; Stuckas, Heiko; Kihara, Terue C; Laurent, Stefan; Kodami, Sahar; Martinez Arbizu, Pedro

2016-01-01

Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima's D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid populations are generally large and continuously undergoing population growth. Benthic and pelagic species abundance data support these findings.

A quantitative visual dashboard to explore exposures to ...

EPA Pesticide Factsheets

The Exposure Prioritization (Ex Priori) model features a simplified, quantitative visual dashboard to explore exposures across chemical space. Diverse data streams are integrated within the interface such that different exposure scenarios for “individual,” “population,” or “professional” time-use profiles can be interchanged to tailor exposure and quantitatively explore multi-chemical signatures of exposure, internalized dose (uptake), body burden, and elimination. Ex Priori will quantitatively extrapolate single-point estimates of both exposure and internal dose for multiple exposure scenarios, factors, products, and pathways. Currently, EPA is investigating its usefulness in life cycle analysis, insofar as its ability to enhance exposure factors used in calculating characterization factors for human health. Presented at 2016 Annual ISES Meeting held in Utrecht, The Netherlands, from 9-13 October 2016.

Definition of information technology architectures for continuous data management and medical device integration in diabetes.

PubMed

Hernando, M Elena; Pascual, Mario; Salvador, Carlos H; García-Sáez, Gema; Rodríguez-Herrero, Agustín; Martínez-Sarriegui, Iñaki; Gómez, Enrique J

2008-09-01

The growing availability of continuous data from medical devices in diabetes management makes it crucial to define novel information technology architectures for efficient data storage, data transmission, and data visualization. The new paradigm of care demands the sharing of information in interoperable systems as the only way to support patient care in a continuum of care scenario. The technological platforms should support all the services required by the actors involved in the care process, located in different scenarios and managing diverse information for different purposes. This article presents basic criteria for defining flexible and adaptive architectures that are capable of interoperating with external systems, and integrating medical devices and decision support tools to extract all the relevant knowledge to support diabetes care.

Dealing with Diversity in Computational Cancer Modeling

PubMed Central

Johnson, David; McKeever, Steve; Stamatakos, Georgios; Dionysiou, Dimitra; Graf, Norbert; Sakkalis, Vangelis; Marias, Konstantinos; Wang, Zhihui; Deisboeck, Thomas S.

2013-01-01

This paper discusses the need for interconnecting computational cancer models from different sources and scales within clinically relevant scenarios to increase the accuracy of the models and speed up their clinical adaptation, validation, and eventual translation. We briefly review current interoperability efforts drawing upon our experiences with the development of in silico models for predictive oncology within a number of European Commission Virtual Physiological Human initiative projects on cancer. A clinically relevant scenario, addressing brain tumor modeling that illustrates the need for coupling models from different sources and levels of complexity, is described. General approaches to enabling interoperability using XML-based markup languages for biological modeling are reviewed, concluding with a discussion on efforts towards developing cancer-specific XML markup to couple multiple component models for predictive in silico oncology. PMID:23700360

Genotypic Diversity for Biomass Accumulation and Shoot-Root Allometry in the Grass Brachypodium distachyon

NASA Astrophysics Data System (ADS)

Jansson, C.; Handakumbura, P. P.; Fortin, D.; Stanfill, B.; Rivas-Ubach, A.

2017-12-01

Predicting carbon uptake, assimilation and allocation for current and future biogeographical environments, including climate, is critical for our ability to select and/or design plant genotypes to meet increasing demand for plant biomass going into food, feed and energy production, while at the same time maintain or increase soil organic matter (SOM for soil fertility and carbon storage, and reduce emission of greenhouse gasses. As has been demonstrated for several plant species allometric relationships may differ between plant genotypes. Exploring plant genotypic diversity for biomass accumulation and allometry will potentially enable selection of genotypes with high CO2 assimilation and favorable allocation of recent photosynthate into above-ground and below-ground biomass. We are investigating genotypic diversity for PFTs in natural accessions of the annual C3 grass Brachypodium distachyon under current and future climate scenarios and how genotypic diversity correlates with metabolite profiles in aboveground and below-ground biomass. In the current study, we compare effects from non-stressed and drought conditions on biomass accumulation and shoot-root allometry.

The genome of the endophytic bacterium H. frisingense GSF30(T) identifies diverse strategies in the Herbaspirillum genus to interact with plants.

PubMed

Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

2013-01-01

The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30(T) has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations.

The genome of the endophytic bacterium H. frisingense GSF30T identifies diverse strategies in the Herbaspirillum genus to interact with plants

PubMed Central

Straub, Daniel; Rothballer, Michael; Hartmann, Anton; Ludewig, Uwe

2013-01-01

The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30T has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations. PMID:23825472

Temporal turnover and the maintenance of diversity in ecological assemblages

PubMed Central

Magurran, Anne E.; Henderson, Peter A.

2010-01-01

Temporal variation in species abundances occurs in all ecological communities. Here, we explore the role that this temporal turnover plays in maintaining assemblage diversity. We investigate a three-decade time series of estuarine fishes and show that the abundances of the individual species fluctuate asynchronously around their mean levels. We then use a time-series modelling approach to examine the consequences of different patterns of turnover, by asking how the correlation between the abundance of a species in a given year and its abundance in the previous year influences the structure of the overall assemblage. Classical diversity measures that ignore species identities reveal that the observed assemblage structure will persist under all but the most extreme conditions. However, metrics that track species identities indicate a narrower set of turnover scenarios under which the predicted assemblage resembles the natural one. Our study suggests that species diversity metrics are insensitive to change and that measures that track species ranks may provide better early warning that an assemblage is being perturbed. It also highlights the need to incorporate temporal turnover in investigations of assemblage structure and function. PMID:20980310

Unveiling the radio cosmos

NASA Astrophysics Data System (ADS)

Vanderlinde, Keith

2017-02-01

Using a radio telescope with no moving parts, the dark energy speeding up the expansion of the Universe can be probed in unprecedented detail, says Keith Vanderlinde, on behalf of the CHIME collaboration.

Generating social impact scenarios: A key step in making technology assessment studies

NASA Technical Reports Server (NTRS)

Jones, M. V.

1975-01-01

The MITRE methodological studies were conducted to define relevant questions in relation to the concept of total impact analysis and to provide a procedure for integrating diverse checklists of questions which trace the initial and secondary impacts of any major technological application or of society's attempts to respond to or redirect that application. Some of the results of that study are presented in tabular form.

Protected area management

USGS Publications Warehouse

Fagre, Daniel B.; Prato, Tony; Wang, Yeqiao

2014-01-01

Designated protected areas are diverse in scope and purpose and have expanded from Yellowstone National Park in the United States, the world’s first national park, to 157,897 parks and protected areas distributed globally. Most are publicly owned and serve multiple needs that reflect regional or national cultures. With ever-increasing threats to the integrity of protected areas, managers are turning to flexible management practices such as scenario planning and adaptive management.

Changes in forest habitat classes under alternative climate and land-use change scenarios in the northeast and midwest, USA

Treesearch

Brian G. Tavernia; Mark D. Nelson; Michael E. Goerndt; Brian F. Walters; Chris Toney

2013-01-01

Large-scale and long-term habitat management plans are needed to maintain the diversity of habitat classes required by wildlife species. Planning efforts would benefit from assessments of potential climate and land-use change effects on habitats. We assessed climate and land-use driven changes in areas of closed- and open-canopy forest across the Northeast and Midwest...

Assessing uncertainties in land cover projections.

PubMed

Alexander, Peter; Prestele, Reinhard; Verburg, Peter H; Arneth, Almut; Baranzelli, Claudia; Batista E Silva, Filipe; Brown, Calum; Butler, Adam; Calvin, Katherine; Dendoncker, Nicolas; Doelman, Jonathan C; Dunford, Robert; Engström, Kerstin; Eitelberg, David; Fujimori, Shinichiro; Harrison, Paula A; Hasegawa, Tomoko; Havlik, Petr; Holzhauer, Sascha; Humpenöder, Florian; Jacobs-Crisioni, Chris; Jain, Atul K; Krisztin, Tamás; Kyle, Page; Lavalle, Carlo; Lenton, Tim; Liu, Jiayi; Meiyappan, Prasanth; Popp, Alexander; Powell, Tom; Sands, Ronald D; Schaldach, Rüdiger; Stehfest, Elke; Steinbuks, Jevgenijs; Tabeau, Andrzej; van Meijl, Hans; Wise, Marshall A; Rounsevell, Mark D A

2017-02-01

Understanding uncertainties in land cover projections is critical to investigating land-based climate mitigation policies, assessing the potential of climate adaptation strategies and quantifying the impacts of land cover change on the climate system. Here, we identify and quantify uncertainties in global and European land cover projections over a diverse range of model types and scenarios, extending the analysis beyond the agro-economic models included in previous comparisons. The results from 75 simulations over 18 models are analysed and show a large range in land cover area projections, with the highest variability occurring in future cropland areas. We demonstrate systematic differences in land cover areas associated with the characteristics of the modelling approach, which is at least as great as the differences attributed to the scenario variations. The results lead us to conclude that a higher degree of uncertainty exists in land use projections than currently included in climate or earth system projections. To account for land use uncertainty, it is recommended to use a diverse set of models and approaches when assessing the potential impacts of land cover change on future climate. Additionally, further work is needed to better understand the assumptions driving land use model results and reveal the causes of uncertainty in more depth, to help reduce model uncertainty and improve the projections of land cover. © 2016 John Wiley & Sons Ltd.

Avoided economic impacts of energy demand changes by 1.5 and 2 °C climate stabilization

NASA Astrophysics Data System (ADS)

Park, Chan; Fujimori, Shinichiro; Hasegawa, Tomoko; Takakura, Jun’ya; Takahashi, Kiyoshi; Hijioka, Yasuaki

2018-04-01

Energy demand associated with space heating and cooling is expected to be affected by climate change. There are several global projections of space heating and cooling use that take into consideration climate change, but a comprehensive uncertainty of socioeconomic and climate conditions, including a 1.5 °C global mean temperature change, has never been assessed. This paper shows the economic impact of changes in energy demand for space heating and cooling under multiple socioeconomic and climatic conditions. We use three shared socioeconomic pathways as socioeconomic conditions. For climate conditions, we use two representative concentration pathways that correspond to 4.0 °C and 2.0 °C scenarios, and a 1.5 °C scenario driven from the 2.0 °C scenario with assumption in conjunction with five general circulation models. We find that the economic impacts of climate change are largely affected by socioeconomic assumptions, and global GDP change rates range from +0.21% to ‑2.01% in 2100 under the 4.0 °C scenario, depending on the socioeconomic condition. Sensitivity analysis that differentiates the thresholds of heating and cooling degree days clarifies that the threshold is a strong factor that generates these differences. Meanwhile, the impact of the 1.5 °C is small regardless of socioeconomic assumptions (‑0.02% to ‑0.06%). The economic loss caused by differences in socioeconomic assumption under the 1.5 °C scenario is much smaller than that under the 2 °C scenario, which implies that stringent climate mitigation can work as a risk hedge to socioeconomic development diversity.

Flood hazard assessment for french NPPs

NASA Astrophysics Data System (ADS)

Rebour, Vincent; Duluc, Claire-Marie; Guimier, Laurent

2015-04-01

This paper presents the approach for flood hazard assessment for NPP which is on-going in France in the framework of post-Fukushima activities. These activities were initially defined considering both European "stress tests" of NPPs pursuant to the request of the European Council, and the French safety audit of civilian nuclear facilities in the light of the Fukushima Daiichi accident. The main actors in that process are the utility (EDF is, up to date, the unique NPP's operator in France), the regulatory authority (ASN) and its technical support organization (IRSN). This paper was prepared by IRSN, considering official positions of the other main actors in the current review process, it was not officially endorsed by them. In France, flood hazard to be considered for design basis definition (for new NPPs and for existing NPPs in periodic safety reviews conducted every 10 years) was revised before Fukushima-Daichi accident, due to le Blayais NPP December 1999 experience (partial site flooding and loss of some safety classified systems). The paper presents in the first part an overview of the revised guidance for design basis flood. In order to address design extension conditions (conditions that could result from natural events exceeding the design basis events), a set of flooding scenarios have been defined by adding margins on the scenarios that are considered for the design. Due to the diversity of phenomena to be considered for flooding hazard, the margin assessment is specific to each flooding scenario in terms of parameter to be penalized and of degree of variation of this parameter. The general approach to address design extension conditions is presented in the second part of the paper. The next parts present the approach for five flooding scenarios including design basis scenario and additional margin to define design extension scenarios.

Patient Perceptions of Breast Cancer Risk in Imaging-Detected Low-Risk Scenarios and Thresholds for Desired Intervention: A Multi-Institution Survey.

PubMed

Grimm, Lars J; Shelby, Rebecca A; Knippa, Emily E; Langman, Eun L; Miller, Lauren S; Whiteside, Beth E; Soo, Mary Scott C

2018-06-01

To determine women's perceptions of breast cancer risk and thresholds for desiring biopsy when considering BI-RADS 3 and 4A scenarios and recommendations, respectively. Women presenting for screening mammography from five geographically diverse medical centers were surveyed. Demographic information and baseline anxiety were queried. Participants were presented with scenarios of short-term imaging follow-up recommendations (ie, BI-RADS 3) and biopsy recommendations (ie, BI-RADS 4A) for low-risk mammographic abnormalities and asked to estimate their breast cancer risk for each scenario. Participants reported the threshold (ie, likelihood of cancer) where they would feel comfortable undergoing short-term imaging follow-up and biopsy and their anticipated regret for choosing short-term follow-up versus biopsy. Analysis of 2,747 surveys showed that participants estimated breast cancer risk of 32.8% for a BI-RADS 3 and 41.1% for a BI-RADS 4A scenarios are significantly greater rates than clinically established rates (<2% [P < .001] and 2%-10% [P < .001], respectively). Over one-half (55.4%) of participants reported they would never want imaging follow-up if there was any chance of cancer; two-thirds (66.2%) reported they would desire biopsy if there was any chance of cancer. Participants reported greater anticipated regret (P < .001) and less relief and confidence (P < .001) with the decision to undergo follow-up imaging versus biopsy. Women overestimate breast cancer risk associated with both BI-RADS 3 and 4A scenarios and desire very low biopsy thresholds. Greater anticipated regret and less relief and confidence was reported with the choice to undergo short-term imaging follow-up compared with biopsy. Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Portfolio optimization for seed selection in diverse weather scenarios.

PubMed

Marko, Oskar; Brdar, Sanja; Panić, Marko; Šašić, Isidora; Despotović, Danica; Knežević, Milivoje; Crnojević, Vladimir

2017-01-01

The aim of this work was to develop a method for selection of optimal soybean varieties for the American Midwest using data analytics. We extracted the knowledge about 174 varieties from the dataset, which contained information about weather, soil, yield and regional statistical parameters. Next, we predicted the yield of each variety in each of 6,490 observed subregions of the Midwest. Furthermore, yield was predicted for all the possible weather scenarios approximated by 15 historical weather instances contained in the dataset. Using predicted yields and covariance between varieties through different weather scenarios, we performed portfolio optimisation. In this way, for each subregion, we obtained a selection of varieties, that proved superior to others in terms of the amount and stability of yield. According to the rules of Syngenta Crop Challenge, for which this research was conducted, we aggregated the results across all subregions and selected up to five soybean varieties that should be distributed across the network of seed retailers. The work presented in this paper was the winning solution for Syngenta Crop Challenge 2017.

Reducing the life cycle GHG emissions of microalgal biodiesel through integration with ethanol production system.

PubMed

Maranduba, Henrique Leonardo; Robra, Sabine; Nascimento, Iracema Andrade; da Cruz, Rosenira Serpa; Rodrigues, Luciano Brito; de Almeida Neto, José Adolfo

2015-10-01

Despite environmental benefits of algal-biofuels, the energy-intensive systems for producing microalgae-feedstock may result in high GHG emissions. Trying to overcome energy-costs, this research analyzed the biodiesel production system via dry-route, based on Chlorella vulgaris cultivated in raceways, by comparing the GHG-footprints of diverse microalgae-biodiesel scenarios. These involved: the single system of biomass production (C0); the application of pyrolysis on the residual microalgal biomass (cake) from the oil extraction process (C1); the same as C0, with anaerobic cake co-digested with cattle manure (C2); the same conditions as in C1 and C2, by integrating in both cases (respectively C3 and C4), the microalgae cultivation with an autonomous ethanol distillery. The reduction of GHG emissions in scenarios with no such integration (C1 and C2), compared to CO, was insignificant (0.53% and 4.67%, respectively), whereas in the scenarios with integration with ethanol production system, the improvements were 53.57% for C3 and 63.84% for C4. Copyright © 2015 Elsevier Ltd. All rights reserved.

Portfolio optimization for seed selection in diverse weather scenarios

PubMed Central

Brdar, Sanja; Panić, Marko; Šašić, Isidora; Despotović, Danica; Knežević, Milivoje; Crnojević, Vladimir

2017-01-01

The aim of this work was to develop a method for selection of optimal soybean varieties for the American Midwest using data analytics. We extracted the knowledge about 174 varieties from the dataset, which contained information about weather, soil, yield and regional statistical parameters. Next, we predicted the yield of each variety in each of 6,490 observed subregions of the Midwest. Furthermore, yield was predicted for all the possible weather scenarios approximated by 15 historical weather instances contained in the dataset. Using predicted yields and covariance between varieties through different weather scenarios, we performed portfolio optimisation. In this way, for each subregion, we obtained a selection of varieties, that proved superior to others in terms of the amount and stability of yield. According to the rules of Syngenta Crop Challenge, for which this research was conducted, we aggregated the results across all subregions and selected up to five soybean varieties that should be distributed across the network of seed retailers. The work presented in this paper was the winning solution for Syngenta Crop Challenge 2017. PMID:28863173

Predicting the distributions of Egypt's medicinal plants and their potential shifts under future climate change.

PubMed

Kaky, Emad; Gilbert, Francis

2017-01-01

Climate change is one of the most difficult of challenges to conserving biodiversity, especially for countries with few data on the distributions of their taxa. Species distribution modelling is a modern approach to the assessment of the potential effects of climate change on biodiversity, with the great advantage of being robust to small amounts of data. Taking advantage of a recently validated dataset, we use the medicinal plants of Egypt to identify hotspots of diversity now and in the future by predicting the effect of climate change on the pattern of species richness using species distribution modelling. Then we assess how Egypt's current Protected Area network is likely to perform in protecting plants under climate change. The patterns of species richness show that in most cases the A2a 'business as usual' scenario was more harmful than the B2a 'moderate mitigation' scenario. Predicted species richness inside Protected Areas was higher than outside under all scenarios, indicating that Egypt's PAs are well placed to help conserve medicinal plants.

Rarity in aquatic microbes: placing protists on the map.

PubMed

Logares, Ramiro; Mangot, Jean-François; Massana, Ramon

2015-12-01

Most microbial richness at any given time tends to be represented by low-abundance (rare) taxa, which are collectively referred to as the "rare biosphere". Here we review works on the rare biosphere using high-throughput sequencing (HTS), with a particular focus on unicellular eukaryotes or protists. Evidence thus far indicates that the rare biosphere encompasses dormant as well as metabolically active microbes that could potentially play key roles in ecosystem functioning. Rare microbes appear to have biogeography, and sometimes the observed patterns can be similar to what is observed among abundant taxa, suggesting similar community-structuring mechanisms. There is limited evidence indicating that the rare biosphere contains taxa that are phylogenetically distantly related to abundant counterparts; therefore, the rare biosphere may act as a reservoir of deep-branching phylogenetic diversity. The potential role of the rare biosphere as a bank of redundant functions that can help to maintain continuous ecosystem function following oscillations in taxonomic abundances is hypothesized as its main ecological role. Future studies focusing on rare microbes are crucial for advancing our knowledge of microbial ecology and evolution and unveiling their links with ecosystem function. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Nanoplasmonic probes of RNA folding and assembly during pre-mRNA splicing

NASA Astrophysics Data System (ADS)

Nguyen, Anh H.; Lee, Jong Uk; Sim, Sang Jun

2016-02-01

RNA splicing plays important roles in transcriptome and proteome diversity. Herein, we describe the use of a nanoplasmonic system that unveils RNA folding and assembly during pre-mRNA splicing wherein the quantification of mRNA splice variants is not taken into account. With a couple of SERS-probes and plasmonic probes binding at the boundary sites of exon-2/intron-2 and intron-2/exon-3 of the pre-mature RNA of the β-globin gene, the splicing process brings the probes into the plasmonic bands. For plasmonic probes, a plasmon shift increase of ~29 nm, corresponding to intron removal and exon-2 and exon-3 connection to form the mRNA molecule, is measured by plasmonic coupling. The increased scattering intensity and surface-enhanced Raman scattering (SERS) fingerprinting reveal the clear dynamics of pre-mRNA splicing. Moreover, a time-resolved experiment of individual RNA molecules exhibited a successful splicing and an inhibited splicing event by 33 μM biflavonoid isoginkgetin, a general inhibitor of RNA splicing. The results suggest that the RNA splicing is successfully monitored with the nanoplasmonic system. Thus, this platform can be useful for studying RNA nanotechnology, biomolecular folding, alternative splicing, and maturation of microRNA.

Following the Footsteps of Chlamydial Gene Regulation

PubMed Central

Domman, D.; Horn, M.

2015-01-01

Regulation of gene expression ensures an organism responds to stimuli and undergoes proper development. Although the regulatory networks in bacteria have been investigated in model microorganisms, nearly nothing is known about the evolution and plasticity of these networks in obligate, intracellular bacteria. The phylum Chlamydiae contains a vast array of host-associated microbes, including several human pathogens. The Chlamydiae are unique among obligate, intracellular bacteria as they undergo a complex biphasic developmental cycle in which large swaths of genes are temporally regulated. Coupled with the low number of transcription factors, these organisms offer a model to study the evolution of regulatory networks in intracellular organisms. We provide the first comprehensive analysis exploring the diversity and evolution of regulatory networks across the phylum. We utilized a comparative genomics approach to construct predicted coregulatory networks, which unveiled genus- and family-specific regulatory motifs and architectures, most notably those of virulence-associated genes. Surprisingly, our analysis suggests that few regulatory components are conserved across the phylum, and those that are conserved are involved in the exploitation of the intracellular niche. Our study thus lends insight into a component of chlamydial evolution that has otherwise remained largely unexplored. PMID:26424812

Mixing and matching TREK/TRAAK subunits generate heterodimeric K2P channels with unique properties

PubMed Central

Blin, Sandy; Ben Soussia, Ismail; Kim, Eun-Jin; Brau, Frédéric; Kang, Dawon; Lesage, Florian; Bichet, Delphine

2016-01-01

The tandem of pore domain in a weak inwardly rectifying K+ channel (Twik)-related acid-arachidonic activated K+ channel (TRAAK) and Twik-related K+ channels (TREK) 1 and TREK2 are active as homodimers gated by stretch, fatty acids, pH, and G protein-coupled receptors. These two-pore domain potassium (K2P) channels are broadly expressed in the nervous system where they control excitability. TREK/TRAAK KO mice display altered phenotypes related to nociception, neuroprotection afforded by polyunsaturated fatty acids, learning and memory, mood control, and sensitivity to general anesthetics. These channels have emerged as promising targets for the development of new classes of anesthetics, analgesics, antidepressants, neuroprotective agents, and drugs against addiction. Here, we show that the TREK1, TREK2, and TRAAK subunits assemble and form active heterodimeric channels with electrophysiological, regulatory, and pharmacological properties different from those of homodimeric channels. Heteromerization occurs between all TREK variants produced by alternative splicing and alternative translation initiation. These results unveil a previously unexpected diversity of K2P channels that will be challenging to analyze in vivo, but which opens new perspectives for the development of clinically relevant drugs. PMID:27035965

Delineation of metabolic gene clusters in plant genomes by chromatin signatures

PubMed Central

Yu, Nan; Nützmann, Hans-Wilhelm; MacDonald, James T.; Moore, Ben; Field, Ben; Berriri, Souha; Trick, Martin; Rosser, Susan J.; Kumar, S. Vinod; Freemont, Paul S.; Osbourn, Anne

2016-01-01

Plants are a tremendous source of diverse chemicals, including many natural product-derived drugs. It has recently become apparent that the genes for the biosynthesis of numerous different types of plant natural products are organized as metabolic gene clusters, thereby unveiling a highly unusual form of plant genome architecture and offering novel avenues for discovery and exploitation of plant specialized metabolism. Here we show that these clustered pathways are characterized by distinct chromatin signatures of histone 3 lysine trimethylation (H3K27me3) and histone 2 variant H2A.Z, associated with cluster repression and activation, respectively, and represent discrete windows of co-regulation in the genome. We further demonstrate that knowledge of these chromatin signatures along with chromatin mutants can be used to mine genomes for cluster discovery. The roles of H3K27me3 and H2A.Z in repression and activation of single genes in plants are well known. However, our discovery of highly localized operon-like co-regulated regions of chromatin modification is unprecedented in plants. Our findings raise intriguing parallels with groups of physically linked multi-gene complexes in animals and with clustered pathways for specialized metabolism in filamentous fungi. PMID:26895889

A non-canonical mechanism for Crm1-export cargo complex assembly

PubMed Central

Fischer, Ute; Schäuble, Nico; Schütz, Sabina; Altvater, Martin; Chang, Yiming; Boulos Faza, Marius; Panse, Vikram Govind

2015-01-01

The transport receptor Crm1 mediates the export of diverse cargos containing leucine-rich nuclear export signals (NESs) through complex formation with RanGTP. To ensure efficient cargo release in the cytoplasm, NESs have evolved to display low affinity for Crm1. However, mechanisms that overcome low affinity to assemble Crm1-export complexes in the nucleus remain poorly understood. In this study, we reveal a new type of RanGTP-binding protein, Slx9, which facilitates Crm1 recruitment to the 40S pre-ribosome-associated NES-containing adaptor Rio2. In vitro, Slx9 binds Rio2 and RanGTP, forming a complex. This complex directly loads Crm1, unveiling a non-canonical stepwise mechanism to assemble a Crm1-export complex. A mutation in Slx9 that impairs Crm1-export complex assembly inhibits 40S pre-ribosome export. Thus, Slx9 functions as a scaffold to optimally present RanGTP and the NES to Crm1, therefore, triggering 40S pre-ribosome export. This mechanism could represent one solution to the paradox of weak binding events underlying rapid Crm1-mediated export. DOI: http://dx.doi.org/10.7554/eLife.05745.001 PMID:25895666

A novel procedure for the identification of chaos in complex biological systems

NASA Astrophysics Data System (ADS)

Bazeia, D.; Pereira, M. B. P. N.; Brito, A. V.; Oliveira, B. F. De; Ramos, J. G. G. S.

2017-03-01

We demonstrate the presence of chaos in stochastic simulations that are widely used to study biodiversity in nature. The investigation deals with a set of three distinct species that evolve according to the standard rules of mobility, reproduction and predation, with predation following the cyclic rules of the popular rock, paper and scissors game. The study uncovers the possibility to distinguish between time evolutions that start from slightly different initial states, guided by the Hamming distance which heuristically unveils the chaotic behavior. The finding opens up a quantitative approach that relates the correlation length to the average density of maxima of a typical species, and an ensemble of stochastic simulations is implemented to support the procedure. The main result of the work shows how a single and simple experimental realization that counts the density of maxima associated with the chaotic evolution of the species serves to infer its correlation length. We use the result to investigate others distinct complex systems, one dealing with a set of differential equations that can be used to model a diversity of natural and artificial chaotic systems, and another one, focusing on the ocean water level.

Exploring the functional significance of sterol glycosyltransferase enzymes.

PubMed

Singh, Gaurav; Dhar, Yogeshwar Vikram; Asif, Mehar Hasan; Misra, Pratibha

2018-01-01

Steroidal alkaloids (SAs) are widely synthesized and distributed in plants manifesting as natural produce endowed with potential for medicinal, pesticidal and other high-value usages. Glycosylation of these SAs raises complex and diverse glycosides in plant cells that indeed govern numerous functional aspects. During the glycosylation process of these valuable metabolites, the addition of carbohydrate molecule(s) is catalyzed by enzymes known as sterol glycosyltransferases (SGTs), commonly referred to as UGTs, leading to the production of steryl glycosides (SGs). The ratio of SGs and nonglyco-conjugated SAs are different in different plant species, however, their biosynthesis in the cell is controlled by different environmental factors. The aim of this review is to evaluate the current SGT enzyme research and the functional consequences of glycomodification of SAs on the physiology and plant development, which together are associated with the plant's primary processes. Pharmaceutical, industrial, and other potential uses of saponins have also been discussed and their use in therapeutics has been unveiled by in silico analysis. The field of biotransformation or conversion of nonglycosylated to glycosylated phytosterols by the activity of SGTs, making them soluble, available and more useful for humankind is the new field of interest towards drug therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Emergence of Antimicrobial-Resistant Escherichia coli of Animal Origin Spreading in Humans

PubMed Central

Skurnik, David; Clermont, Olivier; Guillard, Thomas; Launay, Adrien; Danilchanka, Olga; Pons, Stéphanie; Diancourt, Laure; Lebreton, François; Kadlec, Kristina; Roux, Damien; Jiang, Deming; Dion, Sara; Aschard, Hugues; Denamur, Maurice; Cywes-Bentley, Colette; Schwarz, Stefan; Tenaillon, Olivier; Andremont, Antoine; Picard, Bertrand; Mekalanos, John; Brisse, Sylvain; Denamur, Erick

2016-01-01

In the context of the great concern about the impact of human activities on the environment, we studied 403 commensal Escherichia coli/Escherichia clade strains isolated from several animal and human populations that have variable contacts to one another. Multilocus sequence typing (MLST) showed a decrease of diversity 1) in strains isolated from animals that had an increasing contact with humans and 2) in all strains that had increased antimicrobial resistance. A specific B1 phylogroup clonal complex (CC87, Institut Pasteur schema nomenclature) of animal origin was identified and characterized as being responsible for the increased antimicrobial resistance prevalence observed in strains from the environments with a high human-mediated antimicrobial pressure. CC87 strains have a high capacity of acquiring and disseminating resistance genes with specific metabolic and genetic determinants as demonstrated by high-throughput sequencing and phenotyping. They are good mouse gut colonizers but are not virulent. Our data confirm the predominant role of human activities in the emergence of antimicrobial resistance in the environmental bacterial strains and unveil a particular E. coli clonal complex of animal origin capable of spreading antimicrobial resistance to other members of microbial communities. PMID:26613786

In Situ Nanocalorimetric Investigations of Plasma Assisted Deposited Poly(ethylene oxide)-like Films by Specific Heat Spectroscopy.

PubMed

Madkou, Sherif; Melnichu, Iurii; Choukourov, Andrei; Krakovsky, Ivan; Biederman, Hynek; Schönhals, Andreas

2016-04-28

In recent years, highly cross-linked plasma polymers have started to unveil their potential in numerous biomedical applications in thin-film form. However, conventional diagnostic methods often fail due to their diverse molecular dynamics conformations. Here, glassy dynamics and the melting transition of thin PEO-like plasma assisted deposited (ppPEO) films (thickness 100 nm) were in situ studied by a combination of specific heat spectroscopy, utilizing a pJ/K sensitive ac-calorimeter chip, and composition analytical techniques. Different cross-linking densities were obtained by different plasma powers during the deposition of the films. Glassy dynamics were observed for all values of the plasma power. It was found that the glassy dynamics slows down with increasing the plasma power. Moreover, the underlying relaxation time spectra broaden indicating that the molecular motions become more heterogeneous with increasing plasma power. In a second set of the experiment, the melting behavior of the ppPEO films was studied. The melting temperature of ppPEO was found to decrease with increasing plasma power. This was explained by a decrease of the order in the crystals due to formation of chemical defects during the plasma process.

Veiled communication: is uncovering necessary for psychiatric assessment?

PubMed

Mistry, Himanshu; Bhugra, Dinesh; Chaleby, Kutaiba; Khan, Farooq; Sauer, Justin

2009-12-01

Facial expressions are significant to decipher information during a dialogue and more so in a clinical consultation. Veils (Niqab) worn by Muslim women may pose a clinical dilemma for the psychiatric assessment especially if clinicians are not aware of their religious significance. To investigate whether clinical judgment is affected if full facial expressions are not accessible, we conducted an email survey of psychiatrists and psychologists across the world who frequently work in these situations. Of 25 colleagues contacted 16 responded and 11 of them agreed for their comments to be included in the study. Nine out of 11 believed clinical assessment may be compromised, although respondents were aware of cultural sensitivity around the issue. Two out of 11 however, felt fully able to assess the mental state of a veiled woman. Some professionals reported that they feel unable to assess or treat if the request to take the veil off is declined. This small survey demonstrates the diverse opinions on whether unveiling is necessary for psychiatric assessment. Further qualitative examination of this area is needed to develop wider consensus and guidance to mental health care professionals who may be dealing with these groups.

Long-Duration Gamma-Ray Burst Host Galaxies in Emission and Absorption

NASA Astrophysics Data System (ADS)

Perley, Daniel A.; Niino, Yuu; Tanvir, Nial R.; Vergani, Susanna D.; Fynbo, Johan P. U.

2016-12-01

The galaxy population hosting long-duration GRBs provides a means to constrain the progenitor and an opportunity to use these violent explosions to characterize the nature of the high-redshift universe. Studies of GRB host galaxies in emission reveal a population of star-forming galaxies with great diversity, spanning a wide range of masses, metallicities, and redshifts. However, as a population GRB hosts are significantly less massive and poorer in metals than the hosts of other core-collapse transients, suggesting that GRB production is only efficient at metallicities significantly below Solar. GRBs may also prefer compact galaxies, and dense and/or central regions of galaxies, more than other types of core-collapse explosion. Meanwhile, studies of hosts in absorption against the luminous GRB optical afterglow provide a unique means of unveiling properties of the ISM in even the faintest and most distant galaxies; these observations are helping to constrain the chemical evolution of galaxies and the properties of interstellar dust out to very high redshifts. New ground- and space-based instrumentation, and the accumulation of larger and more carefully-selected samples, are continually enhancing our view of the GRB host population.

Clostridial Binary Toxins: Basic Understandings that Include Cell Surface Binding and an Internal "Coup de Grâce".

PubMed

Stiles, Bradley G

2017-01-01

Clostridium species can make a remarkable number of different protein toxins, causing many diverse diseases in humans and animals. The binary toxins of Clostridium botulinum, C. difficile, C. perfringens, and C. spiroforme are one group of enteric-acting toxins that attack the actin cytoskeleton of various cell types. These enterotoxins consist of A (enzymatic) and B (cell binding/membrane translocation) components that assemble on the targeted cell surface or in solution, forming a multimeric complex. Once translocated into the cytosol via endosomal trafficking and acidification, the A component dismantles the filamentous actin-based cytoskeleton via mono-ADP-ribosylation of globular actin. Knowledge of cell surface receptors and how these usurped, host-derived molecules facilitate intoxication can lead to novel ways of defending against these clostridial binary toxins. A molecular-based understanding of the various steps involved in toxin internalization can also unveil therapeutic intervention points that stop the intoxication process. Furthermore, using these bacterial proteins as medicinal shuttle systems into cells provides intriguing possibilities in the future. The pertinent past and state-of-the-art present, regarding clostridial binary toxins, will be evident in this chapter.

Life in the "plastisphere": microbial communities on plastic marine debris.

PubMed

Zettler, Erik R; Mincer, Tracy J; Amaral-Zettler, Linda A

2013-07-02

Plastics are the most abundant form of marine debris, with global production rising and documented impacts in some marine environments, but the influence of plastic on open ocean ecosystems is poorly understood, particularly for microbial communities. Plastic marine debris (PMD) collected at multiple locations in the North Atlantic was analyzed with scanning electron microscopy (SEM) and next-generation sequencing to characterize the attached microbial communities. We unveiled a diverse microbial community of heterotrophs, autotrophs, predators, and symbionts, a community we refer to as the "Plastisphere". Pits visualized in the PMD surface conformed to bacterial shapes suggesting active hydrolysis of the hydrocarbon polymer. Small-subunit rRNA gene surveys identified several hydrocarbon-degrading bacteria, supporting the possibility that microbes play a role in degrading PMD. Some Plastisphere members may be opportunistic pathogens (the authors, unpublished data) such as specific members of the genus Vibrio that dominated one of our plastic samples. Plastisphere communities are distinct from surrounding surface water, implying that plastic serves as a novel ecological habitat in the open ocean. Plastic has a longer half-life than most natural floating marine substrates, and a hydrophobic surface that promotes microbial colonization and biofilm formation, differing from autochthonous substrates in the upper layers of the ocean.

Unveiling the molecular mechanism of brassinosteroids: Insights from structure-based molecular modeling studies.

PubMed

Lei, Beilei; Liu, Jiyuan; Yao, Xiaojun

2015-12-01

Brassinosteroid (BR) phytohormones play indispensable roles in plant growth and development. Brassinolide (BL) and 24-epibrassinolide (24-epiBL) are the most active ones among the BRs reported thus far. Unfortunately, the extremely low natural content and intricate synthesis process limit their popularization in agricultural production. Earlier reports to discover alternative compounds have resulted in molecules with nearly same scaffold structure and without diversity in chemical space. In the present study, receptors structure based BRs regulation mechanism was analyzed. First, we examined the detailed binding interactions and their dynamic stability between BL and its receptor BRI1 and co-receptor BAK1. Then, the binding modes and binding free energies for 24-epiBL and a series of representative BRs binding with BRI1 and BRI1-BAK1 were carried out by molecular docking, energy minimization and MM-PBSA free energy calculation. The obtained binding structures and energetic results provided vital insights into the structural factors affecting the activity from both receptors and BRs aspects. Subsequently, the obtained knowledge will serve as valuable guidance to build pharmacophore models for rational screening of new scaffold alternative BRs. Copyright © 2015 Elsevier Inc. All rights reserved.

Research advances on microbial genetics in China in 2015.

PubMed

Xie, Jian-ping; Han, Yu-bo; Liu, Gang; Bai, Lin-quan

2016-09-01

In 2015, there are significant progresses in many aspects of the microbial genetics in China. To showcase the contribution of Chinese scientists in microbial genetics, this review surveys several notable progresses in microbial genetics made largely by Chinese scientists, and some key findings are highlighted. For the basic microbial genetics, the components, structures and functions of many macromolecule complexes involved in gene expression regulation have been elucidated. Moreover, the molecular basis underlying the recognition of foreign nucleic acids by microbial immune systems was unveiled. We also illustrated the biosynthetic pathways and regulators of multiple microbial compounds, novel enzyme reactions, and new mechanisms regulating microbial gene expression. And new findings were obtained in the microbial development, evolution and population genetics. For the industrial microbiology, more understanding on the molecular basis of the microbial factory has been gained. For the pathogenic microbiology, the genetic circuits of several pathogens were depicted, and significant progresses were achieved for understanding the pathogen-host interaction and revealing the genetic mechanisms underlying antimicrobial resistance, emerging pathogens and environmental microorganisms at the genomic level. In future, the genetic diversity of microbes can be used to obtain specific products, while gut microbiome is gathering momentum.

Evolution of plant δ 1-pyrroline-5-carboxylate reductases from phylogenetic and structural perspectives

DOE PAGES

Forlani, Giuseppe; Makarova, Kira S.; Ruszkowski, Milosz; ...

2015-08-03

Proline plays a crucial role in cell growth and stress responses, and its accumulation is essential for the tolerance of adverse environmental conditions in plants. Two routes are used to biosynthesize proline in plants. The main route uses glutamate as a precursor, while in the other route proline is derived from ornithine. The terminal step of both pathways, the conversion of δ 1-pyrroline-5-carboxylate (P5C) to L-proline, is catalyzed by P5C reductase (P5CR) using NADH or NADPH as a cofactor. Since P5CRs are important housekeeping enzymes, they are conserved across all domains of life and appear to be relatively unaffected throughoutmore » evolution. However, global analysis of these enzymes unveiled significant functional diversity in the preference for cofactors (NADPH vs. NADH), variation in metal dependence and the differences in the oligomeric state. In our study we investigated evolutionary patterns through phylogenetic and structural analysis of P5CR representatives from all kingdoms of life, with emphasis on the plant species. We attempted to correlate local sequence/structure variation among the functionally and structurally characterized members of the family.« less