Aluminum tolerance is associated with higher MATE1 gene copy-number in maize

USDA-ARS?s Scientific Manuscript database

Genome structure variation, including copy-number (CNV) and presence/absence variation (PAV), comprise a large extent of maize genetic diversity but their effect on phenotypes remains largely unexplored. Here we describe how copy-number variation in a major aluminum (Al) tolerance locus contributes ...

Inhibition of HIV-1 Replication by Secondary Metabolites From Endophytic Fungi of Desert Plants

PubMed Central

Wellensiek, Brian P.; Ramakrishnan, Rajesh; Bashyal, Bharat P.; Eason, Yvette; Gunatilaka, A. A. Leslie; Ahmad, Nafees

2013-01-01

Most antiretroviral drugs currently in use to treat an HIV-1 infection are chemically synthesized and lead to the development of viral resistance, as well as cause severe toxicities. However, a largely unexplored source for HIV-1 drug discovery is endophytic fungi that live in a symbiotic relationship with plants. These fungi produce biologically active secondary metabolites, which are natural products that are beneficial to the host. We prepared several hundred extracts from endophytic fungi of desert plants and evaluated the inhibitory effects on HIV-1 replication of those extracts that showed less than 30% cytotoxicity in T-lymphocytes. Those extracts that inhibited viral replication were fractionated in order to isolate the compounds responsible for activity. Multiple rounds of fractionation and antiviral evaluation lead to the identification of four compounds, which almost completely impede HIV-1 replication. These studies demonstrate that metabolites from endophytic fungi of desert plants can serve as a viable source for identifying potent inhibitors of HIV-1 replication. PMID:23961302

The Characteristics of Mathematical Creativity

ERIC Educational Resources Information Center

Sriraman, Bharath

2004-01-01

Mathematical creativity ensures the growth of mathematics as a whole. However, the source of this growth, the creativity of the mathematician, is a relatively unexplored area in mathematics and mathematics education. In order to investigate how mathematicians create mathematics, a qualitative study involving five creative mathematicians was…

Let's Blog About Health! Exploring the Persuasiveness of a Personal HIV Blog Compared to an Institutional HIV Website.

PubMed

Neubaum, German; Krämer, Nicole C

2015-01-01

On HIV blogs, people living with HIV share their intimate thoughts and experiences with the world in the form of personal online diaries. While previous research investigated the reasons why patients engage in blogging activities, the effects of such diaries on nondiseased recipients are largely unexplored. Following an experimental design, this study (n = 261) tested whether a one-time exposure to a personal HIV blog has greater persuasive effects on its readers than an institutional HIV website providing the same content. Results showed that although source credibility was perceived as higher when reading the HIV website from an official institution, blog readers had more positive attitudes and a higher self-efficacy toward condom use than website readers. Implications for health message design are discussed.

Peering through Jupiter’s clouds with radio spectral imaging

NASA Astrophysics Data System (ADS)

de Pater, Imke; Sault, R. J.; Butler, Bryan; DeBoer, David; Wong, Michael H.

2016-06-01

Radio wavelengths can probe altitudes in Jupiter’s atmosphere below its visible cloud layers. We used the Very Large Array to map this unexplored region down to ~8 bar, ~100 kilometers below the visible clouds. Our maps reveal a dynamically active planet at pressures less than 2 to 3 bar. A radio-hot belt exists, consisting of relatively transparent regions (a low ammonia concentration, NH3 being the dominant source of opacity) probing depths to over ~8 bar; these regions probably coincide with 5-micrometer hot spots. Just to the south we distinguish an equatorial wave, bringing up ammonia gas from Jupiter’s deep atmosphere. This wave has been theorized to produce the 5-micrometer hot spots; we observed the predicted radio counterpart of such hot spots.

Unlocking the potential of metagenomics through replicated experimental design.

PubMed

Knight, Rob; Jansson, Janet; Field, Dawn; Fierer, Noah; Desai, Narayan; Fuhrman, Jed A; Hugenholtz, Phil; van der Lelie, Daniel; Meyer, Folker; Stevens, Rick; Bailey, Mark J; Gordon, Jeffrey I; Kowalchuk, George A; Gilbert, Jack A

2012-06-07

Metagenomics holds enormous promise for discovering novel enzymes and organisms that are biomarkers or drivers of processes relevant to disease, industry and the environment. In the past two years, we have seen a paradigm shift in metagenomics to the application of cross-sectional and longitudinal studies enabled by advances in DNA sequencing and high-performance computing. These technologies now make it possible to broadly assess microbial diversity and function, allowing systematic investigation of the largely unexplored frontier of microbial life. To achieve this aim, the global scientific community must collaborate and agree upon common objectives and data standards to enable comparative research across the Earth's microbiome. Improvements in comparability of data will facilitate the study of biotechnologically relevant processes, such as bioprospecting for new glycoside hydrolases or identifying novel energy sources.

Unconventional Deterrence Strategy

DTIC Science & Technology

2005-06-01

200 words) This thesis examines a largely unexplored area of deterrence theory – unconventional deterrence. Unconventional deterrence is defined...hypothesis of deterrence theory which says that the balance of the opponents’ military capabilities is the basic determinant of successful deterrence...

Mechanisms of Sibling Socialization in Normative Family Development

ERIC Educational Resources Information Center

Whiteman, Shawn D.; Becerra, Julia M.; Killoren, Sarah E.

2009-01-01

Siblings are important sources of social influence throughout childhood and adolescence. Nevertheless, the processes by which siblings influence one another remain relatively unexplored. We highlight two theories of sibling influence--sibling deidentification and social learning--that offer insights as to how and why siblings develop similar and…

De novo assembly of soybean wild relatives for pan-genome analysis of diversity and agronomic traits.

PubMed

Li, Ying-hui; Zhou, Guangyu; Ma, Jianxin; Jiang, Wenkai; Jin, Long-guo; Zhang, Zhouhao; Guo, Yong; Zhang, Jinbo; Sui, Yi; Zheng, Liangtao; Zhang, Shan-shan; Zuo, Qiyang; Shi, Xue-hui; Li, Yan-fei; Zhang, Wan-ke; Hu, Yiyao; Kong, Guanyi; Hong, Hui-long; Tan, Bing; Song, Jian; Liu, Zhang-xiong; Wang, Yaoshen; Ruan, Hang; Yeung, Carol K L; Liu, Jian; Wang, Hailong; Zhang, Li-juan; Guan, Rong-xia; Wang, Ke-jing; Li, Wen-bin; Chen, Shou-yi; Chang, Ru-zhen; Jiang, Zhi; Jackson, Scott A; Li, Ruiqiang; Qiu, Li-juan

2014-10-01

Wild relatives of crops are an important source of genetic diversity for agriculture, but their gene repertoire remains largely unexplored. We report the establishment and analysis of a pan-genome of Glycine soja, the wild relative of cultivated soybean Glycine max, by sequencing and de novo assembly of seven phylogenetically and geographically representative accessions. Intergenomic comparisons identified lineage-specific genes and genes with copy number variation or large-effect mutations, some of which show evidence of positive selection and may contribute to variation of agronomic traits such as biotic resistance, seed composition, flowering and maturity time, organ size and final biomass. Approximately 80% of the pan-genome was present in all seven accessions (core), whereas the rest was dispensable and exhibited greater variation than the core genome, perhaps reflecting a role in adaptation to diverse environments. This work will facilitate the harnessing of untapped genetic diversity from wild soybean for enhancement of elite cultivars.

Large contact noise in graphene field-effect transistors

NASA Astrophysics Data System (ADS)

Karnatak, Paritosh; Sai, Phanindra; Goswami, Srijit; Ghatak, Subhamoy; Kaushal, Sanjeev; Ghosh, Arindam

Fluctuations in the electrical resistance at the interface of atomically thin materials and metals, or the contact noise, can adversely affect the device performance but remains largely unexplored. We have investigated contact noise in graphene field effect transistors of varying device geometry and contact configuration, with channel carrier mobility ranging from 5,000 to 80,000 cm2V-1s-1. A phenomenological model developed for contact noise due to current crowding for two dimensional conductors, shows a dominant contact contribution to the measured resistance noise in all graphene field effect transistors when measured in the two-probe or invasive four probe configurations, and surprisingly, also in nearly noninvasive four probe (Hall bar) configuration in the high mobility devices. We identify the fluctuating electrostatic environment of the metal-channel interface as the major source of contact noise, which could be generic to two dimensional material-based electronic devices. The work was financially supported by the Department of Science and Technology, India and Tokyo Electron Limited.

Microbial community dynamics in the forefield of glaciers.

PubMed

Bradley, James A; Singarayer, Joy S; Anesio, Alexandre M

2014-11-22

Retreating ice fronts (as a result of a warming climate) expose large expanses of deglaciated forefield, which become colonized by microbes and plants. There has been increasing interest in characterizing the biogeochemical development of these ecosystems using a chronosequence approach. Prior to the establishment of plants, microbes use autochthonously produced and allochthonously delivered nutrients for growth. The microbial community composition is largely made up of heterotrophic microbes (both bacteria and fungi), autotrophic microbes and nitrogen-fixing diazotrophs. Microbial activity is thought to be responsible for the initial build-up of labile nutrient pools, facilitating the growth of higher order plant life in developed soils. However, it is unclear to what extent these ecosystems rely on external sources of nutrients such as ancient carbon pools and periodic nitrogen deposition. Furthermore, the seasonal variation of chronosequence dynamics and the effect of winter are largely unexplored. Modelling this ecosystem will provide a quantitative evaluation of the key processes and could guide the focus of future research. Year-round datasets combined with novel metagenomic techniques will help answer some of the pressing questions in this relatively new but rapidly expanding field, which is of growing interest in the context of future large-scale ice retreat.

Microbial community dynamics in the forefield of glaciers

PubMed Central

Bradley, James A.; Singarayer, Joy S.; Anesio, Alexandre M.

2014-01-01

Retreating ice fronts (as a result of a warming climate) expose large expanses of deglaciated forefield, which become colonized by microbes and plants. There has been increasing interest in characterizing the biogeochemical development of these ecosystems using a chronosequence approach. Prior to the establishment of plants, microbes use autochthonously produced and allochthonously delivered nutrients for growth. The microbial community composition is largely made up of heterotrophic microbes (both bacteria and fungi), autotrophic microbes and nitrogen-fixing diazotrophs. Microbial activity is thought to be responsible for the initial build-up of labile nutrient pools, facilitating the growth of higher order plant life in developed soils. However, it is unclear to what extent these ecosystems rely on external sources of nutrients such as ancient carbon pools and periodic nitrogen deposition. Furthermore, the seasonal variation of chronosequence dynamics and the effect of winter are largely unexplored. Modelling this ecosystem will provide a quantitative evaluation of the key processes and could guide the focus of future research. Year-round datasets combined with novel metagenomic techniques will help answer some of the pressing questions in this relatively new but rapidly expanding field, which is of growing interest in the context of future large-scale ice retreat. PMID:25274358

Do differences in future sulfate emission pathways matter for near-term climate? A case study for the Asian monsoon

NASA Astrophysics Data System (ADS)

Bartlett, Rachel E.; Bollasina, Massimo A.; Booth, Ben B. B.; Dunstone, Nick J.; Marenco, Franco; Messori, Gabriele; Bernie, Dan J.

2018-03-01

Anthropogenic aerosols could dominate over greenhouse gases in driving near-term hydroclimate change, especially in regions with high present-day aerosol loading such as Asia. Uncertainties in near-future aerosol emissions represent a potentially large, yet unexplored, source of ambiguity in climate projections for the coming decades. We investigated the near-term sensitivity of the Asian summer monsoon to aerosols by means of transient modelling experiments using HadGEM2-ES under two existing climate change mitigation scenarios selected to have similar greenhouse gas forcing, but to span a wide range of plausible global sulfur dioxide emissions. Increased sulfate aerosols, predominantly from East Asian sources, lead to large regional dimming through aerosol-radiation and aerosol-cloud interactions. This results in surface cooling and anomalous anticyclonic flow over land, while abating the western Pacific subtropical high. The East Asian monsoon circulation weakens and precipitation stagnates over Indochina, resembling the observed southern-flood-northern-drought pattern over China. Large-scale circulation adjustments drive suppression of the South Asian monsoon and a westward extension of the Maritime Continent convective region. Remote impacts across the Northern Hemisphere are also generated, including a northwestward shift of West African monsoon rainfall induced by the westward displacement of the Indian Ocean Walker cell, and temperature anomalies in northern midlatitudes linked to propagation of Rossby waves from East Asia. These results indicate that aerosol emissions are a key source of uncertainty in near-term projection of regional and global climate; a careful examination of the uncertainties associated with aerosol pathways in future climate assessments must be highly prioritised.

Differential Relations between Facets of Complex Problem Solving and Students' Immigration Background

ERIC Educational Resources Information Center

Sonnleitner, Philipp; Brunner, Martin; Keller, Ulrich; Martin, Romain

2014-01-01

Whereas the assessment of complex problem solving (CPS) has received increasing attention in the context of international large-scale assessments, its fairness in regard to students' cultural background has gone largely unexplored. On the basis of a student sample of 9th-graders (N = 299), including a representative number of immigrant students (N…

Millimeter transient point sources in the SPTpol 100 square degree survey

DOE PAGES

Whitehorn, N.; Natoli, T.; Ade, P. A. R.; ...

2016-10-18

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

MILLIMETER TRANSIENT POINT SOURCES IN THE SPTpol 100 SQUARE DEGREE SURVEY

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

Whitehorn, N.; Haan, T. de; George, E. M.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg{sup 2} patch of sky centered atmore » R.A. 23{sup h}30{sup m} and decl. −55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. One candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low ( p = 0.01) to confirm detection.« less

Millimeter transient point sources in the SPTpol 100 square degree survey

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

Whitehorn, N.; Natoli, T.; Ade, P. A. R.

The millimeter transient sky is largely unexplored, with measurements limited to follow-up of objects detected at other wavelengths. High-angular-resolution telescopes, designed for measurement of the cosmic microwave background (CMB), offer the possibility to discover new, unknown transient sources in this band—particularly the afterglows of unobserved gamma-ray bursts (GRBs). Here, we use the 10 m millimeter-wave South Pole Telescope, designed for the primary purpose of observing the CMB at arcminute and larger angular scales, to conduct a search for such objects. During the 2012–2013 season, the telescope was used to continuously observe a 100 deg 2 patch of sky centered atmore » R.A. 23 h30 m and decl. –55° using the polarization-sensitive SPTpol camera in two bands centered at 95 and 150 GHz. These 6000 hr of observations provided continuous monitoring for day- to month-scale millimeter-wave transient sources at the 10 mJy level. As a result, one candidate object was observed with properties broadly consistent with a GRB afterglow, but at a statistical significance too low (p = 0.01) to confirm detection.« less

Non-invasive Fetal ECG Signal Quality Assessment for Multichannel Heart Rate Estimation.

PubMed

Andreotti, Fernando; Graser, Felix; Malberg, Hagen; Zaunseder, Sebastian

2017-12-01

The noninvasive fetal ECG (NI-FECG) from abdominal recordings offers novel prospects for prenatal monitoring. However, NI-FECG signals are corrupted by various nonstationary noise sources, making the processing of abdominal recordings a challenging task. In this paper, we present an online approach that dynamically assess the quality of NI-FECG to improve fetal heart rate (FHR) estimation. Using a naive Bayes classifier, state-of-the-art and novel signal quality indices (SQIs), and an existing adaptive Kalman filter, FHR estimation was improved. For the purpose of training and validating the proposed methods, a large annotated private clinical dataset was used. The suggested classification scheme demonstrated an accuracy of Krippendorff's alpha in determining the overall quality of NI-FECG signals. The proposed Kalman filter outperformed alternative methods for FHR estimation achieving accuracy. The proposed algorithm was able to reliably reflect changes of signal quality and can be used in improving FHR estimation. NI-ECG signal quality estimation and multichannel information fusion are largely unexplored topics. Based on previous works, multichannel FHR estimation is a field that could strongly benefit from such methods. The developed SQI algorithms as well as resulting classifier were made available under a GNU GPL open-source license and contributed to the FECGSYN toolbox.

Phylogenetic and structural response of heterotrophic bacteria to dissolved organic matter of different chemical composition in a continuous culture study.

PubMed

Landa, M; Cottrell, M T; Kirchman, D L; Kaiser, K; Medeiros, P M; Tremblay, L; Batailler, N; Caparros, J; Catala, P; Escoubeyrou, K; Oriol, L; Blain, S; Obernosterer, I

2014-06-01

Dissolved organic matter (DOM) and heterotrophic bacteria are highly diverse components of the ocean system, and their interactions are key in regulating the biogeochemical cycles of major elements. How chemical and phylogenetic diversity are linked remains largely unexplored to date. To investigate interactions between bacterial diversity and DOM, we followed the response of natural bacterial communities to two sources of phytoplankton-derived DOM over six bacterial generation times in continuous cultures. Analyses of total hydrolysable neutral sugars and amino acids, and ultrahigh resolution mass spectrometry revealed large differences in the chemical composition of the two DOM sources. According to 454 pyrosequences of 16S ribosomal ribonucleic acid genes, diatom-derived DOM sustained higher levels of bacterial richness, evenness and phylogenetic diversity than cyanobacteria-derived DOM. These distinct community structures were, however, not associated with specific taxa. Grazing pressure affected bacterial community composition without changing the overall pattern of bacterial diversity levels set by DOM. Our results demonstrate that resource composition can shape several facets of bacterial diversity without influencing the phylogenetic composition of bacterial communities, suggesting functional redundancy at different taxonomic levels for the degradation of phytoplankton-derived DOM. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Ocean plankton. Environmental characteristics of Agulhas rings affect interocean plankton transport.

PubMed

Villar, Emilie; Farrant, Gregory K; Follows, Michael; Garczarek, Laurence; Speich, Sabrina; Audic, Stéphane; Bittner, Lucie; Blanke, Bruno; Brum, Jennifer R; Brunet, Christophe; Casotti, Raffaella; Chase, Alison; Dolan, John R; d'Ortenzio, Fabrizio; Gattuso, Jean-Pierre; Grima, Nicolas; Guidi, Lionel; Hill, Christopher N; Jahn, Oliver; Jamet, Jean-Louis; Le Goff, Hervé; Lepoivre, Cyrille; Malviya, Shruti; Pelletier, Eric; Romagnan, Jean-Baptiste; Roux, Simon; Santini, Sébastien; Scalco, Eleonora; Schwenck, Sarah M; Tanaka, Atsuko; Testor, Pierre; Vannier, Thomas; Vincent, Flora; Zingone, Adriana; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Acinas, Silvia G; Bork, Peer; Boss, Emmanuel; de Vargas, Colomban; Gorsky, Gabriel; Ogata, Hiroyuki; Pesant, Stéphane; Sullivan, Matthew B; Sunagawa, Shinichi; Wincker, Patrick; Karsenti, Eric; Bowler, Chris; Not, Fabrice; Hingamp, Pascal; Iudicone, Daniele

2015-05-22

Agulhas rings provide the principal route for ocean waters to circulate from the Indo-Pacific to the Atlantic basin. Their influence on global ocean circulation is well known, but their role in plankton transport is largely unexplored. We show that, although the coarse taxonomic structure of plankton communities is continuous across the Agulhas choke point, South Atlantic plankton diversity is altered compared with Indian Ocean source populations. Modeling and in situ sampling of a young Agulhas ring indicate that strong vertical mixing drives complex nitrogen cycling, shaping community metabolism and biogeochemical signatures as the ring and associated plankton transit westward. The peculiar local environment inside Agulhas rings may provide a selective mechanism contributing to the limited dispersal of Indian Ocean plankton populations into the Atlantic. Copyright © 2015, American Association for the Advancement of Science.

Red Maple (Acer rubrum) Aerial Parts as a Source of Bioactive Phenolics.

PubMed

Zhang, Yan; Ma, Hang; Yuan, Tao; Seeram, Navindra P

2015-08-01

The bark and stems of red maple (Acer rubrum) are reported to contain bioactive phenolics but its aerial parts, namely, flowers and leaves, remain largely unexplored. This is unfortunate considering that various parts of the red maple were used for traditional medicinal purposes by the indigenous peoples of eastern North America, where this species is found. Herein, we report the identification of twenty-five (1-25) phenolics, including two new galloyl derivatives (1 and 2), from red maple flowers and leaves. Of these, ten compounds (1-10), including the new compounds, were isolated and identified by NMR and HRESIMS data while the remaining fifteen compounds (11-25) were identified by HPLC-DAD analyses (by comparison with chemical standards). The isolates (1-10), along with the clinical drug, acarbose, were evaluated for their alpha-glucosidase enzyme inhibitory activities.

Automated source classification of new transient sources

NASA Astrophysics Data System (ADS)

Oertel, M.; Kreikenbohm, A.; Wilms, J.; DeLuca, A.

2017-10-01

The EXTraS project harvests the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) onboard the ESA XMM-Newton mission since its launch. This includes a search for fast transients, missed by standard image analysis, and a search and characterization of variability in hundreds of thousands of sources. We present an automated classification scheme for new transient sources in the EXTraS project. The method is as follows: source classification features of a training sample are used to train machine learning algorithms (performed in R; randomForest (Breiman, 2001) in supervised mode) which are then tested on a sample of known source classes and used for classification.

Student Attitudes towards and Use of ICT in Course Study, Work and Social Activity: A Technology Acceptance Model Approach

ERIC Educational Resources Information Center

Edmunds, Rob; Thorpe, Mary; Conole, Grainne

2012-01-01

The increasing use of information and communication technology (ICT) in higher education has been explored largely in relation to student experience of coursework and university life. Students' lives and experience beyond the university have been largely unexplored. Research into student experience of ICT used a validated model--the technology…

In College and in Recovery: Reasons for Joining a Collegiate Recovery Program

ERIC Educational Resources Information Center

Laudet, Alexandre B.; Harris, Kitty; Kimball, Thomas; Winters, Ken C.; Moberg, D. Paul

2016-01-01

Objective: Collegiate Recovery Programs (CRPs), a campus-based peer support model for students recovering from substance abuse problems, grew exponentially in the past decade, yet remain unexplored. Methods: This mixed-methods study examines students' reasons for CRP enrollment to guide academic institutions and referral sources. Students (N =…

Evaluating the Toxicity Pathways Using High-Throughput Environmental Chemical Data

EPA Science Inventory

The application of HTS methods to the characterization of human phenotypic response to environmental chemicals is a largely unexplored area of pharmacogenomics. The U.S. Environmental Protection Agency (EPA), through its ToxCast program, is developing predictive toxicity approach...

Anxiolytic action of pterostilbene: involvement of hippocampal ERK phosphorylation

USDA-ARS?s Scientific Manuscript database

Pterostilbene, a natural analog of resveratrol, has diverse health-beneficial properties. However, the neurological activities of this compound are largely unexplored. Here we report that pterostilbene shows anxiolytic action by downregulating phosphorylated levels of ERKs in the hippocampus of mice...

Fermi: The Gamma-Ray Large Area Telescope Mission Status

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Space Telescope Mission Status

NASA Technical Reports Server (NTRS)

McEnery, Julie E

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of a population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2015-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10 seconds of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Space Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Childhood Rituals and Executive Functions

ERIC Educational Resources Information Center

Tregay, Jenifer; Gilmour, Jane; Charman, Tony

2009-01-01

Repetitive and ritualistic behaviours (RRBs) are a feature of both typical and atypical development. While the cognitive correlates of these behaviours have been investigated in some neurodevelopmental conditions these links remain largely unexplored in typical development. The current study examined the relationship between RRBs and executive…

The Expanding Diversity of RNA Viruses in Vertebrates.

PubMed

Wang, Wenqiang; Han, Guan-Zhu

2018-06-01

The diversity of RNA viruses in vertebrates remains largely unexplored. The discovery of 214 novel vertebrate-associated RNA viruses will likely help us to understand the diversity and evolution of RNA viruses in vertebrates. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of sound source directivity on auralizations

NASA Astrophysics Data System (ADS)

Sheets, Nathan W.; Wang, Lily M.

2002-05-01

Auralization, the process of rendering audible the sound field in a simulated space, is a useful tool in the design of acoustically sensitive spaces. The auralization depends on the calculation of an impulse response between a source and a receiver which have certain directional behavior. Many auralizations created to date have used omnidirectional sources; the effects of source directivity on auralizations is a relatively unexplored area. To examine if and how the directivity of a sound source affects the acoustical results obtained from a room, we used directivity data for three sources in a room acoustic modeling program called Odeon. The three sources are: violin, piano, and human voice. The results from using directional data are compared to those obtained using omnidirectional source behavior, both through objective measure calculations and subjective listening tests.

Predatory response of Xylocoris flavipes to bruchid pests of stored food legumes

Treesearch

Sharlene E. Sing; Richard T. Arbogast

2008-01-01

Biological control may provide an affordable and sustainable option for reducing losses to pest Bruchidae in stored food legumes, a crucial source of human dietary protein. Previous investigations have focused primarily on the role of parasitism in bruchid biological control, while the potential of generalist predators has been comparatively unexplored. The true bug...

Cytogenetic effect of Alternanthera philoxeroides (alligator weed) on Agasicles hygrophila (Coleoptera: Chrysomelidae) in its native range

USDA-ARS?s Scientific Manuscript database

Plant polyploidy potentially affects plant-insect interactions; however, its effect on insect fitness remains largely unexplored. Alternanthera philoxeroides is a South American amphibious Amaranthaceae, which invades aquatic and terrestrial habitats. Different morphotypes and cytotypes were identif...

Voting contagion: Modeling and analysis of a century of U.S. presidential elections

PubMed Central

de Aguiar, Marcus A. M.

2017-01-01

Social influence plays an important role in human behavior and decisions. Sources of influence can be divided as external, which are independent of social context, or as originating from peers, such as family and friends. An important question is how to disentangle the social contagion by peers from external influences. While a variety of experimental and observational studies provided insight into this problem, identifying the extent of contagion based on large-scale observational data with an unknown network structure remains largely unexplored. By bridging the gap between the large-scale complex systems perspective of collective human dynamics and the detailed approach of social sciences, we present a parsimonious model of social influence, and apply it to a central topic in political science—elections and voting behavior. We provide an analytical expression of the county vote-share distribution, which is in excellent agreement with almost a century of observed U.S. presidential election data. Analyzing the social influence topography over this period reveals an abrupt phase transition from low to high levels of social contagion, and robust differences among regions. These results suggest that social contagion effects are becoming more instrumental in shaping large-scale collective political behavior, with implications on democratic electoral processes and policies. PMID:28542409

Networks of triboelectric nanogenerators for harvesting water wave energy: a potential approach toward blue energy.

PubMed

Chen, Jun; Yang, Jin; Li, Zhaoling; Fan, Xing; Zi, Yunlong; Jing, Qingshen; Guo, Hengyu; Wen, Zhen; Pradel, Ken C; Niu, Simiao; Wang, Zhong Lin

2015-03-24

With 70% of the earth's surface covered with water, wave energy is abundant and has the potential to be one of the most environmentally benign forms of electric energy. However, owing to lack of effective technology, water wave energy harvesting is almost unexplored as an energy source. Here, we report a network design made of triboelectric nanogenerators (TENGs) for large-scale harvesting of kinetic water energy. Relying on surface charging effect between the conventional polymers and very thin layer of metal as electrodes for each TENG, the TENG networks (TENG-NW) that naturally float on the water surface convert the slow, random, and high-force oscillatory wave energy into electricity. On the basis of the measured output of a single TENG, the TENG-NW is expected to give an average power output of 1.15 MW from 1 km(2) surface area. Given the compelling features, such as being lightweight, extremely cost-effective, environmentally friendly, easily implemented, and capable of floating on the water surface, the TENG-NW renders an innovative and effective approach toward large-scale blue energy harvesting from the ocean.

Soft X-Ray Second Harmonic Generation as an Interfacial Probe

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

Lam, R. K.; Raj, S. L.; Pascal, T. A.

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (~284 eV) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from themore » first atomic layer at the open surface. This technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.« less

Soft X-Ray Second Harmonic Generation as an Interfacial Probe

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

Lam, R. K.; Raj, S. L.; Pascal, T. A.

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (~284 eV) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from themore » first atomic layer at the open surface. Here, this technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.« less

Search for Hidden Particles: a new experiment proposal

NASA Astrophysics Data System (ADS)

De Lellis, G.

2015-08-01

Searches for new physics with accelerators are being performed at the LHC, looking for high massive particles coupled to matter with ordinary strength. We propose a new experiment meant to search for very weakly coupled particles in the few GeV mass domain. The existence of such particles, foreseen in different models beyond the Standard Model, is largely unexplored from the experimental point of view. A beam dump facility, built at CERN in the north area, using 400 GeV protons is a copious factory of charmed hadrons and it could be used to probe the existence of such particles. The beam dump is also an ideal source of tau neutrinos, the less known particle in the Standard Model. In particular, tau anti-neutrinos have not been observed so far. We therefore propose an experiment to search for hidden particles and study tau neutrino physics at the same time.

Search for Hidden Particles (SHiP): a new experiment proposal

NASA Astrophysics Data System (ADS)

De Lellis, G.

2015-06-01

Searches for new physics with accelerators are being performed at the LHC, looking for high massive particles coupled to matter with ordinary strength. We propose a new experimental facility meant to search for very weakly coupled particles in the few GeV mass domain. The existence of such particles, foreseen in different theoretical models beyond the Standard Model, is largely unexplored from the experimental point of view. A beam dump facility, built at CERN in the north area, using 400 GeV protons is a copious factory of charmed hadrons and could be used to probe the existence of such particles. The beam dump is also an ideal source of tau neutrinos, the less known particle in the Standard Model. In particular, tau anti-neutrinos have not been observed so far. We therefore propose an experiment to search for hidden particles and study tau neutrino physics at the same time.

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

Heslar, John; Chu, Shih-I.

Recently, the study of near- and below- threshold regime harmonics as a potential source of intense coherent vacuum-ultraviolet radiation has received considerable attention. However, the dynamical origin of these lower harmonics, particularly for the molecular systems, is less understood and largely unexplored. Here we perform the first fully ab initio and high precision 3D quantum study of the below- and near-threshold harmonic generation of H 2 + molecules in an intense 800-nm near-infrared (NIR) laser field. Furthermore, combining with a synchrosqueezing transform of the quantum time-frequency spectrum and an extended semiclassical analysis, we explore in-depth the roles of various quantummore » trajectories, including short- and long trajectories, multiphoton trajectories, resonance-enhanced trajectories, and multiple rescattering trajectories of the below- and near- threshold harmonic generation processes. Our results shed new light on the dynamical origin of the below- and near-threshold harmonic generation and various quantum trajectories for diatomic molecules for the first time.« less

Soft X-Ray Second Harmonic Generation as an Interfacial Probe

DOE PAGES

Lam, R. K.; Raj, S. L.; Pascal, T. A.; ...

2018-01-08

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (~284 eV) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from themore » first atomic layer at the open surface. Here, this technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.« less

pyQms enables universal and accurate quantification of mass spectrometry data.

PubMed

Leufken, Johannes; Niehues, Anna; Sarin, L Peter; Wessel, Florian; Hippler, Michael; Leidel, Sebastian A; Fufezan, Christian

2017-10-01

Quantitative mass spectrometry (MS) is a key technique in many research areas (1), including proteomics, metabolomics, glycomics, and lipidomics. Because all of the corresponding molecules can be described by chemical formulas, universal quantification tools are highly desirable. Here, we present pyQms, an open-source software for accurate quantification of all types of molecules measurable by MS. pyQms uses isotope pattern matching that offers an accurate quality assessment of all quantifications and the ability to directly incorporate mass spectrometer accuracy. pyQms is, due to its universal design, applicable to every research field, labeling strategy, and acquisition technique. This opens ultimate flexibility for researchers to design experiments employing innovative and hitherto unexplored labeling strategies. Importantly, pyQms performs very well to accurately quantify partially labeled proteomes in large scale and high throughput, the most challenging task for a quantification algorithm. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Single photon energy dispersive x-ray diffraction

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

Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando

2014-03-15

With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signalmore » from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.« less

X-ray phase-contrast imaging at 100 keV on a conventional source

PubMed Central

Thüring, T.; Abis, M.; Wang, Z.; David, C.; Stampanoni, M.

2014-01-01

X-ray grating interferometry is a promising imaging technique sensitive to attenuation, refraction and scattering of the radiation. Applications of this technique in the energy range between 80 and 150 keV pose severe technical challenges, and are still mostly unexplored. Phase-contrast X-ray imaging at such high energies is of relevant scientific and industrial interest, in particular for the investigation of strongly absorbing or thick materials as well as for medical imaging. Here we show the successful implementation of a Talbot-Lau interferometer operated at 100 keV using a conventional X-ray tube and a compact geometry, with a total length of 54 cm. We present the edge-on illumination of the gratings in order to overcome the current fabrication limits. Finally, the curved structures match the beam divergence and allow a large field of view on a short and efficient setup. PMID:24903579

Probing the neutron star spin evolution in the young Small Magellanic Cloud Be/X-ray binary SXP 1062

NASA Astrophysics Data System (ADS)

Popov, S. B.; Turolla, R.

2012-03-01

The newly discovered Be/X-ray binary in the Small Magellanic Cloud, SXP 1062, provides the first example of a robust association with a supernova remnant (SNR). The short age estimated for the SNR qualifies SXP 1062 as the youngest known source in its class, ?. As such, it allows us to test current models of magnetorotational evolution of neutron stars in a still unexplored regime. Here we discuss possible evolutionary scenarios for SXP 1062 in an attempt to reconcile its long spin period, ?, and short age. Although several options can be considered, like an anomalously long initial period or the presence of a fossil disc, our results indicate that SXP 1062 may host a neutron star born with a large initial magnetic field, typically in excess of ˜ 1014 G, which then decayed to ˜ 1013 G.

Soft X-Ray Second Harmonic Generation as an Interfacial Probe

NASA Astrophysics Data System (ADS)

Lam, R. K.; Raj, S. L.; Pascal, T. A.; Pemmaraju, C. D.; Foglia, L.; Simoncig, A.; Fabris, N.; Miotti, P.; Hull, C. J.; Rizzuto, A. M.; Smith, J. W.; Mincigrucci, R.; Masciovecchio, C.; Gessini, A.; Allaria, E.; De Ninno, G.; Diviacco, B.; Roussel, E.; Spampinati, S.; Penco, G.; Di Mitri, S.; Trovò, M.; Danailov, M.; Christensen, S. T.; Sokaras, D.; Weng, T.-C.; Coreno, M.; Poletto, L.; Drisdell, W. S.; Prendergast, D.; Giannessi, L.; Principi, E.; Nordlund, D.; Saykally, R. J.; Schwartz, C. P.

2018-01-01

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (˜284 eV ) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from the first atomic layer at the open surface. This technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.

Natural Models for Autonomous Control of Spatial Navigation, Sensing, and Guidance

DTIC Science & Technology

2013-06-26

mantis shrimp, inspired largely by our efforts, can be found at: The Oatmeal - http://theoatmeal.com/ comics /mantis_shrimp. Courtesy of these guys...Ecology and Environmental Education (20-21 January, Tainan, Taiwan). 14 M How, NJ Marshall 2012 Polarisation vision, an unexplored channel for

Student Preferences for Instructional Methods in an Accounting Curriculum

ERIC Educational Resources Information Center

Abeysekera, Indra

2015-01-01

Student preferences among instructional methods are largely unexplored across the accounting curriculum. The algorithmic rigor of courses and the societal culture can influence these preferences. This study explored students' preferences of instructional methods for learning in six courses of the accounting curriculum that differ in algorithmic…

Preservation and Archives in Vietnam.

ERIC Educational Resources Information Center

Henchy, Judith

This report, based on visits to Vietnamese libraries and archives between 1987 and 1997, examines the largely unexplored corpus of Vietnamese textual resources in research institutions and libraries there and elsewhere, the associated problems of bibliographic control, and issues of preservation. The following topics are addressed: the history of…

Does a Brief Mindfulness Intervention Impact Quiz Performance?

ERIC Educational Resources Information Center

Calma-Birling, Destany; Gurung, Regan A. R.

2017-01-01

Mindfulness practices improve cognition, emotional balance, and well-being in clinical and non-clinical populations. The bulk of mindfulness research in higher education has focused on improving psychological and cognitive variables, leaving academic performance largely unexplored. We investigated the effects of a brief mindfulness intervention on…

Undoing Suggestive Influence on Memory: The Reversibility of the Eyewitness Misinformation Effect

ERIC Educational Resources Information Center

Oeberst, Aileen; Blank, Hartmut

2012-01-01

Presenting inconsistent postevent information about a witnessed incident typically decreases the accuracy of memory reports concerning that event (the "misinformation effect"). Surprisingly, the "reversibility" of the effect (after an initial occurrence) has remained largely unexplored. Based on a "memory conversion" theoretical framework and…

Gene Expression: Sizing it all up

USDA-ARS?s Scientific Manuscript database

Genomic architecture appears to be a largely unexplored component of gene expression. Although surely not the end of the story, we are learning that when it comes to gene expression, size is important. We have been surprised to find that certain patterns of expression, tissue-specific versus constit...

Asymmetries of Knowledge and Epistemic Change in Social Gaming Interaction

ERIC Educational Resources Information Center

Piirainen-Marsh, Arja; Tainio, Liisa

2014-01-01

While a growing number of studies investigate the role of knowledge and interactional management of knowledge asymmetries in conversation analysis, the epistemic organization of multilingual and second language interactions is still largely unexplored. This article addresses this issue by investigating how knowledge asymmetries and changing…

Raw material procurement for termite fishing tools by wild chimpanzees in the Issa valley, Western Tanzania.

PubMed

Almeida-Warren, Katarina; Sommer, Volker; Piel, Alex K; Pascual-Garrido, Alejandra

2017-10-01

Chimpanzee termite fishing has been studied for decades, yet the selective processes preceding the manufacture of fishing tools remain largely unexplored. We investigate raw material selection and potential evidence of forward planning in the chimpanzees of Issa valley, western Tanzania. Using traditional archaeological methods, we surveyed the location of plants from where chimpanzees sourced raw material to manufacture termite fishing tools, relative to targeted mounds. We measured raw material abundance to test for availability and selection. Statistics included Chi-Squared, two-tailed Wilcoxon, and Kruskall-Wallace tests. Issa chimpanzees manufactured extraction tools only from bark, despite availability of other suitable materials (e.g., twigs), and selected particular plant species as raw material sources, which they often also exploit for food. Most plants were sourced 1-16 m away from the mound, with a maximum of 33 m. The line of sight from the targeted mound was obscured for a quarter of these plants. The exclusive use of bark tools despite availability of other suitable materials indicates a possible cultural preference. The fact that Issa chimpanzees select specific plant species and travel some distance to source them suggests some degree of selectivity and, potentially, forward planning. Our results have implications for the reconstruction of early hominin behaviors, particularly with regard to the use of perishable tools, which remain archaeologically invisible. © 2017 Wiley Periodicals, Inc.

Spatial hearing in Cope’s gray treefrog: I. Open and closed loop experiments on sound localization in the presence and absence of noise

PubMed Central

Caldwell, Michael S.; Bee, Mark A.

2014-01-01

The ability to reliably locate sound sources is critical to anurans, which navigate acoustically complex breeding choruses when choosing mates. Yet, the factors influencing sound localization performance in frogs remain largely unexplored. We applied two complementary methodologies, open and closed loop playback trials, to identify influences on localization abilities in Cope’s gray treefrog, Hyla chrysoscelis. We examined localization acuity and phonotaxis behavior of females in response to advertisement calls presented from 12 azimuthal angles, at two signal levels, in the presence and absence of noise, and at two noise levels. Orientation responses were consistent with precise localization of sound sources, rather than binary discrimination between sources on either side of the body (lateralization). Frogs were unable to discriminate between sounds arriving from forward and rearward directions, and accurate localization was limited to forward sound presentation angles. Within this region, sound presentation angle had little effect on localization acuity. The presence of noise and low signal-to-noise ratios also did not strongly impair localization ability in open loop trials, but females exhibited reduced phonotaxis performance consistent with impaired localization during closed loop trials. We discuss these results in light of previous work on spatial hearing in anurans. PMID:24504182

Climate change enhances the mobilisation of naturally occurring metals in high altitude environments.

PubMed

Zaharescu, Dragos G; Hooda, Peter S; Burghelea, Carmen I; Polyakov, Viktor; Palanca-Soler, Antonio

2016-08-01

Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a gene synthesis platform for the efficient large scale production of small genes encoding animal toxins.

PubMed

Sequeira, Ana Filipa; Brás, Joana L A; Guerreiro, Catarina I P D; Vincentelli, Renaud; Fontes, Carlos M G A

2016-12-01

Gene synthesis is becoming an important tool in many fields of recombinant DNA technology, including recombinant protein production. De novo gene synthesis is quickly replacing the classical cloning and mutagenesis procedures and allows generating nucleic acids for which no template is available. In addition, when coupled with efficient gene design algorithms that optimize codon usage, it leads to high levels of recombinant protein expression. Here, we describe the development of an optimized gene synthesis platform that was applied to the large scale production of small genes encoding venom peptides. This improved gene synthesis method uses a PCR-based protocol to assemble synthetic DNA from pools of overlapping oligonucleotides and was developed to synthesise multiples genes simultaneously. This technology incorporates an accurate, automated and cost effective ligation independent cloning step to directly integrate the synthetic genes into an effective Escherichia coli expression vector. The robustness of this technology to generate large libraries of dozens to thousands of synthetic nucleic acids was demonstrated through the parallel and simultaneous synthesis of 96 genes encoding animal toxins. An automated platform was developed for the large-scale synthesis of small genes encoding eukaryotic toxins. Large scale recombinant expression of synthetic genes encoding eukaryotic toxins will allow exploring the extraordinary potency and pharmacological diversity of animal venoms, an increasingly valuable but unexplored source of lead molecules for drug discovery.

The Differential Impact of Wealth versus Income in the College-Going Process

ERIC Educational Resources Information Center

Jez, Su Jin

2014-01-01

College is increasingly essential for economic and social mobility. Current research and public policy devotes significant attention to race, income, and socioeconomic factors in college access. Yet, wealth's role, as differentiated from income, is largely unexplored. This paper examines the differences between wealth and income in the…

Interpersonal Communication in the Workplace: A Largely Unexplored Region

ERIC Educational Resources Information Center

DeKay, Sam H.

2012-01-01

Recent research has identified interpersonal communication skills as critical attributes for new employees and more experienced workers seeking promotion. However, despite the significance of interpersonal communication in the workplace, one's knowledge of these skills and how they may be taught is limited. The two articles comprising this theme…

Hemispheric Asymmetries and Cognitive Flexibility: An ERP and sLORETA Study

ERIC Educational Resources Information Center

Ocklenburg, Sebastian; Gunturkun, Onur; Beste, Christian

2012-01-01

Although functional cerebral asymmetries (FCAs) affect all cognitive domains, their modulation of the efficacy of specific executive functions is largely unexplored. In the present study, we used a lateralized version of the task switching paradigm to investigate the relevance of hemispheric asymmetries for cognitive control processes. Words were…

Elite Cricket Coach Education: A Bourdieusian Analysis

ERIC Educational Resources Information Center

Townsend, Robert C.; Cushion, Christopher

2017-01-01

The social structures within coach education have been largely unexplored, undiscussed, and treated as unproblematic in contributing to coach learning, both in research and practice. The study used semi-structured, in-depth interviews with 11 elite cricket coaches to gather their perceptions of an elite coach education programme. In particular,…

Intervention Fidelity for a Complex Behaviour Change Intervention in Community Pharmacy Addressing Cardiovascular Disease Risk

ERIC Educational Resources Information Center

McNamara, K. P.; O'Reilly, S. L.; George, J.; Peterson, G. M.; Jackson, S. L.; Duncan, G.; Howarth, H.; Dunbar, J. A.

2015-01-01

Background: Delivery of cardiovascular disease (CVD) prevention programs by community pharmacists appears effective and enhances health service access. However, their capacity to implement complex behavioural change processes during patient counselling remains largely unexplored. This study aims to determine intervention fidelity by pharmacists…

Clustering of Risk Behaviours among African American Adults

ERIC Educational Resources Information Center

Baruth, M.; Addy, C. L.; Wilcox, S.; Dowda, M.

2012-01-01

Objectives: Individuals may engage in more than one risk behaviour at any given time. The extent to which risk behaviours cluster among African American adults has been largely unexplored. This study examined the prevalence and clustering of three risk behaviours among African American church members: smoking; low moderate-to-vigorous intensity…

Bridging Developmental Systems Theory and Evolutionary Psychology Using Dynamic Optimization

ERIC Educational Resources Information Center

Frankenhuis, Willem E.; Panchanathan, Karthik; Clark Barrett, H.

2013-01-01

Interactions between evolutionary psychologists and developmental systems theorists have been largely antagonistic. This is unfortunate because potential synergies between the two approaches remain unexplored. This article presents a method that may help to bridge the divide, and that has proven fruitful in biology: dynamic optimization. Dynamic…

Multisensory Interference in Early Deaf Adults

ERIC Educational Resources Information Center

Heimler, Benedetta; Baruffaldi, Francesca; Bonmassar, Claudia; Venturini, Marta; Pavani, Francesco

2017-01-01

Multisensory interactions in deaf cognition are largely unexplored. Unisensory studies suggest that behavioral/neural changes may be more prominent for visual compared to tactile processing in early deaf adults. Here we test whether such an asymmetry results in increased saliency of vision over touch during visuo-tactile interactions. About 23…

Childhood Giftedness, Adolescent Agency: A Systemic Multiple-Case Study

ERIC Educational Resources Information Center

Mudrak, Jiri; Zabrodska, Katerina

2015-01-01

Although considerable research has addressed development from childhood giftedness to adult excellence, subjective perceptions of this development by gifted individuals themselves have remained largely unexplored. This multiple case study examined the ways in which young adults, who in the past had been identified as gifted, made sense of their…

The Association of Childhood Personality on Sexual Risk Taking during Adolescence

ERIC Educational Resources Information Center

Atkins, Robert

2008-01-01

Background: Sexual risk taking during adolescence such as failure to use contraception or condoms is associated with premature parenthood and high rates of sexually transmitted infection. The relation of childhood personality to sexual risk taking during adolescence has been largely unexplored. Methods: Using data collected from participants in…

The Potential Role of Business Intelligence in Church Organizations

ERIC Educational Resources Information Center

Felder, Charmaine

2012-01-01

Business intelligence (BI) involves transforming data into actionable information to make better business decisions that may help improve operations. Although businesses have experienced success with BI, how leaders of church organizations might be able to exploit the advantages of BI in church organizations remains largely unexplored. The purpose…

Goal Setting and Student Achievement: A Longitudinal Study

ERIC Educational Resources Information Center

Moeller, Aleidine J.; Theiler, Janine M.; Wu, Chaorong

2012-01-01

The connection between goals and student motivation has been widely investigated in the research literature, but the relationship of goal setting and student achievement at the classroom level has remained largely unexplored. This article reports the findings of a 5-year quasi-experimental study examining goal setting and student achievement in…

Examining the Determinants of Sexual Violence among Young, Married Women in Southern India

ERIC Educational Resources Information Center

Chibber, Karuna S.; Krupp, Karl; Padian, Nancy; Madhivanan, Purnima

2012-01-01

The prevalence of sexual violence is increasingly being studied in India. Yet the determinants of sexual violence, irrespective of physical violence, remain largely unexplored. Here the authors identify the determinants of sexual violence, and additionally, explore how the presence of physical violence modifies these determinants. A…

The SHiP project at CERN

NASA Astrophysics Data System (ADS)

De Lellis, G.; SHiP Collaboration

2016-07-01

The discovery of the Higgs boson has fully confirmed the Standard Model of particles and fields. Nevertheless, there are still fundamental phenomena, like the existence of dark matter and the baryon asymmetry, which deserve an explanation that could come from the discovery of new particles. Searches for new physics with accelerators are performed at the LHC, looking for high massive particles coupled to matter with ordinary strength. A new experimental facility at CERN meant to search for very weakly coupled particles in the few GeV mass domain has been recently proposed. The existence of such particles, foreseen in different theoretical models beyond the Standard Model, is largely unexplored. A beam dump facility using 400 GeV protons is a copious factory of charmed hadrons and could be used to probe the existence of such particles. The beam dump is also a copious source of neutrinos and in particular it is an ideal source of tau neutrinos, the less known particle in the Standard Model. Indeed, tau anti-neutrinos have not been directly observed so far. We report the physics potential of such an experiment. Resistive Plate Chambers could play a role in the SHiP detector.

The antimicrobial potential of algicolous marine fungi for counteracting multidrug-resistant bacteria: phylogenetic diversity and chemical profiling.

PubMed

Gnavi, Giorgio; Palma Esposito, Fortunato; Festa, Carmen; Poli, Anna; Tedesco, Pietro; Fani, Renato; Monti, Maria Chiara; de Pascale, Donatella; D'Auria, Maria Valeria; Varese, Giovanna Cristina

2016-01-01

Marine fungi represent an important but still largely unexplored source of novel and potentially bioactive secondary metabolites. The antimicrobial activity of nine sterile mycelia isolated from the green alga Flabellia petiolata collected from the Mediterranean Sea was tested on four antibiotic-resistant bacterial strains using extracellular and intracellular extracts obtained from each fungal strain. The isolated fungi were identified at the molecular level and assigned to one of the Dothideomycetes, Sordariomycetes or Eurotiomycetes classes. Following assessment of inhibition of bacterial growth (IC50), all crude extracts were subjected to preliminary (1)H NMR and TLC analysis. According to preliminary pharmacologic and spectroscopic/chromatographic results, extracts of fungal strains MUT 4865, classified as Beauveria bassiana, and MUT 4861, classified as Microascacea sp.2, were selected for LC-HRMS analysis. Chemical profiling of antibacterial extracts from MUT 4861 and MUT 4865 by LC HRMS allowed identification of the main components of the crude extracts. Several sphingosine bases were identified, including a compound previously unreported from natural sources, which gave a rationale to the broad spectrum of antibacterial activity exhibited. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Groundwater Profession in Transition: Discovery toAdaptation

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

Narasimhan, T.N.

2005-04-04

Over the past century and half, groundwater has played an important role in the economic prosperity of the United States. The groundwater profession which has contributed to this prosperity has grown through the contributions of the U.S. and State Geological Surveys,academia, and industry. A century ago, the energies of the profession were channeled towards discovering new sources of groundwater in a largely unexplored land, and exploiting the resources for maximum economic benefit. Experience has since revealed that groundwater systems are finite, and are intimately linked to surface water bodies and the biosphere. A consequence is that aggressive exploitation of groundwatermore » can lead to unacceptable environmental degradation and social cost. At present, the groundwater profession is in a state of transition from one of discovery and exploitation, to one of balancing resource development with avoiding unacceptable damage to the environment. This paper outlines the history of the groundwater profession in the United States since the late nineteenth century, and speculates on what may lie ahead in the near future, as the profession makes the transition from discovering new sources of groundwater to one of better understanding and adapting to nature's constraints.« less

Groundwater Profession in Transition: Discovery toAdaptation

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

Narasimhan, T.N.

Over the past century and half, groundwater has played an important role in the economic prosperity of the United States. The groundwater profession which has contributed to this prosperity has grown through the contributions of the U.S. and State Geological Surveys,academia, and industry. A century ago, the energies of the profession were channeled towards discovering new sources of groundwater in a largely unexplored land, and exploiting the resources for maximum economic benefit. Experience has since revealed that groundwater systems are finite, and are intimately linked to surface water bodies and the biosphere. A consequence is that aggressive exploitation of groundwatermore » can lead to unacceptable environmental degradation and social cost. At present, the groundwater profession is in a state of transition from one of discovery and exploitation, to one of balancing resource development with avoiding unacceptable damage to the environment. This paper outlines the history of the groundwater profession in the United States since the late nineteenth century, and speculates on what may lie ahead in the near future, as the profession makes the transition from discovering new sources of groundwater to one of better understanding and adapting to nature's constraints.« less

Undertaking an Ecological Approach to Advance Game-Based Learning: A Case Study

ERIC Educational Resources Information Center

Shah, Mamta; Foster, Aroutis

2014-01-01

Systematic incorporation of digital games in schools is largely unexplored. This case study explored the ecological conditions necessary for implementing a game-based learning course by examining the interaction between three domains (the innovator, the innovation, and the context). From January-April 2012, one in-service teacher learned and…

Parental Personality and Its Relationship to Socialization of Sadness in Children.

ERIC Educational Resources Information Center

Race, Eleanor; Brand, Ann E.

The relationship between parental personality traits and how parents socialize their children's emotions is largely unexplored. This study examined the association of personality traits such as Neuroticism and Agreeableness, and emotion traits such as Anxiety and Trait Depression to the strategies parents use to socialize their children's sadness,…

Ablation of Cerebellar Nuclei Prevents H-Reflex Down-Conditioning in Rats

ERIC Educational Resources Information Center

Chen, Xiang Yang; Wolpaw, Jonathan R.

2005-01-01

While studies of cerebellar involvement in learning and memory have described plasticity within the cerebellum, its role in acquisition of plasticity elsewhere in the CNS is largely unexplored. This study set out to determine whether the cerebellum is needed for acquisition of the spinal cord plasticity that underlies operantly conditioned…

The Roles of Teacher Leadership in Shanghai Education Success

ERIC Educational Resources Information Center

Pang, Nicholas Sun-keung; Miao, Zhuang

2017-01-01

Teacher leadership is generally accepted as having a critical role in supporting school improvement. However, most knowledge on teacher leadership comes from the West, the roles of teacher leadership in the East, particularly, the most populated country, China, remain largely unexplored. Shanghai students were ranked top in PISA 2009 and PISA 2012…

Developmental Changes in the Primacy of Facial Cues for Emotion Recognition

ERIC Educational Resources Information Center

Leitzke, Brian T.; Pollak, Seth D.

2016-01-01

There have been long-standing differences of opinion regarding the influence of the face relative to that of contextual information on how individuals process and judge facial expressions of emotion. However, developmental changes in how individuals use such information have remained largely unexplored and could be informative in attempting to…

Adolescents' Sociopolitical Values in the Context of Organized Activity Involvement

ERIC Educational Resources Information Center

Oosterhoff, Benjamin; Ferris, Kaitlyn A.; Metzger, Aaron

2017-01-01

Sociopolitical values are hypothesized to form during adolescence, but the developmental and contextual origins of these values have been largely unexplored. A sample of 846 adolescents (M[subscript age] = 15.96, SD = 1.22, range = 13-20 years) reported on their organized activity involvement (volunteering, sports, church, community clubs,…

Native American Mobilization and the Power of Recognition: Theorizing the Effects of Political Acknowledgment

ERIC Educational Resources Information Center

Stokes, DaShanne

2012-01-01

How recognition may empower or restrain Native American mobilization has not received sufficient scholarly attention and remains largely unexplored and under-theorized. This paper contributes a partial remedy to this oversight by explicitly theorizing how political recognition can mediate Native American collective action and lead to differential…

Level of Processing Modulates the Neural Correlates of Emotional Memory Formation

ERIC Educational Resources Information Center

Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

2011-01-01

Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study used a levels-of-processing manipulation to characterize the impact of emotion on…

Synthesis and Chemistry of Organic Geminal Di- and Triazides.

PubMed

Häring, Andreas P; Kirsch, Stefan F

2015-11-06

This review recapitulates all available literature dealing with the synthesis and reactivity of geminal organic di- and triazides. These compound classes are, to a large extent, unexplored despite their promising chemical properties and their simple preparation. In addition, the chemistry of carbonyl diazide (2) and tetraazidomethane (105) is described in separate sections.

Change in abundance of three phytophagous mite species (Acari: Eriophyidae, Tetranychidae) on quackgrass in the presence of choke disease

USDA-ARS?s Scientific Manuscript database

Phytophagous mites and endophytic fungi may interact when sharing a host plant, potentially influencing one another’s growth or population dynamics; however, interactions between them are poorly known and remain largely unexplored. In this study, quantitative associations between three species of ph...

Elevational gradient in the cyclicity of a forest-defoliating insect

Treesearch

Kyle J. Haynes; Andrew M. Liebhold; Derek M. Johnson

2012-01-01

Observed changes in the cyclicity of herbivore populations along latitudinal gradients and the hypothesis that shifts in the importance of generalist versus specialist predators explain such gradients has long been a matter of intense interest. In contrast, elevational gradients in population cyclicity are largely unexplored. We quantified the cyclicity of gypsy moth...

Early Childhood Teachers' Perceptions of the Educational Needs of Military Dependent Children

ERIC Educational Resources Information Center

Stites, Michele Lee

2012-01-01

Military dependent children remain a largely unexplored subject, particularly in early childhood education. In an effort to fill the gap in the current literature, this research study focuses on how early childhood teachers perceive the educational needs of military dependent children. Previous research in the areas of geographic mobility,…

The Tropilaelaps mites threat: An examination of the injuries inflicted on Apis mellifera

USDA-ARS?s Scientific Manuscript database

Tropilaelaps spp. are the most serious parasites of Apis mellifera in Asia. However, much of their biology and ecology are largely unexplored (de Guzman et al., 2017 J. Econ. Entomol. 1-14). Like varroa mites, tropilaelaps mites puncture through the integuments of their bee hosts to feed on hemolymp...

Cognate Effects and Cognitive Control in Patients with Parallel and Differential Bilingual Aphasia

ERIC Educational Resources Information Center

Van der Linden, Lize; Verreyt, Nele; De Letter, Miet; Hemelsoet, Dimitri; Mariën, Peter; Santens, Patrick; Stevens, Michaël; Szmalec, Arnaud; Duyck, Wouter

2018-01-01

Background: Until today, there is no satisfying explanation for why one language may recover worse than another in differential bilingual aphasia. One potential explanation that has been largely unexplored is that differential aphasia is the consequence of a loss of language control rather than a loss of linguistic representations. Language…

Development of L2 Interactional Resources for Online Collaborative Task Accomplishment

ERIC Educational Resources Information Center

Balaman, Ufuk; Sert, Olcay

2017-01-01

Technology-mediated task environments have long been considered integral parts of L2 learning and teaching processes. However, the interactional resources that the learners deploy to complete tasks in these environments have remained largely unexplored due to an overall focus on task design and outcomes rather than task engagement processes. With…

Regional Queensland Parents' Views of Science Education: Some Unexpected Perceptions

ERIC Educational Resources Information Center

Boon, Helen J.

2012-01-01

Low post-compulsory science enrolments for secondary students have been a growing concern across the Western world. Research has examined factors relating to science curricula and students' attitudes about science, but parental views of science education remain largely unexplored in Australia. Because parents have a strong role in shaping their…

Survival and growth of Listeria monocytogenes on whole cantaloupes is dependent on site of contamination and storage temperature

USDA-ARS?s Scientific Manuscript database

Whole cantaloupes (Cucumis melo L), marketed as ‘Rocky Ford’, were implicated in a large multi-state outbreak of listeriosis in the United States in 2011; however, survival and growth of Listeria monocytogenes on whole cantaloupes remains relatively unexplored. The research presented here evaluated ...

How Early Childhood Teachers Perceive the Educational Needs of Military Dependent Children

ERIC Educational Resources Information Center

Stites, Michele L.

2016-01-01

Military dependent children remain a largely unexplored subject, particularly in early childhood education. In an effort to fill the gap in the current literature, this research study focuses on how early childhood teachers perceive the educational needs of military dependent children. Previous research in the areas of geographic mobility,…

Hospital CRM: unexplored frontier of revenue growth?

PubMed

Young, Thomas

2007-10-01

Customer relationship management (CRM) has a less-than-stellar reputation, in large part because efforts to implement it have been piecemeal and not well funded. The technologies now exist to make CRM much more effective than it has been in the past. Many hospitals today are demonstrating a substantial ROI from implementing a comprehensive CRM program.

Language and Social Inclusion: Unexplored Aspects of Intercultural Communication

ERIC Educational Resources Information Center

Musgrave, Simon; Bradshaw, Julie

2014-01-01

Social inclusion policy in Australia has largely ignored key issues of communication for linguistic minorities, across communities and with the mainstream community. In the (now disbanded) Social Inclusion Board's reports (e.g., Social Inclusion Unit, 2009), the emphasis is on the economic aspects of inclusion, while little attention has been paid…

Perceived Energy for Parenting: A New Conceptualization and Scale

ERIC Educational Resources Information Center

Janisse, Heather C.; Barnett, Douglas; Nies, Mary A.

2009-01-01

Parenting may be the most physically and mentally demanding social role people encounter during their life. Personal resources are essential to child rearing, yet perceptions of parenting energy have been largely unexplored. This manuscript reports on the need for and development of a measure of perceived energy for parenting (PEP), as well as a…

Exploring the Contribution of Phonological Memory to Metasyntactic Abilities in Bilingual Children

ERIC Educational Resources Information Center

Fortier, Véronique; Simard, Daphnée

2017-01-01

The contribution of phonological memory to syntactic abilities has been demonstrated in various populations, but its relationship to metasyntactic abilities, defined as the ability to control syntactic aspects of language, remains largely unexplored. This study therefore aims to examine the contribution of phonological memory in the completion of…

Text Simplification and Comprehensible Input: A Case for an Intuitive Approach

ERIC Educational Resources Information Center

Crossley, Scott A.; Allen, David; McNamara, Danielle S.

2012-01-01

Texts are routinely simplified to make them more comprehensible for second language learners. However, the effects of simplification upon the linguistic features of texts remain largely unexplored. Here we examine the effects of one type of text simplification: intuitive text simplification. We use the computational tool, Coh-Metrix, to examine…

More than Memories: Studying Home Movies and the Families Who Made Them

ERIC Educational Resources Information Center

Uhrich, Andy

2008-01-01

Unfairly viewed as poorly made and unwatchable, home movies actually constitute a wide variety of events and images that make them an invaluable and largely unexplored resource for scholars and researchers. The images captured in home movies--first birthdays, parades, vacations, family gatherings, etc.--were originally made by family members to…

The Link between Maltreatment and Juvenile Firesetting: Correlates and Underlying Mechanisms

ERIC Educational Resources Information Center

Root, C.; MacKay, S.; Henderson, J.; Del Bove, G.; Warling, D.

2008-01-01

Objective: Despite the widely held belief that abuse is a risk factor for childhood firesetting, the role of maltreatment in firesetting is largely unexplored. This study reports on a sample of children and adolescents referred to a brief assessment and intervention program for juvenile firesetters. Firesetting histories of maltreated youth were…

The star-forming complex LMC-N79 as a future rival to 30 Doradus

NASA Astrophysics Data System (ADS)

Ochsendorf, Bram B.; Zinnecker, Hans; Nayak, Omnarayani; Bally, John; Meixner, Margaret; Jones, Olivia C.; Indebetouw, Remy; Rahman, Mubdi

2017-11-01

Within the early Universe, `extreme' star formation may have been the norm rather than the exception1,2. Super star clusters (with masses greater than 105 solar masses) are thought to be the modern-day analogues of globular clusters, relics of a cosmic time (redshift z ≳ 2) when the Universe was filled with vigorously star-forming systems3. The giant H ii region 30 Doradus in the Large Magellanic Cloud is often regarded as a benchmark for studies of extreme star formation4. Here, we report the discovery of a massive embedded star-forming complex spanning about 500 pc in the unexplored southwest region of the Large Magellanic Cloud, which manifests itself as a younger, embedded twin of 30 Doradus. Previously known as N79, this region has a star-formation efficiency greater than that of 30 Doradus, by a factor of about 2, as measured over the past 0.5 Myr. Moreover, at the heart of N79 lies the most luminous infrared compact source discovered with large-scale infrared surveys of the Large Magellanic Cloud and Milky Way, possibly a precursor to the central super star cluster of 30 Doradus, R136. The discovery of a nearby candidate super star cluster may provide invaluable information to understand how extreme star formation proceeds in the current and high-redshift Universe.

Can Surface Seeps Elucidate Carbon Cycling in Terrestrial Subsurface Ecosystems in Ophiolite-hosted Serpentinizing Fluids?

NASA Astrophysics Data System (ADS)

Meyer-Dombard, D. R.; Cardace, D.; Woycheese, K. M.; Vallalar, B.; Arcilla, C. A.

2017-12-01

Serpentinization in ophiolite-hosted regimes produces highly reduced, high pH fluids that are often characterized as having copious H2 and CH4 gas, little/no inorganic carbon, and limited electron acceptors. Subsurface microbial biomes shift as deeply-sourced fluids reach the oxygenated surface environment, where organisms capable of metabolizing O2 thrive (Woycheese et al., 2015). The relationship, connection, and communication between surface expressions (such as fluid seeps) and the subsurface biosphere is still largely unexplored. Our work in the Zambales and Palawan ophiolites (Philippines) defines surface habitats with geochemistry, targeted culturing efforts, and community analysis (Cardace et al., 2015; Woycheese et al., 2015). Fluids in the spring sources are largely `typical' and fall in the pH range of 9-11.5 with measurable gas escaping from the subsurface (H2 and CH4 > 10uM, CO2 > 1 mM; Cardace et al., 2015). Outflow channels extend from the source pools. These surface data encourage prediction of the subsurface metabolic landscape. To understand how carbon cycling in the subsurface and surface environments might be related, we focus on community analysis, culturing, and the geochemical context of the ecosystem. Shotgun metagenomic analyses indicate carbon cycling is reliant on methanogenesis, acetogenesis, sulfate reduction, and H2 and CH4 oxidation. Methyl coenzyme M reductase, and formylmethanofuran dehydrogenase were detected, and relative abundance increased near the near-anoxic spring source. In this tropical climate, cellulose is also a likely carbon source, possibly even in the subsurface. Enrichment cultures [pH 8-12] and strains [pH 8-10] from Zambales springs show degradation of cellulose and production of cellulase. DIC, DOC, and 13C of solid substrates show mixed autotrophic/heterotrophic activity. Results indicate a metabolically flexible surface community, and suggest details about carbon cycling in the subsurface.

The taming of the neural crest: a developmental perspective on the origins of morphological covariation in domesticated mammals

NASA Astrophysics Data System (ADS)

Sánchez-Villagra, Marcelo R.; Geiger, Madeleine; Schneider, Richard A.

2016-06-01

Studies on domestication are blooming, but the developmental bases for the generation of domestication traits and breed diversity remain largely unexplored. Some phenotypic patterns of human neurocristopathies are suggestive of those reported for domesticated mammals and disrupting neural crest developmental programmes have been argued to be the source of traits deemed the `domestication syndrome'. These character changes span multiple organ systems and morphological structures. But an in-depth examination within the phylogenetic framework of mammals including domesticated forms reveals that the distribution of such traits is not universal, with canids being the only group showing a large set of predicted features. Modularity of traits tied to phylogeny characterizes domesticated mammals: through selective breeding, individual behavioural and morphological traits can be reordered, truncated, augmented or deleted. Similarly, mammalian evolution on islands has resulted in suites of phenotypic changes like those of some domesticated forms. Many domesticated mammals can serve as valuable models for conducting comparative studies on the evolutionary developmental biology of the neural crest, given that series of their embryos are readily available and that their phylogenetic histories and genomes are well characterized.

A magnified young galaxy from about 500 million years after the Big Bang.

PubMed

Zheng, Wei; Postman, Marc; Zitrin, Adi; Moustakas, John; Shu, Xinwen; Jouvel, Stephanie; Høst, Ole; Molino, Alberto; Bradley, Larry; Coe, Dan; Moustakas, Leonidas A; Carrasco, Mauricio; Ford, Holland; Benítez, Narciso; Lauer, Tod R; Seitz, Stella; Bouwens, Rychard; Koekemoer, Anton; Medezinski, Elinor; Bartelmann, Matthias; Broadhurst, Tom; Donahue, Megan; Grillo, Claudio; Infante, Leopoldo; Jha, Saurabh W; Kelson, Daniel D; Lahav, Ofer; Lemze, Doron; Melchior, Peter; Meneghetti, Massimo; Merten, Julian; Nonino, Mario; Ogaz, Sara; Rosati, Piero; Umetsu, Keiichi; van der Wel, Arjen

2012-09-20

Re-ionization of the intergalactic medium occurred in the early Universe at redshift z ≈ 6-11, following the formation of the first generation of stars. Those young galaxies (where the bulk of stars formed) at a cosmic age of less than about 500 million years (z ≲ 10) remain largely unexplored because they are at or beyond the sensitivity limits of existing large telescopes. Understanding the properties of these galaxies is critical to identifying the source of the radiation that re-ionized the intergalactic medium. Gravitational lensing by galaxy clusters allows the detection of high-redshift galaxies fainter than what otherwise could be found in the deepest images of the sky. Here we report multiband observations of the cluster MACS J1149+2223 that have revealed (with high probability) a gravitationally magnified galaxy from the early Universe, at a redshift of z = 9.6 ± 0.2 (that is, a cosmic age of 490 ± 15 million years, or 3.6 per cent of the age of the Universe). We estimate that it formed less than 200 million years after the Big Bang (at the 95 per cent confidence level), implying a formation redshift of ≲14. Given the small sky area that our observations cover, faint galaxies seem to be abundant at such a young cosmic age, suggesting that they may be the dominant source for the early re-ionization of the intergalactic medium.

NATIONAL CONFERENCE ON MANPOWER TRAINING AND THE OLDER WORKER (WASHINGTON, D.C., JANUARY 17-19, 1966).

ERIC Educational Resources Information Center

Department of Health, Education, and Welfare, Washington, DC.

APPROXIMATELY 225 REPRESENTATIVES OF PUBLIC AND PRIVATE EDUCATION, MANAGEMENT, LABOR, AND FEDERAL, STATE, AND LOCAL AGENCIES PARTICIPATED IN THE CONFERENCE WHICH AIMED TO PROVIDE A COMMON PLATFORM FOR THE MOST INFORMED PEOPLE FROM MANY DISCIPLINES TO FOCUS ON THIS LARGELY UNEXPLORED AREA, IDENTIFY SUCCESSFUL PROGRAMS AND TECHNIQUES, AND IDENTIFY…

Seeing Things Unseen: Fantasy Beliefs and False Reports

ERIC Educational Resources Information Center

Principe, Gabrielle F.; Smith, Eric

2008-01-01

Whereas past research has demonstrated that children's beliefs about the real world can influence their memory for events, the role of fantasy beliefs in children's recall remains largely unexplored. We examine this topic in 5- and 6-year-olds by focusing on how belief in a familiar fantasy figure, namely the Tooth Fairy, is related to children's…

Cloud Computing Adoption and Usage in Community Colleges

ERIC Educational Resources Information Center

Behrend, Tara S.; Wiebe, Eric N.; London, Jennifer E.; Johnson, Emily C.

2011-01-01

Cloud computing is gaining popularity in higher education settings, but the costs and benefits of this tool have gone largely unexplored. The purpose of this study was to examine the factors that lead to technology adoption in a higher education setting. Specifically, we examined a range of predictors and outcomes relating to the acceptance of a…

First-Generation, Low-Income College Students during the First Semester in Higher Education: Challenges and Successes

ERIC Educational Resources Information Center

Chhen Stewart, Lee May

2012-01-01

Typically, studies first-generation, low-income students have focused on the financial aid and academic preparedness to enter college and persist. These researchers have found little data about first-generation, low-income students once they enter higher education. One question largely unexplored has been why some first-generation, low-income…

Interrupted Aspirations: Research and Policy on Gitano Education in a Time of Recession, in Spain

ERIC Educational Resources Information Center

Bereményi, Bálint Ábel; Carrasco, Sílvia

2015-01-01

During the past decade, Gitano students' school success and its cultural, social and emotional consequences have been largely unexplored, particularly in a new context: the deep economic crisis in Spain. This study reviews and analyses the evolution of the research production and the changing contexts of policy trends affecting the "Roma…

Common Challenges for Instructors in Large Online Courses: Strategies to Mitigate Student and Instructor Frustration

ERIC Educational Resources Information Center

Trammell, Beth A.; LaForge, Chera

2017-01-01

Teaching in the online classroom is becoming commonplace for instructors as universities seek to grow enrollments and tap into unexplored markets. Many instructors, however, are often unprepared for the nuances of distance education and apprehensive about making the transition to online learning. This article aims to discuss common challenges for…

Investigating the Sets of Values That Community Members Hold toward Local Nature Centers

ERIC Educational Resources Information Center

Browning, Matthew H. E. M.; Stern, Marc J.; Ardoin, Nicole M.; Heimlich, Joe E.; Petty, Robert; Charles, Cheryl

2017-01-01

While nature center's missions often point to connecting people to nature in various ways, their potential to provide a broader array of services to their communities remains largely unexplored. To better understand the values local community members hold for nature centers, we conducted survey research around 16 centers in the United States.…

What Can You Do with that Degree? College Major and Occupational Status of College Graduates over Time

ERIC Educational Resources Information Center

Roksa, Josipa; Levey, Tania

2010-01-01

While income inequality among college graduates is well documented, inequality in occupational status remains largely unexplored. We examine whether and how occupational specificity of college majors is related to college graduates' transition into the labor market and their subsequent occupational trajectories. Analyses of NLSY79 indicate that…

The Influence of Wealth and Race in Four-Year College Attendance. Research & Occasional Paper Series: CSHE.18.08

ERIC Educational Resources Information Center

Jez, Su Jin

2008-01-01

College is increasingly essential for economic and social mobility. Current research devotes significant attention to race and socioeconomic factors in college access. Yet wealth's role, as differentiated from income, is largely unexplored. Utilizing a nationally representative dataset, this study analyzes the role of wealth among students who…

Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato

Treesearch

Justin B. Runyon; Mark C. Mescher; Gary W. Felton; Consuelo M. De Moraes

2010-01-01

While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C18 fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic...

Immigrant DREAMS: English Learners, the Texas 10% Admissions Plan, and College Academic Success

ERIC Educational Resources Information Center

Vasquez Heilig, Julian; Rodriguez, Cristobal; Somers, Patricia

2011-01-01

English learners (ELs) are facing unique issues in higher education that remain largely unexplored. This research focuses on college choice, enrollment, and graduation among high-achieving ELs who were eligible for automatic admission to any public higher education institution in Texas by having graduated in the top 10% of their high school class.…

Physical Education at Preschools: The Meaning of "Physical Education" to Practitioners at Three Preschool Settings in Scotland

ERIC Educational Resources Information Center

McEvilly, Nollaig; Verheul, Martine; Atencio, Matthew

2015-01-01

Background: Preschool physical education has been largely unexplored by researchers. This article examines the meaning of the term "physical education", in relation to preschool contexts, to 14 practitioners working at three preschool settings in Scotland. Our focus on preschool physical education reflects a change in the language…

Inclusive Practices in the Teaching of Mathematics: Supporting the Work of Effective Primary Teachers

ERIC Educational Resources Information Center

Clarke, Barbara; Faragher, Rhonda

2015-01-01

The practices of effective primary school teachers including students with Down syndrome in their mathematics classes are largely unexplored and many teachers feel unprepared to teach students with intellectual disabilities. A study with cohorts in Victoria and the ACT is underway and here we report a subset of findings concerning the support…

The Effect of Self-Explanation of Pathophysiological Mechanisms of Diseases on Medical Students' Diagnostic Performance

ERIC Educational Resources Information Center

Peixoto, José Maria; Mamede, Sílvia; de Faria, Rosa Malena Delbone; Moura, Alexandre Sampaio; Santos, Silvana Maria Elói; Schmidt, Henk G.

2017-01-01

Self-explanation while diagnosing clinical cases fosters medical students' diagnostic performance. In previous studies on self-explanation, students were free to self-explain any aspect of the case, and mostly clinical knowledge was used. Elaboration on knowledge of pathophysiological mechanisms of diseases has been largely unexplored in studies…

Vertical distribution and seasonality of predatory wasps (Hymenoptera: Vespidae) in a temperate deciduous forest

Treesearch

Michael D. Ulyshen; Villu Soon; James L. Hanula

2011-01-01

Efforts to investigate the vertical dimension of forests continue to refine our thinking on issues of biodiversity and ecology. Arthropod communities exhibit a high degree of vertical stratification in forests worldwide but the vertical distribution patterns of most taxa remain largely unexplored or poorly understood. For example, only 2 studies provide information on...

Evidence of cue synergism in termite corpse response behavior

Treesearch

Michael D. Ulyshen; Thomas G. Shelton

2012-01-01

Subterranean termites of the genus Reticulitermes are known to build walls and tubes and move considerable amounts of soil into wood but the causes of this behavior remain largely unexplored. In laboratory assays, we tested the hypothesis that Reticulitermes virginicus (Banks) would carry more sand into wooden blocks containing corpses compared to corpse-free controls...

Seabird Research and Monitoring Needs in Northwestern México

Treesearch

Lucia Alfaro Eduardo Palacios

2005-01-01

Seabird research in northwestern México has increased in the last 20 years, however many areas remain unexplored and seabird colony inventories are badly needed. Coastal wetlands and adjacent islands from southern Sonora through Nayarit host large colonies of pelecaniforme and other seabirds, but surveys of these areas have been limited and localized. Seabird colonies...

The Case of Cotton Mather's Dog: Reflection and Resonance in American Ecopoetics

ERIC Educational Resources Information Center

Killingsworth, M. Jimmie

2011-01-01

Reflection in its most general sense just means thinking, so that a reflection upon nature amounts to thinking about the more-than-human world. Implied, however, is a particular kind of thinking, first and foremost a product of philosophical idealism and the analogical or mimetic imagination. This implication goes largely unexplored in…

Making Music or Gaining Grades? Assessment Practices in Tertiary Music Ensembles

ERIC Educational Resources Information Center

Harrison, Scott D.; Lebler, Don; Carey, Gemma; Hitchcock, Matt; O'Bryan, Jessica

2013-01-01

Participation in an ensemble is a significant aspect of tertiary music experience. Learning and assessment practices within ensembles have rarely been investigated in Australia and the perceptions of staff and students as to how they learn and are assessed within ensembles remain largely unexplored. This paper reports on part of a larger project…

Practices of Other-Initiated Repair in the Classrooms of Children with Specific Speech and Language Difficulties

ERIC Educational Resources Information Center

Radford, Julie

2010-01-01

Repair practices used by teachers who work with children with specific speech and language difficulties (SSLDs) have hitherto remained largely unexplored. Such classrooms therefore offer a new context for researching repairs and considering how they compare with non-SSLD interactions. Repair trajectories are of interest because they are dialogic…

Applying Neuroscientific Findings to Education: The Good, the Tough, and the Hopeful

ERIC Educational Resources Information Center

Christoff, Kalina

2008-01-01

Advances in neuroscience during the past century have yielded important insights into mental functioning, but their implications for the field of education have remained largely unexplored. In a bold attempt to bridge this gap, Immordino-Yang presents findings from 2 boys, Nico and Brooke, each of whom lost half of his brain. The remarkable…

Unpacking Faculty Engagement: The Types of Activities Faculty Members Report as Publicly Engaged Scholarship during Promotion and Tenure

ERIC Educational Resources Information Center

Glass, Chris R.; Doberneck, Diane M.; Schweitzer, John H.

2011-01-01

While a growing body of scholarship has focused on the personal, professional, and organizational factors that influence faculty members' involvement in publicly engaged scholarship, the nature and scope of faculty publicly engaged scholarship itself has remained largely unexplored. What types of activities are faculty members involved in as…

Risk Factors for Severe Inter-Sibling Violence: A Preliminary Study of a Youth Forensic Sample

ERIC Educational Resources Information Center

Khan, Roxanne; Cooke, David J.

2008-01-01

The perpetration of severe inter-sibling violence (SISV) remains a largely unexplored area of family violence. This article describes an investigation of risk factors for intentional SISV perpetration. A sample of 111 young people under the care of the Scottish criminal justice or welfare systems was studied. A SISV perpetration interview schedule…

Testing the Predictors of Boredom at School: Development and Validation of the Precursors to Boredom Scales

ERIC Educational Resources Information Center

Daschmann, Elena C.; Goetz, Thomas; Stupnisky, Robert H.

2011-01-01

Background: Boredom has been found to be an important emotion for students' learning processes and achievement outcomes; however, the precursors of this emotion remain largely unexplored. Aim: In the current study, scales assessing the precursors to boredom in academic achievement settings were developed and tested. Sample: Participants were 1,380…

Expanding Our View of Authentic Learning: Bridging in and Out-of-School Experiences

ERIC Educational Resources Information Center

Quigley, Cassie

2014-01-01

In this review, I explore the affordances of Wolff-Michael Roth and Pei-Ling Hsu's article, "Space, relations and the learning of science" which brings attention to a largely unexplored area of science education research--the importance of spatial organization within the laboratory. This forum piece examines the four components of…

Influencing the Self-Efficacy of Middle Eastern Women through the Use of a Bulletin Board

ERIC Educational Resources Information Center

Alkhalifa, Eshaa

2008-01-01

Gender studies across the world have produced a wealth of information generated by studies that seek to investigate the existence of a distinction between genders in mathematical-based courses, such as Computer Science courses. However, the Middle Eastern Region remained unexplored largely throughout this effort due to gender segregation during…

The Role of Work-Integrated Learning in Student Preferences of Instructional Methods in an Accounting Curriculum

ERIC Educational Resources Information Center

Abeysekera, Indra

2015-01-01

The role of work-integrated learning in student preferences of instructional methods is largely unexplored across the accounting curriculum. This study conducted six experiments to explore student preferences of instructional methods for learning, in six courses of the accounting curriculum that differed in algorithmic rigor, in the context of a…

In the Heart of Teaching: A Two-Dimensional Conception of Teachers' Relational Competence

ERIC Educational Resources Information Center

Aspelin, Jonas

2017-01-01

Research reveals that teachers' relational competence is crucial for successful education. However, the field is still small and largely unexplored, and arguably needs a better and more precise theoretical starting point. This article seeks to help establish such a starting point, aiming to outline a relational framework based on the philosophies…

First identification of direct collapse black hole candidates in the early Universe in CANDELS/GOODS-S

NASA Astrophysics Data System (ADS)

Pacucci, Fabio; Ferrara, Andrea; Grazian, Andrea; Fiore, Fabrizio; Giallongo, Emanuele; Puccetti, Simonetta

2016-06-01

The first black hole seeds, formed when the Universe was younger than ˜500 Myr, are recognized to play an important role for the growth of early (z ˜ 7) supermassive black holes. While progresses have been made in understanding their formation and growth, their observational signatures remain largely unexplored. As a result, no detection of such sources has been confirmed so far. Supported by numerical simulations, we present a novel photometric method to identify black hole seed candidates in deep multiwavelength surveys. We predict that these highly obscured sources are characterized by a steep spectrum in the infrared (1.6-4.5 μm), I.e. by very red colours. The method selects the only two objects with a robust X-ray detection found in the CANDELS/GOODS-S survey with a photometric redshift z ≳ 6. Fitting their infrared spectra only with a stellar component would require unrealistic star formation rates (≳2000 M⊙ yr-1). To date, the selected objects represent the most promising black hole seed candidates, possibly formed via the direct collapse black hole scenario, with predicted mass >105 M⊙. While this result is based on the best photometric observations of high-z sources available to date, additional progress is expected from spectroscopic and deeper X-ray data. Upcoming observatories, like the JWST, will greatly expand the scope of this work.

Identification and characterisation of isoprene-degrading bacteria in an estuarine environment.

PubMed

Johnston, Antonia; Crombie, Andrew T; El Khawand, Myriam; Sims, Leanne; Whited, Gregg M; McGenity, Terry J; Colin Murrell, J

2017-09-01

Approximately one-third of volatile organic compounds (VOCs) emitted to the atmosphere consists of isoprene, originating from the terrestrial and marine biosphere, with a profound effect on atmospheric chemistry. However, isoprene provides an abundant and largely unexplored source of carbon and energy for microbes. The potential for isoprene degradation in marine and estuarine samples from the Colne Estuary, UK, was investigated using DNA-Stable Isotope Probing (DNA-SIP). Analysis at two timepoints showed the development of communities dominated by Actinobacteria including members of the genera Mycobacterium, Rhodococcus, Microbacterium and Gordonia. Representative isolates, capable of growth on isoprene as sole carbon and energy source, were obtained from marine and estuarine locations, and isoprene-degrading strains of Gordonia and Mycobacterium were characterised physiologically and their genomes were sequenced. Genes predicted to be required for isoprene metabolism, including four-component isoprene monooxygenases (IsoMO), were identified and compared with previously characterised examples. Transcriptional and activity assays of strains growing on isoprene or alternative carbon sources showed that growth on isoprene is an inducible trait requiring a specific IsoMO. This study is the first to identify active isoprene degraders in estuarine and marine environments using DNA-SIP and to characterise marine isoprene-degrading bacteria at the physiological and molecular level. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Absolute Nuv magnitudes of Gaia DR1 astrometric stars and a search for hot companions in nearby systems

NASA Astrophysics Data System (ADS)

Makarov, V. V.

2017-10-01

Accurate parallaxes from Gaia DR1 (TGAS) are combined with GALEX visual Nuv magnitudes to produce absolute Mnuv magnitudes and an ultraviolet HR diagram for a large sample of astrometric stars. A functional fit is derived of the lower envelope main sequence of the nearest 1403 stars (distance <40 pc), which should be reddening-free. Using this empirical fit, 50 nearby stars are selected with significant Nuv excess. These are predominantly late K and early M dwarfs, often associated with X-ray sources, and showing other manifestations of magnetic activity. The sample may include systems with hidden white dwarfs, stars younger than the Pleiades, or, most likely, tight interacting binaries of the BY Dra-type. A separate collection of 40 stars with precise trigonometric parallaxes and Nuv-G colors bluer than 2 mag is presented. It includes several known novae, white dwarfs, and binaries with hot subdwarf (sdOB) components, but most remain unexplored.

Epigenetic genome mining of an endophytic fungus leads to the pleiotropic biosynthesis of natural products.

PubMed

Mao, Xu-Ming; Xu, Wei; Li, Dehai; Yin, Wen-Bing; Chooi, Yit-Heng; Li, Yong-Quan; Tang, Yi; Hu, Youcai

2015-06-22

The small-molecule biosynthetic potential of most filamentous fungi has remained largely unexplored and represents an attractive source for the discovery of new compounds. Genome sequencing of Calcarisporium arbuscula, a mushroom-endophytic fungus, revealed 68 core genes that are involved in natural product biosynthesis. This is in sharp contrast to the predominant production of the ATPase inhibitors aurovertin B and D in the wild-type fungus. Inactivation of a histone H3 deacetylase led to pleiotropic activation and overexpression of more than 75 % of the biosynthetic genes. Sampling of the overproduced compounds led to the isolation of ten compounds of which four contained new structures, including the cyclic peptides arbumycin and arbumelin, the diterpenoid arbuscullic acid A, and the meroterpenoid arbuscullic acid B. Such epigenetic modifications therefore provide a rapid and global approach to mine the chemical diversity of endophytic fungi. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The SHIP facility at CERN

NASA Astrophysics Data System (ADS)

De Lellis, Giovanni

2016-04-01

Searches for new physics with accelerators are being performed at the LHC, looking for high massive particles coupled to matter with ordinary strength. A new experimental facility meant to search for very weakly coupled particles in the few GeV mass domain has been recently proposed. The existence of such particles, foreseen in different theoretical models beyond the Standard Model, is largely unexplored from the experimental point of view. A beam dump facility, built at CERN in the north area, using 400 GeV protons is a copious factory of charmed hadrons and could be used to probe the existence of such particles. The beam dump is also an ideal source of tau neutrinos, the less known particle in the Standard Model. In particular, tau anti-neutrinos have not been directly observed so far. We report the physics potential of such an experiment and outline the performances of a detector operating at the same facility for the search for the τ → μμμ decay.

Selfish genetic elements and sexual selection: their impact on male fertility.

PubMed

Price, Tom A R; Wedell, Nina

2008-03-01

Females of many species mate with more than one male (polyandry), yet the adaptive significance of polyandry is poorly understood. One hypothesis to explain the widespread occurrence of multiple mating is that it may allow females to utilize post-copulatory mechanisms to reduce the risk of fertilizing their eggs with sperm from incompatible males. Selfish genetic elements (SGEs) are ubiquitous in eukaryotes, frequent sources of reproductive incompatibilities, and associated with fitness costs. However, their impact on sexual selection is largely unexplored. In this review we examine the link between SGEs, male fertility and sperm competitive ability. We show there is widespread evidence that SGEs are associated with reduced fertility in both animals and plants, and present some recent data showing that males carrying SGEs have reduced paternity in sperm competition. We also discuss possible reasons why male gametes are particularly vulnerable to the selfish actions of SGEs. The widespread reduction in male fertility caused by SGEs implies polyandry may be a successful female strategy to bias paternity against SGE-carrying males.

Selfish genetic elements and sexual selection: their impact on male fertility.

PubMed

Price, Tom A R; Wedell, Nina

2008-09-01

Females of many species mate with more than one male (polyandry), yet the adaptive significance of polyandry is poorly understood. One hypothesis to explain the widespread occurrence of multiple mating is that it may allow females to utilize post-copulatory mechanisms to reduce the risk of fertilizing their eggs with sperm from incompatible males. Selfish genetic elements (SGEs) are ubiquitous in eukaryotes, frequent sources of reproductive incompatibilities, and associated with fitness costs. However, their impact on sexual selection is largely unexplored. In this review we examine the link between SGEs, male fertility and sperm competitive ability. We show there is widespread evidence that SGEs are associated with reduced fertility in both animals and plants, and present some recent data showing that males carrying SGEs have reduced paternity in sperm competition. We also discuss possible reasons why male gametes are particularly vulnerable to the selfish actions of SGEs. The widespread reduction in male fertility caused by SGEs implies polyandry may be a successful female strategy to bias paternity against SGE-carrying males.

Unravelling the dynamical origin of below- and near-threshold harmonic generation of H 2 + in an intense NIR laser field

DOE PAGES

Heslar, John; Chu, Shih-I.

2016-11-24

Recently, the study of near- and below- threshold regime harmonics as a potential source of intense coherent vacuum-ultraviolet radiation has received considerable attention. However, the dynamical origin of these lower harmonics, particularly for the molecular systems, is less understood and largely unexplored. Here we perform the first fully ab initio and high precision 3D quantum study of the below- and near-threshold harmonic generation of H 2 + molecules in an intense 800-nm near-infrared (NIR) laser field. Furthermore, combining with a synchrosqueezing transform of the quantum time-frequency spectrum and an extended semiclassical analysis, we explore in-depth the roles of various quantummore » trajectories, including short- and long trajectories, multiphoton trajectories, resonance-enhanced trajectories, and multiple rescattering trajectories of the below- and near- threshold harmonic generation processes. Our results shed new light on the dynamical origin of the below- and near-threshold harmonic generation and various quantum trajectories for diatomic molecules for the first time.« less

Protein kinase CK2 enables regulatory T cells to suppress excessive TH2 responses in vivo.

PubMed

Ulges, Alexander; Klein, Matthias; Reuter, Sebastian; Gerlitzki, Bastian; Hoffmann, Markus; Grebe, Nadine; Staudt, Valérie; Stergiou, Natascha; Bohn, Toszka; Brühl, Till-Julius; Muth, Sabine; Yurugi, Hajime; Rajalingam, Krishnaraj; Bellinghausen, Iris; Tuettenberg, Andrea; Hahn, Susanne; Reißig, Sonja; Haben, Irma; Zipp, Frauke; Waisman, Ari; Probst, Hans-Christian; Beilhack, Andreas; Buchou, Thierry; Filhol-Cochet, Odile; Boldyreff, Brigitte; Breloer, Minka; Jonuleit, Helmut; Schild, Hansjörg; Schmitt, Edgar; Bopp, Tobias

2015-03-01

The quality of the adaptive immune response depends on the differentiation of distinct CD4(+) helper T cell subsets, and the magnitude of an immune response is controlled by CD4(+)Foxp3(+) regulatory T cells (Treg cells). However, how a tissue- and cell type-specific suppressor program of Treg cells is mechanistically orchestrated has remained largely unexplored. Through the use of Treg cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 (TH2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the β-subunit of CK2 specifically in Treg cells resulted in the proliferation of a hitherto-unexplored ILT3(+) Treg cell subpopulation that was unable to control the maturation of IRF4(+)PD-L2(+) dendritic cells required for the development of TH2 responses in vivo.

From Service to Action? Students, Volunteering and Community Action in Mid Twentieth-Century Britain

ERIC Educational Resources Information Center

Brewis, Georgina

2010-01-01

Volunteering by higher education students in the UK has a long history which remains largely unexplored despite recent research and policy attention. This article offers a brief overview of the development of student volunteering before the 1960s and then discusses a shift from student social service to Student Community Action in the late 1960s…

An empirical evaluation of two-stage species tree inference strategies using a multilocus dataset from North American pines

Treesearch

Michael DeGiorgio; John Syring; Andrew J. Eckert; Aaron Liston; Richard Cronn; David B. Neale; Noah A. Rosenberg

2014-01-01

Background: As it becomes increasingly possible to obtain DNA sequences of orthologous genes from diverse sets of taxa, species trees are frequently being inferred from multilocus data. However, the behavior of many methods for performing this inference has remained largely unexplored. Some methods have been proven to be consistent given certain evolutionary models,...

Investigating Problem-Based Learning Tutorship in Medical and Engineering Programs in Malaysia

ERIC Educational Resources Information Center

Servant, Virginie F. C.; Dewar, Eleanor F. A.

2015-01-01

Although Malaysia was the first country in Asia to adopt problem-based learning (PBL), the impact that this has had on its tutors remains largely unexplored. This paper details a qualitative study of the changing perceptions of teaching roles in two groups of problem-based learning tutors in two institutional contexts--one in medicine located in…

Mathematical and Computational Aspects of Multiscale Materials Modeling, Mathematics-Numerical analysis, Section II.A.a.3.4, Conference and symposia organization II.A.2.a

DTIC Science & Technology

2015-02-04

dislocation dynamics models ( DDD ), continuum representations). Coupling of these models is difficult. Coupling of atomistics and DDD models has been...explored to some extent, but the coupling between DDD and continuum models of the evolution of large populations of dislocations is essentially unexplored

Is Adolescence a Period of Identity Formation for All Youth? Insights from a Four-Wave Longitudinal Study of Identity Dynamics in Japan

ERIC Educational Resources Information Center

Hatano, Kai; Sugimura, Kazumi

2017-01-01

In the present study, we examined changes in identity dynamics during adolescence using the Dimensions of Identity Development Scale (DIDS), focusing on social and cultural factors possibly affecting identity formation. Identity formation among adolescents outside Western countries is largely unexplored; therefore, we focused on adolescents in…

Declining annual streamflow distributions in the Pacific Northwest United States, 1948-2006

Treesearch

C. H. Luce; Z. A. Holden

2009-01-01

Much of the discussion on climate change and water in the western United States centers on decreased snowpack and earlier spring runoff. Although increasing variability in annual flows has been noted, the nature of those changes is largely unexplored. We tested for trends in the distribution of annual runoff using quantile regression at 43 gages in the Pacific...

The Role of Private Universities in the Provision of Higher Education in Uganda: Growth and Challenges

ERIC Educational Resources Information Center

Mugabi, H.

2012-01-01

Although the first private university in Uganda was founded in 1988 and the private university sector has since grown rapidly to become one of the most prominent features of higher education (HE) in Uganda, the contribution of private universities (PUs) to the provision of HE has remained largely unexplored and as such, less understood. The…

Variation in flood tolerance of container-grown seedlings of swamp white oak, bur oak, and white oak

Treesearch

Michael P. Walsh; J.W. Van Sambeek; Mark V. Coggeshall

2008-01-01

How much variation in flood tolerance exists among seedlings within oak species, given the flood frequency of sites from which acorns are collected, has been largely unexplored. Our studies examined initial growth and flood tolerance for seedlings of swamp white oak (Quercus bicolor Willd.), bur oak (Q. macrocarpa L.), and white...

Harm Reduction for the Prevention of Youth Gambling Problems: Lessons Learned From Adolescent High-Risk Behavior Prevention Programs

ERIC Educational Resources Information Center

Dickson, Laurie M.; Derevensky, Jeffrey L.; Gupta, Rina

2004-01-01

Despite the growing popularity of the harm reduction approach in the field of adolescent alcohol and substance abuse, a harm reduction approach to prevention and treatment of youth problem gambling remains largely unexplored. This article poses the question of whether the harm reduction paradigm is a promising approach to the prevention of…

Listening to Music: Helping Children Regulate Their Emotions and Improve Learning in the Classroom

ERIC Educational Resources Information Center

Foran, Lucille M.

2009-01-01

Early education teachers are familiar with using music and rhythm as tools for learning language and building memory. However, the potential of music to help across all special education settings is largely unexplored. Work with music has been widely judged helpful in cases of psychological trauma, yet people do not know why it is helpful. The…

The Use and Role of Pop Culture in Heritage Language Learning: A Study of Advanced Learners of Korean

ERIC Educational Resources Information Center

Choi, Jayoung; Yi, Youngjoo

2012-01-01

Despite the important use of pop culture in many instructional settings, its use in the heritage language (HL) classroom remains largely unexplored. Thus, this article reports findings from classroom-based qualitative research that examined the use and role of pop culture in advanced Korean HL learners' literacy engagement and identity…

Chandra observations of dying radio sources in galaxy clusters

NASA Astrophysics Data System (ADS)

Murgia, M.; Markevitch, M.; Govoni, F.; Parma, P.; Fanti, R.; de Ruiter, H. R.; Mack, K.-H.

2012-12-01

Context. The dying radio sources represent a very interesting and largely unexplored stage of the active galactic nucleus (AGN) evolution. They are considered to be very rare, and almost all of the few known ones were found in galaxy clusters. However, considering the small number detected so far, it has not been possible to draw any firm conclusions about their X-ray environment. Aims: We present X-ray observations performed with the Chandra satellite of the three galaxy clusters Abell 2276, ZwCl 1829.3+6912, and RX J1852.1+5711, which harbor at their center a dying radio source with an ultra-steep spectrum that we recently discovered. Methods: We analyzed the physical properties of the X-ray emitting gas surrounding these elusive radio sources. We determined the global X-ray properties of the clusters, derived the azimuthally averaged profiles of metal abundance, gas temperature, density, and pressure. Furthermore, we estimated the total mass profiles. Results: The large-scale X-ray emission is regular and spherical, suggesting a relaxed state for these systems. Indeed, we found that the three clusters are also characterized by significant enhancements in the metal abundance and declining temperature profiles toward the central region. For all these reasons, we classified RX J1852.1+5711, Abell 2276, and ZwCl 1829.3+6912 as cool-core galaxy clusters. Conclusions: We calculated the non-thermal pressure of the radio lobes assuming that the radio sources are in the minimum energy condition. For all dying sources we found that this is on average about one to two orders of magnitude lower than that of the external gas, as found for many other radio sources at the center of galaxy groups and clusters. We found marginal evidence for the presence of X-ray surface brightness depressions coincident with the fossil radio lobes of the dying sources in A2276 and ZwCl 1829.3+691. We estimated the outburst age and energy output for these two dying sources. The energy power from the AGN outburst is significantly higher than the X-ray luminosity in both clusters. Indeed, it is sufficient that a small fraction of this power is dissipated in the intra-cluster medium to reheat the cool cores. Appendix is available in electronic form at http://www.aanda.org

Chandra Observations of Dying Radio Sources in Galaxy Clusters

NASA Technical Reports Server (NTRS)

Murgia, M.; Markevitch, M.; Govoni, F.; Parma, P.; Fanti, R.; de Ruiter, H. R.; Mack, K.-H.

2012-01-01

Context. The dying radio sources represent a very interesting and largely unexplored stage of the active galactic nucleus (AGN) evolution. They are considered to be very rare, and almost all of the few known ones were found in galaxy clusters. However, considering the small number detected so far, it has not been possible to draw any firm conclusions about their X-ray environment. Aims. We present X-ray observations performed with the Chandra satellite of the three galaxy clusters Abell 2276, ZwCl 1829.3+6912, and RX J1852.1+5711, which harbor at their center a dying radio source with an ultra-steep spectrum that we recently discovered. Methods. We analyzed the physical properties of the X-ray emitting gas surrounding these elusive radio sources. We determined the global X-ray properties of the clusters, derived the azimuthally averaged profiles of metal abundance, gas temperature, density, and pressure. Furthermore, we estimated the total mass profiles. Results. The large-scale X-ray emission is regular and spherical, suggesting a relaxed state for these systems. Indeed, we found that the three clusters are also characterized by significant enhancements in the metal abundance and declining temperature profiles toward the central region. For all these reasons, we classified RX J1852.1+5711, Abell 2276, and ZwCl 1829.3+6912 as cool-core galaxy clusters. Conclusions. We calculated the non-thermal pressure of the radio lobes assuming that the radio sources are in the minimum energy condition. For all dying sources we found that this is on average about one to two orders of magnitude lower than that of the external gas, as found for many other radio sources at the center of galaxy groups and clusters. We found marginal evidence for the presence of X-ray surface brightness depressions coincident with the fossil radio lobes of the dying sources in A2276 and ZwCl 1829.3+691. We estimated the outburst age and energy output for these two dying sources. The energy power from the AGN outburst is significantly higher than the X-ray luminosity in both clusters. Indeed, it is sufficient that a small fraction of this power is dissipated in the intra-cluster medium to reheat the cool cores.

FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems.

PubMed

Arredondo-Hernandez, Luis Jose Rene; Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa

2017-01-01

A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed.

Allelopathy as a potential strategy to improve microalgae cultivation.

PubMed

Bacellar Mendes, Leonardo Brantes; Vermelho, Alane Beatriz

2013-10-21

One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or predators of the microalgae. Numerous studies have explored the potential of naturally occurring bioactive secondary metabolites, which are natural products from plants and microorganisms, as a source of such compounds. Some of these compounds are herbicides, and marine and freshwater microalgae are a source of these compounds. Microalgae produce a remarkable diversity of biologically active metabolites. Results based on the allelopathic potential of algae have only been described for laboratory-scale production and not for algae cultivation on a pilot scale. The adoption of allelopathy on microalgal strains is an unexplored field and may be a novel solution to improve algae production. Here we present information showing the diversity of allelochemicals from microalgae and the use of an allelopathic approach to control microalgae cultivation on a pilot scale based on R&D activities being carried out in Brazil for biodiesel production.

Allelopathy as a potential strategy to improve microalgae cultivation

PubMed Central

2013-01-01

One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or predators of the microalgae. Numerous studies have explored the potential of naturally occurring bioactive secondary metabolites, which are natural products from plants and microorganisms, as a source of such compounds. Some of these compounds are herbicides, and marine and freshwater microalgae are a source of these compounds. Microalgae produce a remarkable diversity of biologically active metabolites. Results based on the allelopathic potential of algae have only been described for laboratory-scale production and not for algae cultivation on a pilot scale. The adoption of allelopathy on microalgal strains is an unexplored field and may be a novel solution to improve algae production. Here we present information showing the diversity of allelochemicals from microalgae and the use of an allelopathic approach to control microalgae cultivation on a pilot scale based on R&D activities being carried out in Brazil for biodiesel production. PMID:24499580

FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems

PubMed Central

Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa

2017-01-01

A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed. PMID:28114378

A kuroko-type polymetallic sulfide deposit in a submarine silicic caldera

PubMed

Iizasa; Fiske; Ishizuka; Yuasa; Hashimoto; Ishibashi; Naka; Horii; Fujiwara; Imai; Koyama

1999-02-12

Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knoll submarine caldera. The sulfide body is located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a large Kuroko-type polymetallic sulfide deposit in this arc-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits.

Shahejie-Shahejie/Guantao/Wumishan and Carboniferous/Permian Coal-Paleozoic Total Petroleum Systems in the Bohaiwan Basin, China (based on geologic studies for the 2000 World Energy Assessment Project of the U.S. Geological Survey)

USGS Publications Warehouse

Ryder, Robert T.; Qiang, Jin; McCabe, Peter J.; Nuccio, Vito F.; Persits, Felix

2012-01-01

This report discusses the geologic framework and petroleum geology used to assess undiscovered petroleum resources in the Bohaiwan basin province for the 2000 World Energy Assessment Project of the U.S. Geological Survey. The Bohaiwan basin in northeastern China is the largest petroleum-producing region in China. Two total petroleum systems have been identified in the basin. The first, the Shahejie&ndashShahejie/Guantao/Wumishan Total Petroleum System, involves oil and gas generated from mature pods of lacustrine source rock that are associated with six major rift-controlled subbasins. Two assessment units are defined in this total petroleum system: (1) a Tertiary lacustrine assessment unit consisting of sandstone reservoirs interbedded with lacustrine shale source rocks, and (2) a pre-Tertiary buried hills assessment unit consisting of carbonate reservoirs that are overlain unconformably by Tertiary lacustrine shale source rocks. The second total petroleum system identified in the Bohaiwan basin is the Carboniferous/Permian Coal–Paleozoic Total Petroleum System, a hypothetical total petroleum system involving natural gas generated from multiple pods of thermally mature coal beds. Low-permeability Permian sandstones and possibly Carboniferous coal beds are the reservoir rocks. Most of the natural gas is inferred to be trapped in continuous accumulations near the center of the subbasins. This total petroleum system is largely unexplored and has good potential for undiscovered gas accumulations. One assessment unit, coal-sourced gas, is defined in this total petroleum system.

VirSchool: The Effect of Background Music and Immersive Display Systems on Memory for Facts Learned in an Educational Virtual Environment

ERIC Educational Resources Information Center

Fassbender, Eric; Richards, Deborah; Bilgin, Ayse; Thompson, William Forde; Heiden, Wolfgang

2012-01-01

Game technology has been widely used for educational applications, however, despite the common use of background music in games, its effect on learning has been largely unexplored. This paper discusses how music played in the background of a computer-animated history lesson affected participants' memory for facts. A virtual history lesson was…

A Life Course Perspective on the Relationship between Socio-Economic Status and Health: Testing the Divergence Hypothesis

ERIC Educational Resources Information Center

Prus, Steven G.

2004-01-01

While adults from all socio-economic status (SES) levels generally encounter a decline in health as they grow older, research shows that health status is tied to SES at all stages of life. The dynamics of the relationship between SES and health over the life course of adult Canadians, however, remain largely unexplored. This paper tests the…

Metaphor, Metonymy, and Their Interaction in the Production of Semantic Approximations by Monolingual Children: A Corpus Analysis

ERIC Educational Resources Information Center

Pérez-Hernández, Lorena; Duvignau, Karine

2016-01-01

The present study looks into the largely unexplored territory of the cognitive underpinnings of semantic approximations in child language. The analysis of a corpus of 233 semantic approximations produced by 101 monolingual French-speaking children from 1;8 to 4;2 years of age leads to a classification of a significant number of them as instances…

Short-range inverse-square law experiment in space

NASA Technical Reports Server (NTRS)

Paik, H. J.; Moody, M. V.

2002-01-01

Newton's inverse-square law is a cornerstone of General Relativity. Its validity has been demonstrated to better than one part in thousand in ranges greater than 1 cm. The range below 1 mm has been left largely unexplored, due to the difficulties associated with designing sensitive short-range experiments. However, the theoretical rationale for testing Newton's law at ranges below 1 mm has become very strong recently.

Temporal and spectral characteristics of dynamic functional connectivity between resting-state networks reveal information beyond static connectivity

PubMed Central

Yeh, Hsiang J.; Guindani, Michele; Vannucci, Marina; Haneef, Zulfi; Stern, John M.

2018-01-01

Estimation of functional connectivity (FC) has become an increasingly powerful tool for investigating healthy and abnormal brain function. Static connectivity, in particular, has played a large part in guiding conclusions from the majority of resting-state functional MRI studies. However, accumulating evidence points to the presence of temporal fluctuations in FC, leading to increasing interest in estimating FC as a dynamic quantity. One central issue that has arisen in this new view of connectivity is the dramatic increase in complexity caused by dynamic functional connectivity (dFC) estimation. To computationally handle this increased complexity, a limited set of dFC properties, primarily the mean and variance, have generally been considered. Additionally, it remains unclear how to integrate the increased information from dFC into pattern recognition techniques for subject-level prediction. In this study, we propose an approach to address these two issues based on a large number of previously unexplored temporal and spectral features of dynamic functional connectivity. A Generalized Autoregressive Conditional Heteroskedasticity (GARCH) model is used to estimate time-varying patterns of functional connectivity between resting-state networks. Time-frequency analysis is then performed on dFC estimates, and a large number of previously unexplored temporal and spectral features drawn from signal processing literature are extracted for dFC estimates. We apply the investigated features to two neurologic populations of interest, healthy controls and patients with temporal lobe epilepsy, and show that the proposed approach leads to substantial increases in predictive performance compared to both traditional estimates of static connectivity as well as current approaches to dFC. Variable importance is assessed and shows that there are several quantities that can be extracted from dFC signal which are more informative than the traditional mean or variance of dFC. This work illuminates many previously unexplored facets of the dynamic properties of functional connectivity between resting-state networks, and provides a platform for dynamic functional connectivity analysis that facilitates its usage as an investigative measure for healthy as well as abnormal brain function. PMID:29320526

Size matters: bigger is faster.

PubMed

Sereno, Sara C; O'Donnell, Patrick J; Sereno, Margaret E

2009-06-01

A largely unexplored aspect of lexical access in visual word recognition is "semantic size"--namely, the real-world size of an object to which a word refers. A total of 42 participants performed a lexical decision task on concrete nouns denoting either big or small objects (e.g., bookcase or teaspoon). Items were matched pairwise on relevant lexical dimensions. Participants' reaction times were reliably faster to semantically "big" versus "small" words. The results are discussed in terms of possible mechanisms, including more active representations for "big" words, due to the ecological importance attributed to large objects in the environment and the relative speed of neural responses to large objects.

Speed of CMEs and the Magnetic Non-Potentiality of Their Source ARs

NASA Technical Reports Server (NTRS)

Tiwari, Sanjiv K.; Falconer, David A.; Moore, Ronald L.; Venkatakrishnan, P.

2014-01-01

Most fast coronal mass ejections (CMEs) originate from solar active regions (ARs). Non-potentiality of ARs is expected to determine the speed and size of CMEs in the outer corona. Several other unexplored parameters might be important as well. To find out the correlation between the initial speed of CMEs and the non-potentiality of source ARs, we associated over a hundred of CMEs with source ARs via their co-produced flares. The speed of the CMEs are collected from the SOHO LASCO CME catalog. We have used vector magnetograms obtained mainly with HMI/SDO, also with Hinode (SOT/SP) when available within an hour of a CME occurrence, to evaluate various magnetic non-potentiality parameters, e.g. magnetic free-energy proxies, computed magnetic free energy, twist, shear angle, signed shear angle etc. We have also included several other parameters e.g. total unsigned flux, net current, magnetic area of ARs, area of sunspots, to investigate their correlation, if any, with the initial speeds of CMEs. Our preliminary results show that the ARs with larger non-potentiality and area mostly produce fast CMEs but they can also produce slower ones. The ARs with lesser non-potentiality and area generally produce only slower CMEs, however, there are a few exceptions. The total unsigned flux correlate with the non-potentiality parameters and area of ARs but some ARs with large unsigned flux are also found to be least non-potential. A more detailed analysis is underway.

Synthesis of Ti3AuC2, Ti3Au2C2 and Ti3IrC2 by noble metal substitution reaction in Ti3SiC2 for high-temperature-stable Ohmic contacts to SiC

NASA Astrophysics Data System (ADS)

Fashandi, Hossein; Dahlqvist, Martin; Lu, Jun; Palisaitis, Justinas; Simak, Sergei I.; Abrikosov, Igor A.; Rosen, Johanna; Hultman, Lars; Andersson, Mike; Lloyd Spetz, Anita; Eklund, Per

2017-08-01

The large class of layered ceramics encompasses both van der Waals (vdW) and non-vdW solids. While intercalation of noble metals in vdW solids is known, formation of compounds by incorporation of noble-metal layers in non-vdW layered solids is largely unexplored. Here, we show formation of Ti3AuC2 and Ti3Au2C2 phases with up to 31% lattice swelling by a substitutional solid-state reaction of Au into Ti3SiC2 single-crystal thin films with simultaneous out-diffusion of Si. Ti3IrC2 is subsequently produced by a substitution reaction of Ir for Au in Ti3Au2C2. These phases form Ohmic electrical contacts to SiC and remain stable after 1,000 h of ageing at 600 °C in air. The present results, by combined analytical electron microscopy and ab initio calculations, open avenues for processing of noble-metal-containing layered ceramics that have not been synthesized from elemental sources, along with tunable properties such as stable electrical contacts for high-temperature power electronics or gas sensors.

Photometric redshift requirements for lens galaxies in galaxy-galaxy lensing analyses

NASA Astrophysics Data System (ADS)

Nakajima, R.; Mandelbaum, R.; Seljak, U.; Cohn, J. D.; Reyes, R.; Cool, R.

2012-03-01

Weak gravitational lensing is a valuable probe of galaxy formation and cosmology. Here we quantify the effects of using photometric redshifts (photo-z) in galaxy-galaxy lensing, for both sources and lenses, both for the immediate goal of using galaxies with photo-z as lenses in the Sloan Digital Sky Survey (SDSS) and as a demonstration of methodology for large, upcoming weak lensing surveys that will by necessity be dominated by lens samples with photo-z. We calculate the bias in the lensing mass calibration as well as consequences for absolute magnitude (i.e. k-corrections) and stellar mass estimates for a large sample of SDSS Data Release 8 (DR8) galaxies. The redshifts are obtained with the template-based photo-z code ZEBRA on the SDSS DR8 ugriz photometry. We assemble and characterize the calibration samples (˜9000 spectroscopic redshifts from four surveys) to obtain photometric redshift errors and lensing biases corresponding to our full SDSS DR8 lens and source catalogues. Our tests of the calibration sample also highlight the impact of observing conditions in the imaging survey when the spectroscopic calibration covers a small fraction of its footprint; atypical imaging conditions in calibration fields can lead to incorrect conclusions regarding the photo-z of the full survey. For the SDSS DR8 catalogue, we find σΔz/(1+z)= 0.096 and 0.113 for the lens and source catalogues, with flux limits of r= 21 and 21.8, respectively. The photo-z bias and scatter is a function of photo-z and template types, which we exploit to apply photo-z quality cuts. By using photo-z rather than spectroscopy for lenses, dim blue galaxies and L* galaxies up to z˜ 0.4 can be used as lenses, thus expanding into unexplored areas of parameter space. We also explore the systematic uncertainty in the lensing signal calibration when using source photo-z, and both lens and source photo-z; given the size of existing training samples, we can constrain the lensing signal calibration (and therefore the normalization of the surface mass density) to within 2 and 4 per cent, respectively.

Does Equal Access Mean Treat the Same? From Theory to Practice in the Classroom of English as an Additional Language Learner in Ireland--Towards a Transformative Agenda

ERIC Educational Resources Information Center

Kelly, Niamh

2014-01-01

While a substantial body of research exists on First- and Second-Language Acquisition (SLA), research on the language acquisition process that a language minority student goes through when they are acquiring a second language has been largely unexplored. Pedagogical practices that espouse language learning theories facilitate both the language…

Mothers' Attributions Following Their Child's Diagnosis of Autistic Spectrum Disorder: Exploring Links with Maternal Levels of Stress, Depression and Expectations about Their Child's Future

ERIC Educational Resources Information Center

Dale, Emily; Jahoda, Andrew; Knott, Fiona

2006-01-01

Although the impact of autism spectrum disorders (ASDs) on the family is well recognized, the way mothers attempt to make sense of the diagnosis is largely unexplored. However, in other disabilities, attributions have been shown to predict a variety of outcomes including maternal wellbeing and engagement in treatment. Using Weiner's (1985)…

Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium.

PubMed

Catania, Francesco; Lynch, Michael

2010-05-04

In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa) remains a virtually unexplored issue. By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Our observations 1) shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2) are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3) reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.

Lignocellulose-Degrading Microbial Communities in Landfill Sites Represent a Repository of Unexplored Biomass-Degrading Diversity.

PubMed

Ransom-Jones, Emma; McCarthy, Alan J; Haldenby, Sam; Doonan, James; McDonald, James E

2017-01-01

The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, to address the paucity of information on biomass-degrading microbial diversity beyond the gastrointestinal tract, cellulose (cotton) "baits" were incubated in landfill leachate microcosms to enrich the landfill cellulolytic microbial community for taxonomic and functional characterization. Metagenome and 16S rRNA gene amplicon sequencing demonstrated the dominance of Firmicutes , Bacteroidetes , Spirochaetes , and Fibrobacteres in the landfill cellulolytic community. Functional metagenome analysis revealed 8,371 carbohydrate active enzymes (CAZymes) belonging to 244 CAZyme families. In addition to observing biomass-degrading enzymes of anaerobic bacterial "cellulosome" systems of members of the Firmicutes , we report the first detection of the Fibrobacter cellulase system and the Bacteroidetes polysaccharide utilization locus (PUL) in landfill sites. These data provide evidence for the presence of multiple mechanisms of biomass degradation in the landfill microbiome and highlight the extraordinary functional diversity of landfill microorganisms as a rich source of biomass-degrading enzymes of potential biotechnological significance. IMPORTANCE The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, we identified Firmicutes , Spirochaetes , and Fibrobacteres as key phyla in the landfill cellulolytic community, detecting 8,371 carbohydrate active enzymes (CAZymes) that represent at least three of the recognized strategies for cellulose decomposition. These data highlight substantial hydrolytic enzyme diversity in landfill sites as a source of new enzymes for biomass conversion.

Lignocellulose-Degrading Microbial Communities in Landfill Sites Represent a Repository of Unexplored Biomass-Degrading Diversity

PubMed Central

Ransom-Jones, Emma; McCarthy, Alan J.; Haldenby, Sam; Doonan, James

2017-01-01

ABSTRACT The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, to address the paucity of information on biomass-degrading microbial diversity beyond the gastrointestinal tract, cellulose (cotton) “baits” were incubated in landfill leachate microcosms to enrich the landfill cellulolytic microbial community for taxonomic and functional characterization. Metagenome and 16S rRNA gene amplicon sequencing demonstrated the dominance of Firmicutes, Bacteroidetes, Spirochaetes, and Fibrobacteres in the landfill cellulolytic community. Functional metagenome analysis revealed 8,371 carbohydrate active enzymes (CAZymes) belonging to 244 CAZyme families. In addition to observing biomass-degrading enzymes of anaerobic bacterial “cellulosome” systems of members of the Firmicutes, we report the first detection of the Fibrobacter cellulase system and the Bacteroidetes polysaccharide utilization locus (PUL) in landfill sites. These data provide evidence for the presence of multiple mechanisms of biomass degradation in the landfill microbiome and highlight the extraordinary functional diversity of landfill microorganisms as a rich source of biomass-degrading enzymes of potential biotechnological significance. IMPORTANCE The microbial conversion of lignocellulosic biomass for biofuel production represents a renewable alternative to fossil fuels. However, the discovery of new microbial enzymes with high activity is critical for improving biomass conversion processes. While attempts to identify superior lignocellulose-degrading enzymes have focused predominantly on the animal gut, biomass-degrading communities in landfill sites represent an unexplored resource of hydrolytic enzymes for biomass conversion. Here, we identified Firmicutes, Spirochaetes, and Fibrobacteres as key phyla in the landfill cellulolytic community, detecting 8,371 carbohydrate active enzymes (CAZymes) that represent at least three of the recognized strategies for cellulose decomposition. These data highlight substantial hydrolytic enzyme diversity in landfill sites as a source of new enzymes for biomass conversion. PMID:28776044

Unexplored therapeutic opportunities in the human genome.

PubMed

Oprea, Tudor I; Bologa, Cristian G; Brunak, Søren; Campbell, Allen; Gan, Gregory N; Gaulton, Anna; Gomez, Shawn M; Guha, Rajarshi; Hersey, Anne; Holmes, Jayme; Jadhav, Ajit; Jensen, Lars Juhl; Johnson, Gary L; Karlson, Anneli; Leach, Andrew R; Ma'ayan, Avi; Malovannaya, Anna; Mani, Subramani; Mathias, Stephen L; McManus, Michael T; Meehan, Terrence F; von Mering, Christian; Muthas, Daniel; Nguyen, Dac-Trung; Overington, John P; Papadatos, George; Qin, Jun; Reich, Christian; Roth, Bryan L; Schürer, Stephan C; Simeonov, Anton; Sklar, Larry A; Southall, Noel; Tomita, Susumu; Tudose, Ilinca; Ursu, Oleg; Vidovic, Dušica; Waller, Anna; Westergaard, David; Yang, Jeremy J; Zahoránszky-Köhalmi, Gergely

2018-05-01

A large proportion of biomedical research and the development of therapeutics is focused on a small fraction of the human genome. In a strategic effort to map the knowledge gaps around proteins encoded by the human genome and to promote the exploration of currently understudied, but potentially druggable, proteins, the US National Institutes of Health launched the Illuminating the Druggable Genome (IDG) initiative in 2014. In this article, we discuss how the systematic collection and processing of a wide array of genomic, proteomic, chemical and disease-related resource data by the IDG Knowledge Management Center have enabled the development of evidence-based criteria for tracking the target development level (TDL) of human proteins, which indicates a substantial knowledge deficit for approximately one out of three proteins in the human proteome. We then present spotlights on the TDL categories as well as key drug target classes, including G protein-coupled receptors, protein kinases and ion channels, which illustrate the nature of the unexplored opportunities for biomedical research and therapeutic development.

Developmental changes in the primacy of facial cues for emotion recognition.

PubMed

Leitzke, Brian T; Pollak, Seth D

2016-04-01

There have been long-standing differences of opinion regarding the influence of the face relative to that of contextual information on how individuals process and judge facial expressions of emotion. However, developmental changes in how individuals use such information have remained largely unexplored and could be informative in attempting to reconcile these opposing views. The current study tested for age-related differences in how individuals prioritize viewing emotional faces versus contexts when making emotion judgments. To do so, we asked 4-, 8-, and 12-year-old children as well as college students to categorize facial expressions of emotion that were presented with scenes that were either congruent or incongruent with the facial displays. During this time, we recorded participants' gaze patterns via eye tracking. College students directed their visual attention primarily to the face, regardless of contextual information. Children, however, divided their attention between both the face and the context as sources of emotional information depending on the valence of the context. These findings reveal a developmental shift in how individuals process and integrate emotional cues. (c) 2016 APA, all rights reserved).

Mitochondrial-Based Therapeutics for the Treatment of Spinal Cord Injury: Mitochondrial Biogenesis as a Potential Pharmacological Target

PubMed Central

Scholpa, Natalie E.

2017-01-01

Spinal cord injury (SCI) is characterized by an initial trauma followed by a progressive cascade of damage referred to as secondary injury. A hallmark of secondary injury is vascular disruption leading to vasoconstriction and decreased oxygen delivery, which directly reduces the ability of mitochondria to maintain homeostasis and leads to loss of ATP-dependent cellular functions, calcium overload, excitotoxicity, and oxidative stress, further exacerbating injury. Restoration of mitochondria dysfunction during the acute phases of secondary injury after SCI represents a potentially effective therapeutic strategy. This review discusses the past and present pharmacological options for the treatment of SCI as well as current research on mitochondria-targeted approaches. Increased antioxidant activity, inhibition of the mitochondrial permeability transition, alternate energy sources, and manipulation of mitochondrial morphology are among the strategies under investigation. Unfortunately, many of these tactics address single aspects of mitochondrial dysfunction, ultimately proving largely ineffective. Therefore, this review also examines the unexplored therapeutic efficacy of pharmacological enhancement of mitochondrial biogenesis, which has the potential to more comprehensively improve mitochondrial function after SCI. PMID:28935700

Mitochondrial-Based Therapeutics for the Treatment of Spinal Cord Injury: Mitochondrial Biogenesis as a Potential Pharmacological Target.

PubMed

Scholpa, Natalie E; Schnellmann, Rick G

2017-12-01

Spinal cord injury (SCI) is characterized by an initial trauma followed by a progressive cascade of damage referred to as secondary injury. A hallmark of secondary injury is vascular disruption leading to vasoconstriction and decreased oxygen delivery, which directly reduces the ability of mitochondria to maintain homeostasis and leads to loss of ATP-dependent cellular functions, calcium overload, excitotoxicity, and oxidative stress, further exacerbating injury. Restoration of mitochondria dysfunction during the acute phases of secondary injury after SCI represents a potentially effective therapeutic strategy. This review discusses the past and present pharmacological options for the treatment of SCI as well as current research on mitochondria-targeted approaches. Increased antioxidant activity, inhibition of the mitochondrial permeability transition, alternate energy sources, and manipulation of mitochondrial morphology are among the strategies under investigation. Unfortunately, many of these tactics address single aspects of mitochondrial dysfunction, ultimately proving largely ineffective. Therefore, this review also examines the unexplored therapeutic efficacy of pharmacological enhancement of mitochondrial biogenesis, which has the potential to more comprehensively improve mitochondrial function after SCI. U.S. Government work not protected by U.S. copyright.

Localized surface plasmon enhanced photothermal conversion in Bi2Se3 topological insulator nanoflowers

PubMed Central

Guozhi, Jia; Peng, Wang; Yanbang, Zhang; Kai, Chang

2016-01-01

Localized surface plasmons (LSP), the confined collective excitations of electrons in noble metal and doped semiconductor nanostructures, enhance greatly local electric field near the surface of the nanostructures and result in strong optical response. LSPs of ordinary massive electrons have been investigated for a long time and were used as basic ingredient of plasmonics and metamaterials. LSPs of massless Dirac electrons, which could result in novel tunable plasmonic metamaterials in the terahertz and infrared frequency regime, are relatively unexplored. Here we report for first time the observation of LSPs in Bi2Se3 topological insulator hierarchical nanoflowers, which are consisted of a large number of Bi2Se3 nanocrystals. The existence of LSPs can be demonstrated by surface enhanced Raman scattering and absorbance spectra ranging from ultraviolet to near-infrared. LSPs produce an enhanced photothermal effect stimulated by near-infrared laser. The excellent photothermal conversion effect can be ascribed to the existence of topological surface states, and provides us a new way for practical application of topological insulators in nanoscale heat source and cancer therapy. PMID:27172827

Unexpected Biotransformation of the HDAC Inhibitor Vorinostat Yields Aniline-Containing Fungal Metabolites.

PubMed

Adpressa, Donovon A; Stalheim, Kayla J; Proteau, Philip J; Loesgen, Sandra

2017-07-21

The diversity of genetically encoded small molecules produced by filamentous fungi remains largely unexplored, which makes these fungi an attractive source for the discovery of new compounds. However, accessing their full chemical repertoire under common laboratory culture conditions is a challenge. Epigenetic manipulation of gene expression has become a well-established tool for overcoming this obstacle. Here, we report that perturbation of the endophytic ascomycete Chalara sp. 6661, producer of the isofusidienol class of antibiotics, with the HDAC inhibitor vorinostat resulted in the production of four new modified xanthones. The structures of chalanilines A (1) and B (2) and adenosine-coupled xanthones A (3) and B (4) were determined by extensive NMR spectroscopic analyses, and the bioactivities of 1-4 were tested in antibiotic and cytotoxicity assays. Incorporation studies with deuterium-labeled vorinostat indicate that the aniline moiety in chalalanine A is derived from vorinostat itself. Our study shows that Chalara sp. is able to metabolize the HDAC inhibitor vorinostat to release aniline. This is a rare report of fungal biotransformation of the popular epigenetic modifier vorinostat into aniline-containing polyketides.

Ocean acidification reduces demersal zooplankton that reside in tropical coral reefs

NASA Astrophysics Data System (ADS)

Smith, Joy N.; de'Ath, Glenn; Richter, Claudio; Cornils, Astrid; Hall-Spencer, Jason M.; Fabricius, Katharina E.

2016-12-01

The in situ effects of ocean acidification on zooplankton communities remain largely unexplored. Using natural volcanic CO2 seep sites around tropical coral communities, we show a threefold reduction in the biomass of demersal zooplankton in high-CO2 sites compared with sites with ambient CO2. Differences were consistent across two reefs and three expeditions. Abundances were reduced in most taxonomic groups. There were no regime shifts in zooplankton community composition and no differences in fatty acid composition between CO2 levels, suggesting that ocean acidification affects the food quantity but not the quality for nocturnal plankton feeders. Emergence trap data show that the observed reduction in demersal plankton may be partly attributable to altered habitat. Ocean acidification changes coral community composition from branching to massive bouldering coral species, and our data suggest that bouldering corals represent inferior daytime shelter for demersal zooplankton. Since zooplankton represent a major source of nutrients for corals, fish and other planktivores, this ecological feedback may represent an additional mechanism of how coral reefs will be affected by ocean acidification.

Fertilization Is Not a New Beginning: The Relationship between Sperm Longevity and Offspring Performance

PubMed Central

Crean, Angela J.; Dwyer, John M.; Marshall, Dustin J.

2012-01-01

Sperm are the most diverse cell type known: varying not only among- and within- species, but also among- and within-ejaculates of a single male. Recently, the causes and consequences of variability in sperm phenotypes have received much attention, but the importance of within-ejaculate variability remains largely unknown. Correlative evidence suggests that reduced within-ejaculate variation in sperm phenotype increases a male’s fertilization success in competitive conditions; but the transgenerational consequences of within-ejaculate variation in sperm phenotype remain relatively unexplored. Here we examine the relationship between sperm longevity and offspring performance in a marine invertebrate with external fertilization, Styela plicata. Offspring sired by longer-lived sperm had higher performance compared to offspring sired by freshly-extracted sperm of the same ejaculate, both in the laboratory and the field. This indicates that within-ejaculate differences in sperm longevity can influence offspring fitness – a source of variability in offspring phenotypes that has not previously been considered. Links between sperm phenotype and offspring performance may constrain responses to selection on either sperm or offspring traits, with broad ecological and evolutionary implications. PMID:23155458

Localized surface plasmon enhanced photothermal conversion in Bi2Se3 topological insulator nanoflowers.

PubMed

Guozhi, Jia; Peng, Wang; Yanbang, Zhang; Kai, Chang

2016-05-12

Localized surface plasmons (LSP), the confined collective excitations of electrons in noble metal and doped semiconductor nanostructures, enhance greatly local electric field near the surface of the nanostructures and result in strong optical response. LSPs of ordinary massive electrons have been investigated for a long time and were used as basic ingredient of plasmonics and metamaterials. LSPs of massless Dirac electrons, which could result in novel tunable plasmonic metamaterials in the terahertz and infrared frequency regime, are relatively unexplored. Here we report for first time the observation of LSPs in Bi2Se3 topological insulator hierarchical nanoflowers, which are consisted of a large number of Bi2Se3 nanocrystals. The existence of LSPs can be demonstrated by surface enhanced Raman scattering and absorbance spectra ranging from ultraviolet to near-infrared. LSPs produce an enhanced photothermal effect stimulated by near-infrared laser. The excellent photothermal conversion effect can be ascribed to the existence of topological surface states, and provides us a new way for practical application of topological insulators in nanoscale heat source and cancer therapy.

Wide-field ultraviolet imager for astronomical transient studies

NASA Astrophysics Data System (ADS)

Mathew, Joice; Ambily, S.; Prakash, Ajin; Sarpotdar, Mayuresh; Nirmal, K.; G. Sreejith, A.; Safonova, Margarita; Murthy, Jayant; Brosch, Noah

2018-04-01

Though the ultraviolet (UV) domain plays a vital role in the studies of astronomical transient events, the UV time-domain sky remains largely unexplored. We have designed a wide-field UV imager that can be flown on a range of available platforms, such as high-altitude balloons, CubeSats, and larger space missions. The major scientific goals are the variability of astronomical sources, detection of transients such as supernovae, novae, tidal disruption events, and characterizing active galactic nuclei variability. The instrument has a 80 mm aperture with a circular field of view of 10.8 degrees, an angular resolution of ˜22 arcsec, and a 240 - 390 nm spectral observation window. The detector for the instrument is a Microchannel Plate (MCP)-based image intensifier with both photon counting and integration capabilities. An FPGA-based detector readout mechanism and real time data processing have been implemented. The imager is designed in such a way that its lightweight and compact nature are well fitted for the CubeSat dimensions. Here we present various design and developmental aspects of this UV wide-field transient explorer.

Recent Advances and Future Challenges in Modified Mycotoxin Analysis: Why HRMS Has Become a Key Instrument in Food Contaminant Research

PubMed Central

Righetti, Laura; Paglia, Giuseppe; Galaverna, Gianni; Dall’Asta, Chiara

2016-01-01

Mycotoxins are secondary metabolites produced by pathogenic fungi in crops worldwide. These compounds can undergo modification in plants, leading to the formation of a large number of possible modified forms, whose toxicological relevance and occurrence in food and feed is still largely unexplored. The analysis of modified mycotoxins by liquid chromatography–mass spectrometry remains a challenge because of their chemical diversity, the large number of isomeric forms, and the lack of analytical standards. Here, the potential benefits of high-resolution and ion mobility mass spectrometry as a tool for separation and structure confirmation of modified mycotoxins have been investigated/reviewed. PMID:27918432

Ecohydrology of the coastal wetlands of Yucatan Peninsula are related with the submarine groundwater discharges?

NASA Astrophysics Data System (ADS)

Herrera Silveira, J. A.; Morales-Ojeda, S. M.; Medina Gomez, I.; Kantun Manzano, C.; Caamal Sosa, J.; Marino-Tapia, I.; Adame, F.; Teutli Hernandez, C.

2013-05-01

Submarine groundwater discharge (SGD) contributes significantly in the structure and function of coastal ecosystems favoring nutrients and salinity gradients, and with these spatial variability of wetland types and rates of primary production. However, the connectivity between SGD and coastal wetlands remains largely unexplored, especially in the tropics and karstic regions. On the other hand, coastal wetlands could represents exceptionally large carbon (C) stocks, whose protection and restoration can constitute an effective mitigation strategy for climate change. The Yucatán Peninsula is a low-relief carbonate platform and karst geology that permits fast rainfall infiltration, minimal surface flow, and high SGD., which is characterized by a continuum of freshwater wetland, mangroves, seagrasses meadows and coral reefs. Our studies around the Yucatan coastal wetlands related with the ecohydrology, suggest strong connectivity between SGD and mangrove and seagrasses structure and function. Some of the results indicate that SGD are the main source of nitrate and silicate favoring salinity gradient along the coastal lagoons and bays like estuaries. Mangrove forests show the best structural developments where a spring of groundwater is located, these types of mangroves are called locally "petenes" and show large C stocks. Respect to seagrasses, high shoots density has been observed at sites characterized by low salinity and peak nutrients concentration. Further research on groundwater flows among human activities on inland activities, coastal wetlands and marine ecosystems are required in order to develop management strategies for mitigation and adaptation to global climate change

Thermodynamic power of non-Markovianity

PubMed Central

Bylicka, Bogna; Tukiainen, Mikko; Chruściński, Dariusz; Piilo, Jyrki; Maniscalco, Sabrina

2016-01-01

The natural framework to discuss thermodynamics at the quantum level is the theory of open quantum systems. Memory effects arising from strong system-environment correlations may lead to information back-flow, that is non-Markovian behaviour. The relation between non-Markovianity and quantum thermodynamics has been until now largely unexplored. Here we show by means of Landauer’s principle that memory effects control the amount of work extraction by erasure in presence of realistic environments. PMID:27323947

Information Technologies as a Tool for Agricultural Extension and Farmer-to-Farmer Exchange: Mobile-Phone Video Use in Mali and Burkina Faso

ERIC Educational Resources Information Center

Sousa, Fernando; Nicolay, Gian; Home, Robert

2016-01-01

Mobile phones are widespread in the rural areas of Mali and Burkina Faso, but their potential as a tool for knowledge transfer by extension services in the region remains largely unexplored. The aim of this contribution is to evaluate the potential of video on mobile phones as a tool for farmer-to-farmer exchange and agricultural extension in…

Substituent Effects on Thermal Decolorization Rates of Bisbenzospiropyrans

PubMed Central

Lu, Nina T.; Nguyen, Vi N.; Kumar, Satish; McCurdy, Alison

2009-01-01

A novel application of photochromic molecules is to mimic physiological oscillatory calcium signals by reversibly binding and releasing calcium ions in response to light. Substituent changes on the largely unexplored photochromic bisbenzospiropyran scaffold led to significant changes in thermal fading rates in several organic solvents. Excellent correlations have been found between fading rates and empirical Hammett constants as well as calculated ground-state energies. These correlations can be used to improve scaffold design. PMID:16238356

Development of novel drugs from marine surface associated microorganisms.

PubMed

Penesyan, Anahit; Kjelleberg, Staffan; Egan, Suhelen

2010-03-01

While the oceans cover more than 70% of the Earth's surface, marine derived microbial natural products have been largely unexplored. The marine environment is a habitat for many unique microorganisms, which produce biologically active compounds ("bioactives") to adapt to particular environmental conditions. For example, marine surface associated microorganisms have proven to be a rich source for novel bioactives because of the necessity to evolve allelochemicals capable of protecting the producer from the fierce competition that exists between microorganisms on the surfaces of marine eukaryotes. Chemically driven interactions are also important for the establishment of cross-relationships between microbes and their eukaryotic hosts, in which organisms producing antimicrobial compounds ("antimicrobials"), may protect the host surface against over colonisation in return for a nutrient rich environment. As is the case for bioactive discovery in general, progress in the detection and characterization of marine microbial bioactives has been limited by a number of obstacles, such as unsuitable culture conditions, laborious purification processes, and a lack of de-replication. However many of these limitations are now being overcome due to improved microbial cultivation techniques, microbial (meta-) genomic analysis and novel sensitive analytical tools for structural elucidation. Here we discuss how these technical advances, together with a better understanding of microbial and chemical ecology, will inevitably translate into an increase in the discovery and development of novel drugs from marine microbial sources in the future.

Immense essence of excellence: marine microbial bioactive compounds.

PubMed

Bhatnagar, Ira; Kim, Se-Kwon

2010-10-15

Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms) that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic) and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin) or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery.

Immense Essence of Excellence: Marine Microbial Bioactive Compounds

PubMed Central

Bhatnagar, Ira; Kim, Se-Kwon

2010-01-01

Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms) that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic) and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin) or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery. PMID:21116414

The Imaging X-ray Polarimetry Explorer (IXPE)

NASA Astrophysics Data System (ADS)

Weisskopf, Martin C.; Ramsey, Brian; O'Dell, Stephen; Tennant, Allyn; Elsner, Ronald; Soffitta, Paolo; Bellazzini, Ronaldo; Costa, Enrico; Kolodziejczak, Jeffrey; Kaspi, Victoria; Muleri, Fabio; Marshall, Herman; Matt, Giorgio; Romani, Roger

2016-07-01

The Imaging X-ray Polarimetry Explorer (IXPE) expands observation space by simultaneously adding polarization measurements to the array of source properties currently measured (energy, time, and location). IXPE will thus open new dimensions for understanding how X-ray emission is produced in astrophysical objects, especially systems under extreme physical conditions—such as neutron stars and black holes. Polarization singularly probes physical anisotropies—ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin—that are not otherwise measurable. Hence, IXPE complements all other investigations in high-energy astrophysics by adding important and relatively unexplored information to the parameter space for studying cosmic X-ray sources and processes, as well as for using extreme astrophysical environments as laboratories for fundamental physics.

Facile method for site-specific gene integration in Lysobacter enzymogenes for yield improvement of the anti-MRSA antibiotics WAP-8294A and the antifungal antibiotic HSAF.

PubMed

Wang, Yan; Qian, Guoliang; Liu, Fengquan; Li, Yue-Zhong; Shen, Yuemao; Du, Liangcheng

2013-11-15

Lysobacter is a genus of Gram-negative gliding bacteria that are emerged as novel biocontrol agents and new sources of bioactive natural products. The bacteria are naturally resistant to many antibiotics commonly used in transformant selection, which has hampered the genetic manipulations. Here, we described a facile method for quick-and-easy identification of the target transformants from a large population of the wild type and nontarget transformants. The method is based on a distinct yellow-to-black color change as a visual selection marker for site-specific integration of the gene of interest. Through transposon random mutagenesis, we identified a black-colored strain from the yellow-colored L. enzymogenes . The black strain was resulted from a disruption of hmgA, a gene required for tyrosine/phenylalanine metabolism. The disruption of hmgA led to accumulation of dark brown pigments. As proof of principle, we constructed a series of expression vectors for a regulator gene found within the WAP-8294A biosynthetic gene cluster. The yield of WAP-8294A in the black strains increased by 2 fold compared to the wild type. Interestingly, the yield of another antibiotic (HSAF) increased up to 7 fold in the black strains. WAP-8294A is a family of potent anti-MRSA antibiotics and is currently in clinical studies, and HSAF is an antifungal compound with distinct structural features and a novel mode of action. This work represents the first successful metabolic engineering in Lysobacter. The development of this facile method opens a way toward manipulating antibiotic production in the largely unexplored sources.

A Facile Method for Site-specific Gene Integration in Lysobacter enzymogenes for Yield Improvement of the Anti-MRSA Antibiotics WAP-8294A and the Antifungal Antibiotic HSAF

PubMed Central

Wang, Yan; Qian, Guoliang; Liu, Fengquan; Li, Yue-Zhong; Shen, Yuemao; Du, Liangcheng

2013-01-01

Lysobacter is a genus of Gram -negative gliding bacteria that are emerged as novel biocontrol agents and new sources of bioactive natural products. The bacteria are naturally resistant to many antibiotics commonly used in transformant selection, which has hampered the genetic manipulations. Here, we described a facile method for quick -and-easy identification of the target transformants from a large population of the wild type and non-target transformants. The method is based on a distinct yellow-to-black color change as a visual selection marker for site-specific integration of the gene of interest. Through transposon random mutagenesis, we identified a black-colored strain from the yellow-colored L. enzymogenes. The black strain was resulted from a disruption of hmgA, a gene required for tyrosine /phenylalanine metabolism. The disruption of hmgA led to accumulation of dark brown pigments. As proof of principle, we constructed a series of expression vectors for a regulator gene found within the WAP-8294A biosynthetic gene cluster. The yield of WAP-8294A in the black strains increased by 2 fold compared to the wild type. Interestingly, the yield of another antibiotic (HSAF) increased up to 7 fold in the black strains. WAP-8294A is a family of potent anti-MRSA antibiotics and is currently in clinical studies, and HSAF is an antifungal compound with distinct structural features and a novel mode of action. This work represents the first successful metabolic engineering in Lysobacter. The development of this facile method opens a way toward manipulating antibiotic production in the largely unexplored sources. PMID:23937053

Resins and Gums in Historical Iatrosophia Texts from Cyprus – A Botanical and Medico-pharmacological Approach

PubMed Central

Lardos, Andreas; Prieto-Garcia, José; Heinrich, Michael

2011-01-01

This study explores historical iatrosophia texts from Cyprus from a botanical and medico-pharmacological point of view focusing on remedies containing resins and gums. The iatrosophia are a genre of Greek medical literature of Byzantine origin and can be described as medicine handbooks which serve as therapeutic repositories containing recipes or advice. To extract and analyze information on plant usage in such sources – which are largely unedited texts and so far have not been translated – we investigate (i) the relationship of the iatrosophia to Dioscorides’ De Materia Medica as well as historic pharmaceutical books or standard texts on modern phytotherapy and (ii) the validity of the remedies by comparing them to modern scientific data on reported biological activities. In the six texts investigated 27 substances incorporating plant exudates are mentioned. They are obtained from over 43 taxa of higher plants and in particular are used to treat dermatological, gastrointestinal, and respiratory tract conditions. The comparison to historic pharmaceutical books and phytotherapy texts reflects the gradual decline of the use of plant exudates in Western medicine. While remarkable parallels to Dioscorides’ text exist, the non-Dioscoridean influence suggests a complex pattern of knowledge exchange. Overall, this resulted in an integration of knowledge from so far poorly understood sources. The comparison with bioscientific data reveals a fragmentary picture and highlights the potential of these unexplored substances and their uses. Where relevant bioscientific data are available, we generally found a confirmation. This points to a largely rational use of the associated remedies. Taken together, the iatrosophia are a valuable resource for ethnopharmacological and natural product research. Most importantly they contribute to the understanding of the development of herbal medicines in the (Eastern) Mediterranean and Europe. PMID:21772820

Resins and Gums in Historical Iatrosophia Texts from Cyprus - A Botanical and Medico-pharmacological Approach.

PubMed

Lardos, Andreas; Prieto-Garcia, José; Heinrich, Michael

2011-01-01

This study explores historical iatrosophia texts from Cyprus from a botanical and medico-pharmacological point of view focusing on remedies containing resins and gums. The iatrosophia are a genre of Greek medical literature of Byzantine origin and can be described as medicine handbooks which serve as therapeutic repositories containing recipes or advice. To extract and analyze information on plant usage in such sources - which are largely unedited texts and so far have not been translated - we investigate (i) the relationship of the iatrosophia to Dioscorides' De Materia Medica as well as historic pharmaceutical books or standard texts on modern phytotherapy and (ii) the validity of the remedies by comparing them to modern scientific data on reported biological activities. In the six texts investigated 27 substances incorporating plant exudates are mentioned. They are obtained from over 43 taxa of higher plants and in particular are used to treat dermatological, gastrointestinal, and respiratory tract conditions. The comparison to historic pharmaceutical books and phytotherapy texts reflects the gradual decline of the use of plant exudates in Western medicine. While remarkable parallels to Dioscorides' text exist, the non-Dioscoridean influence suggests a complex pattern of knowledge exchange. Overall, this resulted in an integration of knowledge from so far poorly understood sources. The comparison with bioscientific data reveals a fragmentary picture and highlights the potential of these unexplored substances and their uses. Where relevant bioscientific data are available, we generally found a confirmation. This points to a largely rational use of the associated remedies. Taken together, the iatrosophia are a valuable resource for ethnopharmacological and natural product research. Most importantly they contribute to the understanding of the development of herbal medicines in the (Eastern) Mediterranean and Europe.

Exploring the Potential of Predictive Analytics and Big Data in Emergency Care.

PubMed

Janke, Alexander T; Overbeek, Daniel L; Kocher, Keith E; Levy, Phillip D

2016-02-01

Clinical research often focuses on resource-intensive causal inference, whereas the potential of predictive analytics with constantly increasing big data sources remains largely unexplored. Basic prediction, divorced from causal inference, is much easier with big data. Emergency care may benefit from this simpler application of big data. Historically, predictive analytics have played an important role in emergency care as simple heuristics for risk stratification. These tools generally follow a standard approach: parsimonious criteria, easy computability, and independent validation with distinct populations. Simplicity in a prediction tool is valuable, but technological advances make it no longer a necessity. Emergency care could benefit from clinical predictions built using data science tools with abundant potential input variables available in electronic medical records. Patients' risks could be stratified more precisely with large pools of data and lower resource requirements for comparing each clinical encounter to those that came before it, benefiting clinical decisionmaking and health systems operations. The largest value of predictive analytics comes early in the clinical encounter, in which diagnostic and prognostic uncertainty are high and resource-committing decisions need to be made. We propose an agenda for widening the application of predictive analytics in emergency care. Throughout, we express cautious optimism because there are myriad challenges related to database infrastructure, practitioner uptake, and patient acceptance. The quality of routinely compiled clinical data will remain an important limitation. Complementing big data sources with prospective data may be necessary if predictive analytics are to achieve their full potential to improve care quality in the emergency department. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Living Trees are a Major Source of Methane in the Temperate Forest

NASA Astrophysics Data System (ADS)

Covey, Kristofer

2017-04-01

Globally, forests sequester about 1.1 ± 0.8 Pg C yr-1, an ecosystem service worth hundreds of billions of dollars annually. Following the COP21 meeting in Paris, an international consensus emerged: The protection and expansion of forests worldwide is a necessary component of climate mitigation strategies to limit warming to less than 2°C. The physiological processes governing sequestration of CO2 in living trees are well studied and the resulting pattern in global forest carbon sequestration is clear. The role living trees play in the production and emission of methane (CH4) remains unclear, despite the fact it has the potential to offset climate benefits of forest CO2 sequestration. A known but largely unexplored pathway of forest CH4 production involves microbial-based methanogenesis in the wood of living trees. In the first regional-scale study of tree trunk gas composition, we examine the ubiquity and potential source strength of this pathway. Trunk methane concentrations were as high as 67.4% by volume (375,000-times atmospheric), with the highest concentrations found in older angiosperms (18,293 μLṡL-1 ± 3,096). Bark flux chambers from 23 living trees show emissions under field conditions, and large static chambers demonstrate high rates of production in felled Acer rubrum trunk sections. Diffusion flux modeling of trunk concentrations suggests wood-based microflora could produce a global CH4 efflux of 26 Tg CH4 yr-1. Applying these fluxes to provide a spatially explicit map of trunk-based CH4 flux, we estimate the potential relationship between carbon sequestration rates and CH4 emission by forest trees in Eastern North America. Methane emissions from the trunk-based methanogenic pathway could reduce the average climate mitigation value of these temperate forests by 10-30%. We highlight the need to improve earth systems models to account for the full complexity of forest climate interactions and provide a data layer useful in reducing large uncertainty in global methane budgets.

The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

NASA Astrophysics Data System (ADS)

Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Rhodes, N. J.; Schooneveld, E. M.

2008-05-01

The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10Å-1. This opens a still unexplored region of the kinematical (q, ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.

The crystallization water of gypsum rocks is a relevant water source for plants.

PubMed

Palacio, Sara; Azorín, José; Montserrat-Martí, Gabriel; Ferrio, Juan Pedro

2014-08-18

Some minerals, like gypsum, hold water in their crystalline structure. Although still unexplored, the use of such crystallization water by organisms would point to a completely new water source for life, critical under dry conditions. Here we use the fact that the isotopic composition of free water differs from gypsum crystallization water to show that plants can use crystallization water from the gypsum structure. The composition of the xylem sap of gypsum plants during summer shows closer values to gypsum crystallization water than to free soil water. Crystallization water represents a significant water source for organisms growing on gypsum, especially during summer, when it accounts for 70-90% of the water used by shallow-rooted plants. Given the widespread occurrence of gypsum in dry lands throughout the Earth and in Mars, these results may have important implications for arid land reclamation and exobiology.

Synthesis of Dibenzo[hi,st]ovalene and Its Amplified Spontaneous Emission in a Polystyrene Matrix.

PubMed

Paternò, Giuseppe M; Chen, Qiang; Wang, Xiao-Ye; Liu, Junzhi; Motti, Silvia G; Petrozza, Annamaria; Feng, Xinliang; Lanzani, Guglielmo; Müllen, Klaus; Narita, Akimitsu; Scotognella, Francesco

2017-06-06

A large number of graphene molecules, or large polycyclic aromatic hydrocarbons (PAHs), have been synthesized and display various optoelectronic properties. Nevertheless, their potential for application in photonics has remained largely unexplored. Herein, we describe the synthesis of a highly luminescent and stable graphene molecule, namely a substituted dibenzo[hi,st]ovalene (DBO 1), with zigzag edges and elucidate its promising optical-gain properties by means of ultrafast transient absorption spectroscopy. Upon incorporation of DBO into an inert polystyrene matrix, amplified stimulated emission can be observed with a relatively low power threshold (ca. 60 μJ cm -2 ), thus highlighting its high potential for lasing applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Condensed Plasmas under Microgravity

NASA Technical Reports Server (NTRS)

Morfill, G. E.; Thomas, H. M.; Konopka, U.; Rothermel, H.; Zuzic, M.; Ivlev, A.; Goree, J.; Rogers, Rick (Technical Monitor)

1999-01-01

Experiments under microgravity conditions were carried out to study 'condensed' (liquid and crystalline) states of a colloidal plasma (ions, electrons, and charged microspheres). Systems with approximately 10(exp 6) microspheres were produced. The observed systems represent new forms of matter--quasineutral, self-organized plasmas--the properties of which are largely unexplored. In contrast to laboratory measurements, the systems under microgravity are clearly three dimensional (as expected); they exhibit stable vortex flows, sometimes adjacent to crystalline regions, and a central 'void,' free of microspheres.

The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa).

PubMed

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Meli, Federica; Piraino, Stefano

2015-07-29

Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo) in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen) up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo), whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest.

The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa)

PubMed Central

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Meli, Federica; Piraino, Stefano

2015-01-01

Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo) in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen) up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo), whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest. PMID:26230703

Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium

PubMed Central

2010-01-01

Background In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa) remains a virtually unexplored issue. Results By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Conclusions Our observations 1) shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2) are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3) reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes. PMID:20441586

Evolutionary, ecological and biotechnological perspectives on plasmids resident in the human gut mobile metagenome

PubMed Central

Ogilvie, Lesley A.; Firouzmand, Sepinoud; Jones, Brian V.

2012-01-01

Numerous mobile genetic elements (MGE) are associated with the human gut microbiota and collectively referred to as the gut mobile metagenome. The role of this flexible gene pool in development and functioning of the gut microbial community remains largely unexplored, yet recent evidence suggests that at least some MGE comprising this fraction of the gut microbiome reflect the co-evolution of host and microbe in the gastro-intestinal tract. In conjunction, the high level of novel gene content typical of MGE coupled with their predicted high diversity, suggests that the mobile metagenome constitutes an immense and largely unexplored gene-space likely to encode many novel activities with potential biotechnological or pharmaceutical value, as well as being important to the development and functioning of the gut microbiota. Of the various types of MGE that comprise the gut mobile metagenome, plasmids are of particular importance since these elements are often capable of autonomous transfer between disparate bacterial species, and are known to encode accessory functions that increase bacterial fitness in a given environment facilitating bacterial adaptation. In this article current knowledge regarding plasmids resident in the human gut mobile metagenome is reviewed, and available strategies to access and characterize this portion of the gut microbiome are described. The relative merits of these methods and their present as well as prospective impact on our understanding of the human gut microbiota is discussed. PMID:22126801

Clusters of Galaxies and the Cosmic Web with Square Kilometre Array

NASA Astrophysics Data System (ADS)

Kale, Ruta; Dwarakanath, K. S.; Vir Lal, Dharam; Bagchi, Joydeep; Paul, Surajit; Malu, Siddharth; Datta, Abhirup; Parekh, Viral; Sharma, Prateek; Pandey-Pommier, Mamta

2016-12-01

The intra-cluster and inter-galactic media that pervade the large scale structure of the Universe are known to be magnetized at sub-micro Gauss to micro Gauss levels and to contain cosmic rays. The acceleration of cosmic rays and their evolution along with that of magnetic fields in these media is still not well understood. Diffuse radio sources of synchrotron origin associated with the Intra-Cluster Medium (ICM) such as radio halos, relics and mini-halos are direct probes of the underlying mechanisms of cosmic ray acceleration. Observations with radio telescopes such as the Giant Metrewave Radio Telescope, the Very Large Array and the Westerbork Synthesis Radio Telescope have led to the discoveries of about 80 such sources and allowed detailed studies in the frequency range 0.15-1.4 GHz of a few. These studies have revealed scaling relations between the thermal and non-thermal properties of clusters and favour the role of shocks in the formation of radio relics and of turbulent re-acceleration in the formation of radio halos and mini-halos. The radio halos are known to occur in merging clusters and mini-halos are detected in about half of the cool-core clusters. Due to the limitations of current radio telescopes, low mass galaxy clusters and galaxy groups remain unexplored as they are expected to contain much weaker radio sources. Distinguishing between the primary and the secondary models of cosmic ray acceleration mechanisms requires spectral measurements over a wide range of radio frequencies and with high sensitivity. Simulations have also predicted weak diffuse radio sources associated with filaments connecting galaxy clusters. The Square Kilometre Array (SKA) is a next generation radio telescope that will operate in the frequency range of 0.05-20 GHz with unprecedented sensitivities and resolutions. The expected detection limits of SKA will reveal a few hundred to thousand new radio halos, relics and mini-halos providing the first large and comprehensive samples for their study. The wide frequency coverage along with sensitivity to extended structures will be able to constrain the cosmic ray acceleration mechanisms. The higher frequency (>5 GHz) observations will be able to use the Sunyaev-Zel'dovich effect to probe the ICM pressure in addition to tracers such as lobes of head-tail radio sources. The SKA also opens prospects to detect the `off-state' or the lowest level of radio emission from the ICM predicted by the hadronic models and the turbulent re-acceleration models.

A New Paradigm for Robotic Rovers

NASA Astrophysics Data System (ADS)

Clark, P. E.; Curtis, S. A.; Rilee, M. L.

We are in the process of developing rovers with extreme mobility needed to explore remote, rugged terrain. We call these systems Tetrahedral Explorer Technologies (TETs). Architecture is based on conformable tetrahedra, the simplest space-filling form, as building blocks, single or networked, where apices act as nodes from which struts reversibly deploy. The tetrahedral framework acts as a simple skeletal muscular structure. We have already prototyped a simple robotic walker from a single reconfigurable tetrahedron capable of tumbling and a more evolved 12Tetrahedral Walker, the Autonomous Landed Investigator (ALI), which has interior nodes for payload, more continuous motion, and is commandable through a user friendly interface. ALI is an EMS level mission concept which would allow autonomous in situ exploration of the lunar poles within the next decade. ALI would consist of one or more 12tetrahedral walkers capable of rapid locomotion with the many degrees of freedom and equipped for navigation in the unilluminated, inaccessible and thus largely unexplored rugged terrains where lunar resources are likely to be found: the Polar Regions. ALI walkers would act as roving reconnaissance teams for unexplored regions, analyzing samples along the way.

Heroin-related overdose: The unexplored influences of markets, marketing and source-types in the United States.

PubMed

Mars, Sarah G; Fessel, Jason N; Bourgois, Philippe; Montero, Fernando; Karandinos, George; Ciccarone, Daniel

2015-09-01

Heroin overdose, more accurately termed 'heroin-related overdose' due to the frequent involvement of other drugs, is the leading cause of mortality among regular heroin users. (Degenhardt et al., 2010) Heroin injectors are at greater risk of hospital admission for heroin-related overdose (HOD) in the eastern United States where Colombian-sourced powder heroin is sold than in the western US where black 'tar' heroin predominates. (Unick et al., 2014) This paper examines under-researched influences on HOD, both fatal and non-fatal, using data from a qualitative study of injecting drug users of black tar heroin in San Francisco and powder heroin in Philadelphia Data were collected through in-depth, semi-structured interviews carried out in 2012 that were conducted against a background of longer-term participant-observation, ethnographic studies of drug users and dealers in Philadelphia (2007-12) and of users in San Francisco (1994-2007, 2012). Our findings suggest three types of previously unconsidered influences on overdose risk that arise both from structural socio-economic factors and from the physical properties of the heroin source-types: 1) retail market structure including information flow between users; 2) marketing techniques such as branding, free samples and pricing and 3) differences in the physical characteristics of the two major heroin source forms and how they affect injecting techniques and vascular health. Although chosen for their contrasting source-forms, we found that the two cities have contrasting dominant models of drug retailing: San Francisco respondents tended to buy through private dealers and Philadelphia respondents frequented an open-air street market where heroin is branded and free samples are distributed, although each city included both types of drug sales. These market structures and marketing techniques shape the availability of information regarding heroin potency and its dissemination among users who tend to seek out the strongest heroin available on a given day. The physical characteristics of these two source-types, the way they are prepared for injecting and their effects on vein health also differ markedly. The purpose of this paper is to examine some of the unexplored factors that may lead to heroin-related overdose in the United States and to generate hypotheses for further study. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heroin-related overdose: The unexplored influences of markets, marketing and source-types in the United States

PubMed Central

Mars, Sarah G.; Fessel, Jason N.; Bourgois, Philippe; Montero, Fernando; Karandinos, George; Ciccarone, Daniel

2015-01-01

Heroin overdose, more accurately termed ‘heroin-related overdose’ due to the frequent involvement of other drugs, is the leading cause of mortality among regular heroin users. (Degenhardt et al., 2010) Heroin injectors are at greater risk of hospital admission for heroin-related overdose (HOD) in the eastern United States where Colombian-sourced powder heroin is sold than in the western US where black ‘tar’ heroin predominates. (Unick et al., 2014) This paper examines under-researched influences on HOD, both fatal and non-fatal, using data from a qualitative study of injecting drug users of black tar heroin in San Francisco and powder heroin in Philadelphia Data were collected through in-depth, semi-structured interviews carried out in 2012 that were conducted against a background of longer-term participant-observation, ethnographic studies of drug users and dealers in Philadelphia (2007–12) and of users in San Francisco (1994–2007, 2012). Our findings suggest three types of previously unconsidered influences on overdose risk that arise both from structural socio-economic factors and from the physical properties of the heroin source-types: 1) retail market structure including information flow between users; 2) marketing techniques such as branding, free samples and pricing and 3) differences in the physical characteristics of the two major heroin source forms and how they affect injecting techniques and vascular health. Although chosen for their contrasting source-forms, we found that the two cities have contrasting dominant models of drug retailing: San Francisco respondents tended to buy through private dealers and Philadelphia respondents frequented an open-air street market where heroin is branded and free samples are distributed, although each city included both types of drug sales. These market structures and marketing techniques shape the availability of information regarding heroin potency and its dissemination among users who tend to seek out the strongest heroin available on a given day. The physical characteristics of these two source-types, the way they are prepared for injecting and their effects on vein health also differ markedly. The purpose of this paper is to examine some of the unexplored factors that may lead to heroin-related overdose in the United States and to generate hypotheses for further study. PMID:26202771

Informatic analysis reveals Legionella as a source of novel natural products.

PubMed

Johnston, Chad W; Plumb, Jonathan; Li, Xiang; Grinstein, Sergio; Magarvey, Nathan A

2016-06-01

Microbial natural products are a crucial source of bioactive molecules and unique chemical scaffolds. Despite their importance, rediscovery of known natural products from established productive microbes has led to declining interest, even while emergent genomic data suggest that the majority of microbial natural products remain to be discovered. Now, new sources of microbial natural products must be defined in order to provide chemical scaffolds for the next generation of small molecules for therapeutic, agricultural, and industrial purposes. In this work, we use specialized bioinformatic programs, genetic knockouts, and comparative metabolomics to define the genus Legionella as a new source of novel natural products. We show that Legionella spp. hold a diverse collection of biosynthetic gene clusters for the production of polyketide and nonribosomal peptide natural products. To confirm this bioinformatic survey, we create targeted mutants of L. pneumophila and use comparative metabolomics to identify a novel polyketide surfactant. Using spectroscopic techniques, we show that this polyketide possesses a new chemical scaffold, and firmly demonstrate that this unexplored genus is a source for novel natural products.

An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals

PubMed Central

Spiousas, Ignacio; Etchemendy, Pablo E.; Vergara, Ramiro O.; Calcagno, Esteban R.; Eguia, Manuel C.

2015-01-01

In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source. PMID:26222281

An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals.

PubMed

Spiousas, Ignacio; Etchemendy, Pablo E; Vergara, Ramiro O; Calcagno, Esteban R; Eguia, Manuel C

2015-01-01

In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

ATCA observations of the MACS-Planck Radio Halo Cluster Project. II. Radio observations of an intermediate redshift cluster sample

NASA Astrophysics Data System (ADS)

Martinez Aviles, G.; Johnston-Hollitt, M.; Ferrari, C.; Venturi, T.; Democles, J.; Dallacasa, D.; Cassano, R.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Arnaud, M.; Aghanim, N.; Brown, S.; Douspis, M.; Hurier, J.; Intema, H. T.; Langer, M.; Macario, G.; Pointecouteau, E.

2018-04-01

Aim. A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the largely unexplored intermediate redshift range (0.3 < z < 0.44). Methods: In search of diffuse emission, deep radio imaging of the clusters are presented from wide band (1.1-3.1 GHz), full resolution ( 5 arcsec) observations with the Australia Telescope Compact Array (ATCA). The visibilities were also imaged at lower resolution after point source modelling and subtraction and after a taper was applied to achieve better sensitivity to low surface brightness diffuse radio emission. In case of non-detection of diffuse sources, we set upper limits for the radio power of injected diffuse radio sources in the field of our observations. Furthermore, we discuss the dynamical state of the observed clusters based on an X-ray morphological analysis with XMM-Newton. Results: We detect a giant radio halo in PSZ2 G284.97-23.69 (z = 0.39) and a possible diffuse source in the nearly relaxed cluster PSZ2 G262.73-40.92 (z = 0.421). Our sample contains three highly disturbed massive clusters without clear traces of diffuse emission at the observed frequencies. We were able to inject modelled radio haloes with low values of total flux density to set upper detection limits; however, with our high-frequency observations we cannot exclude the presence of RH in these systems because of the sensitivity of our observations in combination with the high z of the observed clusters. The reduced images are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A94

Copper tellurium oxides - A playground for magnetism

NASA Astrophysics Data System (ADS)

Norman, M. R.

2018-04-01

A variety of copper tellurium oxide minerals are known, and many of them exhibit either unusual forms of magnetism, or potentially novel spin liquid behavior. Here, I review a number of the more interesting materials with a focus on their crystalline symmetry and, if known, the nature of their magnetism. Many of these exist (so far) in mineral form only, and most have yet to have their magnetic properties studied. This means a largely unexplored space of materials awaits our exploration.

Copper Tellurium Oxides - A Playground for Magnetism.

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

Norman, M. R.

A variety of copper tellurium oxide minerals are known, and many of them exhibit either unusual forms of magnetism, or potentially novel spin liquid behavior. Here, I review a number of the more interesting materials with a focus on their crystalline symmetry and, if known, the nature of their magnetism. Many of these exist (so far) in mineral form only, and most have yet to have their magnetic properties studied. This means a largely unexplored space of materials awaits our exploration.

Holy Basil Leaf Extract Decreases Tumorigenicity and Metastasis of Aggressive Human Pancreatic Cancer Cells in vitro and in vivo: Potential Role in Therapy

PubMed Central

Shimizu, Tomohiro; Torres, María P.; Chakraborty, Subhankar; Souchek, Joshua J.; Rachagani, Satyanarayana; Kaur, Sukhwinder; Macha, Muzafar; Ganti, Apar K.; Hauke, Ralph J; Batra, Surinder K.

2013-01-01

There is an urgent need to develop alternative therapies against lethal pancreatic cancer (PC). Ocimum sanctum (“Holy Basil”) has been used for thousands of years in traditional Indian medicine, but its anti-tumorigenic effect remains largely unexplored. Here, we show that extracts of O. sanctum leaves inhibit the proliferation, migration, invasion, and induce apoptosis of PC cells in vitro. The expression of genes that promote the proliferation, migration and invasion of PC cells including activated ERK-1/2, FAK, and p65 (subunit of NF-κB), was downregulated in PC cells after O. sanctum treatment. Intraperitoneal injections of the aqueous extract significantly inhibited the growth of orthotopically transplanted PC cells in vivo (p<0.05). Genes that inhibit metastasis (E-cadherin) and induce apoptosis (BAD) were significantly upregulated in tumors isolated from mice treated with O. sanctum extracts, while genes that promote survival (Bcl-2 and Bcl-xL) and chemo/radiation resistance (AURKA, Chk1 and Survivin) were downregulated. Overall, our study suggests that leaves of O. sanctum could be a potential source of novel anticancer compounds in the future. PMID:23523869

Biomass production from electricity using ammonia as an electron carrier in a reverse microbial fuel cell.

PubMed

Khunjar, Wendell O; Sahin, Asli; West, Alan C; Chandran, Kartik; Banta, Scott

2012-01-01

The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC) that fixes CO₂ into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production.

Gendered emotion work around physical health problems in mid- and later-life marriages☆

PubMed Central

Thomeer, Mieke Beth; Reczek, Corinne; Umberson, Debra

2015-01-01

The provision and receipt of emotion work—defined as intentional activities done to promote another’s emotional well-being—are central dimensions of marriage. However, emotion work in response to physical health problems is a largely unexplored, yet likely important, aspect of the marital experience. We analyze dyadic in-depth interviews with husbands and wives in 21 mid-to later-life couples to examine the ways that health-impaired people and their spouses provide, interpret, and explain emotion work. Because physical health problems, emotion work, and marital dynamics are gendered, we consider how these processes differ for women and men. We find that wives provide emotion work regardless of their own health status. Husbands provide emotion work less consistently, typically only when the husbands see themselves as their wife’s primary source of stability or when the husbands view their marriage as balanced. Notions of traditional masculinity preclude some husbands from providing emotion work even when their wife is health-impaired. This study articulates emotion work around physical health problems as one factor that sustains and exacerbates gender inequalities in marriage with implications for emotional and physical well-being. PMID:25661852

Reinforcement learning for routing in cognitive radio ad hoc networks.

PubMed

Al-Rawi, Hasan A A; Yau, Kok-Lim Alvin; Mohamad, Hafizal; Ramli, Nordin; Hashim, Wahidah

2014-01-01

Cognitive radio (CR) enables unlicensed users (or secondary users, SUs) to sense for and exploit underutilized licensed spectrum owned by the licensed users (or primary users, PUs). Reinforcement learning (RL) is an artificial intelligence approach that enables a node to observe, learn, and make appropriate decisions on action selection in order to maximize network performance. Routing enables a source node to search for a least-cost route to its destination node. While there have been increasing efforts to enhance the traditional RL approach for routing in wireless networks, this research area remains largely unexplored in the domain of routing in CR networks. This paper applies RL in routing and investigates the effects of various features of RL (i.e., reward function, exploitation, and exploration, as well as learning rate) through simulation. New approaches and recommendations are proposed to enhance the features in order to improve the network performance brought about by RL to routing. Simulation results show that the RL parameters of the reward function, exploitation, and exploration, as well as learning rate, must be well regulated, and the new approaches proposed in this paper improves SUs' network performance without significantly jeopardizing PUs' network performance, specifically SUs' interference to PUs.

Thaulin-1: The first antimicrobial peptide isolated from the skin of a Patagonian frog Pleurodema thaul (Anura: Leptodactylidae: Leiuperinae) with activity against Escherichia coli.

PubMed

Marani, Mariela M; Perez, Luis O; de Araujo, Alyne Rodrigues; Plácido, Alexandra; Sousa, Carla F; Quelemes, Patrick Veras; Oliveira, Mayara; Gomes-Alves, Ana G; Pueta, Mariana; Gameiro, Paula; Tomás, Ana M; Delerue-Matos, Cristina; Eaton, Peter; Camperi, Silvia A; Basso, Néstor G; de Souza de Almeida Leite, Jose Roberto

2017-03-20

Patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7μM). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of motion correction techniques applied to functional near-infrared spectroscopy data from children

NASA Astrophysics Data System (ADS)

Hu, Xiao-Su; Arredondo, Maria M.; Gomba, Megan; Confer, Nicole; DaSilva, Alexandre F.; Johnson, Timothy D.; Shalinsky, Mark; Kovelman, Ioulia

2015-12-01

Motion artifacts are the most significant sources of noise in the context of pediatric brain imaging designs and data analyses, especially in applications of functional near-infrared spectroscopy (fNIRS), in which it can completely affect the quality of the data acquired. Different methods have been developed to correct motion artifacts in fNIRS data, but the relative effectiveness of these methods for data from child and infant subjects (which is often found to be significantly noisier than adult data) remains largely unexplored. The issue is further complicated by the heterogeneity of fNIRS data artifacts. We compared the efficacy of the six most prevalent motion artifact correction techniques with fNIRS data acquired from children participating in a language acquisition task, including wavelet, spline interpolation, principal component analysis, moving average (MA), correlation-based signal improvement, and combination of wavelet and MA. The evaluation of five predefined metrics suggests that the MA and wavelet methods yield the best outcomes. These findings elucidate the varied nature of fNIRS data artifacts and the efficacy of artifact correction methods with pediatric populations, as well as help inform both the theory and practice of optical brain imaging analysis.

The enduring importance of family wealth: Evidence from the Forbes 400, 1982 to 2013.

PubMed

Korom, Philipp; Lutter, Mark; Beckert, Jens

2017-07-01

The richest 1 percent in the United States is a largely unexplored group, despite its ever-increasing share of the national wealth. The Forbes roster of the richest Americans has often been used to demonstrate the fading of nineteenth-century hereditary fortunes. Based on full panel data from the annual American Forbes 400 ranking (1982-2013), this article goes beyond previous work by examining not only the sources of the very wealthy but also the factors that increase or decrease the likelihood of remaining listed among the American super-rich and the typical patterns of mobility. We find that heirs are more likely to remain listed in the Forbes 400 roster than self-made entrepreneurs, all other things being equal. While scions of great wealth are less likely to drop completely from the list, they are nevertheless more likely to fall gradually in ranking than are self-made multimillionaires. Even though entrepreneurship matters increasingly for becoming super-rich, we conclude that it is first and foremost the ability of rich family dynasties to retain control over corporations and to access sophisticated financial advice that makes fortunes last. Copyright © 2017 Elsevier Inc. All rights reserved.

Species, gender, and identity: cracking petrels' sociochemical code.

PubMed

Mardon, Jérôme; Saunders, Sandra M; Anderson, Marti J; Couchoux, Charline; Bonadonna, Francesco

2010-05-01

Avian chemosignaling remains relatively unexplored, but its potential importance in birds' social behaviors is becoming recognized. Procellariiform seabirds provide particularly appropriate models for investigating these topics as they possess a well-developed olfactory system and unequalled associated capabilities. We present here results from a detailed chemical examination of the uropygial secretions (the main source of avian exogenous chemicals) from 2 petrel species, Antarctic prions and blue petrels. Using gas chromatography-mass spectrometry techniques and recently developed multivariate tools, we demonstrate that the secretions contain critical socioecological information such as species, gender, and individual identity. Importantly, these chemosignals correlate with some of the birds' olfactory behaviors demonstrated in the field. The molecules found to be associated with social information were essentially large unsaturated compounds, suggesting that these may be precursors of, or correlates to the actual airborne signals. Although the species-specific chemosignal may be involved in interspecific competition at the breeding grounds, the role of the sexually specific chemosignal remains unclear. The existence of individually specific signals (i.e., chemical signatures) in these birds has important implications for processes such as individual recognition and genetically based mate choice already suspected for this group. Our results open promising avenues of research for the study of avian chemical communication.

Reinforcement Learning for Routing in Cognitive Radio Ad Hoc Networks

PubMed Central

Al-Rawi, Hasan A. A.; Mohamad, Hafizal; Hashim, Wahidah

2014-01-01

Cognitive radio (CR) enables unlicensed users (or secondary users, SUs) to sense for and exploit underutilized licensed spectrum owned by the licensed users (or primary users, PUs). Reinforcement learning (RL) is an artificial intelligence approach that enables a node to observe, learn, and make appropriate decisions on action selection in order to maximize network performance. Routing enables a source node to search for a least-cost route to its destination node. While there have been increasing efforts to enhance the traditional RL approach for routing in wireless networks, this research area remains largely unexplored in the domain of routing in CR networks. This paper applies RL in routing and investigates the effects of various features of RL (i.e., reward function, exploitation, and exploration, as well as learning rate) through simulation. New approaches and recommendations are proposed to enhance the features in order to improve the network performance brought about by RL to routing. Simulation results show that the RL parameters of the reward function, exploitation, and exploration, as well as learning rate, must be well regulated, and the new approaches proposed in this paper improves SUs' network performance without significantly jeopardizing PUs' network performance, specifically SUs' interference to PUs. PMID:25140350

Historical citizen science to understand and predict climate-driven trout decline

PubMed Central

Ninyerola, Miquel; Hermoso, Virgilio; Filipe, Ana Filipa; Pla, Magda; Villero, Daniel; Brotons, Lluís; Delibes, Miguel

2017-01-01

Historical species records offer an excellent opportunity to test the predictive ability of range forecasts under climate change, but researchers often consider that historical records are scarce and unreliable, besides the datasets collected by renowned naturalists. Here, we demonstrate the relevance of biodiversity records developed through citizen-science initiatives generated outside the natural sciences academia. We used a Spanish geographical dictionary from the mid-nineteenth century to compile over 10 000 freshwater fish records, including almost 4 000 brown trout (Salmo trutta) citations, and constructed a historical presence–absence dataset covering over 2 000 10 × 10 km cells, which is comparable to present-day data. There has been a clear reduction in trout range in the past 150 years, coinciding with a generalized warming. We show that current trout distribution can be accurately predicted based on historical records and past and present values of three air temperature variables. The models indicate a consistent decline of average suitability of around 25% between 1850s and 2000s, which is expected to surpass 40% by the 2050s. We stress the largely unexplored potential of historical species records from non-academic sources to open new pathways for long-term global change science. PMID:28077766

Inflated Sporopollenin Exine Capsules Obtained from Thin-Walled Pollen

NASA Astrophysics Data System (ADS)

Park, Jae Hyeon; Seo, Jeongeun; Jackman, Joshua A.; Cho, Nam-Joon

2016-06-01

Sporopollenin is a physically robust and chemically resilient biopolymer that comprises the outermost layer of pollen walls and is the first line of defense against harsh environmental conditions. The unique physicochemical properties of sporopollenin increasingly motivate the extraction of sporopollenin exine capsules (SECs) from pollen walls as a renewable source of organic microcapsules for encapsulation applications. Despite the wide range of different pollen species with varying sizes and wall thicknesses, faithful extraction of pollen-mimetic SECs has been limited to thick-walled pollen capsules with rigid mechanical properties. There is an unmet need to develop methods for producing SECs from thin-walled pollen capsules which constitute a large fraction of all pollen species and have attractive materials properties such as greater aerosol dispersion. Herein, we report the first successful extraction of inflated SEC microcapsules from a thin-walled pollen species (Zea mays), thereby overcoming traditional challenges with mechanical stability and loss of microstructure. Morphological and compositional characterization of the SECs obtained by the newly developed extraction protocol confirms successful protein removal along with preservation of nanoscale architectural features. Looking forward, there is excellent potential to apply similar strategies across a wide range of unexplored thin-walled pollen species.

Biogeochemical implications of the ubiquitous colonization of marine habitats and redox gradients by Marinobacter species.

PubMed

Handley, Kim M; Lloyd, Jonathan R

2013-01-01

The Marinobacter genus comprises widespread marine bacteria, found in localities as diverse as the deep ocean, coastal seawater and sediment, hydrothermal settings, oceanic basalt, sea-ice, sand, solar salterns, and oil fields. Terrestrial sources include saline soil and wine-barrel-decalcification wastewater. The genus was designated in 1992 for the Gram-negative, hydrocarbon-degrading bacterium Marinobacter hydrocarbonoclasticus. Since then, a further 31 type strains have been designated. Nonetheless, the metabolic range of many Marinobacter species remains largely unexplored. Most species have been classified as aerobic heterotrophs, and assessed for limited anaerobic pathways (fermentation or nitrate reduction), whereas studies of low-temperature hydrothermal sediments, basalt at oceanic spreading centers, and phytoplankton have identified species that possess a respiratory repertoire with significant biogeochemical implications. Notable physiological traits include nitrate-dependent Fe(II)-oxidation, arsenic and fumarate redox cycling, and Mn(II) oxidation. There is also evidence for Fe(III) reduction, and metal(loid) detoxification. Considering the ubiquity and metabolic capabilities of the genus, Marinobacter species may perform an important and underestimated role in the biogeochemical cycling of organics and metals in varied marine habitats, and spanning aerobic-to-anoxic redox gradients.

Atmospheric Ionization Measurements

NASA Astrophysics Data System (ADS)

Slack, Thomas; Mayes, Riley

2015-04-01

The measurement of atmospheric ionization is a largely unexplored science that potentially holds the key to better understanding many different geophysical phenomena through this new and valuable source of data. Through the LaACES program, which is funded by NASA through the Louisiana Space Consortium, students at Loyola University New Orleans have pursued the goal of measuring high altitude ionization for nearly three years, and were the first to successfully collect ionization data at altitudes over 30,000 feet using a scientific weather balloon flown from the NASA Columbia Scientific Ballooning Facility in Palestine, TX. In order to measure atmospheric ionization, the science team uses a lightweight and highly customized sensor known as a Gerdien condenser. Among other branches of science the data is already being used for, such as the study of aerosol pollution levels in the atmosphere, the data may also be useful in meteorology and seismology. Ionization data might provide another variable with which to predict weather or seismic activity more accurately and further in advance. Thomas Slack and Riley Mayes have served as project managers for the experiment, and have extensive knowledge of the experiment from the ground up. LaSPACE Louisiana Space Consortium.

Environmental insults: critical triggers for amyotrophic lateral sclerosis.

PubMed

Yu, Bing; Pamphlett, Roger

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterised by a rapid loss of lower and upper motor neurons. As a complex disease, the ageing process and complicated gene-environment interactions are involved in the majority of cases. Significant advances have been made in unravelling the genetic susceptibility to ALS with massively parallel sequencing technologies, while environmental insults remain a suspected but largely unexplored source of risk. Several studies applying the strategy of Mendelian randomisation have strengthened the link between environmental insults and ALS, but none so far has proved conclusive. We propose a new ALS model which links the current knowledge of genetic factors, ageing and environmental insults. This model provides a mechanism as to how ALS is initiated, with environmental insults playing a critical role. The available evidence has suggested that inherited defect(s) could cause mitochondrial dysfunction, which would establish the primary susceptibility to ALS. Further study of the underlying mechanism may shed light on ALS pathogenesis. Environmental insults are a critical trigger for ALS, particularly in the aged individuals with other toxicant susceptible genes. The identification of ALS triggers could lead to preventive strategies for those individuals at risk.

Biomass Production from Electricity Using Ammonia as an Electron Carrier in a Reverse Microbial Fuel Cell

PubMed Central

West, Alan C.; Chandran, Kartik; Banta, Scott

2012-01-01

The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC) that fixes CO2 into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production. PMID:23028643

Inflated Sporopollenin Exine Capsules Obtained from Thin-Walled Pollen

PubMed Central

Park, Jae Hyeon; Seo, Jeongeun; Jackman, Joshua A.; Cho, Nam-Joon

2016-01-01

Sporopollenin is a physically robust and chemically resilient biopolymer that comprises the outermost layer of pollen walls and is the first line of defense against harsh environmental conditions. The unique physicochemical properties of sporopollenin increasingly motivate the extraction of sporopollenin exine capsules (SECs) from pollen walls as a renewable source of organic microcapsules for encapsulation applications. Despite the wide range of different pollen species with varying sizes and wall thicknesses, faithful extraction of pollen-mimetic SECs has been limited to thick-walled pollen capsules with rigid mechanical properties. There is an unmet need to develop methods for producing SECs from thin-walled pollen capsules which constitute a large fraction of all pollen species and have attractive materials properties such as greater aerosol dispersion. Herein, we report the first successful extraction of inflated SEC microcapsules from a thin-walled pollen species (Zea mays), thereby overcoming traditional challenges with mechanical stability and loss of microstructure. Morphological and compositional characterization of the SECs obtained by the newly developed extraction protocol confirms successful protein removal along with preservation of nanoscale architectural features. Looking forward, there is excellent potential to apply similar strategies across a wide range of unexplored thin-walled pollen species. PMID:27302853

Gendered emotion work around physical health problems in mid- and later-life marriages.

PubMed

Thomeer, Mieke Beth; Reczek, Corinne; Umberson, Debra

2015-01-01

The provision and receipt of emotion work-defined as intentional activities done to promote another's emotional well-being-are central dimensions of marriage. However, emotion work in response to physical health problems is a largely unexplored, yet likely important, aspect of the marital experience. We analyze dyadic in-depth interviews with husbands and wives in 21 mid- to later-life couples to examine the ways that health-impaired people and their spouses provide, interpret, and explain emotion work. Because physical health problems, emotion work, and marital dynamics are gendered, we consider how these processes differ for women and men. We find that wives provide emotion work regardless of their own health status. Husbands provide emotion work less consistently, typically only when the husbands see themselves as their wife's primary source of stability or when the husbands view their marriage as balanced. Notions of traditional masculinity preclude some husbands from providing emotion work even when their wife is health-impaired. This study articulates emotion work around physical health problems as one factor that sustains and exacerbates gender inequalities in marriage with implications for emotional and physical well-being. Copyright © 2014 Elsevier Inc. All rights reserved.

AlloPred: prediction of allosteric pockets on proteins using normal mode perturbation analysis.

PubMed

Greener, Joe G; Sternberg, Michael J E

2015-10-23

Despite being hugely important in biological processes, allostery is poorly understood and no universal mechanism has been discovered. Allosteric drugs are a largely unexplored prospect with many potential advantages over orthosteric drugs. Computational methods to predict allosteric sites on proteins are needed to aid the discovery of allosteric drugs, as well as to advance our fundamental understanding of allostery. AlloPred, a novel method to predict allosteric pockets on proteins, was developed. AlloPred uses perturbation of normal modes alongside pocket descriptors in a machine learning approach that ranks the pockets on a protein. AlloPred ranked an allosteric pocket top for 23 out of 40 known allosteric proteins, showing comparable and complementary performance to two existing methods. In 28 of 40 cases an allosteric pocket was ranked first or second. The AlloPred web server, freely available at http://www.sbg.bio.ic.ac.uk/allopred/home, allows visualisation and analysis of predictions. The source code and dataset information are also available from this site. Perturbation of normal modes can enhance our ability to predict allosteric sites on proteins. Computational methods such as AlloPred assist drug discovery efforts by suggesting sites on proteins for further experimental study.

Biogeochemical implications of the ubiquitous colonization of marine habitats and redox gradients by Marinobacter species

PubMed Central

Handley, Kim M.; Lloyd, Jonathan R.

2013-01-01

The Marinobacter genus comprises widespread marine bacteria, found in localities as diverse as the deep ocean, coastal seawater and sediment, hydrothermal settings, oceanic basalt, sea-ice, sand, solar salterns, and oil fields. Terrestrial sources include saline soil and wine-barrel-decalcification wastewater. The genus was designated in 1992 for the Gram-negative, hydrocarbon-degrading bacterium Marinobacter hydrocarbonoclasticus. Since then, a further 31 type strains have been designated. Nonetheless, the metabolic range of many Marinobacter species remains largely unexplored. Most species have been classified as aerobic heterotrophs, and assessed for limited anaerobic pathways (fermentation or nitrate reduction), whereas studies of low-temperature hydrothermal sediments, basalt at oceanic spreading centers, and phytoplankton have identified species that possess a respiratory repertoire with significant biogeochemical implications. Notable physiological traits include nitrate-dependent Fe(II)-oxidation, arsenic and fumarate redox cycling, and Mn(II) oxidation. There is also evidence for Fe(III) reduction, and metal(loid) detoxification. Considering the ubiquity and metabolic capabilities of the genus, Marinobacter species may perform an important and underestimated role in the biogeochemical cycling of organics and metals in varied marine habitats, and spanning aerobic-to-anoxic redox gradients. PMID:23734151

Mechanisms of sibling socialization in normative family development.

PubMed

Whiteman, Shawn D; Becerra, Julia M; Killoren, Sarah E

2009-01-01

Siblings are important sources of social influence throughout childhood and adolescence. Nevertheless, the processes by which siblings influence one another remain relatively unexplored. We highlight two theories of sibling influence-sibling deidentification and social learning-that offer insights as to how and why siblings develop similar and different attributes, attitudes, and behaviors. Recognizing the need to move past post hoc explanations, we suggest several directions for how these two influence processes can be measured directly in future work. Research on sibling influence also can be improved by integrating these theories and attending to their domains of influence.

The sustainability of healthcare innovations: a concept analysis.

PubMed

Fleiszer, Andrea R; Semenic, Sonia E; Ritchie, Judith A; Richer, Marie-Claire; Denis, Jean-Louis

2015-07-01

To report on an analysis of the concept of the sustainability of healthcare innovations. While there have been significant empirical, theoretical and practical contributions made towards the development and implementation of healthcare innovations, there has been less attention paid to their sustainability. Yet many desired healthcare innovations are not sustained over the long term. There is a need to increase clarity around the concept of innovation sustainability to guide the advancement of knowledge on this topic. Concept analysis. We included literature reviews, theoretical and empirical articles, books and grey literature obtained through database searching (ABI/INFORM, Academic Search Complete, Business Source Complete, CINAHL, Embase, MEDLINE and Web of Science) from 1996-May 2014, reference harvesting and citation searching. We examined sources according to terms and definitions, characteristics, preconditions, outcomes and boundaries to evaluate the maturity of the concept. This concept is partially mature. Healthcare innovation sustainability remains a multi-dimensional, multi-factorial notion that is used inconsistently or ambiguously and takes on different meanings at different times in different contexts. We propose a broad conceptualization that consists of three characteristics: benefits, routinization or institutionalization, and development. We also suggest that sustained innovations are influenced by a variety of preconditions or factors, which are innovation-, context-, leadership- and process-related. Further conceptual development is essential to continue advancing our understanding of the sustainability of healthcare innovations, especially in nursing where this topic remains largely unexplored. © 2015 John Wiley & Sons Ltd.

Geology and hydrocarbon potential of the Hamada and Murzuq basins in western Libya

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

Kirmani, K.U.; Elhaj, F.

1988-08-01

The Hamada and Murzuq intracratonic basins of western Libya form a continuation of the Saharan basin which stretches from Algeria eastward into Tunisia and Libya. The tectonics and sedimentology of this region have been greatly influenced by the Caledonian and Hercynian orogenies. Northwest- and northeast-trending faults are characteristic of the broad, shallow basins. The Cambrian-Ordovician sediments are fluvial to shallow marine. The Silurian constitutes a complete sedimentary cycle, ranging from deep marine shales to shallow marine and deltaic sediments. The Devonian occupies a unique position between two major orogenies. The Mesozoic strata are relatively thin. The Triassic consists of well-developedmore » continental sands, whereas the Jurassic and Cretaceous sediments are mainly lagoonal dolomites, evaporites, and shales. Silurian shales are the primary source rock in the area. The quality of the source rock appears to be better in the deeper part of the basin than on its periphery. The Paleozoic has the best hydrocarbon potential. Hydrocarbons have also been encountered in the Triassic and Carboniferous. In the Hamada basin, the best-known field is the El Hamra, with reserves estimated at 155 million bbl from the Devonian. Significant accumulations of oil have been found in the Silurian. Tlacsin and Tigi are two fields with Silurian production. In the Murzuq basin the Cambrian-Ordovician has the best production capability. However, substantial reserves need to be established before developing any field in this basin. Large areas still remain unexplored in western Libya.« less

Seismic reflection imaging of shallow oceanographic structures

NASA Astrophysics Data System (ADS)

Piété, Helen; Marié, Louis; Marsset, Bruno; Thomas, Yannick; Gutscher, Marc-André

2013-05-01

Multichannel seismic (MCS) reflection profiling can provide high lateral resolution images of deep ocean thermohaline fine structure. However, the shallowest layers of the water column (z < 150 m) have remained unexplored by this technique until recently. In order to explore the feasibility of shallow seismic oceanography (SO), we reprocessed and analyzed four multichannel seismic reflection sections featuring reflectors at depths between 10 and 150 m. The influence of the acquisition parameters was quantified. Seismic data processing dedicated to SO was also investigated. Conventional seismic acquisition systems were found to be ill-suited to the imaging of shallow oceanographic structures, because of a high antenna filter effect induced by large offsets and seismic trace lengths, and sources that typically cannot provide both a high level of emission and fine vertical resolution. We considered a test case, the imagery of the seasonal thermocline on the western Brittany continental shelf. New oceanographic data acquired in this area allowed simulation of the seismic acquisition. Sea trials of a specifically designed system were performed during the ASPEX survey, conducted in early summer 2012. The seismic device featured: (i) four seismic streamers, each consisting of six traces of 1.80 m; (ii) a 1000 J SIG sparker source, providing a 400 Hz signal with a level of emission of 205 dB re 1 μPa @ 1 m. This survey captured the 15 m thick, 30 m deep seasonal thermocline in unprecedented detail, showing images of vertical displacements most probably induced by internal waves.

Visualizing the molecular sociology at the HeLa cell nuclear periphery.

PubMed

Mahamid, Julia; Pfeffer, Stefan; Schaffer, Miroslava; Villa, Elizabeth; Danev, Radostin; Cuellar, Luis Kuhn; Förster, Friedrich; Hyman, Anthony A; Plitzko, Jürgen M; Baumeister, Wolfgang

2016-02-26

The molecular organization of eukaryotic nuclear volumes remains largely unexplored. Here we combined recent developments in cryo-electron tomography (cryo-ET) to produce three-dimensional snapshots of the HeLa cell nuclear periphery. Subtomogram averaging and classification of ribosomes revealed the native structure and organization of the cytoplasmic translation machinery. Analysis of a large dynamic structure-the nuclear pore complex-revealed variations detectable at the level of individual complexes. Cryo-ET was used to visualize previously elusive structures, such as nucleosome chains and the filaments of the nuclear lamina, in situ. Elucidation of the lamina structure provides insight into its contribution to metazoan nuclear stiffness. Copyright © 2016, American Association for the Advancement of Science.

Applying Satellite Data Sources in the Documentation and Landscape Modelling for Graeco-Roman Fortified Sites in the TŪR Abdin Area, Eastern Turkey

NASA Astrophysics Data System (ADS)

Silver, K.; Silver, M.; Törmä, M.; Okkonen, J.; Okkonen, T.

2017-08-01

In 2015-2016 the Finnish-Swedish Archaeological Project in Mesopotamia (FSAPM) initiated a pilot study of an unexplored area in the Tūr Abdin region in Northern Mesopotamia (present-day Mardin Province in southeastern Turkey). FSAPM is reliant on satellite image data sources for prospecting, identifying, recording, and mapping largely unknown archaeological sites as well as studying their landscapes in the region. The purpose is to record and document sites in this endangered area for saving its cultural heritage. The sites in question consist of fortified architectural remains in an ancient border zone between the Graeco-Roman/Byzantine world and Parthia/Persia. The location of the archaeological sites in the terrain and the visible archaeological remains, as well as their dimensions and sizes were determined from the ortorectified satellite images, which also provided coordinates. In addition, field documentation was carried out in situ with photographs and notes. The applicability of various satellite data sources for the archaeological documentation of the project was evaluated. Satellite photographs from three 1968 CORONA missions, i.e. the declassified US government satellite photograph archives were acquired. Furthermore, satellite images included a recent GeoEye-1 Satellite Sensor Image from 2010 with a resolution of 0.5 m. Its applicability for prospecting archaeological sites, studying the terrain and producing landscape models in 3D was confirmed. The GeoEye-1 revealed the ruins of a fortified town and a fortress for their documentation and study. Landscape models for the area of these sites were constructed fusing GeoEye-1 with EU-DEM (European Digital Elevation Model data using SRTM and ASTER GDEM data) in order to understand their locations in the terrain.

FR II radio galaxies at low frequencies - I. Morphology, magnetic field strength and energetics.

PubMed

Harwood, Jeremy J; Croston, Judith H; Intema, Huib T; Stewart, Adam J; Ineson, Judith; Hardcastle, Martin J; Godfrey, Leith; Best, Philip; Brienza, Marisa; Heesen, Volker; Mahony, Elizabeth K; Morganti, Raffaella; Murgia, Matteo; Orrú, Emanuela; Röttgering, Huub; Shulevski, Aleksandar; Wise, Michael W

2016-06-01

Due to their steep spectra, low-frequency observations of Fanaroff-Riley type II (FR II) radio galaxies potentially provide key insights in to the morphology, energetics and spectrum of these powerful radio sources. However, limitations imposed by the previous generation of radio interferometers at metre wavelengths have meant that this region of parameter space remains largely unexplored. In this paper, the first in a series examining FR IIs at low frequencies, we use LOFAR (LOw Frequency ARray) observations between 50 and 160 MHz, along with complementary archival radio and X-ray data, to explore the properties of two FR II sources, 3C 452 and 3C 223. We find that the morphology of 3C 452 is that of a standard FR II rather than of a double-double radio galaxy as had previously been suggested, with no remnant emission being observed beyond the active lobes. We find that the low-frequency integrated spectra of both sources are much steeper than expected based on traditional assumptions and, using synchrotron/inverse-Compton model fitting, show that the total energy content of the lobes is greater than previous estimates by a factor of around 5 for 3C 452 and 2 for 3C 223. We go on to discuss possible causes of these steeper-than-expected spectra and provide revised estimates of the internal pressures and magnetic field strengths for the intrinsically steep case. We find that the ratio between the equipartition magnetic field strengths and those derived through synchrotron/inverse-Compton model fitting remains consistent with previous findings and show that the observed departure from equipartition may in some cases provide a solution to the spectral versus dynamical age disparity.

Mode-locked thin-disk lasers and their potential application for high-power terahertz generation

NASA Astrophysics Data System (ADS)

Saraceno, Clara J.

2018-04-01

The progress achieved in the last few decades in the performance of ultrafast laser systems with high average power has been tremendous, and continues to provide momentum to new exciting applications, both in scientific research and technology. Among the various technological advances that have shaped this progress, mode-locked thin-disk oscillators have attracted significant attention as a unique technology capable of providing ultrashort pulses with high energy (tens to hundreds of microjoules) and at very high repetition rates (in the megahertz regime) from a single table-top oscillator. This technology opens the door to compact high repetition rate ultrafast sources spanning the entire electromagnetic spectrum from the XUV to the terahertz regime, opening various new application fields. In this article, we focus on their unexplored potential as compact driving sources for high average power terahertz generation.

Chemical Fucosylation of a Polysaccharide: A Semisynthetic Access to Fucosylated Chondroitin Sulfate.

PubMed

Laezza, Antonio; Iadonisi, Alfonso; Castro, Cristina De; De Rosa, Mario; Schiraldi, Chiara; Parrilli, Michelangelo; Bedini, Emiliano

2015-07-13

Chemical O-glycosylation of polysaccharides is an almost unexplored reaction. This is mainly due to the difficulties in derivatizing such complex biomacromolecules in a quantitative manner and with a fine control of the obtained structural parameters. In this work, chondroitin raw material from a microbial source was chemo- and regioselectively protected to give two polysaccharide intermediates, that acted in turn as glycosyl acceptors in fucosylation reactions. Further manipulations on the fucosylated polysaccharides, including multiple de-O-benzylation and sulfation, furnished for the first time nonanimal sourced fucosylated chondroitin sulfates (fCSs)-polysaccharides obtained so far exclusively from sea cucumbers (Echinoidea, Holothuroidea) and showing several very interesting biological activities. A semisynthetic fCS was characterized from a structural point of view by means of 2D-NMR techniques, and preliminarily assayed in an anticoagulant test.

Contextualising impacts of logging on tropical rainforest catchment sediment dynamics using the stratigraphic record of in-channel bench deposits

NASA Astrophysics Data System (ADS)

Blake, Will; Walsh, Rory; Bidin, Kawi; Annammala, Kogila

2015-04-01

It is widely recognised that commercial logging and conversion of tropical rainforest to oil palm plantation leads to enhanced fluvial sediment flux to the coastal zone but the dynamics of delivery and mechanisms that act to retain sediment and nutrients within rainforest ecosystems, e.g. riparian zone and floodplain storage, are poorly understood and underexploited as a management tool. While accretion of lateral in-channel bench deposits in response to forest clearance has been demonstrated in temperate landscapes, their development and value as sedimentary archives of catchment response to human disturbance remains largely unexplored in tropical rainforest river systems. Working within the Segama River basin, Sabah, Malaysian Borneo, this study aimed to test the hypothesis that (1) lateral bench development in tropical rainforest rivers systems is enhanced by upstream catchment disturbance and that (2) the sedimentary record of these deposits can be used to infer changes in sediment provenance and intensification of sediment flux associated with logging activities. Sediment cores were taken from in-channel bench deposits with upstream catchment contributing areas of 721 km2 and 2800 km2 respectively. Accretion rates were determined using fallout 210Pb and 137Cs and the timing of peak accumulation was shown to correspond exactly with the known temporal pattern of logging and associated fluvial sediment response over the period 1980 to present following low pre-logging rates. Major and minor element geochemistry of deposits was used to assess the degree of weathering that deposited sediment had experienced. This was linked to surface (heavily weathered) and subsurface (less weathered) sediment sources relating to initial disturbance by logging and post-logging landsliding responses respectively. A shift in the dominant source of deposited material from surface (i.e. topsoil) to subsurface (i.e. relatively unweathered subsoil close to bedrock) origin was observed to coincide with the increase in accretion rates following logging of steep headwater slopes. Coherence of sedimentary, monitoring and observational evidence demonstrates that in-channel bench deposits offer a previously unexplored sedimentary archive of catchment response to logging in tropical rainforest systems and a tool for evaluating the erosional responses of ungauged basins. In-channel bench development due to catchment disturbance may augment ecosystem services provided by the riparian corridors of larger rivers and process knowledge gained from sedimentary archives can be used to underpin future riparian and catchment forest management strategies.

Rock-Eval pyrolysis and vitrinite reflectance results from the Sheep Creek 1 well, Susitna basin, south-central Alaska

USGS Publications Warehouse

Stanley, Richard G.; Lillis, Paul G.; Pawlewicz, Mark J.; Haeussler, Peter J.

2014-01-01

We used Rock-Eval pyrolysis and vitrinite reflectance to examine the petroleum source potential of rock samples from the Sheep Creek 1 well in the Susitna basin of south-central Alaska. The results show that Miocene nonmarine coal, carbonaceous shale, and mudstone are potential sources of hydrocarbons and are thermally immature with respect to the oil window. In the samples that we studied, coals are more organic-rich and more oil-prone than carbonaceous shales and silty mudstones, which appear to be potential sources of natural gas. Lithologically similar rocks may be present in the deeper parts of the subsurface Susitna basin located west of the Sheep Creek 1 well, where they may have been buried deeply enough to generate oil and (or) gas. The Susitna basin is sparsely drilled and mostly unexplored, and no commercial production of hydrocarbons has been obtained. However, the existence of potential source rocks of oil and gas, as shown by our Rock-Eval results, suggests that undiscovered petroleum accumulations may be present in the Susitna basin.

Are all eggs created equal? A case study from the Hawaiian reef-building coral Montipora capitata

NASA Astrophysics Data System (ADS)

Padilla-Gamiño, Jacqueline L.; Bidigare, Robert R.; Barshis, Daniel J.; Alamaru, Ada; Hédouin, Laetitia; Hernández-Pech, Xavier; Kandel, Frederique; Leon Soon, Sherril; Roth, Melissa S.; Rodrigues, Lisa J.; Grottoli, Andrea G.; Portocarrero, Claudia; Wagenhauser, Stephanie A.; Buttler, Fenina; Gates, Ruth D.

2013-03-01

Parental effects have been largely unexplored in marine organisms and may play a significant role in dictating the phenotypic range of traits in coral offspring, influencing their ability to survive environmental challenges. This study explored parental effects and life-stage differences in the Hawaiian reef-building coral Montipora capitata from different environments by examining the biochemical composition of mature coral colonies and their eggs. Our results indicate that there are large biochemical differences between adults and eggs, with the latter containing higher concentration of lipids (mostly wax esters), ubiquitinated proteins (which may indicate high turnover rate of proteins) and antioxidants (e.g., manganese superoxide dismutase). Adults displayed high phenotypic plasticity, with corals from a high-light environment having more wax esters, lighter tissue δ13C signatures and higher Symbiodinium densities than adults from the low-light environment who had higher content of accessory pigments. A green-algal pigment (α-carotene) and powerful antioxidant was present in eggs; it is unclear whether this pigment is acquired from heterotrophic food sources or from endolithic green algae living in the adult coral skeletons. Despite the broad phenotypic plasticity displayed by adults, parental investment in the context of provisioning of energy reserves and antioxidant defense was the same in eggs from the different sites. Such equality in investment maximizes the capacity of all embryos and larvae to cope with challenging conditions associated with floating at the surface and to disperse successfully until an appropriate habitat for settlement is found.

Altered social attention in anorexia nervosa during real social interaction.

PubMed

Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Carli, Lorenza; Todisco, Patrizia; Palomba, Daniela; Galfano, Giovanni

2016-03-17

The capacity to devote attentional resources in response to body-related signals provided by others is still largely unexplored in individuals with Anorexia Nervosa (AN). Here, we tested this capacity through a novel paradigm that mimics a social interaction with a real partner. Healthy individuals (Experiment 1) and individuals with AN (Experiment 2) completed a task with another person which consisted in performing, alternatively, rapid aiming movements to lateralised targets. Generally, this task leads to a form of Inhibition of Return (IOR), which consists of longer reaction times when an individual has to respond to a location previously searched by either himself (individual IOR) or by the partner (social IOR) as compared to previously unexplored locations. IOR is considered as an important attentional mechanism that promotes an effective exploration of the environment during social interaction. Here, healthy individuals displayed both individual and social IOR that were both reliable and of the same magnitude. Individuals with AN displayed a non-significant individual IOR but a reliable social IOR that was also significantly stronger than individual IOR. These results suggest the presence of a reduced sensitivity in processing body-related stimuli conveyed by oneself in individuals with AN which is reflected in action-based attentional processes.

The Laurencia Paradox: An Endless Source of Chemodiversity.

PubMed

Harizani, Maria; Ioannou, Efstathia; Roussis, Vassilios

Nature, the most prolific source of biological and chemical diversity, has provided mankind with treatments for health problems since ancient times and continues to be the most promising reservoir of bioactive chemicals for the development of modern drugs. In addition to the terrestrial organisms that still remain a promising source of new bioactive metabolites, the marine environment, covering approximately 70% of the Earth's surface and containing a largely unexplored biodiversity, offers an enormous resource for the discovery of novel compounds. According to the MarinLit database, more than 27,000 metabolites from marine macro- and microorganisms have been isolated to date providing material and key structures for the development of new products in the pharmaceutical, food, cosmeceutical, chemical, and agrochemical sectors. Algae, which thrive in the euphotic zone, were among the first marine organisms that were investigated as sources of food, nutritional supplements, soil fertilizers, and bioactive metabolites.Red algae of the genus Laurencia are accepted unanimously as one of the richest sources of new secondary metabolites. Their cosmopolitan distribution, along with the chemical variation influenced to a significant degree by environmental and genetic factors, have resulted in an endless parade of metabolites, often featuring multiple halogenation sites.The present contribution, covering the literature until August 2015, offers a comprehensive view of the chemical wealth and the taxonomic problems currently impeding chemical and biological investigations of the genus Laurencia. Since mollusks feeding on Laurencia are, in many cases, bioaccumulating, and utilize algal metabolites as chemical weaponry against natural enemies, metabolites of postulated dietary origin of sea hares that feed on Laurencia species are also included in the present review. Altogether, 1047 secondary metabolites, often featuring new carbocyclic skeletons, have been included.The chapter addresses: (1) the "Laurencia complex", the botanical description and the growth and population dynamics of the genus, as well as its chemical diversity and ecological relations; (2) the secondary metabolites, which are organized according to their chemical structures and are classified into sesquiterpenes, diterpenes, triterpenes, acetogenins, indoles, aromatic compounds, steroids, and miscellaneous compounds, as well as their sources of isolation which are depicted in tabulated form, and (3) the biological activity organized according to the biological target and the ecological functions of Laurencia metabolites.

Energy transfer in a mechanically trapped exciplex.

PubMed

Klosterman, Jeremy K; Iwamura, Munetaka; Tahara, Tahei; Fujita, Makoto

2009-07-15

Host-guest complexes involving M(6)L(4) coordination cages can display unusual photoreactivity, and enclathration of the very large fluorophore bisanthracene resulted in an emissive, mechanically trapped intramolecular exciplex. Mechanically linked intramolecular exciplexes are important for understanding the dependence of energy transfer on donor-acceptor distance, orientation, and electronic coupling but are relatively unexplored. Steady-state and picosecond time-resolved fluorescence measurements have revealed that selective excitation of the encapsulated guest fluorophore results in efficient energy transfer from the excited guest to an emissive host-guest exciplex state.

X-ray and multiwavelength insights into the inner structure of high-luminosity disc-like emitters

NASA Astrophysics Data System (ADS)

Luo, B.; Brandt, W. N.; Eracleous, M.; Wu, Jian; Hall, P. B.; Rafiee, A.; Schneider, D. P.; Wu, Jianfeng

2013-02-01

We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGN) with disc-like Hβ emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have higher redshift (z ≈ 0.6) than the majority of the known disc-like emitters, and they occupy a largely unexplored space in the luminosity-redshift plane. Seven sources have typical AGN X-ray spectra with power-law photon indices of Γ ≈ 1.4-2.0; two of them show some X-ray absorption (column density NH ≈ 1021-1022 cm-2 for neutral gas). The other source, J0850+4451, has only three hard X-ray photons detected and is probably heavily obscured (NH ≳ 3 × 1023 cm-2). This object is also identified as a low-ionization broad absorption line (BAL) quasar based on Mg II λ2799 absorption; it is the first disc-like emitter reported that is also a BAL quasar. The infrared-to-ultraviolet (UV) spectral energy distributions (SEDs) of these eight sources are similar to the mean SEDs of typical quasars with a UV `bump', suggestive of standard accretion discs radiating with high efficiency, which differs from low-luminosity disc-like emitters. Studies of the X-ray-to-optical power-law slope parameters (αOX) indicate that there is no significant excess X-ray emission in these high-luminosity disc-like emitters. Energy budget analysis suggests that for disc-like emitters in general, the inner disc must illuminate and ionize the outer disc efficiently (≈15 per cent of the nuclear ionizing radiation is required on average) via direct illumination and/or scattering. Warped accretion discs are probably needed for direct illumination to work in high-luminosity objects, as their geometrically thin inner discs decrease the amount of direct illumination possible for a flat disc.

Source Memory in Korsakoff Syndrome: Disentangling the Mechanisms of Temporal Confusion.

PubMed

Brion, Mélanie; de Timary, Philippe; Pitel, Anne-Lise; Maurage, Pierre

2017-03-01

Korsakoff syndrome (KS), most frequently resulting from alcohol dependence (ALC), is characterized by severe anterograde amnesia. It has been suggested that these deficits may extend to other memory components, and notably source memory deficits involved in the disorientation and temporal confusion frequently observed in KS. However, the extent of this source memory impairment in KS and its usefulness for the differential diagnosis between ALC and KS remain unexplored. Nineteen patients with KS were compared with 19 alcohol-dependent individuals and 19 controls in a source memory test exploring temporal context confusions ("continuous recognition task"). Episodic memory and psychopathological comorbidities were controlled for. While no source memory deficit was observed in ALC, KS was associated with a significant presence of temporal context confusion, even when the influence of comorbidities was taken into account. This source memory impairment did not appear to be related to performances on episodic memory or executive functions. Patients with KS displayed source memory deficits, as indexed by temporal context confusions. The absence of a relationship with episodic memory performances seems to indicate that source memory impairment is not a mere by-product of amnesia. As ALC was associated with preserved source memory, the presence of temporal context confusion may serve as a complementary tool for the differential diagnosis between ALC and KS. Copyright © 2017 by the Research Society on Alcoholism.

Morphological changes in polycrystalline Fe after compression and release

NASA Astrophysics Data System (ADS)

Gunkelmann, Nina; Tramontina, Diego R.; Bringa, Eduardo M.; Urbassek, Herbert M.

2015-02-01

Despite a number of large-scale molecular dynamics simulations of shock compressed iron, the morphological properties of simulated recovered samples are still unexplored. Key questions remain open in this area, including the role of dislocation motion and deformation twinning in shear stress release. In this study, we present simulations of homogeneous uniaxial compression and recovery of large polycrystalline iron samples. Our results reveal significant recovery of the body-centered cubic grains with some deformation twinning driven by shear stress, in agreement with experimental results by Wang et al. [Sci. Rep. 3, 1086 (2013)]. The twin fraction agrees reasonably well with a semi-analytical model which assumes a critical shear stress for twinning. On reloading, twins disappear and the material reaches a very low strength value.

Human Gut Microbiome: Function Matters.

PubMed

Heintz-Buschart, Anna; Wilmes, Paul

2017-11-22

The human gut microbiome represents a complex ecosystem contributing essential functions to its host. Recent large-scale metagenomic studies have provided insights into its structure and functional potential. However, the functional repertoire which is actually contributed to human physiology remains largely unexplored. Here, by leveraging recent omics datasets, we challenge current assumptions regarding key attributes of the functional gut microbiome, in particular with respect to its variability. We further argue that the closing of existing gaps in functional knowledge should be addressed by a most-wanted gene list, the development and application of molecular and cellular high-throughput measurements, the development and sensible use of experimental models, as well as the direct study of observable molecular effects in the human host. Copyright © 2017 Elsevier Ltd. All rights reserved.

The utility of web mining for epidemiological research: studying the association between parity and cancer risk

PubMed Central

Yoon, Hong-Jun; Xu, Songhua; Han, Xuesong

2016-01-01

Background The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods Using advanced web crawling and tailored information extraction procedures, the authors automatically collected and analyzed the text content of 79 394 online obituary articles published between 1998 and 2014. The collected data included 51 911 cancer (27 330 breast; 9470 lung; 6496 pancreatic; 6342 ovarian; 2273 colon) and 27 483 non-cancer cases. With the derived information, the authors replicated a case-control study design to investigate the association between parity (i.e., childbearing) and cancer risk. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results Parity was found to be associated with a significantly reduced risk of breast cancer (OR = 0.78, 95% CI, 0.75-0.82), pancreatic cancer (OR = 0.78, 95% CI, 0.72-0.83), colon cancer (OR = 0.67, 95% CI, 0.60-0.74), and ovarian cancer (OR = 0.58, 95% CI, 0.54-0.62). Marginal association was found for lung cancer risk (OR = 0.87, 95% CI, 0.81-0.92). The linear trend between increased parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies. PMID:26615183

Construction of a 3D-shaped, natural product like fragment library by fragmentation and diversification of natural products.

PubMed

Prescher, Horst; Koch, Guido; Schuhmann, Tim; Ertl, Peter; Bussenault, Alex; Glick, Meir; Dix, Ina; Petersen, Frank; Lizos, Dimitrios E

2017-02-01

A fragment library consisting of 3D-shaped, natural product-like fragments was assembled. Library construction was mainly performed by natural product degradation and natural product diversification reactions and was complemented by the identification of 3D-shaped, natural product like fragments available from commercial sources. In addition, during the course of these studies, novel rearrangements were discovered for Massarigenin C and Cytochalasin E. The obtained fragment library has an excellent 3D-shape and natural product likeness, covering a novel, unexplored and underrepresented chemical space in fragment based drug discovery (FBDD). Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterisation of novel pH indicator of natural dye Oldenlandia umbellata L.

PubMed

Ramamoorthy, Siva; Mudgal, Gaurav; Rajesh, D; Nawaz Khan, F; Vijayakumar, V; Rajasekaran, C

2009-01-01

Oldenlandia umbellata L., commonly known as 'chay root', belongs to the family Rubiaceae and is one of the unexplored dye-yielding plants. The roots from this plant are the sources of red dye. Extraction protocol and dye characterisation have not been completely studied so far in this plant. Hence, in this article we have used UV spectrophotometry, thin layer chromatography, GC-MS, high-performance liquid chromatography and NMR to identify the five major colouring compounds, including 1,2,3-trimethoxyanthraquinone, 1,3-dimethoxy-2-hydroxyanthraquinone, 1,2-dimethoxyanthraquinone, 1-methoxy-2-hydroxyanthraquinone and 1,2-dihydroxyanthraquinone. It showed application feasibility as a new pH indicator.

Educational games for brain health: revealing their unexplored potential through a neurocognitive approach.

PubMed

Fissler, Patrick; Kolassa, Iris-Tatjana; Schrader, Claudia

2015-01-01

Educational games link the motivational nature of games with learning of knowledge and skills. Here, we go beyond effects on these learning outcomes. We review two lines of evidence which indicate the currently unexplored potential of educational games to promote brain health: First, gaming with specific neurocognitive demands (e.g., executive control), and second, educational learning experiences (e.g., studying foreign languages) improve brain health markers. These markers include cognitive ability, brain function, and brain structure. As educational games allow the combination of specific neurocognitive demands with educational learning experiences, they seem to be optimally suited for promoting brain health. We propose a neurocognitive approach to reveal this unexplored potential of educational games in future research.

Educational games for brain health: revealing their unexplored potential through a neurocognitive approach

PubMed Central

Fissler, Patrick; Kolassa, Iris-Tatjana; Schrader, Claudia

2015-01-01

Educational games link the motivational nature of games with learning of knowledge and skills. Here, we go beyond effects on these learning outcomes. We review two lines of evidence which indicate the currently unexplored potential of educational games to promote brain health: First, gaming with specific neurocognitive demands (e.g., executive control), and second, educational learning experiences (e.g., studying foreign languages) improve brain health markers. These markers include cognitive ability, brain function, and brain structure. As educational games allow the combination of specific neurocognitive demands with educational learning experiences, they seem to be optimally suited for promoting brain health. We propose a neurocognitive approach to reveal this unexplored potential of educational games in future research. PMID:26257697

To investigate or not to investigate? Researchers' views on unexplored atmospheric light phenomena

NASA Astrophysics Data System (ADS)

Caron, Etienne; Faridi, Pouya

2016-02-01

For hundreds of years, scientists have been studying light, which is used nowadays to explore the universe and cure diseases. Here, we present the results of a survey indicating a significant support from a subset of the academic community to investigate rare, unusual and unexplained atmospheric light phenomena that have historically been unexplored by scientists — the transient luminous phenomena in the valley of Hessdalen in Norway in particular. We propose that stable, long-term funding, and thorough investigation of poorly understood and/or unexplored luminous phenomena occurring in the low atmosphere could lead to the creation of new inter-disciplinary research programs in multiple universities, and ultimately, to important fundamental discoveries in the field of atmospheric science, photonics and beyond.

The Imaging X-Ray Polarimetry Explorer (IXPE)

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Ramsey, Brian; O’Dell, Stephen; Tennant, Allyn; Elsner, Ronald; Soffita, Paolo; Bellazzini, Ronaldo; Costa, Enrico; Kolodziejczak, Jeffery; Kaspi, Victoria;

Mushroom Lectins: Specificity, Structure and Bioactivity Relevant to Human Disease

PubMed Central

Hassan, Mohamed Ali Abol; Rouf, Razina; Tiralongo, Evelin; May, Tom W.; Tiralongo, Joe

2015-01-01

Lectins are non-immunoglobulin proteins that bind diverse sugar structures with a high degree of selectivity. Lectins play crucial role in various biological processes such as cellular signaling, scavenging of glycoproteins from the circulatory system, cell–cell interactions in the immune system, differentiation and protein targeting to cellular compartments, as well as in host defence mechanisms, inflammation, and cancer. Among all the sources of lectins, plants have been most extensively studied. However, more recently fungal lectins have attracted considerable attention due to their antitumor, antiproliferative and immunomodulatory activities. Given that only 10% of mushroom species are known and have been taxonomically classified, mushrooms represent an enormous unexplored source of potentially useful and novel lectins. In this review we provide an up-to-date summary on the biochemical, molecular and structural properties of mushroom lectins, as well as their versatile applications specifically focusing on mushroom lectin bioactivity. PMID:25856678

Stable Scalp EEG Spatiospectral Patterns Across Paradigms Estimated by Group ICA.

PubMed

Labounek, René; Bridwell, David A; Mareček, Radek; Lamoš, Martin; Mikl, Michal; Slavíček, Tomáš; Bednařík, Petr; Baštinec, Jaromír; Hluštík, Petr; Brázdil, Milan; Jan, Jiří

2018-01-01

Electroencephalography (EEG) oscillations reflect the superposition of different cortical sources with potentially different frequencies. Various blind source separation (BSS) approaches have been developed and implemented in order to decompose these oscillations, and a subset of approaches have been developed for decomposition of multi-subject data. Group independent component analysis (Group ICA) is one such approach, revealing spatiospectral maps at the group level with distinct frequency and spatial characteristics. The reproducibility of these distinct maps across subjects and paradigms is relatively unexplored domain, and the topic of the present study. To address this, we conducted separate group ICA decompositions of EEG spatiospectral patterns on data collected during three different paradigms or tasks (resting-state, semantic decision task and visual oddball task). K-means clustering analysis of back-reconstructed individual subject maps demonstrates that fourteen different independent spatiospectral maps are present across the different paradigms/tasks, i.e. they are generally stable.

Deterministic control of radiative processes by shaping the mode field

NASA Astrophysics Data System (ADS)

Pellegrino, D.; Pagliano, F.; Genco, A.; Petruzzella, M.; van Otten, F. W.; Fiore, A.

2018-04-01

Quantum dots (QDs) interacting with confined light fields in photonic crystal cavities represent a scalable light source for the generation of single photons and laser radiation in the solid-state platform. The complete control of light-matter interaction in these sources is needed to fully exploit their potential, but it has been challenging due to the small length scales involved. In this work, we experimentally demonstrate the control of the radiative interaction between InAs QDs and one mode of three coupled nanocavities. By non-locally moulding the mode field experienced by the QDs inside one of the cavities, we are able to deterministically tune, and even inhibit, the spontaneous emission into the mode. The presented method will enable the real-time switching of Rabi oscillations, the shaping of the temporal waveform of single photons, and the implementation of unexplored nanolaser modulation schemes.

Plant seed species identification from chemical fingerprints: a high-throughput application of direct analysis in real time mass spectrometry.

PubMed

Lesiak, Ashton D; Cody, Robert B; Dane, A John; Musah, Rabi A

2015-09-01

Plant species identification based on the morphological features of plant parts is a well-established science in botany. However, species identification from seeds has largely been unexplored, despite the fact that the seeds contain all of the genetic information that distinguishes one plant from another. Using seeds of genus Datura plants, we show here that the mass spectrum-derived chemical fingerprints for seeds of the same species are similar. On the other hand, seeds from different species within the same genus display distinct chemical signatures, even though they may contain similar characteristic biomarkers. The intraspecies chemical signature similarities on the one hand, and interspecies fingerprint differences on the other, can be processed by multivariate statistical analysis methods to enable rapid species-level identification and differentiation. The chemical fingerprints can be acquired rapidly and in a high-throughput manner by direct analysis in real time mass spectrometry (DART-MS) analysis of the seeds in their native form, without use of a solvent extract. Importantly, knowledge of the identity of the detected molecules is not required for species level identification. However, confirmation of the presence within the seeds of various characteristic tropane and other alkaloids, including atropine, scopolamine, scopoline, tropine, tropinone, and tyramine, was accomplished by comparison of the in-source collision-induced dissociation (CID) fragmentation patterns of authentic standards, to the fragmentation patterns observed in the seeds when analyzed under similar in-source CID conditions. The advantages, applications, and implications of the chemometric processing of DART-MS derived seed chemical signatures for species level identification and differentiation are discussed.

Chemical composition of preen wax reflects major histocompatibility complex similarity in songbirds.

PubMed

Slade, J W G; Watson, M J; Kelly, T R; Gloor, G B; Bernards, M A; MacDougall-Shackleton, E A

2016-11-16

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIβ genotypes of wild song sparrows (Melospiza melodia). Pairwise chemical distance reflected amino acid distance at MHC for male-female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography-mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates. © 2016 The Author(s).

Extensive Microbial and Functional Diversity within the Chicken Cecal Microbiome

PubMed Central

Sergeant, Martin J.; Constantinidou, Chrystala; Cogan, Tristan A.; Bedford, Michael R.; Penn, Charles W.; Pallen, Mark J.

2014-01-01

Chickens are major source of food and protein worldwide. Feed conversion and the health of chickens relies on the largely unexplored complex microbial community that inhabits the chicken gut, including the ceca. We have carried out deep microbial community profiling of the microbiota in twenty cecal samples via 16S rRNA gene sequences and an in-depth metagenomics analysis of a single cecal microbiota. We recovered 699 phylotypes, over half of which appear to represent previously unknown species. We obtained 648,251 environmental gene tags (EGTs), the majority of which represent new species. These were binned into over two-dozen draft genomes, which included Campylobacter jejuni and Helicobacter pullorum. We found numerous polysaccharide- and oligosaccharide-degrading enzymes encoding within the metagenome, some of which appeared to be part of polysaccharide utilization systems with genetic evidence for the co-ordination of polysaccharide degradation with sugar transport and utilization. The cecal metagenome encodes several fermentation pathways leading to the production of short-chain fatty acids, including some with novel features. We found a dozen uptake hydrogenases encoded in the metagenome and speculate that these provide major hydrogen sinks within this microbial community and might explain the high abundance of several genera within this microbiome, including Campylobacter, Helicobacter and Megamonas. PMID:24657972

Health effects of atmospheric particulates: a medical geology perspective.

PubMed

Duzgoren-Aydin, Nurdan S

2008-01-01

In this review, atmospheric particulates as composite airborne earth materials often containing both natural and anthropogenic components were examined in the context of medical geology. Despite a vast number of both experimental and epidemiological studies confirming the direct and indirect links between atmospheric particulates and human health, the exact nature of mechanisms affecting the particulate-induced pathogenesis largely remains unexplored. Future in depth research on these areas would be most successful if potential mechanisms are examined with reference to the physical (e.g., size, shape and surface), chemical, mineralogical and source characteristics of particulate matters. The underlying goal of this review was to present the relevant terminology and processes proposed in the literature to explain the interfaces and interactions between atmospheric particles and human body within the framework of "atmospheric particle cycles." The complexities of the interactions were demonstrated through case studies focusing on particulate matter air pollution and malignant mesothelioma occurrences due to environmental exposure to erionite-a fibrous zeolite mineral. There is an urgent need for a standard protocol or speciation methods applicable to earth-materials to guide and streamline studies on etiology of mineral-induced diseases. This protocol or speciation methods should provide relevant procedures to determine the level and extent of physical, chemical and mineralogical heterogeneity of particulate matters as well as quantitative in-situ particulate characteristics.

Cardiac torsion and electromagnetic fields: the cardiac bioinformation hypothesis.

PubMed

Burleson, Katharine O; Schwartz, Gary E

2005-01-01

Although in physiology the heart is often referred to as a simple piston pump, there are in fact two additional features that are integral to cardiac physiology and function. First, the heart as it contracts in systole, also rotates and produces torsion due to the structure of the myocardium. Second, the heart produces a significant electromagnetic field with each contraction due to the coordinated depolarization of myocytes producing a current flow. Unlike the electrocardiogram, the magnetic field is not limited to volume conduction and extends outside the body. The therapeutic potential for interaction of this cardioelectromagnetic field both within and outside the body is largely unexplored. It is our hypothesis that the heart functions as a generator of bioinformation that is central to normative functioning of body. The source of this bioinformation is based on: (1) vortex blood flow in the left ventricle; (2) a cardiac electromagnetic field and both; (3) heart sounds; and (4) pulse pressure which produce frequency and amplitude information. Thus, there is a multidimensional role for the heart in physiology and biopsychosocial dynamics. Recognition of these cardiac properties may result in significant implications for new therapies for cardiovascular disease based on increasing cardiac energy efficiency (coherence) and bioinformation from the cardioelectromagnetic field. Research studies to test this hypothesis are suggested.

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) based bioavailability determination of the major classes of phytochemicals.

PubMed

Stylos, Evgenios; Chatziathanasiadou, Maria V; Syriopoulou, Aggeliki; Tzakos, Andreas G

2017-03-15

Natural products derived from plants have served as an inexhausted source for drug discovery and drug development. They have been evolutionary amplified with drug-like properties and have already illustrated immense therapeutic potential over an array of different diseases. However, their incorporation in the drug discovery pipeline has been diminished the last two decades. This was probably due to barriers related to their inherent difficulties to be integrated in high-throughput screening assays as also their largely unexplored bioavailability. Analytical procedures have come into the spotlight, a result of the continuous development of the instrumentation's capabilities as far as detection and separation is concerned. Integral part of this technological evolution is LC-MS instrumentation and its extended use for the determination of various compounds. The fact that it provides extra sensitivity, specificity and good separation in complex samples, makes LC-MS/MS the ultimate tool in the determination of many types of chemical compounds, such as phytochemicals. Herein, we focus on the achievements of the last five years in quantitative analysis of the major classes of phytochemicals (flavonoids, alkaloids, terpenes, glycosides and saponins) in plasma, through LC-MS/MS, as also their bioavailability. Copyright © 2016 Elsevier B.V. All rights reserved.

Coherent inflation for large quantum superpositions of levitated microspheres

NASA Astrophysics Data System (ADS)

Romero-Isart, Oriol

2017-12-01

We show that coherent inflation (CI), namely quantum dynamics generated by inverted conservative potentials acting on the center of mass of a massive object, is an enabling tool to prepare large spatial quantum superpositions in a double-slit experiment. Combined with cryogenic, extreme high vacuum, and low-vibration environments, we argue that it is experimentally feasible to exploit CI to prepare the center of mass of a micrometer-sized object in a spatial quantum superposition comparable to its size. In such a hitherto unexplored parameter regime gravitationally-induced decoherence could be unambiguously falsified. We present a protocol to implement CI in a double-slit experiment by letting a levitated microsphere traverse a static potential landscape. Such a protocol could be experimentally implemented with an all-magnetic scheme using superconducting microspheres.

Moving beyond the current state of the internet

NASA Astrophysics Data System (ADS)

Chen, Edward S.; Davison, Daniel B.

1997-06-01

Whereas the Internet has been greatly publicized in the past few years, its effects on education are still largely unexplored. Here, we discuss the future of the Internet itself and the effect on education. Expanding educational and commercial requirements will result in improved bandwidth and connectivity. Larger address spaces will be required, and the next generation of Internet Protocols will provide the addressability required. The real question—how will all of these changes affect education—is explored here. We believe that Internet resources will be a superb supplement to education, but not replace either tutored learning or written texts.

DGAT and triglyceride synthesis: a new target for obesity treatment?

PubMed

Chen, H C; Farese, R V

2000-07-01

Because triglycerides are considered essential for survival and their synthesis has been thought to occur through a single mechanism, inhibiting triglyceride synthesis has been largely unexplored as a possible target for obesity treatment. However, recent studies indicate that mice lacking acyl CoA:diacylglycerol acyltransferase (DGAT), a key enzyme in triglyceride synthesis, are viable and resistant to diet-induced obesity. Unexpectedly, this resistance is caused by a mechanism involving increased energy expenditure. These findings suggest that inhibiting specific components of triglyceride synthesis, such as DGAT, is feasible and may represent a novel approach to treating obesity.

Conceptualizing recovery capital: expansion of a theoretical construct.

PubMed

Cloud, William; Granfield, Robert

2008-01-01

In order to capture key personal and social resources individuals are able to access in their efforts to overcome substance misuse, we introduced the construct of recovery capital into the literature. The purpose of this paper is to further explore the construct and include discussions of implications unexplored in our previous writings. In this paper we reveal the relationship between access to large amounts of recovery capital and substance misuse maintenance and introduce the concept of negative recovery capital. In doing so, we examine the relationships between negative recovery capital and gender, age, health, mental health, and incarceration.

Measurements of jet-related observables at the LHC

NASA Astrophysics Data System (ADS)

Kokkas, P.

2015-11-01

During the first years of the LHC operation a large amount of jet data was recorded by the ATLAS and CMS experiments. In this review several measurements of jet-related observables are presented, such as multi-jet rates and cross sections, ratios of jet cross sections, jet shapes and event shape observables. All results presented here are based on jet data collected at a centre-of-mass energy of 7 TeV. Data are compared to various Monte Carlo generators, as well as to theoretical next-to-leading-order calculations allowing a test of perturbative Quantum Chromodynamics in a previously unexplored energy region.

Sex-role identification and violent victimization: gender differences in the role of masculinity.

PubMed

Daigle, Leah E; Mummert, Sadie J

2014-01-01

Although sex-role identification has been found to be associated with crime and delinquency, the link between sex-role identification and violent victimization has remained largely unexplored. Using the Add Health data, this study examines sex-role identification and its relationship to violent victimization. The findings suggest that masculinity increases the risk of violent victimization for males, but does not for females. Other differences in risk factors across gender were also found. These findings indicate that masculinity is an important construct in understanding the complexity of why some persons are violently victimized and others are not.

Expanding our view of authentic learning: bridging in and out-of-school experiences

NASA Astrophysics Data System (ADS)

Quigley, Cassie

2014-03-01

In this review, I explore the affordances of Wolff-Michael Roth and Pei-Ling Hsu's article, "Space, relations and the learning of science" which brings attention to a largely unexplored area of science education research—the importance of spatial organization within the laboratory. This forum piece examines the four components of authentic learning and how these components relate to the experiences presented in the original article. Then, it highlights the differences for in and out-of-school experiences as they relate to both authentic learning and episodes presented by Roth and Hsu.

Let Food Be Thy Medicine: Diet, Nutrition, and Biomarkers’ Risk of Alzheimer’s Disease

PubMed Central

Mosconi, Lisa; McHugh, Pauline F.

2015-01-01

Epidemiological evidence linking diet—one of the most important modifiable lifestyle factors—and risk of Alzheimer’s disease (AD)—the most common cause of dementia—is rapidly increasing. However, the biological mechanisms underlying the relationship between dietary nutrients, brain aging, and risk of AD are largely unexplored. Recent studies using brain imaging and biological markers of AD have begun to clarify how diet and nutrition modulate risk of AD in cognitively normal individuals, especially those at increased genetic risk. Such knowledge is critical prior to implementing dietary recommendations for prevention and treatment of disease. PMID:26167396

Extraterrestrial intelligence: an observational approach.

PubMed

Murray, B; Gulkis, S; Edelson, R E

1978-02-03

The microwave region of the electromagnetic spectrum, a plausible regime for signals from extraterrestrial intelligences, is largely unexplored. With new technology, particularly in data processing and low-noise reception, surveys can be conducted over broad regions of frequency and space with existing antennas at flux densities plausible for interstellar signals. An all-sky, broad-band survey lasting perhaps 5 years can be structured so that even negative results would establish significant boundaries on the regime in which such signals may be found. The technology and techniques developed and much of the data acquired would be applicable to radio astronomy and deep-space communications.

'I think positivity breeds positivity': a qualitative exploration of the role of family members in supporting those with chronic musculoskeletal pain to stay at work.

PubMed

McCluskey, Serena; de Vries, Haitze; Reneman, Michiel; Brooks, Joanna; Brouwer, Sandra

2015-07-22

It is proposed that family members are important sources of support in helping those with chronic musculoskeletal pain to remain at work, but the phenomenon remains largely unexplored. The aim of this study was to examine the extent and nature of support provided by family members in this respect. Qualitative data were collected from workers and their 'significant others' (spouses/partners/close family members) in two un-related studies focused on working with pain; one conducted in the United Kingdom (n = 10 dyads) and one in the Netherlands (n = 21 dyads). Thematic analysis techniques were applied to both sets of data independently, and findings were then assimilated to establish common themes. Findings were broadly similar in both studies. Workers acknowledged significant other support in helping them to manage their pain and remain at work, and their descriptions of the type of support provided and required were echoed by their significant others. Three common themes were identified - 'connectivity', 'activity' and 'positivity'. Worker and significant other responses were largely congruent, but significant others provided more in-depth information on the nature of their support, their concerns and the impact on their relationship. This research presents novel insights about the specific contribution made by significant others in helping their relatives with chronic musculoskeletal pain to stay at work. These findings add to the under-represented 'social' dimension of the biopsychosocial model currently applied to our understanding and treatment of pain, and point to harnessing support from significant others as a potentially effective management strategy.

Snowball: resampling combined with distance-based regression to discover transcriptional consequences of a driver mutation

PubMed Central

Xu, Yaomin; Guo, Xingyi; Sun, Jiayang; Zhao, Zhongming

2015-01-01

Motivation: Large-scale cancer genomic studies, such as The Cancer Genome Atlas (TCGA), have profiled multidimensional genomic data, including mutation and expression profiles on a variety of cancer cell types, to uncover the molecular mechanism of cancerogenesis. More than a hundred driver mutations have been characterized that confer the advantage of cell growth. However, how driver mutations regulate the transcriptome to affect cellular functions remains largely unexplored. Differential analysis of gene expression relative to a driver mutation on patient samples could provide us with new insights in understanding driver mutation dysregulation in tumor genome and developing personalized treatment strategies. Results: Here, we introduce the Snowball approach as a highly sensitive statistical analysis method to identify transcriptional signatures that are affected by a recurrent driver mutation. Snowball utilizes a resampling-based approach and combines a distance-based regression framework to assign a robust ranking index of genes based on their aggregated association with the presence of the mutation, and further selects the top significant genes for downstream data analyses or experiments. In our application of the Snowball approach to both synthesized and TCGA data, we demonstrated that it outperforms the standard methods and provides more accurate inferences to the functional effects and transcriptional dysregulation of driver mutations. Availability and implementation: R package and source code are available from CRAN at http://cran.r-project.org/web/packages/DESnowball, and also available at http://bioinfo.mc.vanderbilt.edu/DESnowball/. Contact: zhongming.zhao@vanderbilt.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25192743

Chemical composition of rosehips from different Rosa species: an alternative source of antioxidants for the food industry.

PubMed

Jiménez, Sandra; Jiménez-Moreno, Nerea; Luquin, Asunción; Laguna, Mariano; Rodríguez-Yoldi, María Jesús; Ancín-Azpilicueta, Carmen

2017-07-01

It is important to explore new sources of natural additives because the demand for these compounds by consumers is increasing. These products also provide health benefits and help in food preservation. An unexplored source of nutrients and antioxidant compounds is rosehip, the fleshy fruit of roses. This work compares the antioxidant compound (vitamin C, neutral phenols and acidic phenols) content of four Rosa species rosehips: R. pouzinii, R. corymbifera, R. glauca and R. canina from different geographical zones. Results show quantitative variability in ascorbic acids and neutral phenols content, and quantitative and qualitative differences in acidic phenol content, depending on species. Vitamin C concentration was highly variable depending on species, R. canina being the one with the highest concentration and R. pouzinii the one with the lowest content. Variability was found in total neutral polyphenols concentration and a correlation between freshness of the rosehips and concentration of neutral polyphenols was also found. Significant differences were found in the acidic phenols content among the studied species. Generally antioxidant activity was higher in the vitamin C fraction.

Speed of CMEs and the Magnetic Non-Potentiality of their Source Active Regions

NASA Technical Reports Server (NTRS)

Tiwari, Sanjiv Kumar; Falconer, David Allen; Moore, Ronald L.; Venkatakrishnan, P.; Winebarger, Amy R.; Khazanov, Igor G.

2014-01-01

Most fast coronal mass ejections (CMEs) originate from solar active regions (ARs). Non-potentiality of ARs plausibly determines the speed of CMEs in the outer corona. Several other unexplored parameters might be important as well. To find out the relation between the intial speed of CMEs and the non-potentiality of source ARs, we identified over a hundred of CMEs with source ARs via their co-produced flares. The speed of the CMEs are collected from the SOHO LASCO CME catalog. We have used vector magnetograms obtained with HMI/SDO, to evaluate various magnetic non-potentiality parameters, e.g. magnetic free-energy proxies, twist, shear angle, signed shear angle, net current etc. We have also included several other parameters e.g. total unsigned flux, magnetic area of ARs, area of sunspots, to investigate their correlation, if any, with the initial speeds of CMEs. Our preliminary results show that the ARs with larger non-potentiality and area produce faster CMEs but they can also produce slow ones. The ARs with lesser non-potentiality and area generally produce only slower CMEs.

X-Ray properties of Post-Merger Spheroidal Galaxies: The Missing Link in Understanding the Merger-AGN connection

NASA Astrophysics Data System (ADS)

Nair, Preethi

2017-09-01

We propose to characterize the AGN properties of post-merger spheroidal galaxies, a well-defined, significant post starburst phase in merging galaxies. These galaxies probe the "coalesced" late stage of mergers lying between ULIRGs and quenched elliptical galaxies. They are characterized by shells and tidal tails with lifetimes (0.5 - 1 Gyr) similar to those of low luminosity AGN. The AGN detection fraction for 12 serendipitous Chandra sources is 83%. These `shell' galaxies may represent a key time step in major mergers which has previously been unexplored. We propose to image a well selected sample of 12 shells drawn from SDSS to investigate this missing chapter in mergers.

The nursing shortage: breach of ideology as an unexplored cause.

PubMed

Censullo, Joan L

2008-01-01

The worldwide nursing shortage is unprecedented. Studies show increasing demand for nursing services coupled with a finite nursing supply. Many theories have been developed to explain the nursing shortage, to no avail. One unexplored theory is the psychological contract, which explores the impact of unwritten yet real expectations on work relationships. Understanding breach of the psychological contract is essential to resolution of the ongoing nursing shortage.

The ISOPHOT far-infrared serendipity north ecliptic pole minisurvey

NASA Astrophysics Data System (ADS)

Stickel, M.; Bogun, S.; Lemke, D.; Klaas, U.; Toth, L. V.; Herbstmeier, U.; Richter, G.; Assendorp, R.; Laureijs, R.; Kessler, M. F.; Burgdorf, M.; Beichman, C. A.; Rowan-Robinson, M.; Efstathiou, A.

1998-08-01

The ISOPHOT Serendipity Survey fills the otherwise unused slew time between ISO's fine pointings with measurements in an unexplored wavelength regime near 200 microns. In order to test point source extraction software, the completeness of the detected objects as well as the astrophysical content we investigate a 100 sq degr field near the North ecliptic pole, dubbed ISOPHOT Serendipity Minisurvey field. A total of 21 IRAS point sources were detected on the Serendipity slews crossing the field. 19 of these objects are galaxies, one is a planetary nebula and one is an empty field without a bright optical counterpart. The detection completeness is better than 90% for IRAS sources brighter than 2 Jy at 100 microns and better than 80% for sources brighter than 1.5 Jy. The source detection frequency is about 1 per 40degr slew length, in agreement with previous estimations based on galaxy number counts. After the end of the ISO mission, about 4000 point sources are expected to be found in the Serendipity slews. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) and with the participation of ISAS and NASA. Members of the Consortium on the ISOPHOT Serendipity Survey (CISS) are MPIA Heidelberg, ESA ISO SOC Villafranca, AIP Potsdam, IPAC Pasadena, Imperial College London

Innermost Van Allen Radiation Belt for High Energy Protons at Saturn

NASA Technical Reports Server (NTRS)

Cooper, John F.

2008-01-01

The high energy proton radiation belts of Saturn are energetically dominated by the source from cosmic ray albedo neutron decay (CRAND), trapping of protons from beta decay of neutrons emitted from galactic cosmic ray nuclear interactions with the main rings. These belts were originally discovered in wide gaps between the A-ring, Janus/Epimetheus, Mimas, and Enceladus. The narrow F and G rings significant affected the CRAND protons but did not produce total depletion. Voyager 2 measurements subsequently revealed an outermost CRAND proton belt beyond Enceladus. Although the source rate is small, the trapping times limited by radial magnetospheric diffusion are very long, about ten years at peak measured flux inwards of the G ring, so large fluxes can accumulate unless otherwise limited in the trapping region by neutral gas, dust, and ring body interactions. One proposed final extension of the Cassini Orbiter mission would place perikrone in a 3000-km gap between the inner D ring and the upper atmosphere of Saturn. Experience with CRAND in the Earth's inner Van Allen proton belt suggests that a similar innermost belt might be found in this comparably wide region at Saturn. Radial dependence of magnetospheric diffusion, proximity to the ring neutron source, and northward magnetic offset of Saturn's magnetic equator from the ring plane could potentially produce peak fluxes several orders of magnitude higher than previously measured outside the main rings. Even brief passes through such an intense environment of highly penetrating protons would be a significant concern for spacecraft operations and science observations. Actual fluxes are limited by losses in Saturn's exospheric gas and in a dust environment likely comparable to that of the known CRAND proton belts. The first numerical model of this unexplored radiation belt is presented to determine limits on peak magnitude and radial profile of the proton flux distribution.

Quantifying sources of bias in longitudinal data linkage studies of child abuse and neglect: measuring impact of outcome specification, linkage error, and partial cohort follow-up.

PubMed

Parrish, Jared W; Shanahan, Meghan E; Schnitzer, Patricia G; Lanier, Paul; Daniels, Julie L; Marshall, Stephen W

2017-12-01

Health informatics projects combining statewide birth populations with child welfare records have emerged as a valuable approach to conducting longitudinal research of child maltreatment. The potential bias resulting from linkage misspecification, partial cohort follow-up, and outcome misclassification in these studies has been largely unexplored. This study integrated epidemiological survey and novel administrative data sources to establish the Alaska Longitudinal Child Abuse and Neglect Linkage (ALCANLink) project. Using these data we evaluated and quantified the impact of non-linkage misspecification and single source maltreatment ascertainment use on reported maltreatment risk and effect estimates. The ALCANLink project integrates the 2009-2011 Alaska Pregnancy Risk Assessment Monitoring System (PRAMS) sample with multiple administrative databases through 2014, including one novel administrative source to track out-of-state emigration. For this project we limited our analysis to the 2009 PRAMS sample. We report on the impact of linkage quality, cohort follow-up, and multisource outcome ascertainment on the incidence proportion of reported maltreatment before age 6 and hazard ratios of selected characteristics that are often available in birth cohort linkage studies of maltreatment. Failure to account for out-of-state emigration biased the incidence proportion by 12% (from 28.3% w to 25.2% w ), and the hazard ratio (HR) by as much as 33% for some risk factors. Overly restrictive linkage parameters biased the incidence proportion downwards by 43% and the HR by as much as 27% for some factors. Multi-source linkages, on the other hand, were of little benefit for improving reported maltreatment ascertainment. Using the ALCANLink data which included a novel administrative data source, we were able to observe and quantify bias to both the incidence proportion and HR in a birth cohort linkage study of reported child maltreatment. Failure to account for out-of-state emigration and low-quality linkage methods may induce bias in longitudinal data linkage studies of child maltreatment which other researchers should be aware of. In this study multi-agency linkage did not lead to substantial increased detection of reported maltreatment. The ALCANLink methodology may be a practical approach for other states interested in developing longitudinal birth cohort linkage studies of maltreatment that requires limited resources to implement, provides comprehensive data elements, and can facilitate comparability between studies.

Metastable Prepores in Tension-Free Lipid Bilayers

NASA Astrophysics Data System (ADS)

Ting, Christina L.; Awasthi, Neha; Müller, Marcus; Hub, Jochen S.

2018-03-01

The formation and closure of aqueous pores in lipid bilayers is a key step in various biophysical processes. Large pores are well described by classical nucleation theory, but the free-energy landscape of small, biologically relevant pores has remained largely unexplored. The existence of small and metastable "prepores" was hypothesized decades ago from electroporation experiments, but resolving metastable prepores from theoretical models remained challenging. Using two complementary methods—atomistic simulations and self-consistent field theory of a minimal lipid model—we determine the parameters for which metastable prepores occur in lipid membranes. Both methods consistently suggest that pore metastability depends on the relative volume ratio between the lipid head group and lipid tails: lipids with a larger head-group volume fraction (or shorter saturated tails) form metastable prepores, whereas lipids with a smaller head-group volume fraction (or longer unsaturated tails) form unstable prepores.

Identification of novel compositions of ferromagnetic shape-memory alloys using composition spreads.

PubMed

Takeuchi, I; Famodu, O O; Read, J C; Aronova, M A; Chang, K-S; Craciunescu, C; Lofland, S E; Wuttig, M; Wellstood, F C; Knauss, L; Orozco, A

2003-03-01

Exploration of new ferroic (ferroelectric, ferromagnetic or ferroelastic) materials continues to be a central theme in condensed matter physics and to drive advances in key areas of technology. Here, using thin-film composition spreads, we have mapped the functional phase diagram of the Ni-Mn-Ga system whose Heusler composition Ni(2)MnGa is a well known ferromagnetic shape-memory alloy. A characterization technique that allows detection of martensitic transitions by visual inspection was combined with quantitative magnetization mapping using scanning SQUID (superconducting quantum interference device) microscopy. We find that a large, previously unexplored region outside the Heusler composition contains reversible martensites that are also ferromagnetic. A clear relationship between magnetization and the martensitic transition temperature is observed, revealing a strong thermodynamical coupling between magnetism and martensitic instability across a large fraction of the phase diagram.

Linear distributed source modeling of local field potentials recorded with intra-cortical electrode arrays.

PubMed

Hindriks, Rikkert; Schmiedt, Joscha; Arsiwalla, Xerxes D; Peter, Alina; Verschure, Paul F M J; Fries, Pascal; Schmid, Michael C; Deco, Gustavo

2017-01-01

Planar intra-cortical electrode (Utah) arrays provide a unique window into the spatial organization of cortical activity. Reconstruction of the current source density (CSD) underlying such recordings, however, requires "inverting" Poisson's equation. For inter-laminar recordings, this is commonly done by the CSD method, which consists in taking the second-order spatial derivative of the recorded local field potentials (LFPs). Although the CSD method has been tremendously successful in mapping the current generators underlying inter-laminar LFPs, its application to planar recordings is more challenging. While for inter-laminar recordings the CSD method seems reasonably robust against violations of its assumptions, is it unclear as to what extent this holds for planar recordings. One of the objectives of this study is to characterize the conditions under which the CSD method can be successfully applied to Utah array data. Using forward modeling, we find that for spatially coherent CSDs, the CSD method yields inaccurate reconstructions due to volume-conducted contamination from currents in deeper cortical layers. An alternative approach is to "invert" a constructed forward model. The advantage of this approach is that any a priori knowledge about the geometrical and electrical properties of the tissue can be taken into account. Although several inverse methods have been proposed for LFP data, the applicability of existing electroencephalographic (EEG) and magnetoencephalographic (MEG) inverse methods to LFP data is largely unexplored. Another objective of our study therefore, is to assess the applicability of the most commonly used EEG/MEG inverse methods to Utah array data. Our main conclusion is that these inverse methods provide more accurate CSD reconstructions than the CSD method. We illustrate the inverse methods using event-related potentials recorded from primary visual cortex of a macaque monkey during a motion discrimination task.

Linear distributed source modeling of local field potentials recorded with intra-cortical electrode arrays

PubMed Central

Schmiedt, Joscha; Arsiwalla, Xerxes D.; Peter, Alina; Verschure, Paul F. M. J.; Fries, Pascal; Schmid, Michael C.; Deco, Gustavo

2017-01-01

Planar intra-cortical electrode (Utah) arrays provide a unique window into the spatial organization of cortical activity. Reconstruction of the current source density (CSD) underlying such recordings, however, requires “inverting” Poisson’s equation. For inter-laminar recordings, this is commonly done by the CSD method, which consists in taking the second-order spatial derivative of the recorded local field potentials (LFPs). Although the CSD method has been tremendously successful in mapping the current generators underlying inter-laminar LFPs, its application to planar recordings is more challenging. While for inter-laminar recordings the CSD method seems reasonably robust against violations of its assumptions, is it unclear as to what extent this holds for planar recordings. One of the objectives of this study is to characterize the conditions under which the CSD method can be successfully applied to Utah array data. Using forward modeling, we find that for spatially coherent CSDs, the CSD method yields inaccurate reconstructions due to volume-conducted contamination from currents in deeper cortical layers. An alternative approach is to “invert” a constructed forward model. The advantage of this approach is that any a priori knowledge about the geometrical and electrical properties of the tissue can be taken into account. Although several inverse methods have been proposed for LFP data, the applicability of existing electroencephalographic (EEG) and magnetoencephalographic (MEG) inverse methods to LFP data is largely unexplored. Another objective of our study therefore, is to assess the applicability of the most commonly used EEG/MEG inverse methods to Utah array data. Our main conclusion is that these inverse methods provide more accurate CSD reconstructions than the CSD method. We illustrate the inverse methods using event-related potentials recorded from primary visual cortex of a macaque monkey during a motion discrimination task. PMID:29253006

Investigation of bacterial repopulation after sinus surgery and perioperative antibiotics.

PubMed

Hauser, Leah J; Ir, Diana; Kingdom, Todd T; Robertson, Charles E; Frank, Daniel N; Ramakrishnan, Vijay R

2016-01-01

Endoscopic sinus surgery (ESS) enjoys high success rates, but repopulation with pathogenic bacteria is 1 of the hallmarks of poorer outcomes. There are many hypothesized sources of repopulating bacteria; however, this process remains largely unexplored. This study examined changes in the sinus microbiome after ESS and medical therapies to identify potential sources for postsurgical microbial repopulation. Samples from the anterior nares, ethmoid sinus, and nasopharynx were taken at the time of surgery from 13 subjects undergoing ESS for chronic rhinosinusitis (CRS). Patients were treated postoperatively with 2 weeks of oral antibiotics and saline rinses. The ethmoid sinus was sampled at 2 and 6 weeks postoperatively; microbiota were characterized using quantitative polymerase chain reaction (qPCR) and 16S ribosomal RNA (rRNA) gene sequencing. The Morisita-Horn beta-diversity index (M-H) was used to compare similarity between samples. The bacterial burden of the ethmoid was higher 2 weeks postoperatively than 6 weeks postoperatively (p = 0.01). The 6-week samples most closely represented the anterior nares and ethmoid at surgery (M-H = 0.58 and 0.59, respectively), and were least similar to the nasopharynx (M-H = 0.28). Principal coordinates analysis (PCoA) plots illustrate that the ethmoid microbiota temporarily shifted after surgery and antibiotics but returned toward baseline in many subjects. Bacterial communities colonizing the ethmoid 6 weeks postoperatively were most similar to anterior nasal cavity and pretreatment sinus microbial profiles, indicating a high degree of resilience in the sinonasal microbiome of most subjects. Interestingly, surgery and postoperative antibiotic therapy does not appear to reduce bacterial burden, but rather, shifts the microbial consortia. © 2015 ARS-AAOA, LLC.

Pharmacological and toxicological evaluation of Urtica dioica.

PubMed

Dar, Sabzar Ahmad; Ganai, Farooq Ahmad; Yousuf, Abdul Rehman; Balkhi, Masood-Ul-Hassan; Bhat, Towseef Mohsin; Sharma, Poonam

2013-02-01

Medicinal plants are a largely unexplored source of drug repository. Urtica dioica L. (Urticaceae) is used in traditional medicine to treat diverse conditions. The present study describes the antidiabetic, antiinflammatory, antibacterial activity, and toxicological studies of Urtica dioica. U. dioica leaves were subjected to solvent extraction with hexane, chloroform, ethyl acetate, methanol, and aqueous, respectively, and screened for antidiabetic (300 mg/kg bw by glucose tolerance test; GTT), antiinflammatory (200 mg/kg bw by rat paw edema assay) and antibacterial activities [by disc-diffusion and minimum inhibitory concentration (MIC) assays]. Toxicological studies were carried on Artemia salina and Wistar rats; phytochemical analyses were carried out, using chromatographic and spectroscopic techniques. The aqueous extract of U. dioica (AEUD) significantly (p < 0.001; 67.92%) reduced the blood glucose level during GTT in Wistar rats with an effective dose of 300 mg/kg bw in dose-dependent studies. High-performance liquid chromatography with photodiode-array detection (HPLC-DAD) analysis showed the presence of hydroxycinnamic acid derivatives and flavonoids in AEUD. Hexane Fraction-2 (HF2) exhibited both antiinflammatory activity (48.83% after 3 h), comparable to that of indomethacin (53.48%), and potent antibacterial activity with MIC values ranging from 31.25-250 µg/mL against all the tested strains. Gas chromatography-mass spectrometry (GC-MS) analysis showed fatty acid esters and terpenes as the major constituents of HF2. Toxicity tests showed higher safety margin of all the solvent extracts with LC(50) > 1000 μg/mL each on A. salina. Our results showed that the U. dioica leaves are an interesting source of bioactive compounds, justifying their use in folk medicine, to treat various diseases.

Millimeter and submillimeter spectra of hot cores and diffuse clouds: comparing IRAM and Herschel spectra with CASSIS simulations.

NASA Astrophysics Data System (ADS)

de Luca, Massimo

The primary goal of the PRISMAS Herschel key program is the spectroscopic study of key molecular lines towards bright Galactic star-forming regions and the diffuse interstellar clouds distributed along the lines of sight. Models of the source emission and absorption spectra have been constructed with CASSIS, based on 1) observational evidence in comparable environments, 2) warm-up chemical models with gas-grain networks, and 3) ground-based spectra of various molecules in the target sources obtained at the IRAM 30m telescope. These models include contributions from the hot core, its parental molecular cloud and the foreground diffuse inter-stellar matter. The considerable complexity of the hot core chemistry, together with the huge amount of information buried in the spectra, often prevents a straightforward interpretation of the data without the help simulations. This is particularly true for the largely unexplored wavelength range of HIFI. In this contribution, we compare HIFI and IRAM observations to our models, in order to either consolidate present day assumptions and knowledge of these environments, or to highlight the model limitations, poorly understood physical and chemical conditions or unexpected abundances. We pay particular attention to the ground state tran-sitions of the most important hydrides, which the PRISMAS program has been designed for, though the HIFI spectra are expected to be rich in other molecules as well. List of Authors De Luca, M., Observatoire de Paris, Ecole Normale Supérieure and CNRS, FRANCE; Bell, T., CalTech, UNITED STATES; Coutens, A., CESR, FRANCE; Godard, B., IAS, FRANCE; Gupta, H., JPL, UNITED STATES; Mook-erjea, B., Tata Institute for Fundamental Research, INDIA; and the PRISMAS consortium, PRISMAS, FRANCE

Regulation of Sulphur Assimilation Is Essential for Virulence and Affects Iron Homeostasis of the Human-Pathogenic Mould Aspergillus fumigatus

PubMed Central

Amich, Jorge; Schafferer, Lukas; Haas, Hubertus; Krappmann, Sven

2013-01-01

Sulphur is an essential element that all pathogens have to absorb from their surroundings in order to grow inside their infected host. Despite its importance, the relevance of sulphur assimilation in fungal virulence is largely unexplored. Here we report a role of the bZIP transcription factor MetR in sulphur assimilation and virulence of the human pathogen Aspergillus fumigatus. The MetR regulator is essential for growth on a variety of sulphur sources; remarkably, it is fundamental for assimilation of inorganic S-sources but dispensable for utilization of methionine. Accordingly, it strongly supports expression of genes directly related to inorganic sulphur assimilation but not of genes connected to methionine metabolism. On a broader scale, MetR orchestrates the comprehensive transcriptional adaptation to sulphur-starving conditions as demonstrated by digital gene expression analysis. Surprisingly, A. fumigatus is able to utilize volatile sulphur compounds produced by its methionine catabolism, a process that has not been described before and that is MetR-dependent. The A. fumigatus MetR transcriptional activator is important for virulence in both leukopenic mice and an alternative mini-host model of aspergillosis, as it was essential for the development of pulmonary aspergillosis and supported the systemic dissemination of the fungus. MetR action under sulphur-starving conditions is further required for proper iron regulation, which links regulation of sulphur metabolism to iron homeostasis and demonstrates an unprecedented regulatory crosstalk. Taken together, this study provides evidence that regulation of sulphur assimilation is not only crucial for A. fumigatus virulence but also affects the balance of iron in this prime opportunistic pathogen. PMID:24009505

Performance of Blind Source Separation Algorithms for FMRI Analysis using a Group ICA Method

PubMed Central

Correa, Nicolle; Adali, Tülay; Calhoun, Vince D.

2007-01-01

Independent component analysis (ICA) is a popular blind source separation (BSS) technique that has proven to be promising for the analysis of functional magnetic resonance imaging (fMRI) data. A number of ICA approaches have been used for fMRI data analysis, and even more ICA algorithms exist, however the impact of using different algorithms on the results is largely unexplored. In this paper, we study the performance of four major classes of algorithms for spatial ICA, namely information maximization, maximization of non-gaussianity, joint diagonalization of cross-cumulant matrices, and second-order correlation based methods when they are applied to fMRI data from subjects performing a visuo-motor task. We use a group ICA method to study the variability among different ICA algorithms and propose several analysis techniques to evaluate their performance. We compare how different ICA algorithms estimate activations in expected neuronal areas. The results demonstrate that the ICA algorithms using higher-order statistical information prove to be quite consistent for fMRI data analysis. Infomax, FastICA, and JADE all yield reliable results; each having their strengths in specific areas. EVD, an algorithm using second-order statistics, does not perform reliably for fMRI data. Additionally, for the iterative ICA algorithms, it is important to investigate the variability of the estimates from different runs. We test the consistency of the iterative algorithms, Infomax and FastICA, by running the algorithm a number of times with different initializations and note that they yield consistent results over these multiple runs. Our results greatly improve our confidence in the consistency of ICA for fMRI data analysis. PMID:17540281

Performance of blind source separation algorithms for fMRI analysis using a group ICA method.

PubMed

Correa, Nicolle; Adali, Tülay; Calhoun, Vince D

2007-06-01

Independent component analysis (ICA) is a popular blind source separation technique that has proven to be promising for the analysis of functional magnetic resonance imaging (fMRI) data. A number of ICA approaches have been used for fMRI data analysis, and even more ICA algorithms exist; however, the impact of using different algorithms on the results is largely unexplored. In this paper, we study the performance of four major classes of algorithms for spatial ICA, namely, information maximization, maximization of non-Gaussianity, joint diagonalization of cross-cumulant matrices and second-order correlation-based methods, when they are applied to fMRI data from subjects performing a visuo-motor task. We use a group ICA method to study variability among different ICA algorithms, and we propose several analysis techniques to evaluate their performance. We compare how different ICA algorithms estimate activations in expected neuronal areas. The results demonstrate that the ICA algorithms using higher-order statistical information prove to be quite consistent for fMRI data analysis. Infomax, FastICA and joint approximate diagonalization of eigenmatrices (JADE) all yield reliable results, with each having its strengths in specific areas. Eigenvalue decomposition (EVD), an algorithm using second-order statistics, does not perform reliably for fMRI data. Additionally, for iterative ICA algorithms, it is important to investigate the variability of estimates from different runs. We test the consistency of the iterative algorithms Infomax and FastICA by running the algorithm a number of times with different initializations, and we note that they yield consistent results over these multiple runs. Our results greatly improve our confidence in the consistency of ICA for fMRI data analysis.

Regulation of sulphur assimilation is essential for virulence and affects iron homeostasis of the human-pathogenic mould Aspergillus fumigatus.

PubMed

Amich, Jorge; Schafferer, Lukas; Haas, Hubertus; Krappmann, Sven

2013-01-01

Sulphur is an essential element that all pathogens have to absorb from their surroundings in order to grow inside their infected host. Despite its importance, the relevance of sulphur assimilation in fungal virulence is largely unexplored. Here we report a role of the bZIP transcription factor MetR in sulphur assimilation and virulence of the human pathogen Aspergillus fumigatus. The MetR regulator is essential for growth on a variety of sulphur sources; remarkably, it is fundamental for assimilation of inorganic S-sources but dispensable for utilization of methionine. Accordingly, it strongly supports expression of genes directly related to inorganic sulphur assimilation but not of genes connected to methionine metabolism. On a broader scale, MetR orchestrates the comprehensive transcriptional adaptation to sulphur-starving conditions as demonstrated by digital gene expression analysis. Surprisingly, A. fumigatus is able to utilize volatile sulphur compounds produced by its methionine catabolism, a process that has not been described before and that is MetR-dependent. The A. fumigatus MetR transcriptional activator is important for virulence in both leukopenic mice and an alternative mini-host model of aspergillosis, as it was essential for the development of pulmonary aspergillosis and supported the systemic dissemination of the fungus. MetR action under sulphur-starving conditions is further required for proper iron regulation, which links regulation of sulphur metabolism to iron homeostasis and demonstrates an unprecedented regulatory crosstalk. Taken together, this study provides evidence that regulation of sulphur assimilation is not only crucial for A. fumigatus virulence but also affects the balance of iron in this prime opportunistic pathogen.

The Juno Radiation Monitoring (RM) Investigation

NASA Astrophysics Data System (ADS)

Becker, H. N.; Alexander, J. W.; Adriani, A.; Mura, A.; Cicchetti, A.; Noschese, R.; Jørgensen, J. L.; Denver, T.; Sushkova, J.; Jørgensen, A.; Benn, M.; Connerney, J. E. P.; Bolton, S. J.; Allison, J.; Watts, S.; Adumitroaie, V.; Manor-Chapman, E. A.; Daubar, I. J.; Lee, C.; Kang, S.; McAlpine, W. J.; Di Iorio, T.; Pasqui, C.; Barbis, A.; Lawton, P.; Spalsbury, L.; Loftin, S.; Sun, J.

2017-11-01

The Radiation Monitoring Investigation of the Juno Mission will actively retrieve and analyze the noise signatures from penetrating radiation in the images of Juno's star cameras and science instruments at Jupiter. The investigation's objective is to profile Jupiter's >10-MeV electron environment in regions of the Jovian magnetosphere which today are still largely unexplored. This paper discusses the primary instruments on Juno which contribute to the investigation's data suite, the measurements of camera noise from penetrating particles, spectral sensitivities and measurement ranges of the instruments, calibrations performed prior to Juno's first science orbit, and how the measurements may be used to infer the external relativistic electron environment.

Recent advances in research on the aeolian geomorphology of China's Kumtagh Sand Sea

NASA Astrophysics Data System (ADS)

Dong, Z.; Lv, P.

2014-02-01

The Kumtagh Sand Sea in the hyper-arid region of northwestern China remained largely unexplored until the last decade. It deserves study due to its significance in understanding the evolution of the arid environments in northwestern China, and even central Asia. Aeolian geomorphology in the sand sea has received unprecedented study in the last decade. Encouraging advances have been made in types of aeolian landforms, geological outlines, wind systems, the formation of aeolian landforms, several unique aeolian landforms, aeolian geomorphic regionalization, aeolian geomorphological heritages and tourism development, and aeolian sand hazards and their control. These advances expand our knowledge of aeolian geomorphology.

Properties and applications of chemically functionalized graphene.

PubMed

Craciun, M F; Khrapach, I; Barnes, M D; Russo, S

2013-10-23

The vast and yet largely unexplored family of graphene materials has great potential for future electronic devices with novel functionalities. The ability to engineer the electrical and optical properties in graphene by chemically functionalizing it with a molecule or adatom is widening considerably the potential applications targeted by graphene. Indeed, functionalized graphene has been found to be the best known transparent conductor or a wide gap semiconductor. At the same time, understanding the mechanisms driving the functionalization of graphene with hydrogen is proving to be of fundamental interest for energy storage devices. Here we discuss recent advances on the properties and applications of chemically functionalized graphene.

Tuning bacterial hydrodynamics with magnetic fields

NASA Astrophysics Data System (ADS)

Pierce, C. J.; Mumper, E.; Brown, E. E.; Brangham, J. T.; Lower, B. H.; Lower, S. K.; Yang, F. Y.; Sooryakumar, R.

2017-06-01

Magnetotactic bacteria are a group of motile prokaryotes that synthesize chains of lipid-bound, magnetic nanoparticles called magnetosomes. This study exploits their innate magnetism to investigate previously unexplored facets of bacterial hydrodynamics at surfaces. Through use of weak, uniform, external magnetic fields and local, micromagnetic surface patterns, the relative strength of hydrodynamic, magnetic, and flagellar force components is tuned through magnetic control of the bacteria's orientation. The resulting swimming behaviors provide a means to experimentally determine hydrodynamic parameters and offer a high degree of control over large numbers of living microscopic entities. The implications of this controlled motion for studies of bacterial motility near surfaces and for micro- and nanotechnology are discussed.

Snake River fall Chinook salmon life history investigations, 1/1/2012 - 12/31/2012: Annual report 2002-032-00

USGS Publications Warehouse

Tiffan, Kenneth F.; Connor, Willam P.; Bellgraph, Brian J.; Chittaro, Paul M.

2014-01-01

Finally, we examined the role of different invasive invertebrates in lower Snake River reservoir food webs that are food, or competitors for food, for juvenile fall Chinook salmon. The Siberian prawn, a relatively new invader, is relatively abundant but its role on the food web is largely unexplored. Prawns are successfully reproducing and their diet is 81% Neomysis (an invasive opossum shrimp) which is heavily used at times by juvenile salmon for food. Neomysis has become very abundant in lower Snake River reservoirs in recent years and may be a profitable food item for many fish species.

The Built Environment and Health: Introducing Individual Space-Time Behavior

PubMed Central

Saarloos, Dick; Kim, Jae-Eun; Timmermans, Harry

2009-01-01

Many studies have examined the relationship between the built environment and health. Yet, the question of how and why the environment influences health behavior remains largely unexplored. As health promotion interventions work through the individuals in a targeted population, an explicit understanding of individual behavior is required to formulate and evaluate intervention strategies. Bringing in concepts from various fields, this paper proposes the use of an activity-based modeling approach for understanding and predicting, from the bottom up, how individuals interact with their environment and each other in space and time, and how their behaviors aggregate to population-level health outcomes. PMID:19578457

The Effect of He3 Diffusion on the Pulsational Spectra of DBV Models

NASA Astrophysics Data System (ADS)

Montgomery, M. H.; Winget, D. E.

Isotopic separation is inevitable in white dwarf stars if our understanding of diffusion is correct. This can have many important, and largely unexplored, astrophysical consequences. Asteroseismology gives an opportunity to investigate this possibility. We first examine the relevant timescales for diffusion in these objects, and compare them to the evolutionary timescales in the context of the DBV white dwarfs. We then explore the consequences which He3 separation has on the pulsational spectra of DBV models. Since GD 358 is the best-studied member of this class of variables, we pay particular attention to the way this could affect previous fits.

Bacteria associated with sabellids (Polychaeta: Annelida) as a novel source of surface active compounds.

PubMed

Rizzo, Carmen; Michaud, Luigi; Hörmann, Barbara; Gerçe, Berna; Syldatk, Christoph; Hausmann, Rudolf; De Domenico, Emilio; Lo Giudice, Angelina

2013-05-15

A total of 69 bacteria were isolated from crude oil enrichments of the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum, and screened for biosurfactant (BS) production by conventional methods. Potential BS-producers (30 isolates) were primarily selected due to the production of both interesting spots on thin layer chromatography (TLC) plates and highly stable emulsions (E₂₄ ≥ 50%). Only few strains grew on cetyltrimethylammonium bromide and blood agar plates, indicating the probable production of anionic surfactants. The 16S rRNA gene sequencing revealed that selected isolates mainly belonged to the CFB group of Bacteroidetes, followed by Gammaproteobacteria and Alphaproteobacteria. A number of BS-producers belonged to genera (i.e., Cellulophaga, Cobetia, Cohaesibacter, Idiomarina, Pseudovibrio and Thalassospira) that have been never reported as able to produce BSs, even if they have been previously detected in hydrocarbon-enriched samples. Our results suggest that filter-feeding Polychaetes could represent a novel and yet unexplored source of biosurfactant-producing bacteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

Innovative natural functional ingredients from microalgae.

PubMed

Plaza, Merichel; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

2009-08-26

Nowadays, a wide variety of compounds such as polyphenols, polyunsaturated fatty acids (PUFA), or phytosterols obtained, for example, from wine, fish byproducts, or plants are employed to prepare new functional foods. However, unexplored natural sources of bioactive ingredients are gaining much attention since they can lead to the discovery of new compounds or bioactivities. Microalgae have been proposed as an interesting, almost unlimited, natural source in the search for novel natural functional ingredients, and several works have shown the possibility to find bioactive compounds in these organisms. Some advantages can be associated with the study of microalgae such as their huge diversity, the possibility of being used as natural reactors at controlled conditions, and their ability to produce active secondary metabolites to defend themselves from adverse or extreme conditions. In this contribution, an exhaustive revision is presented involving the research for innovative functional food ingredients from microalgae. The most interesting results in this promising field are discussed including new species composition and bioactivity and new processing and extraction methods. Moreover, the future research trends are critically commented.

Bright attosecond γ-ray pulses from nonlinear Compton scattering with laser-illuminated compound targets

NASA Astrophysics Data System (ADS)

Zhu, Xing-Long; Chen, Min; Yu, Tong-Pu; Weng, Su-Ming; Hu, Li-Xiang; McKenna, Paul; Sheng, Zheng-Ming

2018-04-01

Attosecond light sources have the potential to open up totally unexplored research avenues in ultrafast science. However, the photon energies achievable using existing generation schemes are limited to the keV range. Here, we propose and numerically demonstrate an all-optical mechanism for the generation of bright MeV attosecond γ-photon beams with desirable angular momentum. Using a circularly polarized Laguerre-Gaussian laser pulse focused onto a cone-foil target, dense attosecond bunches ( ≲ 170 as ) of electrons are produced. The electrons interact with the laser pulse which is reflected by a plasma mirror, producing ultra-brilliant (˜1023 photons/s/mm2/mrad2/0.1%BW) multi-MeV (Eγ,max > 30 MeV) isolated attosecond ( ≲ 260 as ) γ-ray pulse trains. Moreover, the angular momentum is transferred to γ-photon beams via nonlinear Compton scattering of ultra-intense tightly focused laser pulse by energetic electrons. Such a brilliant attosecond γ-photon source would provide the possibilities in attosecond nuclear science.

Isolation and Purification of Glycoconjugates from Complex Biological Sources by Recycling HPLC

PubMed Central

Alley, William R.; Mann, Benjamin F.; Hruska, Vlastimil; Novotny, Milos V.

2013-01-01

Among of the most urgent needs of the glycobiology community is to generate libraries of pure carbohydrate standards. While many oligosaccharides have recently been synthesized, some glycans of biomedical importance are still missing in existing collections, or are available in only limited amounts. To address this need, we demonstrate the use of the relatively unexplored technique of recycling high-performance liquid chromatography (R-HPLC) to isolate and purify glycoconjugates from several natural sources. We were able to routinely achieve purities greater than 98%. In several cases, we were able to obtain isomerically pure substances, particularly for glycans with different positional isomerism. These purified substances can then be used in different analytical applications, for example, as standards for mass spectrometry (MS) and capillary-based separations. Moreover, using a bifunctional aromatic amine, the same derivatization agent can be used to enable UV detection of oligosaccharides during their purification and link the isolated molecules to functionalized surfaces and potentially create glycan arrays. PMID:24070405

Heavy ions in space (M0001)

NASA Technical Reports Server (NTRS)

Adams, J. H., Jr.; Slberberg, R.; Tsao, C. H.

1984-01-01

The ojectives are to investigate three components of heavy nuclei in space: (1) a recently observed anomalous component of low-energy nuclei of N, O, and Ne; (2) the heavy nuclei in the Van Allen radiation belts; and (3) the UH nuclei (Z 30) of the galactic radiation. The study of the anomalous flux of N, O, and Ne nuclei in the unexplored energy region above 100 MeV/u is expected to provide new insights into the source of this component. Its observation in this experiment will confirm that these ions are singly charged. Knowledge of the energy spectra of the heavy nuclei observed in the Van Allen belts is expected to enhance the understanding of the origin of the belts (e.g., injection and local acceleration pocesses). The observation of these heavy ions could show, for the first time, that low-energy particles of extraterrestrial origin can diffuse to the innermost parts of the magnetosphere. Measurements of the UH component are expected to contribute information concerning its source, interstellar propagation, and the galactic storage time.

Isolation and purification of glycoconjugates from complex biological sources by recycling high-performance liquid chromatography.

PubMed

Alley, William R; Mann, Benjamin F; Hruska, Vlastimil; Novotny, Milos V

2013-11-05

Among of the most urgent needs of the glycobiology community is to generate libraries of pure carbohydrate standards. While many oligosaccharides have recently been synthesized, some glycans of biomedical importance are still missing in existing collections or are available in only limited amounts. To address this need, we demonstrate the use of the relatively unexplored technique of recycling high-performance liquid chromatography (R-HPLC) to isolate and purify glycoconjugates from several natural sources. We were able to routinely achieve purities greater than 98%. In several cases, we were able to obtain isomerically pure substances, particularly for glycans with different positional isomerism. These purified substances can then be used in different analytical applications, for example, as standards for mass spectrometry (MS) and capillary-based separations. Moreover, using a bifunctional aromatic amine, the same derivatization agent can be used to enable UV detection of oligosaccharides during their purification and link the isolated molecules to functionalized surfaces and potentially create glycan arrays.

Detrital thermochronology of Rhine, Elbe and Meuse river sediment (Central Europe): implications for provenance, erosion and mineral fertility

NASA Astrophysics Data System (ADS)

Glotzbach, C.; Busschers, F. S.; Winsemann, J.

2018-03-01

Here we present detrital apatite fission track (AFT), zircon fission track (ZFT) and a few apatite (U-Th)/He (AHe) data of Middle Pleistocene to modern Rhine, Meuse and Elbe river sediments in order to resolve processes that control detrital age distributions (provenance, erosion and mineral fertility). We used a modelling approach to compare observed with theoretically predicted age distributions from an interpolated in situ AFT and ZFT age map. In situ cooling ages do show large differences in the Rhine drainage basin, facilitating the differentiation between different source regions. Inconsistencies between observed and theoretical age distributions of the Meuse and Elbe samples can be explained by mixing and reworking of sediments with different provenances (Meuse Middle Pleistocene terrace sediment) and a yet unexplored source region with old AFT ages (Elbe samples). Overall, the results show that detrital thermochronology is capable of identifying the provenance of Middle Pleistocene to modern sediments. The AFT age distributions of Rhine sediments are dominated ( 70%) by AFT ages representing the Alps. A possible explanation is higher erosion rates in the Alps as compared to areas outside the Alps. A Late Pleistocene sample from the Upper Rhine Graben contains apatite grains from the Molasse and Hegau volcanics, which we explain with a shift of the headwaters of the Rhine to the north as a result of intense Middle Pleistocene Riss glaciation. Contrary to the observed dominance of Alpine-derived AFT ages in Rhine sediments, the relative contribution of zircon ages with sources in the Alps is lower and significantly decreases downstream, suggesting a major source of zircons outside the Alps. This can be explained by increased zircon fertility of sediments derived from the Rhenish massif. Therefore, we conclude that erosion and mineral fertility are the main processes controlling detrital AFT and ZFT age distributions of the sampled river sediment. In case of the Rhine samples, AFT age distributions are mainly controlled by differences in erosion rates, whereas this impact is completely balanced by differences in mineral fertility for the ZFT data.

NeMedPlant: a database of therapeutic applications and chemical constituents of medicinal plants from north-east region of India

PubMed Central

Meetei, Potshangbam Angamba; Singh, Pankaj; Nongdam, Potshangbam; Prabhu, N Prakash; Rathore, RS; Vindal, Vaibhav

2012-01-01

The North-East region of India is one of the twelve mega biodiversity region, containing many rare and endangered species. A curated database of medicinal and aromatic plants from the regions called NeMedPlant is developed. The database contains traditional, scientific and medicinal information about plants and their active constituents, obtained from scholarly literature and local sources. The database is cross-linked with major biochemical databases and analytical tools. The integrated database provides resource for investigations into hitherto unexplored medicinal plants and serves to speed up the discovery of natural productsbased drugs. Availability The database is available for free at http://bif.uohyd.ac.in/nemedplant/orhttp://202.41.85.11/nemedplant/ PMID:22419844

Overcoming the positive-capture strategy in young children: learning about indeterminacy.

PubMed

Klahr, David; Chen, Zhe

2003-01-01

Two experiments were conducted to examine whether and how 4- and 5-year-olds learn to distinguish determinate from indeterminate evidence. Children were asked to decide whether various patterns of evidence were sufficient to reach unambiguous conclusions. This study replicated the finding that young children tend to use a strategy that, although generally successful, fails on evidence patterns in which a single positive instance co-occurs with an unexplored source of evidence. Experiment 1 demonstrated that this positive-capture strategy is deeply entrenched, even in a meaningful, pragmatic context. With a microgenetic design, Experiment 2 revealed that young children are capable of replacing the positive-capture strategy with a correct strategy when they are exposed to various analogous tasks in several training sessions.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications.

PubMed

Roca, Christophe; Alves, Vitor D; Freitas, Filomena; Reis, Maria A M

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed.

Lipid metabolism and benzo[a]pyrene degradation by Fusarium solani: an unexplored potential.

PubMed

Delsarte, Isabelle; Rafin, Catherine; Mrad, Fida; Veignie, Etienne

2018-04-01

In a search for indigenous soil saprotrophic fungi for bioremediation purposes, Fusarium solani, a saprotrophic fungus belonging to the phylum Ascomycota, was isolated from a fossil carbon contaminated soil. The effect of the carbon source, glucose or olive oil, was investigated in vitro on the biomass produced by F. solani and on the degradation of benzo[a]pyrene (BaP) in mineral medium. After only 12 days of incubation, BaP degradation by F. solani was higher (37.4%) with olive oil used as the carbon source than the one obtained with glucose (4.2%). Catalase activity increased in the presence of olive oil (3.4 μkat mg -1 protein) in comparison with glucose (2.1 μkat mg -1 protein). When olive oil was used as the carbon source, BaP degradation increased up to 76.0% in the presence of a specific catalase inhibitor, 3-Amino-1,2,4-triazole (2 mM). This metabolic engineering strategy based both on the use of olive oil as carbon source (cultivation strategy) and on the blocking of the catalase activity could be an innovative and promising approach for fungal biodegradation of BaP and consequently for bioremediation of soil contaminated with polycyclic aromatic hydrocarbons.

Phylogenetic diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff), detection of polyketide synthase gene and their antagonistic activity analysis.

PubMed

Wang, Ya; Gao, Bo Liang; Li, Xi Xi; Zhang, Zhi Bin; Yan, Ri Ming; Yang, Hui Lin; Zhu, Du

2015-11-01

The biodiversity of plant endophytic fungi is enormous, numerous competent endophytic fungi are capable of providing different forms of fitness benefits to host plants and also could produce a wide array of bioactive natural products, which make them a largely unexplored source of novel compounds with potential bioactivity. In this study, we provided a first insights into revealing the diversity of culturable endophytic fungi in Dongxiang wild rice (Oryza rufipogon Griff.) from China using rDNA-ITS phylogenetic analysis. Here, the potential of fungi in producing bioactive natural products was estimated based on the beta-ketosynthase detected in the polyketide synthase (PKS) gene cluster and on the bioassay of antagonistic activity against two rice phytopathogens Thanatephorus cucumeris and Xanthomonas oryzae. A total of 229 endophytic fungal strains were validated in 19 genera. Among the 24 representative strains, 13 strains displayedantagonistic activity against the phytopathogens. Furthermore, PKS genes were detected in 9 strains, indicating their potential for synthesising PKS compounds. Our study confirms the phylogenetic diversity of endophytic fungi in O. rufipogon G. and highlights that endophytic fungi are not only promising resources of biocontrol agents against phytopathogens of rice plants, but also of bioactive natural products and defensive secondary metabolites. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Psychological implications of living with familial adenomatous polyposis.

PubMed

Claes, E; Renson, M; Delespesse, A; De Hoe, V; Haelterman, G; Kartheuser, A; Van Cutsem, E

2011-09-01

Psychosocial implications of living with FAP remain largely unexplored. This article reviews available literature on three topics: 1) Implications of living with FAP 2) genetic testing and reproductive decision-making and 3) family communication. Papers published until 2009 about psychosocial and behavioral issues in FAP were identified. Psychometric data indicate that FAP patients and at-risk relatives as a group do not exhibit clinical symptoms of mental health problems after clinical or genetic diagnosis. However, some subgroups revealed to be more vulnerable to distress. Also, concerns related to the disease and its consequences were reported. While interest in prenatal diagnosis or preimplantation genetic diagnosis seems to be high it is important to study actual uptake because this may reveal to be much lower. Family members are an important source of information and the few available data suggest that family communication is problematic. The findings described have several shortcomings. They were obtained from only a few studies often conducted using specific or mixed study groups, originating from the 90ties and mostly cross-sectional in nature. For clinical practice, it is important to have more research data on how FAP patients at different ages cope with the disease, on the impact of genetic testing on reproductive decision-making and on family communication. Results reported here need to be confirmed by additional research and new themes need to be explored.

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

Behrman, D.

The book concerns answers to the questions: (1) is solar energy the key to the future of our energy needs; and (2) what are the facts and true potential of this enormous, still largely unexplored source of renewable power. It reviews the knowledge of solar energy from the mirrors that Archimedes used to set a Roman fleet aflame in 215 B.C., to today's plans for designing attractive, affordable domestic solar housing, to tomorrow's dreams of building solar skyscrapers. Many of the sites and the technology applied to harness the Sun's power are described. Solar furnace towers, nine stories high, aremore » located in the Pyrennes in France; research is progressing on solar cells in Massachusetts; and many homes are heated and cooled through solar power. The systems to heat and cool the houses are described; what spatial and architectural modifications they necessitated, why there are still fewer than two hundred solar homes in existence, and what needs to be done before they can reach a mass market are also discussed. Also examined is the energy potential of windmills and the equatorial oceans, where at least 50 percent of the Sun's energy that falls on Earth is concentrated. Behrman reports on the progress of scientists and manufacturers toward making solar energy a viable competitor in the current energy market, and he studies the projections of a future energy crop to be raised on energy plantations. (MCW)« less

Geologic report and recommendations for the cobalt mission to Morocco sponsored by The Trade and Development Program of the International Development Cooperation Agency

USGS Publications Warehouse

Foose, M.P.; Rossman, D.L.

1982-01-01

A mission sponsored by the Trade and Development Program (TDP) of the International Development Cooperation Agency (IDCA) went to Morocco to evaluate the possibility of finding additional sources of cobalt in that country, as well as other types of mineralization. Information obtained during this trip shows Morocco to be a country for which much geologic information is available and in which there are many favorable target areas for future exploration. Work in the Bou Azzer district (Morocco's principal cobalt district) shows that much excellent geologic work has been done in searching for additional deposits. However, a number of useful approaches to locate cobalt have not been tried, and their use might be successful. The potential for undiscovered deposits in the Bou Azzer region seems very high. The cobalt mineralization in the Siroua uplift is different from that in the Bou Azzer district. However, geologic similarities between the two areas suggest that a genetic link may exist between the two types of mineralization. This further indicates that cobalt deposits of the Bou Azzer types might be present in the Siroua region. Examination of the Bleida copper mine shows it to be a well-exposed volcanic hosted stratabound copper deposit. Large unexplored areas containing similar rocks occur near this deposit and may contain as yet undiscovered copper mineralization.

Modulation of surface structure and catalytic properties of cerium oxide nanoparticles by thermal and microwave synthesis techniques

NASA Astrophysics Data System (ADS)

He, Jian; Zhou, Lan; Liu, Jie; Yang, Lu; Zou, Ling; Xiang, Junyu; Dong, Shiwu; Yang, Xiaochao

2017-04-01

Cerium oxide nanoparticles (CNPs) have been intensively explored for biomedical applications in recent few years due to the versatile enzyme mimetic activities of the nanoparticles. However, the control of CNPs quality through the optimization of synthesis conditions remains largely unexplored as most of the previous studies only focus on utilizing the catalytic activities of the nanoparticles. In the present study, CNPs with size about 5 nm were synthesized by thermal decomposition method using traditional convective heating and recently developed microwave irradiation as heating source. The quality of CNPs synthesized by the two heating manner was evaluated. The CNPs synthesized by convective heating were slightly smaller than that synthesized by microwave irradiation heating. The cores of the CNPs synthesized by the two heating manner have similar crystal structure. While the surface subtle structures of the CNPs synthesized by two heating manner were different. The CNPs synthesized by microwave irradiation have more surface reactive hot spot than that synthesized by convective heating as the nanoparticles responded more actively to the redox environment variation. This difference resulted in the higher superoxide dismutase (SOD) mimetic activity of CNPs synthesized by microwave irradiation heating than that of the convective heating. Preliminary experiments indicated that the CNPs synthesized by microwave irradiation heating could better protect cells from oxidative stress due to the higher SOD mimetic activity of the nanoparticles.

Exploration of Uncharted Regions of the Protein Universe

PubMed Central

Jaroszewski, Lukasz; Li, Zhanwen; Krishna, S. Sri; Bakolitsa, Constantina; Wooley, John; Deacon, Ashley M.; Wilson, Ian A.; Godzik, Adam

2009-01-01

The genome projects have unearthed an enormous diversity of genes of unknown function that are still awaiting biological and biochemical characterization. These genes, as most others, can be grouped into families based on sequence similarity. The PFAM database currently contains over 2,200 such families, referred to as domains of unknown function (DUF). In a coordinated effort, the four large-scale centers of the NIH Protein Structure Initiative have determined the first three-dimensional structures for more than 250 of these DUF families. Analysis of the first 248 reveals that about two thirds of the DUF families likely represent very divergent branches of already known and well-characterized families, which allows hypotheses to be formulated about their biological function. The remainder can be formally categorized as new folds, although about one third of these show significant substructure similarity to previously characterized folds. These results infer that, despite the enormous increase in the number and the diversity of new genes being uncovered, the fold space of the proteins they encode is gradually becoming saturated. The previously unexplored sectors of the protein universe appear to be primarily shaped by extreme diversification of known protein families, which then enables organisms to evolve new functions and adapt to particular niches and habitats. Notwithstanding, these DUF families still constitute the richest source for discovery of the remaining protein folds and topologies. PMID:19787035

How predictable is the winter extremely cold days over temperate East Asia?

NASA Astrophysics Data System (ADS)

Luo, Xiao; Wang, Bin

2017-04-01

Skillful seasonal prediction of the number of extremely cold day (NECD) has considerable benefits for climate risk management and economic planning. Yet, predictability of NECD associated with East Asia winter monsoon remains largely unexplored. The present work estimates the NECD predictability in temperate East Asia (TEA, 30°-50°N, 110°-140°E) where the current dynamical models exhibit limited prediction skill. We show that about 50 % of the total variance of the NECD in TEA region is likely predictable, which is estimated by using a physics-based empirical (P-E) model with three consequential autumn predictors, i.e., developing El Niño/La Niña, Eurasian Arctic Ocean temperature anomalies, and geopotential height anomalies over northern and eastern Asia. We find that the barotropic geopotential height anomaly over Asia can persist from autumn to winter, thereby serving as a predictor for winter NECD. Further analysis reveals that the sources of the NECD predictability and the physical basis for prediction of NECD are essentially the same as those for prediction of winter mean temperature over the same region. This finding implies that forecasting seasonal mean temperature can provide useful information for prediction of extreme cold events. Interpretation of the lead-lag linkages between the three predictors and the predictand is provided for stimulating further studies.

Investigation of the Electromagnetic Radiation Emitted by Sub-GeV Electrons in a Bent Crystal.

PubMed

Bandiera, L; Bagli, E; Germogli, G; Guidi, V; Mazzolari, A; Backe, H; Lauth, W; Berra, A; Lietti, D; Prest, M; De Salvador, D; Vallazza, E; Tikhomirov, V

2015-07-10

The radiation emitted by 855 MeV electrons via planar channeling and volume reflection in a 30.5-μm-thick bent Si crystal has been investigated at the MAMI (Mainzer Mikrotron) accelerator. The spectral intensity was much more intense than for an equivalent amorphous material, and peaked in the MeV range in the case of channeling radiation. Differently from a straight crystal, also for an incidence angle larger than the Lindhard angle, the spectral intensity remains nearly as high as for channeling. This is due to volume reflection, for which the intensity remains high at a large incidence angle over the whole angular acceptance, which is equal to the bending angle of the crystal. Monte Carlo simulations demonstrated that incoherent scattering significantly influences both the radiation spectrum and intensity, either for channeling or volume reflection. In the latter case, it has been shown that incoherent scattering increases the radiation intensity due to the contribution of volume-captured particles. As a consequence, the experimental spectrum becomes a mixture of channeling and pure volume reflection radiations. These results allow a better understanding of the radiation emitted by electrons subjected to coherent interactions in bent crystals within a still-unexplored energy range, which is relevant for possible applications for innovative and compact x-ray or γ-ray sources.

New Structural Templates for Clinically Validated and Novel Targets in Antimicrobial Drug Research and Development.

PubMed

Klahn, Philipp; Brönstrup, Mark

The development of bacterial resistance against current antibiotic drugs necessitates a continuous renewal of the arsenal of efficacious drugs. This imperative has not been met by the output of antibiotic research and development of the past decades for various reasons, including the declining efforts of large pharma companies in this area. Moreover, the majority of novel antibiotics are chemical derivatives of existing structures that represent mostly step innovations, implying that the available chemical space may be exhausted. This review negates this impression by showcasing recent achievements in lead finding and optimization of antibiotics that have novel or unexplored chemical structures. Not surprisingly, many of the novel structural templates like teixobactins, lysocin, griselimycin, or the albicidin/cystobactamid pair were discovered from natural sources. Additional compounds were obtained from the screening of synthetic libraries and chemical synthesis, including the gyrase-inhibiting NTBI's and spiropyrimidinetrione, the tarocin and targocil inhibitors of wall teichoic acid synthesis, or the boronates and diazabicyclo[3.2.1]octane as novel β-lactamase inhibitors. A motif that is common to most clinically validated antibiotics is that they address hotspots in complex biosynthetic machineries, whose functioning is essential for the bacterial cell. Therefore, an introduction to the biological targets-cell wall synthesis, topoisomerases, the DNA sliding clamp, and membrane-bound electron transport-is given for each of the leads presented here.

An interspecific barberry hybrid enables genetic dissection of non-host resistance to the stem rust pathogen Puccinia graminis.

PubMed

Bartaula, Radhika; Melo, Arthur T O; Connolly, Bryan A; Jin, Yue; Hale, Iago

2018-04-27

Stem rust, caused by Puccinia graminis (Pg), remains a devastating disease of wheat, and the emergence of new Pg races virulent on deployed resistance genes fuels the ongoing search for sources of durable resistance. Despite its intrinsic durability, non-host resistance (NHR) is largely unexplored as a protection strategy against Pg, partly due to the inherent challenge of developing a genetically tractable system within which NHR segregates. Here, we demonstrate that Pg's far less studied ancestral host, barberry (Berberis spp.), provides such a unique pathosystem. Characterization of a natural population of B. ×ottawensis, an interspecific hybrid of Pg-susceptible B. vulgaris and Pg-resistant B. thunbergii (Bt), reveals that this uncommon nothospecies can be used to dissect the genetic mechanism(s) of Pg-NHR exhibited by Bt. Artificial inoculation of a natural population of B. ×ottawensis accessions, verified via genotyping by sequencing to be first-generation hybrids, revealed 51% susceptible, 33% resistant, and 16% intermediate phenotypes. Characterization of a B. ×ottawensis full sib family excluded the possibility of maternal inheritance of the resistance. By demonstrating segregation of Pg-NHR in a hybrid population, this study challenges the assumed irrelevance of Bt to Pg epidemiology and lays a novel foundation for the genetic dissection of NHR to one of agriculture's most studied pathogens.

Eicosapentaenoic and docosahexaenoic acids enriched polyunsaturated fatty acids from the coastal marine fish of Bay of Bengal and their therapeutic value.

PubMed

Bera, Rabindranath; Dhara, Tushar K; Bhadra, Ranjan; Majumder, Gopal C; Sen, Parimal C

2010-12-01

Eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) enriched polyunsaturated fatty acids (PUFA) significantly present in marine fish oil emerge as preventive agents for combating many health problems specially in chronic or metabolic disorders. The fish in the coastal area of Bay of Bengal has remained unexplored with respect to EPA/DHA enriched PUFA content in its oils, although it may be a potential source in harnessing the health benefit. In this study, seven varieties of the coastal fish were analysed for the content of EPA/DHA. The one locally known as lotte, (Harpadon nehereus) though has low content of total lipids, was found to have high EPA/DHA in its oil. The phospholipids rich fraction was extracted from the total fish oil. The EPA/DHA enriched PUFA was isolated to investigate the potential use for health benefits. EPA/DHA is found to act as protective agent against mercury poisoning studied in cell culture as well as in animal mode. It is found to be highly preventive in diabetes. The lotte is available in the coastal area of Bay of Bengal adjoining West Bengal, India in large scale and it is the first report showing EPA/DHA enriched PUFA in these fish oil that can be availed to harness in important health benefits.

Access to food outlets and children's nutritional intake in urban China: a difference-in-difference analysis.

PubMed

Wang, Rui; Shi, Lu

2012-06-30

In recent years supermarkets and fast food restaurants have been replacing those "wet markets" of independent vendors as the major food sources in urban China. Yet how these food outlets relate to children's nutritional intake remains largely unexplored. Using a longitudinal survey of households and communities in China, this study examines the effect of the urban built food environment (density of wet markets, density of supermarkets, and density of fast food restaurants) on children's nutritional intake (daily caloric intake, daily carbohydrate intake, daily protein intake, and daily fat intake). Children aged 6-18 (n = 185) living in cities were followed from 2004 to 2006, and difference-in-difference models are used to address the potential issue of omitted variable bias. Results suggest that the density of wet markets, rather than that of supermarkets, positively predicts children's four dimensions of nutritional intake. In the caloric intake model and the fat intake model, the positive effect of neighborhood wet market density on children's nutritional intake is stronger with children from households of lower income. With their cheaper prices and/or fresher food supply, wet markets are likely to contribute a substantial amount of nutritional intake for children living nearby, especially those in households with lower socioeconomic status. For health officials and urban planners, this study signals a sign of warning as wet markets are disappearing from urban China's food environment.

Fast Neural Dynamics of Proactive Cognitive Control in a Task-Switching Analogue of the Wisconsin Card Sorting Test.

PubMed

Gema Díaz-Blancat; Juan García-Prieto; Fernando Maestú; Francisco Barceló

2018-05-01

One common assumption has been that prefrontal executive control is mostly required for target detection (Posner and Petersen in Ann Rev Neurosci 13:25-42, 1990). Alternatively, cognitive control has also been related to anticipatory updating of task-set (contextual) information, a view that highlights proactive control processes. Frontoparietal cortical networks contribute to both proactive control and reactive target detection, although their fast dynamics are still largely unexplored. To examine this, we analyzed rapid magnetoencephalographic (MEG) source activations elicited by task cues and target cards in a task-cueing analogue of the Wisconsin Card Sorting Test. A single-task (color sorting) condition with equivalent perceptual and motor demands was used as a control. Our results revealed fast, transient and largely switch-specific MEG activations across frontoparietal and cingulo-opercular regions in anticipation of target cards, including (1) early (100-200 ms) cue-locked MEG signals at visual, temporo-parietal and prefrontal cortices of the right hemisphere (i.e., calcarine sulcus, precuneus, inferior frontal gyrus, anterior insula and supramarginal gyrus); and (2) later cue-locked MEG signals at the right anterior and posterior insula (200-300 ms) and the left temporo-parietal junction (300-500 ms). In all cases larger MEG signal intensity was observed in switch relative to repeat cueing conditions. Finally, behavioral restart costs and test scores of working memory capacity (forward digit span) correlated with cue-locked MEG activations at key nodes of the frontoparietal network. Together, our findings suggest that proactive cognitive control of task rule updating can be fast and transiently implemented within less than a second and in anticipation of target detection.

Low-frequency connectivity is associated with mild traumatic brain injury.

PubMed

Dunkley, B T; Da Costa, L; Bethune, A; Jetly, R; Pang, E W; Taylor, M J; Doesburg, S M

2015-01-01

Mild traumatic brain injury (mTBI) occurs from a closed-head impact. Often referred to as concussion, about 20% of cases complain of secondary psychological sequelae, such as disorders of attention and memory. Known as post-concussive symptoms (PCS), these problems can severely disrupt the patient's quality of life. Changes in local spectral power, particularly low-frequency amplitude increases and/or peak alpha slowing have been reported in mTBI, but large-scale connectivity metrics based on inter-regional amplitude correlations relevant for integration and segregation in functional brain networks, and their association with disorders in cognition and behaviour, remain relatively unexplored. Here, we used non-invasive neuroimaging with magnetoencephalography to examine functional connectivity in a resting-state protocol in a group with mTBI (n = 20), and a control group (n = 21). We observed a trend for atypical slow-wave power changes in subcortical, temporal and parietal regions in mTBI, as well as significant long-range increases in amplitude envelope correlations among deep-source, temporal, and frontal regions in the delta, theta, and alpha bands. Subsequently, we conducted an exploratory analysis of patterns of connectivity most associated with variability in secondary symptoms of mTBI, including inattention, anxiety, and depression. Differential patterns of altered resting state neurophysiological network connectivity were found across frequency bands. This indicated that multiple network and frequency specific alterations in large scale brain connectivity may contribute to overlapping cognitive sequelae in mTBI. In conclusion, we show that local spectral power content can be supplemented with measures of correlations in amplitude to define general networks that are atypical in mTBI, and suggest that certain cognitive difficulties are mediated by disturbances in a variety of alterations in network interactions which are differentially expressed across canonical neurophysiological frequency ranges.

In vitro evaluation of the antiviral properties of Shilajit and investigation of its mechanisms of action.

PubMed

Cagno, Valeria; Donalisio, Manuela; Civra, Andrea; Cagliero, Cecilia; Rubiolo, Patrizia; Lembo, David

2015-05-26

Shilajit, a herbomineral substance exuded from rocks in steep mountainous regions, has been used for thousands of years by the Indian Ayurvedic and Siddha systems of traditional medicine to relieve ailments and enhance quality of life. Although a large number of therapeutic properties have been ascribed to Shilajit, its therapeutic potential is still largely unexplored by modern research and many of its claimed bioactivities lack scientific validation. The present study was undertaken to investigate the antiviral activity of Shilajit against a panel of viruses including herpes simplex type 1 and 2 (HSV-1, HSV-2), human cytomegalovirus (HCMV), human respiratory syncytial virus (RSV), human rotavirus (HRV), and vesicular stomatitis virus (VSV). The antiviral activity of Shilajit was assayed in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virucidal and time-of-addition assays. Shilajit exhibited a dose-dependent inhibitory activity against HSV1, HSV2, HCMV, and RSV infectivity in vitro (EC50 values: 31.08μg/ml, 12.85μg/ml, 34.54μg/ml, and 30.35μg/ml, respectively), but was inactive against HRV and VSV. Humic acid, a constituent of Shilajit, displayed the same spectrum of activity. Partial virus inactivation and interference with virus attachment were both found to contribute to the antiviral activity of Shilajit. The results of the present study demonstrate that Shilajit is endowed with broad, yet specific, antiviral activity in vitro and constitutes a natural source of antiviral substances. Further work remains to be done to assess its efficacy in vivo. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

“Surviving is not the same as living”: Cancer and Sobrevivencia in Puerto Rico

PubMed Central

Dyer, Karen E.

2015-01-01

“Cancer survivorship” is an evolving concept that has been elaborated to a large extent in the mainland U.S. through the work of national advocacy organizations, and it has served as a source of cohesion for many people who have experienced cancer. However, anthropologists and other social scientists have argued that dominant meanings of survivorship—such as the idea of “cancer as a gift” or the role of positive thinking in influencing the disease course—reflect distinctively American cultural values, and survivorship outside the U.S. has remained largely unexplored even while the concept has gained some traction globally. This paper explores how the concepts of “survivorship” and “survivor” are engaged in the setting of Puerto Rico, an unincorporated territory of the U.S., and how well they are seen to explain the nature of post-treatment life. Ethnographic fieldwork for this study was conducted over 12 months split between two field visits (2 months and 10 months) between June 2010 and March 2012 in San Juan, the capital city, and Ponce, a smaller city on the southern coast. This paper is based on interviews with 23 participants treated for cancer as young adults. Participants drew from many of the prevailing discourses of survivorship—such as transformation and the importance of optimism—as well as from what they understood to be distinctive aspects of Puerto Rican culture and identity, in the crafting of a local understanding of post-treatment life. Support organizations played a key role in shaping roles and expectations associated with having had cancer, and in solidifying particular views of survivorship more broadly. PMID:25785670

Mechanisms of induced susceptibility to Diplodia tip blight in drought-stressed Austrian pine.

PubMed

Sherwood, Patrick; Villari, Caterina; Capretti, Paolo; Bonello, Pierluigi

2015-05-01

Plants experiencing drought stress are frequently more susceptible to pathogens, likely via alterations in physiology that create favorable conditions for pathogens. Common plant responses to drought include the production of reactive oxygen species (ROS) and the accumulation of free amino acids (AAs), particularly proline. These same phenomena also frequently occur during pathogenic attack. Therefore, drought-induced perturbations in AA and ROS metabolism could potentially contribute to the observed enhanced susceptibility. Furthermore, nitrogen (N) availability can influence AA accumulation and affect plant resistance, but its contributions to drought-induced susceptibility are largely unexplored. Here we show that drought induces accumulation of hydrogen peroxide (H2O2) in Austrian pine (Pinus nigra Arnold) shoots, but that shoot infection by the blight and canker pathogen Diplodia sapinea (Fr.) Fuckel leads to large reductions in H2O2 levels in droughted plants. In in vitro assays, H2O2 was toxic to D. sapinea, and the fungus responded to this oxidative stress by increasing catalase and peroxidase activities, resulting in substantial H2O2 degradation. Proline increased in response to drought and infection when examined independently, but unlike all other AAs, proline further increased in infected shoots of droughted trees. In the same tissues, the proline precursor, glutamate, decreased significantly. Proline was found to protect D. sapinea from H2O2 damage, while also serving as a preferred N source in vitro. Fertilization increased constitutive and drought-induced levels of some AAs, but did not affect plant resistance. A new model integrating interactions of proline and H2O2 metabolism with drought and fungal infection of plants is proposed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MEBS, a software platform to evaluate large (meta)genomic collections according to their metabolic machinery: unraveling the sulfur cycle

PubMed Central

Zapata-Peñasco, Icoquih; Poot-Hernandez, Augusto Cesar; Eguiarte, Luis E

2017-01-01

Abstract The increasing number of metagenomic and genomic sequences has dramatically improved our understanding of microbial diversity, yet our ability to infer metabolic capabilities in such datasets remains challenging. We describe the Multigenomic Entropy Based Score pipeline (MEBS), a software platform designed to evaluate, compare, and infer complex metabolic pathways in large “omic” datasets, including entire biogeochemical cycles. MEBS is open source and available through https://github.com/eead-csic-compbio/metagenome_Pfam_score. To demonstrate its use, we modeled the sulfur cycle by exhaustively curating the molecular and ecological elements involved (compounds, genes, metabolic pathways, and microbial taxa). This information was reduced to a collection of 112 characteristic Pfam protein domains and a list of complete-sequenced sulfur genomes. Using the mathematical framework of relative entropy (H΄), we quantitatively measured the enrichment of these domains among sulfur genomes. The entropy of each domain was used both to build up a final score that indicates whether a (meta)genomic sample contains the metabolic machinery of interest and to propose marker domains in metagenomic sequences such as DsrC (PF04358). MEBS was benchmarked with a dataset of 2107 non-redundant microbial genomes from RefSeq and 935 metagenomes from MG-RAST. Its performance, reproducibility, and robustness were evaluated using several approaches, including random sampling, linear regression models, receiver operator characteristic plots, and the area under the curve metric (AUC). Our results support the broad applicability of this algorithm to accurately classify (AUC = 0.985) hard-to-culture genomes (e.g., Candidatus Desulforudis audaxviator), previously characterized ones, and metagenomic environments such as hydrothermal vents, or deep-sea sediment. Our benchmark indicates that an entropy-based score can capture the metabolic machinery of interest and can be used to efficiently classify large genomic and metagenomic datasets, including uncultivated/unexplored taxa. PMID:29069412

The utility of web mining for epidemiological research: studying the association between parity and cancer risk.

PubMed

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua; Han, Xuesong

2016-05-01

The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Using advanced web crawling and tailored information extraction procedures, the authors automatically collected and analyzed the text content of 79 394 online obituary articles published between 1998 and 2014. The collected data included 51 911 cancer (27 330 breast; 9470 lung; 6496 pancreatic; 6342 ovarian; 2273 colon) and 27 483 non-cancer cases. With the derived information, the authors replicated a case-control study design to investigate the association between parity (i.e., childbearing) and cancer risk. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Parity was found to be associated with a significantly reduced risk of breast cancer (OR = 0.78, 95% CI, 0.75-0.82), pancreatic cancer (OR = 0.78, 95% CI, 0.72-0.83), colon cancer (OR = 0.67, 95% CI, 0.60-0.74), and ovarian cancer (OR = 0.58, 95% CI, 0.54-0.62). Marginal association was found for lung cancer risk (OR = 0.87, 95% CI, 0.81-0.92). The linear trend between increased parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

DOE PAGES

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua; ...

2015-11-27

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

MEBS, a software platform to evaluate large (meta)genomic collections according to their metabolic machinery: unraveling the sulfur cycle.

PubMed

De Anda, Valerie; Zapata-Peñasco, Icoquih; Poot-Hernandez, Augusto Cesar; Eguiarte, Luis E; Contreras-Moreira, Bruno; Souza, Valeria

2017-11-01

The increasing number of metagenomic and genomic sequences has dramatically improved our understanding of microbial diversity, yet our ability to infer metabolic capabilities in such datasets remains challenging. We describe the Multigenomic Entropy Based Score pipeline (MEBS), a software platform designed to evaluate, compare, and infer complex metabolic pathways in large "omic" datasets, including entire biogeochemical cycles. MEBS is open source and available through https://github.com/eead-csic-compbio/metagenome_Pfam_score. To demonstrate its use, we modeled the sulfur cycle by exhaustively curating the molecular and ecological elements involved (compounds, genes, metabolic pathways, and microbial taxa). This information was reduced to a collection of 112 characteristic Pfam protein domains and a list of complete-sequenced sulfur genomes. Using the mathematical framework of relative entropy (H΄), we quantitatively measured the enrichment of these domains among sulfur genomes. The entropy of each domain was used both to build up a final score that indicates whether a (meta)genomic sample contains the metabolic machinery of interest and to propose marker domains in metagenomic sequences such as DsrC (PF04358). MEBS was benchmarked with a dataset of 2107 non-redundant microbial genomes from RefSeq and 935 metagenomes from MG-RAST. Its performance, reproducibility, and robustness were evaluated using several approaches, including random sampling, linear regression models, receiver operator characteristic plots, and the area under the curve metric (AUC). Our results support the broad applicability of this algorithm to accurately classify (AUC = 0.985) hard-to-culture genomes (e.g., Candidatus Desulforudis audaxviator), previously characterized ones, and metagenomic environments such as hydrothermal vents, or deep-sea sediment. Our benchmark indicates that an entropy-based score can capture the metabolic machinery of interest and can be used to efficiently classify large genomic and metagenomic datasets, including uncultivated/unexplored taxa. © The Author 2017. Published by Oxford University Press.

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

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

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

Supercapacitors of nanocrystalline metal-organic frameworks.

PubMed

Choi, Kyung Min; Jeong, Hyung Mo; Park, Jung Hyo; Zhang, Yue-Biao; Kang, Jeung Ku; Yaghi, Omar M

2014-07-22

The high porosity of metal-organic frameworks (MOFs) has been used to achieve exceptional gas adsorptive properties but as yet remains largely unexplored for electrochemical energy storage devices. This study shows that MOFs made as nanocrystals (nMOFs) can be doped with graphene and successfully incorporated into devices to function as supercapacitors. A series of 23 different nMOFs with multiple organic functionalities and metal ions, differing pore sizes and shapes, discrete and infinite metal oxide backbones, large and small nanocrystals, and a variety of structure types have been prepared and examined. Several members of this series give high capacitance; in particular, a zirconium MOF exhibits exceptionally high capacitance. It has the stack and areal capacitance of 0.64 and 5.09 mF cm(-2), about 6 times that of the supercapacitors made from the benchmark commercial activated carbon materials and a performance that is preserved over at least 10000 charge/discharge cycles.

Linking salmon aquaculture synergies and trade-offs on ecosystem services to human wellbeing constituents.

PubMed

Outeiro, Luis; Villasante, Sebastian

2013-12-01

Salmon aquaculture has emerged as a successful economic industry generating high economic revenues to invest in the development of Chiloe region, Southern Chile. However, salmon aquaculture also consumes a substantial amount of ecosystem services, and the direct and indirect impacts on human wellbeing are still unknown and unexplored. This paper identifies the synergies and trade-offs caused by the salmon industry on a range of ecosystem services. The results show that large economic benefits due to the increase of provisioning ecosystem services are also causing a reduction on regulating and cultural services. Despite the improvement on average income and poverty levels experienced in communities closely associated with the sector, this progress is not large enough and social welfare did not improve substantially over the last decade. The rest of human wellbeing constituents in Chiloe region have not changed significantly compared to the development in the rest of the country.

Solid friction between soft filaments.

PubMed

Ward, Andrew; Hilitski, Feodor; Schwenger, Walter; Welch, David; Lau, A W C; Vitelli, Vincenzo; Mahadevan, L; Dogic, Zvonimir

2015-06-01

Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional forces are unexpectedly large, scale logarithmically with sliding velocity as in solid-like friction, and exhibit complex dependence on the filaments' overlap length. We also show that a reduction of the frictional force by orders of magnitude, associated with a transition from solid-like friction to Stokes's drag, can be induced by coating F-actin with polymeric brushes. Furthermore, we observe similar transitions in filamentous microtubules and bacterial flagella. Our findings demonstrate how altering a filament's elasticity, structure and interactions can be used to engineer interfilament friction and thus tune the properties of fibrous composite materials.

Solid friction between soft filaments

NASA Astrophysics Data System (ADS)

Ward, Andrew; Hilitski, Feodor; Schwenger, Walter; Welch, David; Lau, A. W. C.; Vitelli, Vincenzo; Mahadevan, L.; Dogic, Zvonimir

2015-06-01

Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional forces are unexpectedly large, scale logarithmically with sliding velocity as in solid-like friction, and exhibit complex dependence on the filaments’ overlap length. We also show that a reduction of the frictional force by orders of magnitude, associated with a transition from solid-like friction to Stokes’s drag, can be induced by coating F-actin with polymeric brushes. Furthermore, we observe similar transitions in filamentous microtubules and bacterial flagella. Our findings demonstrate how altering a filament’s elasticity, structure and interactions can be used to engineer interfilament friction and thus tune the properties of fibrous composite materials.

The colibactin warhead crosslinks DNA

NASA Astrophysics Data System (ADS)

Vizcaino, Maria I.; Crawford, Jason M.

2015-05-01

Members of the human microbiota are increasingly being correlated to human health and disease states, but the majority of the underlying microbial metabolites that regulate host-microbe interactions remain largely unexplored. Select strains of Escherichia coli present in the human colon have been linked to the initiation of inflammation-induced colorectal cancer through an unknown small-molecule-mediated process. The responsible non-ribosomal peptide-polyketide hybrid pathway encodes ‘colibactin’, which belongs to a largely uncharacterized family of small molecules. Genotoxic small molecules from this pathway that are capable of initiating cancer formation have remained elusive due to their high instability. Guided by metabolomic analyses, here we employ a combination of NMR spectroscopy and bioinformatics-guided isotopic labelling studies to characterize the colibactin warhead, an unprecedented substituted spirobicyclic structure. The warhead crosslinks duplex DNA in vitro, providing direct experimental evidence for colibactin's DNA-damaging activity. The data support unexpected models for both colibactin biosynthesis and its mode of action.

Metastable Prepores in Tension-Free Lipid Bilayers

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

Ting, Christina L.; Awasthi, Neha; Muller, Marcus

The formation and closure of aqueous pores in lipid bilayers is a key step in various biophysical processes. Large pores are well described by classical nucleation theory, but the free-energy landscape of small, biologically relevant pores has remained largely unexplored. The existence of small and metastable “prepores” was hypothesized decades ago from electroporation experiments, but resolving metastable prepores from theoretical models remained challenging. Using two complementary methods—atomistic simulations and self-consistent field theory of a minimal lipid model—we determine the parameters for which metastable prepores occur in lipid membranes. Here, both methods consistently suggest that pore metastability depends on the relativemore » volume ratio between the lipid head group and lipid tails: lipids with a larger head-group volume fraction (or shorter saturated tails) form metastable prepores, whereas lipids with a smaller head-group volume fraction (or longer unsaturated tails) form unstable prepores.« less

What Controls Thermo-osmosis? Molecular Simulations Show the Critical Role of Interfacial Hydrodynamics

NASA Astrophysics Data System (ADS)

Fu, Li; Merabia, Samy; Joly, Laurent

2017-11-01

Thermo-osmotic and related thermophoretic phenomena can be found in many situations from biology to colloid science, but the underlying molecular mechanisms remain largely unexplored. Using molecular dynamics simulations, we measure the thermo-osmosis coefficient by both mechanocaloric and thermo-osmotic routes, for different solid-liquid interfacial energies. The simulations reveal, in particular, the crucial role of nanoscale interfacial hydrodynamics. For nonwetting surfaces, thermo-osmotic transport is largely amplified by hydrodynamic slip at the interface. For wetting surfaces, the position of the hydrodynamic shear plane plays a key role in determining the amplitude and sign of the thermo-osmosis coefficient. Finally, we measure a giant thermo-osmotic response of the water-graphene interface, which we relate to the very low interfacial friction displayed by this system. These results open new perspectives for the design of efficient functional interfaces for, e.g., waste-heat harvesting.

What Controls Thermo-osmosis? Molecular Simulations Show the Critical Role of Interfacial Hydrodynamics.

PubMed

Fu, Li; Merabia, Samy; Joly, Laurent

2017-11-24

Thermo-osmotic and related thermophoretic phenomena can be found in many situations from biology to colloid science, but the underlying molecular mechanisms remain largely unexplored. Using molecular dynamics simulations, we measure the thermo-osmosis coefficient by both mechanocaloric and thermo-osmotic routes, for different solid-liquid interfacial energies. The simulations reveal, in particular, the crucial role of nanoscale interfacial hydrodynamics. For nonwetting surfaces, thermo-osmotic transport is largely amplified by hydrodynamic slip at the interface. For wetting surfaces, the position of the hydrodynamic shear plane plays a key role in determining the amplitude and sign of the thermo-osmosis coefficient. Finally, we measure a giant thermo-osmotic response of the water-graphene interface, which we relate to the very low interfacial friction displayed by this system. These results open new perspectives for the design of efficient functional interfaces for, e.g., waste-heat harvesting.

Solid friction between soft filaments

DOE PAGES

Ward, Andrew; Hilitski, Feodor; Schwenger, Walter; ...

2015-03-02

Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional forces are unexpectedly large, scale logarithmically with sliding velocity as in solid-like friction, and exhibit complex dependence on the filaments’ overlap length. We also show that a reduction of the frictional force by orders of magnitude, associated with a transition from solid-like friction to Stokes’s drag,more » can be induced by coating F-actin with polymeric brushes. Furthermore, we observe similar transitions in filamentous microtubules and bacterial flagella. In conclusion, our findings demonstrate how altering a filament’s elasticity, structure and interactions can be used to engineer interfilament friction and thus tune the properties of fibrous composite materials.« less

Non-classical photon correlation in a two-dimensional photonic lattice.

PubMed

Gao, Jun; Qiao, Lu-Feng; Lin, Xiao-Feng; Jiao, Zhi-Qiang; Feng, Zhen; Zhou, Zheng; Gao, Zhen-Wei; Xu, Xiao-Yun; Chen, Yuan; Tang, Hao; Jin, Xian-Min

2016-06-13

Quantum interference and quantum correlation, as two main features of quantum optics, play an essential role in quantum information applications, such as multi-particle quantum walk and boson sampling. While many experimental demonstrations have been done in one-dimensional waveguide arrays, it remains unexplored in higher dimensions due to tight requirement of manipulating and detecting photons in large-scale. Here, we experimentally observe non-classical correlation of two identical photons in a fully coupled two-dimensional structure, i.e. photonic lattice manufactured by three-dimensional femtosecond laser writing. Photon interference consists of 36 Hong-Ou-Mandel interference and 9 bunching. The overlap between measured and simulated distribution is up to 0.890 ± 0.001. Clear photon correlation is observed in the two-dimensional photonic lattice. Combining with controllably engineered disorder, our results open new perspectives towards large-scale implementation of quantum simulation on integrated photonic chips.

Metastable Prepores in Tension-Free Lipid Bilayers

DOE PAGES

Ting, Christina L.; Awasthi, Neha; Muller, Marcus; ...

2018-03-23

The formation and closure of aqueous pores in lipid bilayers is a key step in various biophysical processes. Large pores are well described by classical nucleation theory, but the free-energy landscape of small, biologically relevant pores has remained largely unexplored. The existence of small and metastable “prepores” was hypothesized decades ago from electroporation experiments, but resolving metastable prepores from theoretical models remained challenging. Using two complementary methods—atomistic simulations and self-consistent field theory of a minimal lipid model—we determine the parameters for which metastable prepores occur in lipid membranes. Here, both methods consistently suggest that pore metastability depends on the relativemore » volume ratio between the lipid head group and lipid tails: lipids with a larger head-group volume fraction (or shorter saturated tails) form metastable prepores, whereas lipids with a smaller head-group volume fraction (or longer unsaturated tails) form unstable prepores.« less

The Genetic Basis of Natural Variation in Caenorhabditis elegans Telomere Length

PubMed Central

Cook, Daniel E.; Zdraljevic, Stefan; Tanny, Robyn E.; Seo, Beomseok; Riccardi, David D.; Noble, Luke M.; Rockman, Matthew V.; Alkema, Mark J.; Braendle, Christian; Kammenga, Jan E.; Wang, John; Kruglyak, Leonid; Félix, Marie-Anne; Lee, Junho; Andersen, Erik C.

2016-01-01

Telomeres are involved in the maintenance of chromosomes and the prevention of genome instability. Despite this central importance, significant variation in telomere length has been observed in a variety of organisms. The genetic determinants of telomere-length variation and their effects on organismal fitness are largely unexplored. Here, we describe natural variation in telomere length across the Caenorhabditis elegans species. We identify a large-effect variant that contributes to differences in telomere length. The variant alters the conserved oligonucleotide/oligosaccharide-binding fold of protection of telomeres 2 (POT-2), a homolog of a human telomere-capping shelterin complex subunit. Mutations within this domain likely reduce the ability of POT-2 to bind telomeric DNA, thereby increasing telomere length. We find that telomere-length variation does not correlate with offspring production or longevity in C. elegans wild isolates, suggesting that naturally long telomeres play a limited role in modifying fitness phenotypes in C. elegans. PMID:27449056

Diel Surface Temperature Range Scales with Lake Size

PubMed Central

Woolway, R. Iestyn; Jones, Ian D.; Maberly, Stephen C.; French, Jon R.; Livingstone, David M.; Monteith, Donald T.; Simpson, Gavin L.; Thackeray, Stephen J.; Andersen, Mikkel R.; Battarbee, Richard W.; DeGasperi, Curtis L.; Evans, Christopher D.; de Eyto, Elvira; Feuchtmayr, Heidrun; Hamilton, David P.; Kernan, Martin; Krokowski, Jan; Rimmer, Alon; Rose, Kevin C.; Rusak, James A.; Ryves, David B.; Scott, Daniel R.; Shilland, Ewan M.; Smyth, Robyn L.; Staehr, Peter A.; Thomas, Rhian; Waldron, Susan; Weyhenmeyer, Gesa A.

2016-01-01

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored. PMID:27023200

Conservation lessons from large-mammal manipulations in East African savannas: the KLEE, UHURU, and GLADE experiments.

PubMed

Goheen, Jacob R; Augustine, David J; Veblen, Kari E; Kimuyu, Duncan M; Palmer, Todd M; Porensky, Lauren M; Pringle, Robert M; Ratnam, Jayashree; Riginos, Corinna; Sankaran, Mahesh; Ford, Adam T; Hassan, Abdikadir A; Jakopak, Rhiannon; Kartzinel, Tyler R; Kurukura, Samson; Louthan, Allison M; Odadi, Wilfred O; Otieno, Tobias O; Wambua, Alois M; Young, Hillary S; Young, Truman P

2018-05-11

African savannas support an iconic fauna, but they are undergoing large-scale population declines and extinctions of large (>5 kg) mammals. Long-term, controlled, replicated experiments that explore the consequences of this defaunation (and its replacement with livestock) are rare. The Mpala Research Centre in Laikipia County, Kenya, hosts three such experiments, spanning two adjacent ecosystems and environmental gradients within them: the Kenya Long-Term Exclosure Experiment (KLEE; since 1995), the Glade Legacies and Defaunation Experiment (GLADE; since 1999), and the Ungulate Herbivory Under Rainfall Uncertainty experiment (UHURU; since 2008). Common themes unifying these experiments are (1) evidence of profound effects of large mammalian herbivores on herbaceous and woody plant communities; (2) competition and compensation across herbivore guilds, including rodents; and (3) trophic cascades and other indirect effects. We synthesize findings from the past two decades to highlight generalities and idiosyncrasies among these experiments, and highlight six lessons that we believe are pertinent for conservation. The removal of large mammalian herbivores has dramatic effects on the ecology of these ecosystems; their ability to rebound from these changes (after possible refaunation) remains unexplored. © 2018 New York Academy of Sciences.

Key Role of the Scavenger Receptor MARCO in Mediating Adenovirus Infection and Subsequent Innate Responses of Macrophages.

PubMed

Maler, Mareike D; Nielsen, Peter J; Stichling, Nicole; Cohen, Idan; Ruzsics, Zsolt; Wood, Connor; Engelhard, Peggy; Suomalainen, Maarit; Gyory, Ildiko; Huber, Michael; Müller-Quernheim, Joachim; Schamel, Wolfgang W A; Gordon, Siamon; Jakob, Thilo; Martin, Stefan F; Jahnen-Dechent, Willi; Greber, Urs F; Freudenberg, Marina A; Fejer, György

2017-08-01

The scavenger receptor MARCO is expressed in several subsets of naive tissue-resident macrophages and has been shown to participate in the recognition of various bacterial pathogens. However, the role of MARCO in antiviral defense is largely unexplored. Here, we investigated whether MARCO might be involved in the innate sensing of infection with adenovirus and recombinant adenoviral vectors by macrophages, which elicit vigorous immune responses in vivo Using cells derived from mice, we show that adenovirus infection is significantly more efficient in MARCO-positive alveolar macrophages (AMs) and in AM-like primary macrophage lines (Max Planck Institute cells) than in MARCO-negative bone marrow-derived macrophages. Using antibodies blocking ligand binding to MARCO, as well as gene-deficient and MARCO-transfected cells, we show that MARCO mediates the rapid adenovirus transduction of macrophages. By enhancing adenovirus infection, MARCO contributes to efficient innate virus recognition through the cytoplasmic DNA sensor cGAS. This leads to strong proinflammatory responses, including the production of interleukin-6 (IL-6), alpha/beta interferon, and mature IL-1α. These findings contribute to the understanding of viral pathogenesis in macrophages and may open new possibilities for the development of tools to influence the outcome of infection with adenovirus or adenovirus vectors. IMPORTANCE Macrophages play crucial roles in inflammation and defense against infection. Several macrophage subtypes have been identified with differing abilities to respond to infection with both natural adenoviruses and recombinant adenoviral vectors. Adenoviruses are important respiratory pathogens that elicit vigorous innate responses in vitro and in vivo The cell surface receptors mediating macrophage type-specific adenovirus sensing are largely unknown. The scavenger receptor MARCO is expressed on some subsets of naive tissue-resident macrophages, including lung alveolar macrophages. Its role in antiviral macrophage responses is largely unexplored. Here, we studied whether the differential expression of MARCO might contribute to the various susceptibilities of macrophage subtypes to adenovirus. We demonstrate that MARCO significantly enhances adenovirus infection and innate responses in macrophages. These results help to understand adenoviral pathogenesis and may open new possibilities to influence the outcome of infection with adenoviruses or adenovirus vectors. Copyright © 2017 Maler et al.

Public health policies to encourage healthy eating habits: recent perspectives

PubMed Central

Gorski, Mary T; Roberto, Christina A

2015-01-01

There is an urgent need to address unhealthy dietary patterns at the population level. Poor diet and physical inactivity are key drivers of the obesity pandemic, and they are among the leading causes of preventable death and disability in nearly every country in the world. As countries grapple with the growing obesity prevalence, many innovative policy options to reduce overeating and improve diet quality remain largely unexplored. We describe recent trends in eating habits and consequences for public health, vulnerabilities to unhealthy eating, and the role for public health policies. We reviewed recent public health policies to promote healthier diet patterns, including mandates, restrictions, economic incentives, marketing limits, information provision, and environmental defaults. PMID:29355201

Paved With Good Intentions: Do Public Health and Human Service Providers Contribute to Racial/Ethnic Disparities in Health?

PubMed Central

van Ryn, Michelle; Fu, Steven S.

2003-01-01

There is extensive evidence of racial/ethnic disparities in receipt of health care. The potential contribution of provider behavior to such disparities has remained largely unexplored. Do health and human service providers behave in ways that contribute to systematic inequities in care and outcomes? If so, why does this occur? The authors build on existing evidence to provide an integrated, coherent, and sound approach to research on providers’ contributions to racial/ethnic disparities. They review the evidence regarding provider contributions to disparities in outcomes and describe a causal model representing an integrated set of hypothesized mechanisms through which health care providers’ behaviors may contribute to these disparities. PMID:12554578

Direct quantitative measurement of the C═O⋅⋅⋅H–C bond by atomic force microscopy

PubMed Central

Kawai, Shigeki; Nishiuchi, Tomohiko; Kodama, Takuya; Spijker, Peter; Pawlak, Rémy; Meier, Tobias; Tracey, John; Kubo, Takashi; Meyer, Ernst; Foster, Adam S.

2017-01-01

The hydrogen atom—the smallest and most abundant atom—is of utmost importance in physics and chemistry. Although many analysis methods have been applied to its study, direct observation of hydrogen atoms in a single molecule remains largely unexplored. We use atomic force microscopy (AFM) to resolve the outermost hydrogen atoms of propellane molecules via very weak C═O⋅⋅⋅H–C hydrogen bonding just before the onset of Pauli repulsion. The direct measurement of the interaction with a hydrogen atom paves the way for the identification of three-dimensional molecules such as DNAs and polymers, building the capabilities of AFM toward quantitative probing of local chemical reactivity. PMID:28508080

Public health policies to encourage healthy eating habits: recent perspectives.

PubMed

Gorski, Mary T; Roberto, Christina A

2015-01-01

There is an urgent need to address unhealthy dietary patterns at the population level. Poor diet and physical inactivity are key drivers of the obesity pandemic, and they are among the leading causes of preventable death and disability in nearly every country in the world. As countries grapple with the growing obesity prevalence, many innovative policy options to reduce overeating and improve diet quality remain largely unexplored. We describe recent trends in eating habits and consequences for public health, vulnerabilities to unhealthy eating, and the role for public health policies. We reviewed recent public health policies to promote healthier diet patterns, including mandates, restrictions, economic incentives, marketing limits, information provision, and environmental defaults.

Composition-matched molecular “solders” for semiconductors

NASA Astrophysics Data System (ADS)

Dolzhnikov, Dmitriy S.; Zhang, Hao; Jang, Jaeyoung; Son, Jae Sung; Panthani, Matthew G.; Shibata, Tomohiro; Chattopadhyay, Soma; Talapin, Dmitri V.

2015-01-01

We propose a general strategy to synthesize largely unexplored soluble chalcogenidometallates of cadmium, lead, and bismuth. These compounds can be used as “solders” for semiconductors widely used in photovoltaics and thermoelectrics. The addition of solder helped to bond crystal surfaces and link nano- or mesoscale particles together. For example, CdSe nanocrystals with Na2Cd2Se3 solder was used as a soluble precursor for CdSe films with electron mobilities exceeding 300 square centimeters per volt-second. CdTe, PbTe, and Bi2Te3 powders were molded into various shapes in the presence of a small additive of composition-matched chalcogenidometallate or chalcogel, thus opening new design spaces for semiconductor technologies.

Paved with good intentions: do public health and human service providers contribute to racial/ethnic disparities in health?

PubMed

van Ryn, Michelle; Fu, Steven S

2003-02-01

There is extensive evidence of racial/ethnic disparities in receipt of health care. The potential contribution of provider behavior to such disparities has remained largely unexplored. Do health and human service providers behave in ways that contribute to systematic inequities in care and outcomes? If so, why does this occur? The authors build on existing evidence to provide an integrated, coherent, and sound approach to research on providers' contributions to racial/ethnic disparities. They review the evidence regarding provider contributions to disparities in outcomes and describe a causal model representing an integrated set of hypothesized mechanisms through which health care providers' behaviors may contribute to these disparities.

The potential of plant microbiota in reducing postharvest food loss.

PubMed

Buchholz, Franziska; Kostić, Tanja; Sessitsch, Angela; Mitter, Birgit

2018-03-26

The role of the plant microbiota in plant establishment, growth and health is well studied, but the dynamics of postharvest crop microbiota and its role in postharvest crop quality are largely unexplored, although food loss is an enormous issue worldwide. The microbiota might be especially important during crop storage by either preventing or favouring rots, or quality loss due to, for example, sprouting, saccharification, water loss or spoilage. We need more research on plant-microbe interactions in postharvest crops to be in future able to provide microbial solutions for plant production along the whole food chain from field to fork. © 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

The joint center for energy storage research: A new paradigm for battery research and development

NASA Astrophysics Data System (ADS)

Crabtree, George

2015-03-01

The Joint Center for Energy Storage Research (JCESR) seeks transformational change in transportation and the electricity grid driven by next generation high performance, low cost electricity storage. To pursue this transformative vision JCESR introduces a new paradigm for battery research: integrating discovery science, battery design, research prototyping and manufacturing collaboration in a single highly interactive organization. This new paradigm will accelerate the pace of discovery and innovation and reduce the time from conceptualization to commercialization. JCESR applies its new paradigm exclusively to beyond-lithium-ion batteries, a vast, rich and largely unexplored frontier. This review presents JCESR's motivation, vision, mission, intended outcomes or legacies and first year accomplishments.

Developmental origin and lineage plasticity of endogenous cardiac stem cells

PubMed Central

Santini, Maria Paola; Forte, Elvira; Harvey, Richard P.; Kovacic, Jason C.

2016-01-01

Over the past two decades, several populations of cardiac stem cells have been described in the adult mammalian heart. For the most part, however, their lineage origins and in vivo functions remain largely unexplored. This Review summarizes what is known about different populations of embryonic and adult cardiac stem cells, including KIT+, PDGFRα+, ISL1+ and SCA1+ cells, side population cells, cardiospheres and epicardial cells. We discuss their developmental origins and defining characteristics, and consider their possible contribution to heart organogenesis and regeneration. We also summarize the origin and plasticity of cardiac fibroblasts and circulating endothelial progenitor cells, and consider what role these cells have in contributing to cardiac repair. PMID:27095490

De novo assembly of human genomes with massively parallel short read sequencing.

PubMed

Li, Ruiqiang; Zhu, Hongmei; Ruan, Jue; Qian, Wubin; Fang, Xiaodong; Shi, Zhongbin; Li, Yingrui; Li, Shengting; Shan, Gao; Kristiansen, Karsten; Li, Songgang; Yang, Huanming; Wang, Jian; Wang, Jun

2010-02-01

Next-generation massively parallel DNA sequencing technologies provide ultrahigh throughput at a substantially lower unit data cost; however, the data are very short read length sequences, making de novo assembly extremely challenging. Here, we describe a novel method for de novo assembly of large genomes from short read sequences. We successfully assembled both the Asian and African human genome sequences, achieving an N50 contig size of 7.4 and 5.9 kilobases (kb) and scaffold of 446.3 and 61.9 kb, respectively. The development of this de novo short read assembly method creates new opportunities for building reference sequences and carrying out accurate analyses of unexplored genomes in a cost-effective way.

Internalized Homophobia Influences Perceptions of Men's Sexual Orientation from Photos of Their Faces.

PubMed

Tskhay, Konstantin O; Rule, Nicholas O

2017-04-01

Although researchers have explored the perceiver characteristics that make people accurate at identifying others' sexual orientations, characteristics of the targets remain largely unexplored. In the current study, we examined how individual differences in internalized homophobia among gay men can affect perceptions of their sexual orientation by asking 49 individuals to judge the sexual orientations of 78 gay men from photos of their faces. We found that gay men reporting higher levels of internalized homophobia were less likely to have come out of the closet and were, in turn, less likely to be perceived as gay. Thus, internalized homophobia and the concealment of one's sexual minority status can impact perceptions of sexual orientation.

Stochastic voyages into uncharted chemical space produce a representative library of all possible drug-like compounds

PubMed Central

Virshup, Aaron M.; Contreras-García, Julia; Wipf, Peter; Yang, Weitao; Beratan, David N.

2013-01-01

The “small molecule universe” (SMU), the set of all synthetically feasible organic molecules of 500 Daltons molecular weight or less, is estimated to contain over 1060 structures, making exhaustive searches for structures of interest impractical. Here, we describe the construction of a “representative universal library” spanning the SMU that samples the full extent of feasible small molecule chemistries. This library was generated using the newly developed Algorithm for Chemical Space Exploration with Stochastic Search (ACSESS). ACSESS makes two important contributions to chemical space exploration: it allows the systematic search of the unexplored regions of the small molecule universe, and it facilitates the mining of chemical libraries that do not yet exist, providing a near-infinite source of diverse novel compounds. PMID:23548177

Using electronic patient records to discover disease correlations and stratify patient cohorts.

PubMed

Roque, Francisco S; Jensen, Peter B; Schmock, Henriette; Dalgaard, Marlene; Andreatta, Massimo; Hansen, Thomas; Søeby, Karen; Bredkjær, Søren; Juul, Anders; Werge, Thomas; Jensen, Lars J; Brunak, Søren

2011-08-01

Electronic patient records remain a rather unexplored, but potentially rich data source for discovering correlations between diseases. We describe a general approach for gathering phenotypic descriptions of patients from medical records in a systematic and non-cohort dependent manner. By extracting phenotype information from the free-text in such records we demonstrate that we can extend the information contained in the structured record data, and use it for producing fine-grained patient stratification and disease co-occurrence statistics. The approach uses a dictionary based on the International Classification of Disease ontology and is therefore in principle language independent. As a use case we show how records from a Danish psychiatric hospital lead to the identification of disease correlations, which subsequently can be mapped to systems biology frameworks.

Isolation of antimicrobial producing Actinobacteria from soil samples.

PubMed

Elbendary, Afaf Ahmed; Hessain, Ashgan Mohamed; El-Hariri, Mahmoud Darderi; Seida, Ahmed Adel; Moussa, Ihab Mohamed; Mubarak, Ayman Salem; Kabli, Saleh A; Hemeg, Hassan A; El Jakee, Jakeen Kamal

2018-01-01

Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms ( S. aureus , Bacillus cereus , E. coli , K. pneumoniae , P. aeruginosa , S. Typhi, C. albicans , A. niger and A. flavus ). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae , Kocuria rosea , Streptomyces griseus , Streptomyces flaveolus and Actinobacteria . Using ethyl acetate extraction method the isolates culture's supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

Measurement of the ionization produced by sub-keV silicon nuclear recoils in a CCD dark matter detector

DOE PAGES

Chavarria, A. E.; Collar, J. I.; Peña, J. R.; ...

2016-10-15

We report a measurement of the ionization efficiency of silicon nuclei recoiling with sub-keV kinetic energy in the bulk silicon of a charge-coupled device (CCD). Nuclear recoils are produced by low-energy neutrons (<24 keV) from a 124Sb– 9Be photoneutron source, and their ionization signal is measured down to 60 eV electron equivalent. This energy range, previously unexplored, is relevant for the detection of low-mass dark matter particles. The measured efficiency is found to deviate from the extrapolation to low energies of the Lindhard model. Furthermore, this measurement also demonstrates the sensitivity to nuclear recoils of CCDs employed by DAMIC, amore » dark matter direct detection experiment located in the SNOLAB underground laboratory.« less

Low Evapotranspiration Enhances the Resilience of Peatland Carbon Stocks to Fire

NASA Astrophysics Data System (ADS)

Kettridge, N.; Lukenbach, M. C.; Hokanson, K. J.; Hopkinson, C.; Devito, K. J.; Petrone, R. M.; Mendoza, C. A.; Waddington, J. M.

2017-09-01

Boreal peatlands may be vulnerable to projected changes in the wildfire regime under future climates. Extreme drying during the sensitive postfire period may exceed peatland ecohydrological resilience, triggering long-term degradation of these globally significant carbon stocks. Despite these concerns, we show low peatland evapotranspiration at both the plot- and landscape-scale postfire, in water-limited peatlands dominated by feather moss that are ubiquitous across continental western Canada. Low postfire evapotranspiration enhances the resilience of carbon stocks in such peatlands to wildfire disturbance and reinforces their function as a regional source of water. Near-surface water repellency may provide an important, previously unexplored, regulator of peatland evapotranspiration that can induce low evapotranspiration in the initial postfire years by restricting the supply of water to the peat surface.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications

PubMed Central

Roca, Christophe; Alves, Vitor D.; Freitas, Filomena; Reis, Maria A. M.

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed. PMID:25914689

The physics and early history of the intergalactic medium

NASA Astrophysics Data System (ADS)

Barkana, Rennan; Loeb, Abraham

2007-04-01

The intergalactic medium—the cosmic gas that fills the great spaces between the galaxies—is affected by processes ranging from quantum fluctuations in the very early Universe to radiative emission from newly formed stars. This gives the intergalactic medium a dual role as a powerful probe both of fundamental physics and of astrophysics. The heading of fundamental physics includes conditions in the very early Universe and cosmological parameters that determine the age of the Universe and its matter content. The astrophysics refers to chapters of the long cosmic history of stars and galaxies that are being revealed through the effects of stellar feedback on the cosmic gas. This review describes the physics of the intergalactic medium, focusing on recent theoretical and observational developments in understanding early cosmic history. In particular, the earliest generation of stars is thought to have transformed the Universe from darkness to light and to have had an enormous impact on the intergalactic medium. Half a million years after the Big Bang the Universe was filled with atomic hydrogen. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms back into free electrons and ions. From the observed spectral absorption signatures of the gas between us and distant sources, we know that the process of reionization pervaded most of space a billion years after the Big Bang, so that only a small fraction of the primordial hydrogen atoms remained between galaxies. Knowing exactly when and how the reionization process happened is a primary goal of cosmologists, because this would tell us when the early stars and black holes formed and in what kinds of galaxies. The distribution and clustering of these galaxies is particularly interesting since it is driven by primordial density fluctuations in the dark matter. Cosmic reionization is beginning to be understood with the help of theoretical models and computer simulations. Numerical simulations of reionization are computationally challenging, as they require radiative transfer across large cosmological volumes as well as sufficiently high resolution to identify the sources of the ionizing radiation in the infant Universe. Rapid progress in our understanding is expected with additional observational input. A wide variety of instruments currently under design—including large-aperture infrared telescopes on the ground or in space (JWST), and low-frequency radio telescope arrays for the detection of redshifted 21 cm radiation—will probe the first sources of light during an epoch in cosmic history that has been largely unexplored so far. The new observations and the challenges for theoretical models and numerical simulations will motivate intense work in this field over the coming decade.

A case for archaeological reconnaissance of the Cabo Catoche-Porvenir region of the northeastern Yucatan Peninsula

NASA Technical Reports Server (NTRS)

Duller, Charles E.

1990-01-01

Satellite remote sensing technology is a tool with which archaeologists can, with relative ease, survey a region that is otherwise inaccessible. The northeast corner of the Yucatan Peninsula is such an area: it is isolated and sparsely inhabited, with dense forest and extensive swamps. From Cabo Catoche inland to Cancun, this remote corner of the ancient Maya world is virtually unexplored. Recent satellite images disclose evidence of past human activity in this unexplored region and offer a compelling argument for an archaeological reconnaissance.

Genetic Distinctiveness of Rye In situ Accessions from Portugal Unveils a New Hotspot of Unexplored Genetic Resources

PubMed Central

Monteiro, Filipa; Vidigal, Patrícia; Barros, André B.; Monteiro, Ana; Oliveira, Hugo R.; Viegas, Wanda

2016-01-01

Rye (Secale cereale L.) is a cereal crop of major importance in many parts of Europe and rye breeders are presently very concerned with the restrict pool of rye genetic resources available. Such narrowing of rye genetic diversity results from the presence of “Petkus” pool in most modern rye varieties as well as “Petkus” × “Carsten” heterotic pool in hybrid rye breeding programs. Previous studies on rye's genetic diversity revealed moreover a common genetic background on landraces (ex situ) and cultivars, regardless of breeding level or geographical origin. Thus evaluation of in situ populations is of utmost importance to unveil “on farm” diversity, which is largely undervalued. Here, we perform the first comprehensive assessment of rye's genetic diversity and population structuring using cultivars, ex situ landraces along a comprehensive sampling of in situ accessions from Portugal, through a molecular-directed analysis using SSRs markers. Rye genetic diversity and population structure analysis does not present any geographical trend but disclosed marked differences between genetic backgrounds of in situ accessions and those of cultivars/ex situ collections. Such genetic distinctiveness of in situ accessions highlights their unexplored potential as new genetic resources, which can be used to boost rye breeding strategies and the production of new varieties. Overall, our study successfully demonstrates the high prospective impact of comparing genetic diversity and structure of cultivars, ex situ, and in situ samples in ascertaining the status of plant genetic resources (PGR). PMID:27630658

Cortical Hierarchies Perform Bayesian Causal Inference in Multisensory Perception

PubMed Central

Rohe, Tim; Noppeney, Uta

2015-01-01

To form a veridical percept of the environment, the brain needs to integrate sensory signals from a common source but segregate those from independent sources. Thus, perception inherently relies on solving the “causal inference problem.” Behaviorally, humans solve this problem optimally as predicted by Bayesian Causal Inference; yet, the underlying neural mechanisms are unexplored. Combining psychophysics, Bayesian modeling, functional magnetic resonance imaging (fMRI), and multivariate decoding in an audiovisual spatial localization task, we demonstrate that Bayesian Causal Inference is performed by a hierarchy of multisensory processes in the human brain. At the bottom of the hierarchy, in auditory and visual areas, location is represented on the basis that the two signals are generated by independent sources (= segregation). At the next stage, in posterior intraparietal sulcus, location is estimated under the assumption that the two signals are from a common source (= forced fusion). Only at the top of the hierarchy, in anterior intraparietal sulcus, the uncertainty about the causal structure of the world is taken into account and sensory signals are combined as predicted by Bayesian Causal Inference. Characterizing the computational operations of signal interactions reveals the hierarchical nature of multisensory perception in human neocortex. It unravels how the brain accomplishes Bayesian Causal Inference, a statistical computation fundamental for perception and cognition. Our results demonstrate how the brain combines information in the face of uncertainty about the underlying causal structure of the world. PMID:25710328

Fire in the vein: Heroin acidity and its proximal effect on users’ health

PubMed Central

Ciccarone, Daniel; Harris, Magdalena

2016-01-01

The loss of functioning veins (venous sclerosis) is a root cause of suffering for long-term heroin injectors. In addition to perpetual frustration and loss of pleasure/esteem, venous sclerosis leads to myriad medical consequences including skin infections, for example, abscess, and possibly elevated HIV/HCV risks due to injection into larger jugular and femoral veins. The etiology of venous sclerosis is unknown and users’ perceptions of cause/meaning unexplored. This commentary stems from our hypothesis that venous sclerosis is causally related to heroin acidity, which varies by heroin source-form and preparation. We report pilot study data on first ever in vivo measurements of heroin pH and as well as qualitative data on users’ concerns and perceptions regarding the caustic nature of heroin and its effects. Heroin pH testing in natural settings is feasible and a useful tool for further research. Our preliminary findings, for example, that different heroin source-forms and preparations have a two log difference in acidity, have potentially broad, vital and readily implementable harm reduction implications. PMID:26077143

Fire in the vein: Heroin acidity and its proximal effect on users' health.

PubMed

Ciccarone, Daniel; Harris, Magdalena

2015-11-01

The loss of functioning veins (venous sclerosis) is a root cause of suffering for long-term heroin injectors. In addition to perpetual frustration and loss of pleasure/esteem, venous sclerosis leads to myriad medical consequences including skin infections, for example, abscess, and possibly elevated HIV/HCV risks due to injection into larger jugular and femoral veins. The etiology of venous sclerosis is unknown and users' perceptions of cause/meaning unexplored. This commentary stems from our hypothesis that venous sclerosis is causally related to heroin acidity, which varies by heroin source-form and preparation. We report pilot study data on first ever in vivo measurements of heroin pH and as well as qualitative data on users' concerns and perceptions regarding the caustic nature of heroin and its effects. Heroin pH testing in natural settings is feasible and a useful tool for further research. Our preliminary findings, for example, that different heroin source-forms and preparations have a two log difference in acidity, have potentially broad, vital and readily implementable harm reduction implications. Copyright © 2015. Published by Elsevier B.V.

Petroleum geology of the Gulf of Lion (Mediterranean offshore-France)

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

Vially, R.; Jean-Jacques, B.; Alain, I.E.M.

1995-08-01

The onshore sedimentary basins of Camargue and the northern edge of the Gulf of Lion have been explored since the middle of the last century. The results of this petroleum exploration were poor despite two small oil discoveries: the Oligocene onshore Gallician field and the Triassic onshore Gabian field (respectively 7000 tons and 23000 tons of oil production). Eleven wells were drilled offshore (from 1968 to 1985), all located on highs of the pre-Tertiary substratum. Few oil and gas shows were proven by only three of these wells. The seismic data base has been fully reinterpreted. The mapping of themore » pre-Tertiary substratum shows wide unexplored grabens in the Gulf of Lion. Some Oligocene prospects have been evidenced which are either stratigraphic traps or faulted blocks associated to salt seals. A new set of geochemical analysis of the Oligocene source rock has been performed as well as systematic generation and migration models (1D and 2D models) leading to the definition of an effective oil kitchen of an Oligocene lacustrine source rock (type 1).« less

Delay effects in the human sensory system during balancing.

PubMed

Stepan, Gabor

2009-03-28

Mechanical models of human self-balancing often use the Newtonian equations of inverted pendula. While these mathematical models are precise enough on the mechanical side, the ways humans balance themselves are still quite unexplored on the control side. Time delays in the sensory and motoric neural pathways give essential limitations to the stabilization of the human body as a multiple inverted pendulum. The sensory systems supporting each other provide the necessary signals for these control tasks; but the more complicated the system is, the larger delay is introduced. Human ageing as well as our actual physical and mental state affects the time delays in the neural system, and the mechanical structure of the human body also changes in a large range during our lives. The human balancing organ, the labyrinth, and the vision system essentially adapted to these relatively large time delays and parameter regions occurring during balancing. The analytical study of the simplified large-scale time-delayed models of balancing provides a Newtonian insight into the functioning of these organs that may also serve as a basis to support theories and hypotheses on balancing and vision.

The performance of low-cost commercial cloud computing as an alternative in computational chemistry.

PubMed

Thackston, Russell; Fortenberry, Ryan C

2015-05-05

The growth of commercial cloud computing (CCC) as a viable means of computational infrastructure is largely unexplored for the purposes of quantum chemistry. In this work, the PSI4 suite of computational chemistry programs is installed on five different types of Amazon World Services CCC platforms. The performance for a set of electronically excited state single-point energies is compared between these CCC platforms and typical, "in-house" physical machines. Further considerations are made for the number of cores or virtual CPUs (vCPUs, for the CCC platforms), but no considerations are made for full parallelization of the program (even though parallelization of the BLAS library is implemented), complete high-performance computing cluster utilization, or steal time. Even with this most pessimistic view of the computations, CCC resources are shown to be more cost effective for significant numbers of typical quantum chemistry computations. Large numbers of large computations are still best utilized by more traditional means, but smaller-scale research may be more effectively undertaken through CCC services. © 2015 Wiley Periodicals, Inc.

Pathfinding in a large vertebrate axon tract: isotypic interactions guide retinotectal axons at multiple choice points

PubMed Central

Pittman, Andrew J.; Law, Mei-Yee; Chien, Chi-Bin

2008-01-01

Summary Navigating axons respond to environmental guidance signals, but can also follow axons that have gone before—pioneer axons. Pioneers have been studied extensively in simple systems, but the role of axon-axon interactions remains largely unexplored in large vertebrate axon tracts, where cohorts of identical axons could potentially use isotypic interactions to guide each other through multiple choice points. Furthermore, the relative importance of axon-axon interactions compared to axon-autonomous receptor function has not been assessed. Here we test the role of axon-axon interactions in retinotectal development, by devising a technique to selectively remove or replace early-born retinal ganglion cells (RGCs). We find that early RGCs are both necessary and sufficient for later axons to exit the eye. Furthermore, introducing misrouted axons by transplantation reveals that guidance from eye to tectum relies heavily on interactions between axons, including both pioneer-follower and community effects. We conclude that axon-axon interactions and ligand-receptor signaling have coequal roles, cooperating to ensure the fidelity of axon guidance in developing vertebrate tracts. PMID:18653554

Raman counting of heavy minerals in turbidites: Indus Fan, IODP Expedition 355

NASA Astrophysics Data System (ADS)

Andò, Sergio

2017-04-01

Raman spectroscopy is an innovative tool with tremendous potential. Thorny long-standing problems that cannot be solved confidently with a polarizing microscope alone, such as the determination of opaque heavy minerals or of detrital grains as small as a few microns, can finally be addressed. Heavy-mineral species commonly found in sediments convey specific information on the genesis of their source rocks and are therefore crucial in provenance diagnoses and palaeotectonic reconstructions. A high-resolution mineralogical study of Indus Fan turbiditic sediments cored during IODP Expedition 355 (Arabian Sea Monsoon) in the Laxmi Basin was carried out to investigate and quantify the different compositional signatures of sand and silt fractions. Silt and sand in turbidite deposits recovered at IODP Sites U1456 and U1457 were chosen as the best natural archive for this source-to-sink study. An integrated mineralogical dataset was obtained by coupling traditional and innovative single-grain heavy-mineral analyses. Reliable quantitative results even in the medium to fine silt classes, which represent the dominant sediment sizes encountered in the recovered cores, were obtained by point-counting of single grains under the microscope assisted by Micro-Raman spectroscopy. Preliminary data from the studied turbidites document rich and diverse heavy-mineral assemblages in both sand and silty-sand fractions. Multiple varietal studies of amphibole, epidote and garnet varieties, representing the dominant heavy-mineral trial in orogenic detritus derived from collided ranges such as the Himalaya, were performed to highlight the wide unexplored potential of Raman spectroscopy when applied to provenance studies. Discriminating within the isomorphous series of garnets is possible, and diverse pyralspite and ugrandite garnets are distinguished by the position of characteristic peaks found at high frequencies and caused by Si-O stretching modes (873-880 cm-1 in ugrandites, 907-926 cm-1 in pyralspites; Bersani et al., 2009; Andò et al., 2009). Raman discrimination of amphibole varieties is also possible and the diagnostic position and shape of the more intense OH stretching bands (frequencies between 3600 and 3700 cm-1) are particularly helpful (Vezzoli et al., 2016). Raman discrimination of epidote-group minerals was tackled by using a new data set of the characteristic vibrational modes in the high-frequency region to facilitate distinction from other silicates and distinguish different varieties. A protocol to separate heavy minerals from the silt fraction, starting from a few grams of sediments only, was developed at the Laboratory for Provenance Studies of Milano-Bicocca. An appropriate data base of Raman spectra of detrital minerals is essential to apply this method routinely in future provenance studies of deep-sea turbidites. Such a new methodological approach plays a potentially key role to differentiate among the diverse Himalayan versus Indian Peninsular sources of detritus and opens up a new frontier for future studies of the largely unexplored deep-marine sedimentary record. Cited references S. Andò, D. Bersani, P. Vignola, E. Garzanti, 2009. Raman spectroscopy as an effective tool for high-resolution heavy-mineral analysis: examples from major Himalayan and Alpine fluvio-deltaic systems. Spectrochimica Acta Part A 73, 3, 450-455. D. Bersani, S. Andò, P. Vignola, G. Moltifiori, I.G. Marino, P.P. Lottici, V. Diella, 2009. Micro-Raman spectroscopy as a routine tool for garnet analysis. Spectrochimica Acta Part A 73, 3, 484-491. G. Vezzoli, E. Garzanti, M. Limonta, S. Andò, S. Yang, 2016. Erosion patterns in the Changjiang (Yangtze River) catchment revealed by bulk-sample versus single-mineral provenance budgets. Geomorphology 261, 177-192.

The Bolivian source rocks: Sub Andean Zone-Madre de Dios-Chaco

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

Moretti, I.; Montemurro, G.; Aguilera, E.

A complete study of source rocks has been carried out in the Bolivian foothills and foreland (Sub Andean Zone, Chaco and Madre de Dios) in order to quantify the petroleum potential of the area. Besides the classical mid-Devonian source rocks (Tequeje Formation in the north, Limoncito Formation in the center and Los Monos Formation in the south), others are important: the Tomachi Formation (late Devonian) in the north and the Copacabana Formation (Upper Carboniferous-lower Permian) in the northern Sub Andean Zone. Both show an excellent potential with S{sub 2} over 50 mg HC/g and average values higher than 10 mgmore » HC/g over few hundred meters. The Latest Cretaceous Flora Formation present locally a high potential but is very thin. Almost all the source rocks matured during the Neogene due to the subsidence in the Andean foreland and in the piggyback basins, and are thus involved on the current petroleum system. Silurian and Lower Paleozoic units also contain thick shale beds, but these source rocks were mature before the Jurassic in the south of the country. In the center, the Silurian is not nowadays overmature and may play an important role. The different zones are compared based on their Source Potential Index which indicates that the richest areas are the northern Sub Andean Zone and the Madre de Dios basin with SPI greater than 10 t/m{sup 2}. Since these two areas remain almost unexplored, these results allow us to be optimistic about the possibilities for future exploration.« less

Inhibitory and modulatory inputs to the vocal central pattern generator of a teleost fish

PubMed Central

Rosner, Elisabeth; Rohmann, Kevin N.; Bass, Andrew H.

2018-01-01

Abstract Vocalization is a behavioral feature that is shared among multiple vertebrate lineages, including fish. The temporal patterning of vocal communication signals is set, in part, by central pattern generators (CPGs). Toadfishes are well‐established models for CPG coding of vocalization at the hindbrain level. The vocal CPG comprises three topographically separate nuclei: pre‐pacemaker, pacemaker, motor. While the connectivity between these nuclei is well understood, their neurochemical profile remains largely unexplored. The highly vocal Gulf toadfish, Opsanus beta, has been the subject of previous behavioral, neuroanatomical and neurophysiological studies. Combining transneuronal neurobiotin‐labeling with immunohistochemistry, we map the distribution of inhibitory neurotransmitters and neuromodulators along with gap junctions in the vocal CPG of this species. Dense GABAergic and glycinergic label is found throughout the CPG, with labeled somata immediately adjacent to or within CPG nuclei, including a distinct subset of pacemaker neurons co‐labeled with neurobiotin and glycine. Neurobiotin‐labeled motor and pacemaker neurons are densely co‐labeled with the gap junction protein connexin 35/36, supporting the hypothesis that transneuronal neurobiotin‐labeling occurs, at least in part, via gap junction coupling. Serotonergic and catecholaminergic label is also robust within the entire vocal CPG, with additional cholinergic label in pacemaker and prepacemaker nuclei. Likely sources of these putative modulatory inputs are neurons within or immediately adjacent to vocal CPG neurons. Together with prior neurophysiological investigations, the results reveal potential mechanisms for generating multiple classes of social context‐dependent vocalizations with widely divergent temporal and spectral properties. PMID:29424431

Microplastics pollution after the removal of the Costa Concordia wreck: First evidences from a biomonitoring case study.

PubMed

Avio, Carlo Giacomo; Cardelli, Lara Roberta; Gorbi, Stefania; Pellegrini, David; Regoli, Francesco

2017-08-01

Microplastics (MPs) represent a matter of growing concern for the marine environment. Their ingestion has been documented in several species worldwide, but the impact of specific anthropogenic activities remains largely unexplored. In this study, MPs were characterized in different benthic fish sampled after 2.5 years of huge engineering operations for the parbuckling project on the Costa Concordia wreck at Giglio Island. Fish collected in proximity of the wreck showed a high ingestion of microplastics compared to both fish from a control area and values reported worldwide. Also the elevated percentage of nylon, polypropylene lines and the presence of polystyrene are quite unusual for marine organisms sampled in natural field conditions, thus supporting the possible relationship of ingested microplastics with maritime operations during wreck removal. On the other hand, the use of transplanted mussels revealed a lower frequency of ingested MPs, and did not discriminate differences between the wreck and the control area. Some variations were observed in terms of typology and size of particles between surface- and bottom-caged mussels highlighting the influence of a different distribution of MPs along the water column. In conclusion, this study demonstrated that MPs pollution in the area of Costa Concordia was more evident on benthonic environment than on seawater column, providing novel insights on the possibility of using appropriate sentinel organisms for monitoring specific anthropogenic sources of MPs pollution in the marine environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sensory complementation and antipredator behavioural compensation in acid-impacted juvenile Atlantic salmon.

PubMed

Elvidge, C K; Macnaughton, C J; Brown, G E

2013-05-01

Prey incorporate multiple forms of publicly available information on predation risk into threat-sensitive antipredator behaviours. Changes in information availability have previously been demonstrated to elicit transient alterations in behavioural patterns, while the effects of long-term deprivation of particular forms of information remain largely unexplored. Damage-released chemical alarm cues from the epidermis of fishes are rendered non-functional under weakly acidic conditions (pH < 6.6), depriving fish of an important source of information on predation risk in acidified waterbodies. We addressed the effects of long-term deprivation on the antipredator responses to different combinations of chemical and visual threat cues via in situ observations of wild, free-swimming 0(+) Atlantic salmon (Salmo salar) fry in four neutral and four weakly acidic nursery streams. In addition, a cross-population transplant experiment and natural interannual variation in acidity enabled the examination of provenance and environment as causes of the observed differences in response. Fish living under weakly acidic conditions demonstrate significantly greater or hypersensitive antipredator responses to visual cues compared to fish under neutral conditions. Under neutral conditions, fish demonstrate complementary (additive or synergistic) effects of paired visual and chemical cues consistent with threat-sensitive responses. Cross-population transplants and interannual comparisons of responses strongly support the conclusion that differences in antipredator responses between neutral and weakly acidic streams result from the loss of chemical information on predation risk, as opposed to population-derived differences in behaviours.

YSZ thin films with minimized grain boundary resistivity

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

Mills, Edmund M.; Kleine-Boymann, Matthias; Janek, Juergen

2016-03-31

In recent years, interface engineering of solid electrolytes has been explored to increase their ionic conductivity and improve the performance of solid oxide fuel cells and other electrochemical power sources. It has been observed that the ionic conductivity of epitaxially grown thin films of some electrolytes is dramatically enhanced, which is often attributed to effects (e. g. strain-induced mobility changes) at the heterophase boundary with the substrate. Still largely unexplored is the possibility of manipulation of grain boundary resistivity in polycrystalline solid electrolyte films, clearly a limiting factor in their ionic conductivity. Here we report that the ionic conductivity ofmore » yttria stabilized zirconia thin films with nano-­ columnar grains grown on a MgO substrate nearly reaches that of the corresponding single crystal when the thickness of the films becomes less than roughly 8 nm (smaller by a factor of three at 500°C). Using impedance spectroscopy, the grain boundary resistivity was probed as a function of film thickness. The resistivity of the grain boundaries near the film- substrate interface and film surface (within 4 nm of each) was almost entirely eliminated. This minimization of grain boundary resistivity is attributed to Mg2+ diffusion from the MgO substrate into the YSZ grain boundaries, which is supported by time of flight secondary ion mass spectroscopy measurements. We suggest grain boundary “design” as an attractive method to obtain highly conductive solid electrolyte thin films.« less

The dehydration stress of couch grass is associated with its lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA.

PubMed

Janská, Anna; Svoboda, Pavel; Spiwok, Vojtěch; Kučera, Ladislav; Ovesná, Jaroslava

2018-05-02

The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

YSZ thin films with minimized grain boundary resistivity

DOE PAGES

Mills, Edmund M.; Kleine-Boymann, Matthias; Janek, Juergen; ...

2016-03-31

In recent years, interface engineering of solid electrolytes has been explored to increase their ionic conductivity and improve the performance of solid oxide fuel cells and other electrochemical power sources. It has been observed that the ionic conductivity of epitaxially grown thin films of some electrolytes is dramatically enhanced, which is often attributed to effects (e.g. strain-induced mobility changes) at the heterophase boundary with the substrate. Still largely unexplored is the possibility of manipulation of grain boundary resistivity in polycrystalline solid electrolyte films, clearly a limiting factor in their ionic conductivity. Here in this paper, we report that the ionicmore » conductivity of yttria stabilized zirconia thin films with nano-columnar grains grown on a MgO substrate nearly reaches that of the corresponding single crystal when the thickness of the films becomes less than roughly 8 nm (smaller by a factor of three at 500 °C). Using impedance spectroscopy, the grain boundary resistivity was probed as a function of film thickness. The resistivity of the grain boundaries near the film–substrate interface and film surface (within 4 nm of each) was almost entirely eliminated. This minimization of grain boundary resistivity is attributed to Mg 2+ diffusion from the MgO substrate into the YSZ grain boundaries, which is supported by time of flight secondary ion mass spectroscopy measurements. We suggest grain boundary “design” as an attractive method to obtain highly conductive solid electrolyte thin films.« less

Stable Isotope-Assisted Metabolic Profiling Reveals Growth Mode Dependent Differential Metabolism and Multiple Catabolic Pathways of l-Phenylalanine in Rubrivivax benzoatilyticus JA2.

PubMed

Mekala, Lakshmi Prasuna; Mohammed, Mujahid; Chintalapati, Sasikala; Chintalapati, Venkata Ramana

2018-01-05

Anoxygenic phototrophic bacteria are metabolically versatile and survive under different growth modes using diverse organic compounds, yet their metabolic diversity is largely unexplored. In the present study, we employed stable-isotope-assisted metabolic profiling to unravel the l-phenylalanine catabolism in Rubrivivax benzoatilyticus JA2 under varying growth modes. Strain JA2 grows under anaerobic and aerobic conditions by utilizing l-phenylalanine as a nitrogen source. Furthermore, ring-labeled 13 C 6 -phenylalanine feeding followed by liquid chromatography-mass spectrometry exometabolite profiling revealed 60 labeled metabolic features (M + 6, M + 12, and M + 18) derived solely from l-phenylalanine, of which 11 were identified, 7 putatively identified, and 42 unidentified under anaerobic and aerobic conditions. However, labeled metabolites were significantly higher in aerobic compared to anaerobic conditions. Furthermore, detected metabolites and enzyme activities indicated multiple l-phenylalanine catabolic routes mainly Ehrlich, homogentisate-dependent melanin, benzenoid, and unidentified pathways operating under anaerobic and aerobic conditions in strain JA2. Interestingly, the study indicated l-phenylalanine-dependent and independent benzenoid biosynthesis in strain JA2 and a differential flux of l-phenylalanine to Ehrlich and benzenoid pathways under anaerobic and aerobic conditions. Additionally, unidentified labeled metabolites strongly suggest the presence of unknown phenylalanine catabolic routes in strain JA2. Overall, the study uncovered the l-phenylalanine catabolic diversity in strain JA2 and demonstrated the potential of stable isotope-assisted metabolomics in unraveling the hidden metabolic repertoire.

Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

PubMed

Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

2015-04-21

The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ∼67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden.

Differential Response of Fish Assemblages to Coral Reef-Based Seaweed Farming

PubMed Central

Hehre, E. James; Meeuwig, J. J.

2015-01-01

As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1) marine protected areas (MPAs) were established, (2) neither MPAs nor blast fishing was present (hence “unprotected”), and (3) blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs. PMID:25822342

Differential response of fish assemblages to coral reef-based seaweed farming.

PubMed

Hehre, E James; Meeuwig, J J

2015-01-01

As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1) marine protected areas (MPAs) were established, (2) neither MPAs nor blast fishing was present (hence "unprotected"), and (3) blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs.

Distribution of isoflavones and coumestrol in neglected tropical and subtropical legumes.

PubMed

Leuner, Olga; Havlik, Jaroslav; Hummelova, Jana; Prokudina, Elena; Novy, Pavel; Kokoska, Ladislav

2013-02-01

Isoflavones and coumestrol from dietary legumes are plant constituents showing multiple beneficial effects on humans. Owing to their ability to bind with mammalian estrogenic receptors and thereby intervention in several kinds of hormone-related cancers, they have received much attention. Soybean (Glycine max) is currently the major source of isoflavonoids in human diet. However, dozens of tropical and subtropical leguminous species remain unexplored for their isoflavonoids content. We have analyzed 55 extracts from 41 tropical and subtropical legume species used either in human or animal diet by high-performance liquid chromatography for the content of soy isoflavones, biochanin A, daidzein, daidzin, formononetin, genistein, genistin, sissotrin, ononin and the coumestan coumestrol. Genistein and biochanin A were the most abundant compounds. The highest content of genistein was found in aerial parts of Andira macrothyrsa, seeds of Pachyrhizus tuberosus and aerial parts of Calopogonium mucunoides (598, 250 and 184 µg g(-1), respectively) and biochanin A in aerial parts of Cratylia argentea, C. mucunoides and flowers of A. macrothyrsa (76, 53 and 40 µg g(-1), respectively). None of the samples tested was richer overall source of soy isoflavones and coumestrol than soybean; nevertheless several species (C. mucunoides or A. macrothyrsa) may serve as a promising source of individual compounds. Copyright © 2012 Society of Chemical Industry.

Nanosats for a Radio Interferometer Observatory in Space

NASA Astrophysics Data System (ADS)

Cecconi, B.; Katsanevras, S.; Puy, D.; Bentum, M.

2015-10-01

During the last decades, astronomy and space physics changed dramatically our knowledge of the evolution of the Universe. However, our view is still incomplete in the very low frequency range (1- 30 MHz), which is thus one of the last unexplored astrophysical spectral band. Below 30 MHz, ionospheric fluctuations severely perturb groundbased observations. They are impossible below 10 MHz due to the ionospheric cutoff. In addition, man made radio interferences makes it even more difficult to observe from ground at low frequencies. Deploying a radio instrument in space is the only way to open this new window on the Universe. Among the many science objectives for such type of instrumentations, we can find cosmological studies such as the Dark Ages of the Universe, the remote astrophysical objects, pulsars and fast transients, the interstellar medium. The following Solar system and Planetary objectives are also very important: - Sun-Earth Interactions: The Sun is strongly influencing the interplanetary medium (IPM) and the terrestrial geospatial environment. The evolution mechanisms of coronal mass ejections (CME) and their impact on solar system bodies are still not fully understood. This results in large inaccuracies on the eruption models and prediction tools, and their consequences on the Earth environment. Very low frequency radio imaging capabilities (especially for the Type II solar radio bursts, which are linked with interplanetary shocks) should allow the scientific community to make a big step forward in understanding of the physics and the dynamics of these phenomena, by observing the location of the radio source, how they correlate with their associated shocks and how they propagate within the IPM. - Planets and Exoplanets: The Earth and the fourgiant planets are hosting strong magnetic fields producing large magnetospheres. Particle acceleration are very efficient therein and lead to emitting intense low frequency radio waves in their auroral regions. These radio emissions are produced through the Cyclotron Maser Instability (CMI). Locating the radio sources and tracing back their path along magnetic field lines leads to the particle acceleration regions. This diagnostic is powerful remote sensing tool for studying the dynamics of planetary magnetospheres. Planetary lightnings are also a source electromagnetic radiation, which allows us to sound both planetary atmospheric and ionospheric properties. Finally, the potential observations of exoplanetary radio emissions at low frequencies are a very promising way of getting intrinsic properties of exoplanets such as their sidereal rotation period, the inclination of their rotation axis or magnetic axis, the intensity of their internal magnetic field, etc…

Can sediments at hydrocarbon seep sites represent a source for marine bioavailable iron? — A case study from the South China Sea

NASA Astrophysics Data System (ADS)

Li, N.; Feng, D.; Chen, D.

2017-12-01

Niu Li1, Dong Feng1,2, and Duofu Chen2,31CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. 2Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China. 3Hadal Science and Technology Research Center, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China. Iron is an essential micronutrient and commonly considered to be one of the key-limiting factors for biological productivity in many ocean regions. Seafloor Fe supply should be most efficient in suboxic conditions. Recent studies shown that widely spread anoxic environments can develop in hydrocarbon seep sediment and local bottom water, owing to the occurrence of aerobic and/or anaerobic methane oxidation. Under this condition, the iron in sediment can be reduced to dissolved Fe2+ in the ocean. However, questions remain about whether the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean, and the control factor for the transformation of iron in the sediment remains largely unexplored. For a number of hydrocarbon seeps from the northern and southern South China Sea, the iron speciation, pyrite sulfur isotope, and iron isotope, as well as the major and trace elements are used to constrain the intensity of cold seep, and its impact on transformation of iron in sediment. Samples from both areas show sediment iron lost during the high methane flux conditions, owing to the suboxic conditions cause by aerobic methane oxidation. On the other hand, high sediment iron content accompanied by high sulfur content can be seen during the conditions of high methane flux without the occurrence of aerobic methane oxidation, which is possible ascribed to the anaerobic methane oxidation and the release of iron through seep activity. This study reveals the transformation of iron in the sediment is closely related to the methane flux and the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean. Acknowledgments: Funding was provided by the NSF of China (Grants: 41422602 and 41373085).

Microbial communities mediating algal detritus turnover under anaerobic conditions

PubMed Central

Morrison, Jessica M.; Murphy, Chelsea L.; Baker, Kristina; Zamor, Richard M.; Nikolai, Steve J.; Wilder, Shawn; Elshahed, Mostafa S.

2017-01-01

Background Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. Results Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta), Chara sp. strain IWP1 (Charophyceae), and kelp Ascophyllum nodosum (phylum Phaeophyceae), using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT), sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT), and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL) as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes), Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate. Lineages enriched included the uncultured groups VadinBC27 and WCHB1-69 within the Bacteroidetes, genus Spirochaeta and the uncultured group SHA-4 within Spirochaetes, Ruminococcaceae, Lachnospiraceae, Yongiibacter, Geosporobacter, and Acidaminobacter within the Firmicutes, and genera Kluyvera, Pantoea, Edwardsiella and Aeromonas, and Buttiauxella within the Gamma-Proteobaceteria order Enterobacteriales. Conclusions Our results represent the first systematic survey of microbial communities mediating turnover of algal biomass under anaerobic conditions, and highlights the diversity of lineages putatively involved in the degradation process. PMID:28097050

Spatiotemporal canards in neural field equations

NASA Astrophysics Data System (ADS)

Avitabile, D.; Desroches, M.; Knobloch, E.

2017-04-01

Canards are special solutions to ordinary differential equations that follow invariant repelling slow manifolds for long time intervals. In realistic biophysical single-cell models, canards are responsible for several complex neural rhythms observed experimentally, but their existence and role in spatially extended systems is largely unexplored. We identify and describe a type of coherent structure in which a spatial pattern displays temporal canard behavior. Using interfacial dynamics and geometric singular perturbation theory, we classify spatiotemporal canards and give conditions for the existence of folded-saddle and folded-node canards. We find that spatiotemporal canards are robust to changes in the synaptic connectivity and firing rate. The theory correctly predicts the existence of spatiotemporal canards with octahedral symmetry in a neural field model posed on the unit sphere.

Materials chemistry. Composition-matched molecular "solders" for semiconductors.

PubMed

Dolzhnikov, Dmitriy S; Zhang, Hao; Jang, Jaeyoung; Son, Jae Sung; Panthani, Matthew G; Shibata, Tomohiro; Chattopadhyay, Soma; Talapin, Dmitri V

2015-01-23

We propose a general strategy to synthesize largely unexplored soluble chalcogenidometallates of cadmium, lead, and bismuth. These compounds can be used as "solders" for semiconductors widely used in photovoltaics and thermoelectrics. The addition of solder helped to bond crystal surfaces and link nano- or mesoscale particles together. For example, CdSe nanocrystals with Na2Cd2Se3 solder was used as a soluble precursor for CdSe films with electron mobilities exceeding 300 square centimeters per volt-second. CdTe, PbTe, and Bi2Te3 powders were molded into various shapes in the presence of a small additive of composition-matched chalcogenidometallate or chalcogel, thus opening new design spaces for semiconductor technologies. Copyright © 2015, American Association for the Advancement of Science.

Substantially Enhancing Quantum Coherence of Electrons in Graphene via Electron-Plasmon Coupling.

PubMed

Cheng, Guanghui; Qin, Wei; Lin, Meng-Hsien; Wei, Laiming; Fan, Xiaodong; Zhang, Huayang; Gwo, Shangjr; Zeng, Changgan; Hou, J G; Zhang, Zhenyu

2017-10-13

The interplays between different quasiparticles in solids lay the foundation for a wide spectrum of intriguing quantum effects, yet how the collective plasmon excitations affect the quantum transport of electrons remains largely unexplored. Here we provide the first demonstration that when the electron-plasmon coupling is introduced, the quantum coherence of electrons in graphene is substantially enhanced with the quantum coherence length almost tripled. We further develop a microscopic model to interpret the striking observations, emphasizing the vital role of the graphene plasmons in suppressing electron-electron dephasing. The novel and transformative concept of plasmon-enhanced quantum coherence sheds new insight into interquasiparticle interactions, and further extends a new dimension to exploit nontrivial quantum phenomena and devices in solid systems.

Observations of Pulsed Emission from Pulsars

NASA Astrophysics Data System (ADS)

Kramer, Michael

2008-02-01

This brief review summarises what we know observationally about the pulsed emission of pulsars across the electromagnetic spectrum. I describe the wide range of timescales observed in the properties of pulsed emission which cover about 18 orders of magnitude. Future advances in observations capabilities, most notably at gamma-ray and radio frequencies, are expected to significantly enhance our understanding of pulsars and their emission, as a large fraction of our discovery phase space is still unexplored. The first glimpse of the plethora of unknown phenomena yet to be found was given recently by the discovery of new classes of neutron stars such as Rotating Radio Transients (RRATs) and Intermittent Pulsars. We discuss these discoveries and demonstrate how they provide useful information for our understanding of pulsed emission in general.

Some partial-unit-memory convolutional codes

NASA Technical Reports Server (NTRS)

Abdel-Ghaffar, K.; Mceliece, R. J.; Solomon, G.

1991-01-01

The results of a study on a class of error correcting codes called partial unit memory (PUM) codes are presented. This class of codes, though not entirely new, has until now remained relatively unexplored. The possibility of using the well developed theory of block codes to construct a large family of promising PUM codes is shown. The performance of several specific PUM codes are compared with that of the Voyager standard (2, 1, 6) convolutional code. It was found that these codes can outperform the Voyager code with little or no increase in decoder complexity. This suggests that there may very well be PUM codes that can be used for deep space telemetry that offer both increased performance and decreased implementational complexity over current coding systems.

The Relation Between Supervisors' Big Five Personality Traits and Employees' Experiences of Abusive Supervision.

PubMed

Camps, Jeroen; Stouten, Jeroen; Euwema, Martin

2016-01-01

The present study investigates the relation between supervisors' personality traits and employees' experiences of supervisory abuse, an area that - to date - remained largely unexplored in previous research. Field data collected from 103 supervisor-subordinate dyads showed that contrary to our expectations supervisors' agreeableness and neuroticism were not significantly related to abusive supervision, nor were supervisors' extraversion or openness to experience. Interestingly, however, our findings revealed a positive relation between supervisors' conscientiousness and abusive supervision. That is, supervisors high in conscientiousness were more likely to be perceived as an abusive supervisor by their employees. Overall, our findings do suggest that supervisors' Big Five personality traits explain only a limited amount of the variability in employees' experiences of abusive supervision.

Imaging nanobubble nucleation and hydrogen spillover during electrocatalytic water splitting.

PubMed

Hao, Rui; Fan, Yunshan; Howard, Marco D; Vaughan, Joshua C; Zhang, Bo

2018-06-05

Nucleation and growth of hydrogen nanobubbles are key initial steps in electrochemical water splitting. These processes remain largely unexplored due to a lack of proper tools to probe the nanobubble's interfacial structure with sufficient spatial and temporal resolution. We report the use of superresolution microscopy to image transient formation and growth of single hydrogen nanobubbles at the electrode/solution interface during electrocatalytic water splitting. We found hydrogen nanobubbles can be generated even at very early stages in water electrolysis, i.e., ∼500 mV before reaching its thermodynamic reduction potential. The ability to image single nanobubbles on an electrode enabled us to observe in real time the process of hydrogen spillover from ultrathin gold nanocatalysts supported on indium-tin oxide.

Talk that talk: storytelling and analysis rooted in African American oral tradition.

PubMed

Banks-Wallace, JoAnne

2002-03-01

Stories are the foundation of qualitative research. However, the development of qualitative methods rooted in oral traditions remains largely unexplored by researchers. The contextual and historical influences on storytelling and storytaking are critical features of the African American oral tradition that are often ignored or minimized in qualitative research. Despite the complex and often contentious history of African Americans, their oral traditions have not been explored to reveal the depth of their lived experiences and the way those experiences inform their health concerns. The purpose of this article is twofold. First, dialogues about storytelling and storytaking are revisited and critiqued. Second, a comprehensive analytic process for gathering and interpreting stories rooted in African American oral tradition is outlined.

Cultural Evolutionary Perspectives on Creativity and Human Innovation.

PubMed

Fogarty, Laurel; Creanza, Nicole; Feldman, Marcus W

2015-12-01

Cultural traits originate through creative or innovative processes, which might be crucial to understanding how culture evolves and accumulates. However, because of its complexity and apparent subjectivity, creativity has remained largely unexplored as the dynamic underpinning of cultural evolution. Here, we explore the approach to innovation commonly taken in theoretical studies of cultural evolution and discuss its limitations. Drawing insights from cognitive science, psychology, archeology, and even animal behavior, it is possible to generate a formal description of creativity and to incorporate a dynamic theory of creativity into models of cultural evolution. We discuss the implications of such models for our understanding of the archaeological record and the history of hominid culture. Copyright © 2015 Elsevier Ltd. All rights reserved.

A polarized Drell-Yan experiment to probe the dynamics of the nucleon sea

DOE PAGES

Kleinjan, David W.

2015-01-01

In QCD, nucleon spin comes from the sum of the quark spin, gluon spin, and the quark and gluon orbital angular momentum, but how these different components contribute and the interplay among them is not yet understood. For instance, sea quark orbital contribution remains largely unexplored. Measurements of the Sivers function for the sea quarks will provide a probe of the sea quark orbital contribution. The upcoming E1039 experiment at Fermilab will measure the Sivers asymmetry of the sea quarks via the Drell-Yan process using a 120 GeV unpolarized proton beam directed a transversely polarized ammonia target. Lastly, we reportmore » on the status and plans of the E1039 polarized Drell-Yan experiment.« less

A polarized Drell-Yan experiment to probe the dynamics of the nucleon sea

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

Kleinjan, David

In QCD, nucleon spin comes from the sum of the quark spin, gluon spin, and the quark and gluon orbital angular momentum, but how these different components contribute and the interplay among them is not yet understood. For instance, sea quark orbital contribution remains largely unexplored. Measurements of the Sivers function for the sea quarks will provide a probe of the sea quark orbital contribution. The upcoming E1039 experiment at Fermilab will measure the Sivers asymmetry of the sea quarks via the Drell-Yan process using a 120 GeV unpolarized proton beam directed a transversely polarized ammonia target. We report onmore » the status and plans of the E1039 polarized Drell-Yan experiment.« less

Olfactory gene expression in migrating adult sockeye salmon Oncorhynchus nerka.

PubMed

Bett, N N; Hinch, S G; Kaukinen, K H; Li, S; Miller, K M

2018-04-16

Expression of 12 olfactory genes was analysed in adult sockeye salmon Oncorhynchus nerka nearing spawning grounds and O. nerka that had strayed from their natal migration route. Variation was found in six of these genes, all of which were olfc olfactory receptors and had lower expression levels in salmon nearing spawning grounds. The results may reflect decreased sensitivity to natal water olfactory cues as these fish are no longer seeking the correct migratory route. The expression of olfactory genes during the olfactory-mediated spawning migration of Pacific salmon Oncorhynchus spp. is largely unexplored and these findings demonstrate a link between migratory behaviours and olfactory plasticity that provides a basis for future molecular research on salmon homing. © 2018 The Fisheries Society of the British Isles.

The joint center for energy storage research: A new paradigm for battery research and development

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

Crabtree, George

2015-03-30

The Joint Center for Energy Storage Research (JCESR) seeks transformational change in transportation and the electricity grid driven by next generation high performance, low cost electricity storage. To pursue this transformative vision JCESR introduces a new paradigm for battery research: integrating discovery science, battery design, research prototyping and manufacturing collaboration in a single highly interactive organization. This new paradigm will accelerate the pace of discovery and innovation and reduce the time from conceptualization to commercialization. JCESR applies its new paradigm exclusively to beyond-lithium-ion batteries, a vast, rich and largely unexplored frontier. This review presents JCESR's motivation, vision, mission, intended outcomesmore » or legacies and first year accomplishments.« less

Interactions Between HIV/AIDS and the Environment: Toward a Syndemic Framework

PubMed Central

Bolton, Susan; Walson, Judd L.

2013-01-01

Although the social, economic, and political dimensions of the HIV/AIDS epidemic have been studied in considerable depth, the relationship between HIV/AIDS and its environmental causes and consequences remains largely unexplored. We reviewed the evidence of interactions between ecosystem health and the HIV/AIDS pandemic. We hypothesized a syndemic between environmental degradation and HIV/AIDS; they exhibit bidirectional, self-reinforcing interactions. We have presented a syndemic framework detailing multiple synergistic relationships. This framework hinges on the vulnerability of populations as the linchpin between the pandemic and environmental health. A coherent research and practice agenda for addressing the syndemic that focuses on the 2 issues as not only concurrent but also intertwined phenomena is urgently needed. PMID:23237167

Engineering cyanobacteria to generate high-value products.

PubMed

Ducat, Daniel C; Way, Jeffrey C; Silver, Pamela A

2011-02-01

Although many microorganisms have been used for the bioindustrial generation of valuable metabolites, the productive potential of cyanobacterial species has remained largely unexplored. Cyanobacteria possess several advantages as organisms for bioindustrial processes, including simple input requirements, tolerance of marginal agricultural environments, rapid genetics, and carbon-neutral applications that could be leveraged to address global climate change concerns. Here, we review recent research involving the engineering of cyanobacterial species for the production of valuable bioindustrial compounds, including natural cyanobacterial products (e.g. sugars and isoprene), biofuels (e.g. alcohols, alkanes and hydrogen), and other commodity chemicals. Biological and economic obstacles to scaled cyanobacterial production are highlighted, and methods for increasing cyanobacterial production efficiencies are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Linking Temperamental Shyness and Social Anxiety in Childhood and Adolescence: Moderating Influences of Sex and Age.

PubMed

Tsui, Tiffany Y L; Lahat, Ayelet; Schmidt, Louis A

2017-10-01

Although childhood shyness has been linked to social anxiety problems, the factors playing a role in this association have gone largely unexplored. Here we examined the potential moderating roles of sex and age on this relation in a sample of 119 (75 girls) children (10-12 years) and adolescents (14-16 years). As predicted, shyness was positively associated with social anxiety symptoms. Sex, but not age, served as a moderating factor in linking shyness and social anxiety. Specifically, shyness was more strongly associated with social anxiety symptoms among girls than boys. These results suggest the importance of considering sex differences when examining the relation between shyness and social anxiety in childhood and adolescence.

Genomic Encyclopedia of Type Strains of the Genus Bifidobacterium

PubMed Central

Milani, Christian; Lugli, Gabriele Andrea; Duranti, Sabrina; Turroni, Francesca; Bottacini, Francesca; Mangifesta, Marta; Sanchez, Borja; Viappiani, Alice; Mancabelli, Leonardo; Taminiau, Bernard; Delcenserie, Véronique; Barrangou, Rodolphe; Margolles, Abelardo; van Sinderen, Douwe

2014-01-01

Bifidobacteria represent one of the dominant microbial groups that are present in the gut of various animals, being particularly prevalent during the suckling stage of life of humans and other mammals. However, the overall genome structure of this group of microorganisms remains largely unexplored. Here, we sequenced the genomes of 42 representative (sub)species across the Bifidobacterium genus and used this information to explore the overall genetic picture of this bacterial group. Furthermore, the genomic data described here were used to reconstruct the evolutionary development of the Bifidobacterium genus. This reconstruction suggests that its evolution was substantially influenced by genetic adaptations to obtain access to glycans, thereby representing a common and potent evolutionary force in shaping bifidobacterial genomes. PMID:25085493

NASA's New Discovery Missions

NASA Image and Video Library

2017-01-04

On Jan. 4, 2017 NASA announced the selection of two missions to explore previously unexplored asteroids. The first mission, called Lucy, will study asteroids, known as Trojan asteroids, trapped by Jupiter’s gravity. The Psyche mission will explore a very large and rare object in the solar system’s asteroid belt that’s made of metal, and scientists believe might be the exposed core of a planet that lost its rocky outer layers from a series of violent collisions. Lucy is targeted for launch in 2021 and Psyche in 2023. Both missions have the potential to open new windows on one of the earliest eras in the history of our solar system – a time less than 10 million years after the birth of our sun.

Grating-assisted coupling to nanophotonic circuits in microcrystalline diamond thin films.

PubMed

Rath, Patrik; Khasminskaya, Svetlana; Nebel, Christoph; Wild, Christoph; Pernice, Wolfram Hp

2013-01-01

Synthetic diamond films can be prepared on a waferscale by using chemical vapour deposition (CVD) on suitable substrates such as silicon or silicon dioxide. While such films find a wealth of applications in thermal management, in X-ray and terahertz window design, and in gyrotron tubes and microwave transmission lines, their use for nanoscale optical components remains largely unexplored. Here we demonstrate that CVD diamond provides a high-quality template for realizing nanophotonic integrated optical circuits. Using efficient grating coupling devices prepared from partially etched diamond thin films, we investigate millimetre-sized optical circuits and achieve single-mode waveguiding at telecoms wavelengths. Our results pave the way towards broadband optical applications for sensing in harsh environments and visible photonic devices.

Babinet-Inverted Optical Yagi-Uda Antenna for Unidirectional Radiation to Free Space

NASA Astrophysics Data System (ADS)

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Choe, Jong-Ho; Lee, Jongcheon; Lee, Jaesoong; Jeong, Heejeong; Kim, Un Jeong; Park, Yeonsang; Song, In Yong; Park, Q.-Han; Hwang, Sung Woo; Kim, Kinam; Lee, Chang-Won

2014-06-01

Plasmonic nanoantennas are key elements in nanophotonics capable of directing radiation or enhancing the transition rate of a quantum emitter. Slot-type magnetic-dipole nanoantennas, which are complementary structures of typical electric-dipole-type antennas, have received little attention, leaving their antenna properties largely unexplored. Here we present a novel magnetic-dipole-fed multi-slot optical Yagi-Uda antenna. By engineering the relative phase of the interacting surface plasmon polaritons between the slot elements, we demonstrate that the optical antenna exhibits highly unidirectional radiation to free space. The unique features of the slot-based magnetic nanoantenna provide a new possibility of achieving integrated features such as energy transfer from one waveguide to another by working as a future optical via.

Early stage of plastic deformation in thin films undergoing electromigration

NASA Astrophysics Data System (ADS)

Valek, B. C.; Tamura, N.; Spolenak, R.; Caldwell, W. A.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Bravman, J. C.; Batterman, B. W.; Nix, W. D.; Patel, J. R.

2003-09-01

Electromigration occurs when a high current density drives atomic motion from the cathode to the anode end of a conductor, such as a metal interconnect line in an integrated circuit. While electromigration eventually causes macroscopic damage, in the form of voids and hillocks, the earliest stage of the process when the stress in individual micron-sized grains is still building up is largely unexplored. Using synchrotron-based x-ray microdiffraction during an in-situ electromigration experiment, we have discovered an early prefailure mode of plastic deformation involving preferential dislocation generation and motion and the formation of a subgrain structure within individual grains of a passivated Al (Cu) interconnect. This behavior occurs long before macroscopic damage (hillocks and voids) is observed.

Modelling impacts of climate change on arable crop diseases: progress, challenges and applications.

PubMed

Newbery, Fay; Qi, Aiming; Fitt, Bruce Dl

2016-08-01

Combining climate change, crop growth and crop disease models to predict impacts of climate change on crop diseases can guide planning of climate change adaptation strategies to ensure future food security. This review summarises recent developments in modelling climate change impacts on crop diseases, emphasises some major challenges and highlights recent trends. The use of multi-model ensembles in climate change modelling and crop modelling is contributing towards measures of uncertainty in climate change impact projections but other aspects of uncertainty remain largely unexplored. Impact assessments are still concentrated on few crops and few diseases but are beginning to investigate arable crop disease dynamics at the landscape level. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Magnetour: Surfing planetary systems on electromagnetic and multi-body gravity fields

NASA Astrophysics Data System (ADS)

Lantoine, Gregory; Russell, Ryan P.; Anderson, Rodney L.; Garrett, Henry B.

2017-09-01

A comprehensive tour of the complex outer planet systems is a central goal in space science. However, orbiting multiple moons of the same planet would be extremely prohibitive using traditional propulsion and power technologies. In this paper, a new mission concept, named Magnetour, is presented to facilitate the exploration of outer planet systems and address both power and propulsion challenges. This approach would enable a single spacecraft to orbit and travel between multiple moons of an outer planet, without significant propellant or onboard power source. To achieve this free-lunch 'Grand Tour', Magnetour exploits the unexplored combination of magnetic and multi-body gravitational fields of planetary systems, with a unique focus on using a bare electrodynamic tether for power and propulsion. Preliminary results indicate that the Magnetour concept is sound and is potentially highly promising at Jupiter.

Optimal pollution mitigation in Monterey Bay based on coastal radar data and nonlinear dynamics.

PubMed

Coulliette, Chad; Lekien, Francois; Paduan, Jeffrey D; Haller, George; Marsden, Jerrold E

2007-09-15

High-frequency (HF) radar technology produces detailed velocity maps near the surface of estuaries and bays. The use of velocity data in environmental prediction, nonetheless, remains unexplored. In this paper, we uncover a striking flow structure in coastal radar observations of Monterey Bay, along the California coastline. This complex structure governs the spread of organic contaminants, such as agricultural runoff which is a typical source of pollution in the bay. We show that a HF radar-based pollution release scheme using this flow structure reduces the impact of pollution on the coastal environment in the bay. We predict the motion of the Lagrangian flow structures from finite-time Lyapunov exponents of the coastal HF velocity data. From this prediction, we obtain optimal release times, at which pollution leaves the bay most efficiently.

Anticancer Drugs from Marine Flora: An Overview

PubMed Central

Sithranga Boopathy, N.; Kathiresan, K.

2010-01-01

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease. PMID:21461373

Degradation of Highly Alloyed Metal Halide Perovskite Precursor Inks: Mechanism and Storage Solutions

DOE PAGES

Dou, Benjia; Wheeler, Lance M.; Christians, Jeffrey A.; ...

2018-03-14

Whereas the promise of metal halide perovskite (MHP) photovoltaics (PV) is that they can combine high efficiency with solution-processability, the chemistry occurring in precursor inks is largely unexplored. Herein, we investigate the degradation of MHP solutions based on the most widely used solvents, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). For the MHP inks studied, which contain formamidinium (FA+), methylammonium (MA+), cesium (Cs+), lead (Pb2+), bromide (Br-), and iodide (I-), dramatic compositional changes are observed following storage of the inks in nitrogen in the dark. We show that hydrolysis of DMF in the precursor solution forms dimethylammonium formate, which subsequently incorporatesmore » into the MHP film to compromise the ability of Cs+ and MA+ to stabilize FA+-based MHP. The changes in solution chemistry lead to a modification of the perovskite film stoichiometry, band gap, and structure. The solid precursor salts are stable when ball-milled into a powder, allowing for the storage of large quantities of stoichiometric precursor materials.« less

Size-Dependent Melting Behavior of Colloidal In, Sn, and Bi Nanocrystals

PubMed Central

Liu, Minglu; Wang, Robert Y.

2015-01-01

Colloidal nanocrystals are a technologically important class of nanostructures whose phase change properties have been largely unexplored. Here we report on the melting behavior of In, Sn, and Bi nanocrystals dispersed in a polymer matrix. This polymer matrix prevents the nanocrystals from coalescing with one another and enables previously unaccessed observations on the melting behavior of colloidal nanocrystals. We measure the melting temperature, melting enthalpy, and melting entropy of colloidal nanocrystals with diameters of approximately 10 to 20 nm. All of these properties decrease as nanocrystal size decreases, although the depression rate for melting temperature is comparatively slower than that of melting enthalpy and melting entropy. We also observe an elevated melting temperature during the initial melt-freeze cycle that we attribute to surface stabilization from the organic ligands on the nanocrystal surface. Broad endothermic melting valleys and very large supercoolings in our calorimetry data suggest that colloidal nanocrystals exhibit a significant amount of surface pre-melting and low heterogeneous nucleation probabilities during freezing. PMID:26573146

Survey of Neurological Disorders in Children Aged 9-15 Years in Northern India.

PubMed

Kumar, Rashmi; Bhave, Anupama; Bhargava, Roli; Agarwal, G G

2016-04-01

The prevalence of neurological disorders in resource-poor settings, although likely to be high, is largely unexplored. The prevalence and risk factors for neurological disorders, including epilepsy and intellectual, motor, vision, and hearing deficits, in children aged 9 to 15 years in the community were investigated. A new instrument was developed, validated, and used in a 2-stage community survey for neurological disorders in Lucknow, India. Screen-positives and random proportion of screen-negatives were validated using predefined criteria. Prevalence of different neurological disorders was calculated by weighted proportions. Of 6431 children screened, 221 were positive. A total of 214 screen-positives and 251 screen-negatives were validated. Prevalence of neurological disorders was 31.3 per 1000 children of this age group (weighted 95% confidence interval = 16.5, 46.4). The final model for risk factors included age, mud house, delayed cry at birth, and previous head injury. The prevalence of neurological disorders is high in this region. Predictors of neurological disorders are largely modifiable. © The Author(s) 2015.

Finite-size correction scheme for supercell calculations in Dirac-point two-dimensional materials.

PubMed

Rocha, C G; Rocha, A R; Venezuela, P; Garcia, J H; Ferreira, M S

2018-06-19

Modern electronic structure calculations are predominantly implemented within the super cell representation in which unit cells are periodically arranged in space. Even in the case of non-crystalline materials, defect-embedded unit cells are commonly used to describe doped structures. However, this type of computation becomes prohibitively demanding when convergence rates are sufficiently slow and may require calculations with very large unit cells. Here we show that a hitherto unexplored feature displayed by several 2D materials may be used to achieve convergence in formation- and adsorption-energy calculations with relatively small unit-cell sizes. The generality of our method is illustrated with Density Functional Theory calculations for different 2D hosts doped with different impurities, all of which providing accuracy levels that would otherwise require enormously large unit cells. This approach provides an efficient route to calculating the physical properties of 2D systems in general but is particularly suitable for Dirac-point materials doped with impurities that break their sublattice symmetry.

Hydrodynamics of insect spermatozoa

NASA Astrophysics Data System (ADS)

Pak, On Shun; Lauga, Eric

2010-11-01

Microorganism motility plays important roles in many biological processes including reproduction. Many microorganisms propel themselves by propagating traveling waves along their flagella. Depending on the species, propagation of planar waves (e.g. Ceratium) and helical waves (e.g. Trichomonas) were observed in eukaryotic flagellar motion, and hydrodynamic models for both were proposed in the past. However, the motility of insect spermatozoa remains largely unexplored. An interesting morphological feature of such cells, first observed in Tenebrio molitor and Bacillus rossius, is the double helical deformation pattern along the flagella, which is characterized by the presence of two superimposed helical flagellar waves (one with a large amplitude and low frequency, and the other with a small amplitude and high frequency). Here we present the first hydrodynamic investigation of the locomotion of insect spermatozoa. The swimming kinematics, trajectories and hydrodynamic efficiency of the swimmer are computed based on the prescribed double helical deformation pattern. We then compare our theoretical predictions with experimental measurements, and explore the dependence of the swimming performance on the geometric and dynamical parameters.

Current crowding mediated large contact noise in graphene field-effect transistors

PubMed Central

Karnatak, Paritosh; Sai, T. Phanindra; Goswami, Srijit; Ghatak, Subhamoy; Kaushal, Sanjeev; Ghosh, Arindam

2016-01-01

The impact of the intrinsic time-dependent fluctuations in the electrical resistance at the graphene–metal interface or the contact noise, on the performance of graphene field-effect transistors, can be as adverse as the contact resistance itself, but remains largely unexplored. Here we have investigated the contact noise in graphene field-effect transistors of varying device geometry and contact configuration, with carrier mobility ranging from 5,000 to 80,000 cm2 V−1 s−1. Our phenomenological model for contact noise because of current crowding in purely two-dimensional conductors confirms that the contacts dominate the measured resistance noise in all graphene field-effect transistors in the two-probe or invasive four-probe configurations, and surprisingly, also in nearly noninvasive four-probe (Hall bar) configuration in the high-mobility devices. The microscopic origin of contact noise is directly linked to the fluctuating electrostatic environment of the metal–channel interface, which could be generic to two-dimensional material-based electronic devices. PMID:27929087

Degradation of Highly Alloyed Metal Halide Perovskite Precursor Inks: Mechanism and Storage Solutions

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

Dou, Benjia; Wheeler, Lance M.; Christians, Jeffrey A.

Whereas the promise of metal halide perovskite (MHP) photovoltaics (PV) is that they can combine high efficiency with solution-processability, the chemistry occurring in precursor inks is largely unexplored. Herein, we investigate the degradation of MHP solutions based on the most widely used solvents, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). For the MHP inks studied, which contain formamidinium (FA+), methylammonium (MA+), cesium (Cs+), lead (Pb2+), bromide (Br-), and iodide (I-), dramatic compositional changes are observed following storage of the inks in nitrogen in the dark. We show that hydrolysis of DMF in the precursor solution forms dimethylammonium formate, which subsequently incorporatesmore » into the MHP film to compromise the ability of Cs+ and MA+ to stabilize FA+-based MHP. The changes in solution chemistry lead to a modification of the perovskite film stoichiometry, band gap, and structure. The solid precursor salts are stable when ball-milled into a powder, allowing for the storage of large quantities of stoichiometric precursor materials.« less

Current crowding mediated large contact noise in graphene field-effect transistors

NASA Astrophysics Data System (ADS)

Karnatak, Paritosh; Sai, T. Phanindra; Goswami, Srijit; Ghatak, Subhamoy; Kaushal, Sanjeev; Ghosh, Arindam

2016-12-01

The impact of the intrinsic time-dependent fluctuations in the electrical resistance at the graphene-metal interface or the contact noise, on the performance of graphene field-effect transistors, can be as adverse as the contact resistance itself, but remains largely unexplored. Here we have investigated the contact noise in graphene field-effect transistors of varying device geometry and contact configuration, with carrier mobility ranging from 5,000 to 80,000 cm2 V-1 s-1. Our phenomenological model for contact noise because of current crowding in purely two-dimensional conductors confirms that the contacts dominate the measured resistance noise in all graphene field-effect transistors in the two-probe or invasive four-probe configurations, and surprisingly, also in nearly noninvasive four-probe (Hall bar) configuration in the high-mobility devices. The microscopic origin of contact noise is directly linked to the fluctuating electrostatic environment of the metal-channel interface, which could be generic to two-dimensional material-based electronic devices.

The Genetic Basis of Natural Variation in Caenorhabditis elegans Telomere Length.

PubMed

Cook, Daniel E; Zdraljevic, Stefan; Tanny, Robyn E; Seo, Beomseok; Riccardi, David D; Noble, Luke M; Rockman, Matthew V; Alkema, Mark J; Braendle, Christian; Kammenga, Jan E; Wang, John; Kruglyak, Leonid; Félix, Marie-Anne; Lee, Junho; Andersen, Erik C

2016-09-01

Telomeres are involved in the maintenance of chromosomes and the prevention of genome instability. Despite this central importance, significant variation in telomere length has been observed in a variety of organisms. The genetic determinants of telomere-length variation and their effects on organismal fitness are largely unexplored. Here, we describe natural variation in telomere length across the Caenorhabditis elegans species. We identify a large-effect variant that contributes to differences in telomere length. The variant alters the conserved oligonucleotide/oligosaccharide-binding fold of protection of telomeres 2 (POT-2), a homolog of a human telomere-capping shelterin complex subunit. Mutations within this domain likely reduce the ability of POT-2 to bind telomeric DNA, thereby increasing telomere length. We find that telomere-length variation does not correlate with offspring production or longevity in C. elegans wild isolates, suggesting that naturally long telomeres play a limited role in modifying fitness phenotypes in C. elegans. Copyright © 2016 by the Genetics Society of America.

Temperature-driven topological transition in 1T'-MoTe2

NASA Astrophysics Data System (ADS)

Berger, Ayelet Notis; Andrade, Erick; Kerelsky, Alexander; Edelberg, Drew; Li, Jian; Wang, Zhijun; Zhang, Lunyong; Kim, Jaewook; Zaki, Nader; Avila, Jose; Chen, Chaoyu; Asensio, Maria C.; Cheong, Sang-Wook; Bernevig, Bogdan A.; Pasupathy, Abhay N.

2018-01-01

The topology of Weyl semimetals requires the existence of unique surface states. Surface states have been visualized in spectroscopy measurements, but their connection to the topological character of the material remains largely unexplored. 1T'-MoTe2, presents a unique opportunity to study this connection. This material undergoes a phase transition at 240 K that changes the structure from orthorhombic (putative Weyl semimetal) to monoclinic (trivial metal), while largely maintaining its bulk electronic structure. Here, we show from temperature-dependent quasiparticle interference measurements that this structural transition also acts as a topological switch for surface states in 1T'-MoTe2. At low temperature, we observe strong quasiparticle scattering, consistent with theoretical predictions and photoemission measurements for the surface states in this material. In contrast, measurements performed at room temperature show the complete absence of the scattering wavevectors associated with the trivial surface states. These distinct quasiparticle scattering behaviors show that 1T'-MoTe2 is ideal for separating topological and trivial electronic phenomena via temperature-dependent measurements.

Anticancer drugs from marine flora: an overview.

PubMed

Sithranga Boopathy, N; Kathiresan, K

2010-01-01

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

Spatially distributed potential of landfill biogas production and electric power generation in Brazil.

PubMed

Lima, Rodolfo M; Santos, Afonso H M; Pereira, Camilo R S; Flauzino, Bárbara K; Pereira, Ana Cristina O S; Nogueira, Fábio J H; Valverde, José Alfredo R

2018-04-01

Due to the relatively low investment, operation costs, and technical requirements, landfills are still the most widespread alternative for final disposal of municipal solid waste (MSW). The biogas produced in the landfill, a renewable energy source, may be an important alternative for electric power generation. Brazil has a significant number of operating landfills, which receive the most part of the collected MSW. However, the country has only 17 landfill biogas power plants (LBPPs), resulting in about 122 MW of capacity. The United Kingdom, for instance, which is about 3 times smaller than Brazil in population, has 442 LBPPs (corresponding to 1051 MW of capacity). This fact highlights a considerable unexplored potential of landfill biogas in Brazil. It is also important to estimate this potential throughout the country to provide information for the government, researchers and companies in decision making, planning and formulation of public policies regarding this use of landfill biogas. Therefore, this study aims at estimating the spatially distributed potential of landfill biogas production that can be used for electric power generation in Brazil from 2015 to 2045, considering two scenarios: (i) operating sanitary landfills and (ii) hypothetical scenario of Territorial Arrangements (TA) comprising every Brazilian city, considering one landfill per TA. The total installed capacity estimated in 2018 for scenario 1 is about 523 MW and 87% of this number are related to LBPPs bigger than 1 MW. In this same year, the total installed capacity estimated for scenario 2 is 768 MW and 95% of this number are related to LBPPs bigger than 1 MW. These results emphasize that Brazil has a considerable unexplored potential of landfill biogas and the importance of municipal consortiums for MSW management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlation of Lactobacillus rhamnosus Genotypes and Carbohydrate Utilization Signatures Determined by Phenotype Profiling

PubMed Central

Lambert, Jolanda; van Limpt, Kees; Wels, Michiel; Smokvina, Tamara; Knol, Jan; Kleerebezem, Michiel

2015-01-01

Lactobacillus rhamnosus is a bacterial species commonly colonizing the gastrointestinal (GI) tract of humans and also frequently used in food products. While some strains have been studied extensively, physiological variability among isolates of the species found in healthy humans or their diet is largely unexplored. The aim of this study was to characterize the diversity of carbohydrate utilization capabilities of human isolates and food-derived strains of L. rhamnosus in relation to their niche of isolation and genotype. We investigated the genotypic and phenotypic diversity of 25 out of 65 L. rhamnosus strains from various niches, mainly human feces and fermented dairy products. Genetic fingerprinting of the strains by amplified fragment length polymorphism (AFLP) identified 11 distinct subgroups at 70% similarity and suggested niche enrichment within particular genetic clades. High-resolution carbohydrate utilization profiling (OmniLog) identified 14 carbon sources that could be used by all of the strains tested for growth, while the utilization of 58 carbon sources differed significantly between strains, enabling the stratification of L. rhamnosus strains into three metabolic clusters that partially correlate with the genotypic clades but appear uncorrelated with the strain's origin of isolation. Draft genome sequences of 8 strains were generated and employed in a gene-trait matching (GTM) analysis together with the publicly available genomes of L. rhamnosus GG (ATCC 53103) and HN001 for several carbohydrates that were distinct for the different metabolic clusters: l-rhamnose, cellobiose, l-sorbose, and α-methyl-d-glucoside. From the analysis, candidate genes were identified that correlate with l-sorbose and α-methyl-d-glucoside utilization, and the proposed function of these genes could be confirmed by heterologous expression in a strain lacking the genes. This study expands our insight into the phenotypic and genotypic diversity of the species L. rhamnosus and explores the relationships between specific carbohydrate utilization capacities and genotype and/or niche adaptation of this species. PMID:26048937

Polonium-210 accumulates in a lake receiving coal mine discharges-anthropogenic or natural?

PubMed

Nelson, A W; Eitrheim, E S; Knight, A W; May, D; Wichman, M D; Forbes, T Z; Schultz, M K

2017-02-01

Coal is an integral part of global energy production; however, coal mining is associated with numerous environmental health impacts. It is well documented that coal-mine waste can contaminate the environment with naturally-occurring radionuclides from the uranium-238 ( 238 U) decay series. However, the behavior of the final radionuclide in the 238 U-series, i.e., polonium-210 ( 210 Po) arising from coal-mine waste-water discharge is largely unexplored. Here, results of a year-long (2014-2015) field study, in which the concentrations of 210 Po in sediments and surface water of a lake that receives coal-mine waste-water discharge in West Virginia are presented. Initial measurements identified levels of 210 Po in the lake sediments that were in excess of that which could be attributed to ambient U-series parent radionuclides; and were indicative of discharge site contamination of the lake ecosystem. However, control sediment obtained from a similar lake system in Iowa (an area with no coal mining or unconventional drilling) suggests that the levels of 210 Po in the lake are a natural phenomenon; and are likely unrelated to waste-water treatment discharges. Elevated levels of 210 Po have been reported in lake bottom sediments previously, yet very little information is available on the radioecological implications of 210 Po accumulation in lake bottom sediments. The findings of this study suggest that (Monthly Energy Review, 2016) the natural accumulation and retention of 210 Po in lake sediments may be a greater than previously considered (Chadwick et al., 2013) careful selection of control sites is important to prevent the inappropriate attribution of elevated levels of NORM in lake bottom ecosystems to industrial sources; and (Van Hook, 1979) further investigation of the source-terms and potential impacts on elevated 210 Po in lake-sediment ecosystems is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

IgG4 subclass antibodies impair antitumor immunity in melanoma

PubMed Central

Karagiannis, Panagiotis; Gilbert, Amy E.; Josephs, Debra H.; Ali, Niwa; Dodev, Tihomir; Saul, Louise; Correa, Isabel; Roberts, Luke; Beddowes, Emma; Koers, Alexander; Hobbs, Carl; Ferreira, Silvia; Geh, Jenny L.C.; Healy, Ciaran; Harries, Mark; Acland, Katharine M.; Blower, Philip J.; Mitchell, Tracey; Fear, David J.; Spicer, James F.; Lacy, Katie E.; Nestle, Frank O.; Karagiannis, Sophia N.

2013-01-01

Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10–driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4+-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell–mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches. PMID:23454746

Diversity and Distribution of Thermophilic Bacteria in Hot Springs of Pakistan.

PubMed

Amin, Arshia; Ahmed, Iftikhar; Salam, Nimaichand; Kim, Byung-Yong; Singh, Dharmesh; Zhi, Xiao-Yang; Xiao, Min; Li, Wen-Jun

2017-07-01

Chilas and Hunza areas, located in the Main Mantle Thrust and Main Karakoram Thrust of the Himalayas, host a range of geochemically diverse hot springs. This Himalayan geothermal region encompassed hot springs ranging in temperature from 60 to 95 °C, in pH from 6.2 to 9.4, and in mineralogy from bicarbonates (Tato Field), sulfates (Tatta Pani) to mixed type (Murtazaabad). Microbial community structures in these geothermal springs remained largely unexplored to date. In this study, we report a comprehensive, culture-independent survey of microbial communities in nine samples from these geothermal fields by employing a bar-coded pyrosequencing technique. The bacterial phyla Proteobacteria and Chloroflexi were dominant in all samples from Tato Field, Tatta Pani, and Murtazaabad. The community structures however depended on temperature, pH, and physicochemical parameters of the geothermal sites. The Murtazaabad hot springs with relatively higher temperature (90-95 °C) favored the growth of phylum Thermotogae, whereas the Tatta Pani thermal spring site TP-H3-b (60 °C) favored the phylum Proteobacteria. At sites with low silica and high temperature, OTUs belonging to phylum Chloroflexi were dominant. Deep water areas of the Murtazaabad hot springs favored the sulfur-reducing bacteria. About 40% of the total OTUs obtained from these samples were unclassified or uncharacterized, suggesting the presence of many undiscovered and unexplored microbiota. This study has provided novel insights into the nature of ecological interactions among important taxa in these communities, which in turn will help in determining future study courses in these sites.

Unexplored Character Diversity in Onychophora (Velvet Worms): A Comparative Study of Three Peripatid Species

PubMed Central

Oliveira, Ivo de Sena; Franke, Franziska Anni; Hering, Lars; Schaffer, Stefan; Rowell, David M.; Weck-Heimann, Andreas; Monge-Nájera, Julián; Morera-Brenes, Bernal; Mayer, Georg

2012-01-01

Low character variation among onychophoran species has been an obstacle for taxonomic and phylogenetic studies in the past, however we have identified a number of new and informative characters using morphological, molecular, and chromosomal techniques. Our analyses involved a detailed examination of Epiperipatus biolleyi from Costa Rica, Eoperipatus sp. from Thailand, and a new onychophoran species and genus from Costa Rica, Principapillatus hitoyensis gen. et sp. nov.. Scanning electron microscopy on embryos and specimens of varying age revealed novel morphological characters and character states, including the distribution of different receptor types along the antennae, the arrangement and form of papillae on the head, body and legs, the presence and shape of interpedal structures and fields of modified scales on the ventral body surface, the arrangement of lips around the mouth, the number, position and structure of crural tubercles and anal gland openings, and the presence and shape of embryonic foot projections. Karyotypic analyses revealed differences in the number and size of chromosomes among the species studied. The results of our phylogenetic analyses using mitochondrial COI and 12S rRNA gene sequences are in line with morphological and karyotype data. However, our data show a large number of unexplored, albeit informative, characters in the Peripatidae. We suggest that analysing these characters in additional species would help unravel species diversity and phylogeny in the Onychophora, and that inconsistencies among most diagnostic features used for the peripatid genera in the literature could be addressed by identifying a suite of characters common to all peripatids. PMID:23284667

Radiation of the high-order plasmonic modes of large gold nanospheres excited by surface plasmon polaritons.

PubMed

Chen, Jing-Dong; Xiang, Jin; Jiang, Shuai; Dai, Qiao-Feng; Tie, Shao-Long; Lan, Sheng

2018-05-17

Large metallic nanoparticles with sizes comparable to the wavelength of light are expected to support high-order plasmon modes exhibiting resonances in the visible to near infrared spectral range. However, the radiation behavior of high-order plasmon modes, including scattering spectra and radiation patterns, remains unexplored. Here, we report on the first observation and characterization of the high-order plasmon modes excited in large gold nanospheres by using the surface plasmon polaritons generated on the surface of a thin gold film. The polarization-dependent scattering spectra were measured by inserting a polarization analyzer in the collection channel and the physical origins of the scattering peaks observed in the scattering spectra were clearly identified. More interestingly, the radiation of electric quadrupoles and octupoles was resolved in both frequency and spatial domains. In addition, the angular dependences of the radiation intensity for all plasmon modes were extracted by fitting the polarization-dependent scattering spectra with multiple Lorentz line shapes. A significant enhancement of the electric field was found in the gap plasmon modes and it was employed to generate hot-electron intraband luminescence. Our findings pave the way for exploiting the high-order plasmon modes of large metallic nanoparticles in the manipulation of light radiation and light-matter interaction.

Van Hove singularities and excitonic effects in the optical conductivity of twisted bilayer graphene.

PubMed

Havener, Robin W; Liang, Yufeng; Brown, Lola; Yang, Li; Park, Jiwoong

2014-06-11

We report a systematic study of the optical conductivity of twisted bilayer graphene (tBLG) across a large energy range (1.2-5.6 eV) for various twist angles, combined with first-principles calculations. At previously unexplored high energies, our data show signatures of multiple van Hove singularities (vHSs) in the tBLG bands as well as the nonlinearity of the single layer graphene bands and their electron-hole asymmetry. Our data also suggest that excitonic effects play a vital role in the optical spectra of tBLG. Including electron-hole interactions in first-principles calculations is essential to reproduce the shape of the conductivity spectra, and we find evidence of coherent interactions between the states associated with the multiple vHSs in tBLG.

Fragment-Based Screening of a Natural Product Library against 62 Potential Malaria Drug Targets Employing Native Mass Spectrometry

PubMed Central

2018-01-01

Natural products are well known for their biological relevance, high degree of three-dimensionality, and access to areas of largely unexplored chemical space. To shape our understanding of the interaction between natural products and protein targets in the postgenomic era, we have used native mass spectrometry to investigate 62 potential protein targets for malaria using a natural-product-based fragment library. We reveal here 96 low-molecular-weight natural products identified as binding partners of 32 of the putative malarial targets. Seventy-nine (79) fragments have direct growth inhibition on Plasmodium falciparum at concentrations that are promising for the development of fragment hits against these protein targets. This adds a fragment library to the published HTS active libraries in the public domain. PMID:29436819

Effect of screening on the transport of polyelectrolytes through nanopores

NASA Astrophysics Data System (ADS)

Oukhaled, G.; Bacri, L.; Mathé, J.; Pelta, J.; Auvray, L.

2008-05-01

We study the transport of dextran sulfate molecules (Mw=8000 Da) through a bacterial α-hemolysin channel inserted into a bilayer lipid membrane submitted to an external electric field. We detect the current blockades induced by the molecules threading through one pore and vary the ionic strength in an unexplored range starting at 10-3 M. In the conditions of the experiment, the polyelectrolyte molecules enter the pore only if the Debye screening length is smaller than the pore radius in agreement with theory. We also observe that large potentials favour the passage of the molecules. The distribution of blockade durations suggests that a complex process governs the kinetics of the molecules. The dwelling time increases sharply as the Debye length increases and approaches the pore radius.

Modern Advances in Genetic Testing: Ethical Challenges and Training Implications for Current and Future Psychologists

PubMed Central

Richmond-Rakerd, Leah S.

2014-01-01

The ethical implications for psychological practice of genetic testing are largely unexplored. Predictive testing can have a significant impact on health and well-being, and increasing numbers of individuals with knowledge of their risk for various disorders are likely to present for psychotherapy. In addition, more people will struggle with the decision of whether to obtain information regarding their genetic material. Psychologists will need to have the appropriate knowledge and clinical skills to effectively counsel this population. This article highlights the relevant ethical issues surrounding psychological treatment of individuals pursuing or considering undergoing genetic testing. These issues are extended to psychologists working in research, education, and policy domains. Recommendations for graduate training programs to facilitate current and future practitioner competence are also discussed. PMID:24707160

New insight on the response of bacteria to fluoride.

PubMed

Breaker, R R

2012-01-01

Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biology, which has implications for a number of issues that are central to the use of fluoride for dental care. Below I provide a summary of our findings, comment on some of the key prospects for expanding our understanding of fluoride's effects on biology, and propose some future uses of this knowledge. Copyright © 2012 S. Karger AG, Basel.

New Insight on the Response of Bacteria to Fluoride

PubMed Central

Breaker, R.R.

2012-01-01

Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biology, which has implications for a number of issues that are central to the use of fluoride for dental care. Below I provide a summary of our findings, comment on some of the key prospects for expanding our understanding of fluoride's effects on biology, and propose some future uses of this knowledge. PMID:22327376

Breather soliton dynamics in microresonators

NASA Astrophysics Data System (ADS)

Yu, Mengjie; Jang, Jae K.; Okawachi, Yoshitomo; Griffith, Austin G.; Luke, Kevin; Miller, Steven A.; Ji, Xingchen; Lipson, Michal; Gaeta, Alexander L.

2017-02-01

The generation of temporal cavity solitons in microresonators results in coherent low-noise optical frequency combs that are critical for applications in spectroscopy, astronomy, navigation or telecommunications. Breather solitons also form an important part of many different classes of nonlinear wave systems, manifesting themselves as a localized temporal structure that exhibits oscillatory behaviour. To date, the dynamics of breather solitons in microresonators remains largely unexplored, and its experimental characterization is challenging. Here we demonstrate the excitation of breather solitons in two different microresonator platforms based on silicon nitride and on silicon. We investigate the dependence of the breathing frequency on pump detuning and observe the transition from period-1 to period-2 oscillation. Our study constitutes a significant contribution to understanding the soliton dynamics within the larger context of nonlinear science.

Structural and Functional Studies of a Pyran Synthase Domain from a trans-Acyltransferase Assembly Line.

PubMed

Wagner, Drew T; Zhang, Zhicheng; Meoded, Roy A; Cepeda, Alexis J; Piel, Jörn; Keatinge-Clay, Adrian T

2018-04-20

trans-Acyltransferase assembly lines possess enzymatic domains often not observed in their better characterized cis-acyltransferase counterparts. Within this repertoire of largely unexplored biosynthetic machinery is a class of enzymes called the pyran synthases that catalyze the formation of five- and six-membered cyclic ethers from diverse polyketide chains. The 1.55 Å resolution crystal structure of a pyran synthase domain excised from the ninth module of the sorangicin assembly line highlights the similarity of this enzyme to the ubiquitous dehydratase domain and provides insight into the mechanism of ring formation. Functional assays of point mutants reveal the central importance of the active site histidine that is shared with the dehydratases as well as the supporting role of a neighboring semiconserved asparagine.

Fragment-Based Screening of a Natural Product Library against 62 Potential Malaria Drug Targets Employing Native Mass Spectrometry.

PubMed

Vu, Hoan; Pedro, Liliana; Mak, Tin; McCormick, Brendan; Rowley, Jessica; Liu, Miaomiao; Di Capua, Angela; Williams-Noonan, Billy; Pham, Ngoc B; Pouwer, Rebecca; Nguyen, Bao; Andrews, Katherine T; Skinner-Adams, Tina; Kim, Jessica; Hol, Wim G J; Hui, Raymond; Crowther, Gregory J; Van Voorhis, Wesley C; Quinn, Ronald J

2018-04-13

Natural products are well known for their biological relevance, high degree of three-dimensionality, and access to areas of largely unexplored chemical space. To shape our understanding of the interaction between natural products and protein targets in the postgenomic era, we have used native mass spectrometry to investigate 62 potential protein targets for malaria using a natural-product-based fragment library. We reveal here 96 low-molecular-weight natural products identified as binding partners of 32 of the putative malarial targets. Seventy-nine (79) fragments have direct growth inhibition on Plasmodium falciparum at concentrations that are promising for the development of fragment hits against these protein targets. This adds a fragment library to the published HTS active libraries in the public domain.

Practitioner Views on the Impacts, Challenges, and Barriers in Supporting Older Survivors of Sexual Violence.

PubMed

Bows, Hannah

2018-07-01

Despite half a century of research on both sexual violence and elder abuse, the intersection between the two remains largely unexplored. Using theoretical lenses of feminist criminology and critical feminist gerontology, this article explores the intersection between age and sexual violence drawing on interviews with 23 practitioners supporting older survivors (aged 60 and over). They reported physical and emotional effects of sexual violence leading to limited lifestyles, disengagement from social networks, and reliance on pathogenic coping strategies. Provision of effective support was complicated by challenges associated with aging bodies and the social stigma associated with both sexual victimhood and older age. Additional challenges lay in supporting older male survivors and those living with dementia. The article ends by discussing implications for practice and an agenda for future research.

The Relation Between Supervisors’ Big Five Personality Traits and Employees’ Experiences of Abusive Supervision

PubMed Central

Camps, Jeroen; Stouten, Jeroen; Euwema, Martin

2016-01-01

The present study investigates the relation between supervisors’ personality traits and employees’ experiences of supervisory abuse, an area that – to date – remained largely unexplored in previous research. Field data collected from 103 supervisor-subordinate dyads showed that contrary to our expectations supervisors’ agreeableness and neuroticism were not significantly related to abusive supervision, nor were supervisors’ extraversion or openness to experience. Interestingly, however, our findings revealed a positive relation between supervisors’ conscientiousness and abusive supervision. That is, supervisors high in conscientiousness were more likely to be perceived as an abusive supervisor by their employees. Overall, our findings do suggest that supervisors’ Big Five personality traits explain only a limited amount of the variability in employees’ experiences of abusive supervision. PMID:26903919

Nonlinear control of high-frequency phonons in spider silk

NASA Astrophysics Data System (ADS)

Schneider, Dirk; Gomopoulos, Nikolaos; Koh, Cheong Y.; Papadopoulos, Periklis; Kremer, Friedrich; Thomas, Edwin L.; Fytas, George

2016-10-01

Spider dragline silk possesses superior mechanical properties compared with synthetic polymers with similar chemical structure due to its hierarchical structure comprised of partially crystalline oriented nanofibrils. To date, silk’s dynamic mechanical properties have been largely unexplored. Here we report an indirect hypersonic phononic bandgap and an anomalous dispersion of the acoustic-like branch from inelastic (Brillouin) light scattering experiments under varying applied elastic strains. We show the mechanical nonlinearity of the silk structure generates a unique region of negative group velocity, that together with the global (mechanical) anisotropy provides novel symmetry conditions for gap formation. The phononic bandgap and dispersion show strong nonlinear strain-dependent behaviour. Exploiting material nonlinearity along with tailored structural anisotropy could be a new design paradigm to access new types of dynamic behaviour.

Is Trust for Sale? The Effectiveness of Financial Compensation for Repairing Competence- versus Integrity-Based Trust Violations.

PubMed

Haesevoets, Tessa; Reinders Folmer, Chris; Van Hiel, Alain

2015-01-01

Despite the popularity of financial compensation as a means for addressing trust violations, the question whether (more) money can indeed buy trust back remains largely unexplored. In the present research, we focus on the role of violation type and compensation size. The results of a scenario study and a laboratory experiment show that financial compensation can effectively promote the restoration of trust for transgressions that indicate a lack of competence. Conversely, for transgressions which signal a lack of integrity, financial compensation is not an effective tool to repair trust. Moreover, our findings indicate that for both violation types, overcompensation has no positive effects on top of the impact of equal compensation. These findings therefore show that when it comes to trust, money cannot buy everything.

Advanced policy options to regulate sugar-sweetened beverages to support public health.

PubMed

Pomeranz, Jennifer L

2012-02-01

Consumption of sugar-sweetened beverages (SSBs) has increased worldwide. As public health studies expose the detrimental impact of SSBs, consumer protection and public health advocates have called for increased government control. A major focus has been on restricting marketing of SSBs to children, but many innovative policy options--legally defensible ways to regulate SSBs and support public health--are largely unexplored. We describe the public health, economic, and retail marketing research related to SSBs (including energy drinks). We review policy options available to governments, including mandatory factual disclosures, earmarked taxation, and regulating sales, including placement within retail and food service establishments, and schools. Our review describes recent international initiatives and classifies options available in the United States by jurisdiction (federal, state, and local) based on legal viability.

Integrality and separability of multitouch interaction techniques in 3D manipulation tasks.

PubMed

Martinet, Anthony; Casiez, Géry; Grisoni, Laurent

2012-03-01

Multitouch displays represent a promising technology for the display and manipulation of data. While the manipulation of 2D data has been widely explored, 3D manipulation with multitouch displays remains largely unexplored. Based on an analysis of the integration and separation of degrees of freedom, we propose a taxonomy for 3D manipulation techniques with multitouch displays. Using that taxonomy, we introduce Depth-Separated Screen-Space (DS3), a new 3D manipulation technique based on the separation of translation and rotation. In a controlled experiment, we compared DS3 with Sticky Tools and Screen-Space. Results show that separating the control of translation and rotation significantly affects performance for 3D manipulation, with DS3 performing faster than the two other techniques.

Marine natural products: a new wave of drugs?

PubMed Central

Montaser, Rana; Luesch, Hendrik

2011-01-01

The largely unexplored marine world that presumably harbors the most biodiversity may be the vastest resource to discover novel ‘validated’ structures with novel modes of action that cover biologically relevant chemical space. Several challenges, including the supply problem and target identification, need to be met for successful drug development of these often complex molecules; however, approaches are available to overcome the hurdles. Advances in technologies such as sampling strategies, nanoscale NMR for structure determination, total chemical synthesis, fermentation and biotechnology are all crucial to the success of marine natural products as drug leads. We illustrate the high degree of innovation in the field of marine natural products, which in our view will lead to a new wave of drugs that flow into the market and pharmacies in the future. PMID:21882941

Freezing behavior as a response to sexual visual stimuli as demonstrated by posturography.

PubMed

Mouras, Harold; Lelard, Thierry; Ahmaidi, Said; Godefroy, Olivier; Krystkowiak, Pierre

2015-01-01

Posturographic changes in motivational conditions remain largely unexplored in the context of embodied cognition. Over the last decade, sexual motivation has been used as a good canonical working model to study motivated social interactions. The objective of this study was to explore posturographic variations in response to visual sexual videos as compared to neutral videos. Our results support demonstration of a freezing-type response in response to sexually explicit stimuli compared to other conditions, as demonstrated by significantly decreased standard deviations for (i) the center of pressure displacement along the mediolateral and anteroposterior axes and (ii) center of pressure's displacement surface. These results support the complexity of the motor correlates of sexual motivation considered to be a canonical functional context to study the motor correlates of motivated social interactions.

Rotator side chains trigger cooperative transition for shape and function memory effect in organic semiconductors.

PubMed

Chung, Hyunjoong; Dudenko, Dmytro; Zhang, Fengjiao; D'Avino, Gabriele; Ruzié, Christian; Richard, Audrey; Schweicher, Guillaume; Cornil, Jérôme; Beljonne, David; Geerts, Yves; Diao, Ying

2018-01-18

Martensitic transition is a solid-state phase transition involving cooperative movement of atoms, mostly studied in metallurgy. The main characteristics are low transition barrier, ultrafast kinetics, and structural reversibility. They are rarely observed in molecular crystals, and hence the origin and mechanism are largely unexplored. Here we report the discovery of martensitic transition in single crystals of two different organic semiconductors. In situ microscopy, single-crystal X-ray diffraction, Raman and nuclear magnetic resonance spectroscopy, and molecular simulations combined indicate that the rotating bulky side chains trigger cooperative transition. Cooperativity enables shape memory effect in single crystals and function memory effect in thin film transistors. We establish a molecular design rule to trigger martensitic transition in organic semiconductors, showing promise for designing next-generation smart multifunctional materials.

Brain Neoplasm and the Potential Impact on Self-Identity

PubMed Central

Anderson-Shaw, Lisa; Baslet, Gaston; Villano, J. Lee

2011-01-01

Cancers of the brain can cause alterations in a person’s neurocognitive abilities, and in some patients can even challenge their concept of self and self-identity. Cancer treatment may offer some hope for longer survival, but residual neurocognitive alterations generally remain. Individualized care for these patients should include information related to anticipated effects of their disease or treatments affecting their perception or expression of self. At present, the concepts of self and self-identity are largely unexplored in neuro-oncology, but we will discuss this clinical population in order to highlight the need for further clinical evaluation of these phenomena among patients with brain neoplasm. Finally, we will briefly note the need for a clinical tool to assess self and self-identity changes in brain tumor patients. PMID:22247810

The transcriptome of Bathymodiolus azoricus gill reveals expression of genes from endosymbionts and free-living deep-sea bacteria.

PubMed

Egas, Conceição; Pinheiro, Miguel; Gomes, Paula; Barroso, Cristina; Bettencourt, Raul

2012-08-01

Deep-sea environments are largely unexplored habitats where a surprising number of species may be found in large communities, thriving regardless of the darkness, extreme cold, and high pressure. Their unique geochemical features result in reducing environments rich in methane and sulfides, sustaining complex chemosynthetic ecosystems that represent one of the most surprising findings in oceans in the last 40 years. The deep-sea Lucky Strike hydrothermal vent field, located in the Mid Atlantic Ridge, is home to large vent mussel communities where Bathymodiolus azoricus represents the dominant faunal biomass, owing its survival to symbiotic associations with methylotrophic or methanotrophic and thiotrophic bacteria. The recent transcriptome sequencing and analysis of gill tissues from B. azoricus revealed a number of genes of bacterial origin, hereby analyzed to provide a functional insight into the gill microbial community. The transcripts supported a metabolically active microbiome and a variety of mechanisms and pathways, evidencing also the sulfur and methane metabolisms. Taxonomic affiliation of transcripts and 16S rRNA community profiling revealed a microbial community dominated by thiotrophic and methanotrophic endosymbionts of B. azoricus and the presence of a Sulfurovum-like epsilonbacterium.

Analysis and imaging of biocidal agrochemicals using ToF-SIMS.

PubMed

Converso, Valerio; Fearn, Sarah; Ware, Ecaterina; McPhail, David S; Flemming, Anthony J; Bundy, Jacob G

2017-09-06

ToF-SIMS has been increasingly widely used in recent years to look at biological matrices, in particular for biomedical research, although there is still a lot of development needed to maximise the value of this technique in the life sciences. The main issue for biological matrices is the complexity of the mass spectra and therefore the difficulty to specifically and precisely detect analytes in the biological sample. Here we evaluated the use of ToF-SIMS in the agrochemical field, which remains a largely unexplored area for this technique. We profiled a large number of biocidal active ingredients (herbicides, fungicides, and insecticides); we then selected fludioxonil, a halogenated fungicide, as a model compound for more detailed study, including the effect of co-occurring biomolecules on detection limits. There was a wide range of sensitivity of the ToF-SIMS for the different active ingredient compounds, but fludioxonil was readily detected in real-world samples (wheat seeds coated with a commercial formulation). Fludioxonil did not penetrate the seed to any great depth, but was largely restricted to a layer coating the seed surface. ToF-SIMS has clear potential as a tool for not only detecting biocides in biological samples, but also mapping their distribution.

Ambient Air Temperature Does Not Predict whether Small or Large Workers Forage in Bumble Bees (Bombus impatiens).

PubMed

Couvillon, Margaret J; Fitzpatrick, Ginny; Dornhaus, Anna

Bumble bees are important pollinators of crops and other plants. However, many aspects of their basic biology remain relatively unexplored. For example, one important and unusual natural history feature in bumble bees is the massive size variation seen between workers of the same nest. This size polymorphism may be an adaptation for division of labor, colony economics, or be nonadaptive. It was also suggested that perhaps this variation allows for niche specialization in workers foraging at different temperatures: larger bees might be better suited to forage at cooler temperatures and smaller bees might be better suited to forage at warmer temperatures. This we tested here using a large, enclosed growth chamber, where we were able to regulate the ambient temperature. We found no significant effect of ambient or nest temperature on the average size of bees flying to and foraging from a suspended feeder. Instead, bees of all sizes successfully flew and foraged between 16°C and 36°C. Thus, large bees foraged even at very hot temperatures, which we thought might cause overheating. Size variation therefore could not be explained in terms of niche specialization for foragers at different temperatures.

The link between maltreatment and juvenile firesetting: correlates and underlying mechanisms.

PubMed

Root, C; Mackay, S; Henderson, J; Del Bove, G; Warling, D

2008-02-01

Despite the widely held belief that abuse is a risk factor for childhood firesetting, the role of maltreatment in firesetting is largely unexplored. This study reports on a sample of children and adolescents referred to a brief assessment and intervention program for juvenile firesetters. Firesetting histories of maltreated youth were compared to a group of firesetting youth with no maltreatment history. Participants included 205 children and youth aged 4-17 years and their caregivers. Assessments were completed with a standardized protocol. Forty-eight percent of the sample had a history of maltreatment as reported by caregivers; 26% of the sample had experienced more than one type of maltreatment. When compared to the non-maltreated group, children with histories of maltreatment demonstrated more frequent fire involvement, more versatility regarding ignition sources and targets, and a greater likelihood of an immediate family stressor as a motive for firesetting (all p<.05). Maltreated children were more likely to become involved with fire out of anger (p=.001), and there was also a trend towards higher rates of recidivism (p=.07). Children's externalizing behavior partially mediated the influence of maltreatment on specific fire-related outcomes of children (OR=1.10; 95% CI=1.04-1.17; p=.001). Within a juvenile firesetting population, the presence of maltreatment is a risk factor for a more severe course of firesetting. The findings also suggest that the link between maltreatment and firesetting is operating partially through heightened emotional and behavioral difficulties. This study demonstrates that maltreatment is a risk factor that contributes to a more severe course of juvenile fire involvement, and that the link between maltreatment and firesetting operates largely through heightened behavioral and emotional difficulties. These findings highlight the need for mental health clinicians to (a) be aware that these two serious clinical issues frequently co-occur, (b) screen for fire-related behaviors and maltreatment during general assessments, and (c) consider maltreatment status when thinking about the risk of firesetting.

Microbial and Metabolic Diversity of the Alkaline Hot Springs of Paoha Island: A Late Archean and Proterozoic Ocean Analogue Environment.

NASA Astrophysics Data System (ADS)

Foster, I. S.; Demirel, C.; Hyde, A.; Motamedi, S.; Frantz, C. M.; Stamps, B. W.; Nunn, H. S.; Oremland, R. S.; Rosen, M.; Miller, L. G.; Corsetti, F. A.; Spear, J. R.

2016-12-01

Paoha Island formed 450 years ago within Mono Lake, California, as a result of magmatic activity in the underlying Long Valley Caldera. Previous studies of Paoha Island hot springs focused on the presence of novel organisms adapted to high levels of arsenic (114-138 µM). However, the microbial community structure, relationship with Mono Lake, and preservation potential of these communities remains largely unexplored. Here, we present water chemistry, 16S and 18S rRNA gene sequences, and metagenomic data for spring water and biofilms sampled on a recently exposed mudflat along the shoreline of Paoha Island. Spring waters were hypoxic, alkaline, and saline, had variable temperature (39-70 °C near spring sources) and high concentrations of arsenic, sulfide and reduced organic compounds. Thermodynamic modeling based on spring water chemistry indicated that sulfide and methane oxidation were the most energetically favorable respiratory metabolisms. 16S rRNA gene sequencing revealed distinct communities in different biofilms: red biofilms were dominated by arsenite-oxidizing phototrophs within the Ectothiorhodospiraceae, while OTUs most closely related to the cyanobacterial genus Arthrospira were present in green biofilms, as well as a large proportion of sequences assigned to sulfur-oxidizing bacteria. Metagenomic analysis identified genes related to arsenic resistance, arsenic oxidation/reduction, sulfur oxidation and photosynthesis. Eukaryotic rRNA gene sequencing analyses revealed few detectable taxa in spring biofilms and waters compared to Mono Lake; springs receiving splash from the lake were dominated by the alga Picocystis. The co-occurrence of hypoxia, high pH, and close proximity of anoxygenic and oxygenic phototrophic mats makes this site a potential Archean/Proterozoic analogue environment, but suggests that similar environments if preserved in the rock record, may not preserve evidence for community dynamics or the existence of photosynthetic metabolisms.

Realistic molecular model of kerogen's nanostructure

NASA Astrophysics Data System (ADS)

Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E.; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J.-M.; Coasne, Benoit

2016-05-01

Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp2/sp3 hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms.

Chemical composition and antimicrobial activity of fatty acid methyl ester of Quercus leucotrichophora fruits.

PubMed

Sati, Ankita; Sati, Sushil Chandra; Sati, Nitin; Sati, O P

2017-03-01

Natural fats and dietary oils are chief source of fatty acids and are well known to have antimicrobial activities against various microbes. The chemical composition and antimicrobial activities of fatty acids from fruits of white Oak (Quercus leucotrichophora) are yet unexplored and therefore the present study for the first time determines the fatty acid composition, and the antibacterial and antifungal activities of fatty acid methyl esters (FAME) of the white Oak plant found along the Himalayan region of Uttarakhand, India. The GCMS analysis revealed the presence of higher amount of saturated fatty acids than unsaturated fatty acids. FAME extract of fruits of Q. leucotrichophora demonstrated better antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. The present studies clearly establish the potential of the fruits of Q. leucotrichophora for use in soap, cosmetics and pharmaceutical industries.

Rethinking early Earth phosphorus geochemistry

PubMed Central

Pasek, Matthew A.

2008-01-01

Phosphorus is a key biologic element, and a prebiotic pathway leading to its incorporation into biomolecules has been difficult to ascertain. Most potentially prebiotic phosphorylation reactions have relied on orthophosphate as the source of phosphorus. It is suggested here that the geochemistry of phosphorus on the early Earth was instead controlled by reduced oxidation state phosphorus compounds such as phosphite (HPO32−), which are more soluble and reactive than orthophosphates. This reduced oxidation state phosphorus originated from extraterrestrial material that fell during the heavy bombardment period or was produced during impacts, and persisted in the mildly reducing atmosphere. This alternate view of early Earth phosphorus geochemistry provides an unexplored route to the formation of pertinent prebiotic phosphorus compounds, suggests a facile reaction pathway to condensed phosphates, and is consistent with the biochemical usage of reduced oxidation state phosphorus compounds in life today. Possible studies are suggested that may detect reduced oxidation state phosphorus compounds in ancient Archean rocks. PMID:18195373

The bacterial skin microbiome in psoriatic arthritis, an unexplored link in pathogenesis: challenges and opportunities offered by recent technological advances.

PubMed

Castelino, Madhura; Eyre, Stephen; Upton, Mathew; Ho, Pauline; Barton, Anne

2014-05-01

The resident microbial community, harboured by humans in sites such as the skin and gastrointestinal tract, is enormous, representing a candidate environmental factor affecting susceptibility to complex diseases, where both genetic and environmental risk factors are important. The potential of microorganisms to influence the human immune system is considerable, given their ubiquity. The impact of the host-gene-microbe interaction on the maintenance of health and the development of disease has not yet been assessed robustly in chronic inflammatory conditions. PsA represents a model inflammatory disease to explore the role of the microbiome because skin involvement and overlap with IBD implicates both the skin and gastrointestinal tract as sources of microbial triggers for PsA. In parallel with genetic studies, characterization of the host microbiota may benefit our understanding of the microbial contribution to disease pathogenesis-knowledge that may eventually inform the development of novel therapeutics.

A fast, open source implementation of adaptive biasing potentials uncovers a ligand design strategy for the chromatin regulator BRD4

NASA Astrophysics Data System (ADS)

Dickson, Bradley M.; de Waal, Parker W.; Ramjan, Zachary H.; Xu, H. Eric; Rothbart, Scott B.

2016-10-01

In this communication we introduce an efficient implementation of adaptive biasing that greatly improves the speed of free energy computation in molecular dynamics simulations. We investigated the use of accelerated simulations to inform on compound design using a recently reported and clinically relevant inhibitor of the chromatin regulator BRD4 (bromodomain-containing protein 4). Benchmarking on our local compute cluster, our implementation achieves up to 2.5 times more force calls per day than plumed2. Results of five 1 μs-long simulations are presented, which reveal a conformational switch in the BRD4 inhibitor between a binding competent and incompetent state. Stabilization of the switch led to a -3 kcal/mol improvement of absolute binding free energy. These studies suggest an unexplored ligand design principle and offer new actionable hypotheses for medicinal chemistry efforts against this druggable epigenetic target class.

IBD Selection for the 288kg Prototype SoLid Module

NASA Astrophysics Data System (ADS)

Saunders, D.; SoLid Collaboration

2017-09-01

The SoLid experiment aims to make a measurement of very short baseline neutrino oscillations using reactor antineutrinos. Key to its sensitivity are the experiment’s high spatial and energy resolution, combined with a very suitable reactor source and excellent background rejection. Placed on the surface at just 5 m from the reactor core, the cosmic flux and reactor output lead to a challenging environment. The fine segmentation of the detector, 5 cm cubes, allows the topology of events to be studied to previously unseen precision. This offers new and unexplored handles for tackling these backgrounds - a key requirement for SoLid physics aims. Using the most recent SoLid prototype (288 kg, 20% scale), we present the first selection to focus on IBD signals. This includes descriptions of SoLid signals and backgrounds, and demonstration that the segmentation can lead to gains in orders of magnitude in background rejection.

A fast, open source implementation of adaptive biasing potentials uncovers a ligand design strategy for the chromatin regulator BRD4

PubMed Central

Dickson, Bradley M.; Ramjan, Zachary H.; Xu, H. Eric

2016-01-01

In this communication we introduce an efficient implementation of adaptive biasing that greatly improves the speed of free energy computation in molecular dynamics simulations. We investigated the use of accelerated simulations to inform on compound design using a recently reported and clinically relevant inhibitor of the chromatin regulator BRD4 (bromodomain-containing protein 4). Benchmarking on our local compute cluster, our implementation achieves up to 2.5 times more force calls per day than plumed2. Results of five 1 μs-long simulations are presented, which reveal a conformational switch in the BRD4 inhibitor between a binding competent and incompetent state. Stabilization of the switch led to a −3 kcal/mol improvement of absolute binding free energy. These studies suggest an unexplored ligand design principle and offer new actionable hypotheses for medicinal chemistry efforts against this druggable epigenetic target class. PMID:27782467

Realistic molecular model of kerogen's nanostructure.

PubMed

Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J-M; Coasne, Benoit

2016-05-01

Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp(2)/sp(3) hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms.

Rethinking early Earth phosphorus geochemistry.

PubMed

Pasek, Matthew A

2008-01-22

Phosphorus is a key biologic element, and a prebiotic pathway leading to its incorporation into biomolecules has been difficult to ascertain. Most potentially prebiotic phosphorylation reactions have relied on orthophosphate as the source of phosphorus. It is suggested here that the geochemistry of phosphorus on the early Earth was instead controlled by reduced oxidation state phosphorus compounds such as phosphite (HPO(3)(2-)), which are more soluble and reactive than orthophosphates. This reduced oxidation state phosphorus originated from extraterrestrial material that fell during the heavy bombardment period or was produced during impacts, and persisted in the mildly reducing atmosphere. This alternate view of early Earth phosphorus geochemistry provides an unexplored route to the formation of pertinent prebiotic phosphorus compounds, suggests a facile reaction pathway to condensed phosphates, and is consistent with the biochemical usage of reduced oxidation state phosphorus compounds in life today. Possible studies are suggested that may detect reduced oxidation state phosphorus compounds in ancient Archean rocks.

The Bursting Pulsar GRO J1744-28: the slowest transitional pulsar?

NASA Astrophysics Data System (ADS)

Court, J. M. C.; Altamirano, D.; Sanna, A.

2018-06-01

GRO J1744-28 (the Bursting Pulsar) is a neutron star low-mass X-ray binary which shows highly structured X-ray variability near the end of its X-ray outbursts. In this letter we show that this variability is analogous to that seen in Transitional Millisecond Pulsars such as PSR J1023+0038: `missing link' systems consisting of a pulsar nearing the end of its recycling phase. As such, we show that the Bursting Pulsar may also be associated with this class of objects. We discuss the implications of this scenario; in particular, we discuss the fact that the Bursting Pulsar has a significantly higher spin period and magnetic field than any other known transitional pulsar. If the Bursting Pulsar is indeed transitional, then this source opens a new window of opportunity to test our understanding of these systems in an entirely unexplored physical regime.

The genomic landscape of human cellular circadian variation points to a novel role for the signalosome

PubMed Central

Gaspar, Ludmila; Howald, Cedric; Popadin, Konstantin; Maier, Bert; Mauvoisin, Daniel; Moriggi, Ermanno; Gutierrez-Arcelus, Maria; Falconnet, Emilie; Borel, Christelle; Kunz, Dieter; Kramer, Achim; Gachon, Frederic; Dermitzakis, Emmanouil T; Antonarakis, Stylianos E

2017-01-01

The importance of natural gene expression variation for human behavior is undisputed, but its impact on circadian physiology remains mostly unexplored. Using umbilical cord fibroblasts, we have determined by genome-wide association how common genetic variation impacts upon cellular circadian function. Gene set enrichment points to differences in protein catabolism as one major source of clock variation in humans. The two most significant alleles regulated expression of COPS7B, a subunit of the COP9 signalosome. We further show that the signalosome complex is imported into the nucleus in timed fashion to stabilize the essential circadian protein BMAL1, a novel mechanism to oppose its proteasome-mediated degradation. Thus, circadian clock properties depend in part upon a genetically-encoded competition between stabilizing and destabilizing forces, and genetic alterations in these mechanisms provide one explanation for human chronotype. PMID:28869038

The Bursting Pulsar GRO J1744-28: the Slowest Transitional Pulsar?

NASA Astrophysics Data System (ADS)

Court, J. M. C.; Altamirano, D.; Sanna, A.

2018-04-01

GRO J1744-28 (the Bursting Pulsar) is a neutron star LMXB which shows highly structured X-ray variability near the end of its X-ray outbursts. In this letter we show that this variability is analogous to that seen in Transitional Millisecond Pulsars such as PSR J1023+0038: `missing link' systems consisting of a pulsar nearing the end of its recycling phase. As such, we show that the Bursting Pulsar may also be associated with this class of objects. We discuss the implications of this scenario; in particular, we discuss the fact that the Bursting Pulsar has a significantly higher spin period and magnetic field than any other known Transitional Pulsar. If the Bursting Pulsar is indeed transitional, then this source opens a new window of oppurtunity to test our understanding of these systems in an entirely unexplored physical regime.

Insights on antimicrobial resistance, biofilms and the use of phytochemicals as new antimicrobial agents.

PubMed

Borges, Anabela; Saavedra, Maria J; Simões, Manuel

2015-01-01

Antimicrobial resistance is one of the most serious public health problems. This is of particular concern when bacteria become resistant to various antimicrobial agents simultaneously and when they form biofilms. Consequently, therapeutic options for the treatment of infections have become limited, leading frequently to recurrent infections, treatment failure and increase of morbidity and mortality. Both, persistence and spread of antibiotic resistance, in combination with decreased effectiveness and increased toxicity of current antibiotics have emphasized the urgent need to search alternative sources of antimicrobial substances. Plants are recognized as a source of unexplored chemical structures with high therapeutic potential, including antimicrobial activity against clinically important microorganisms. Additionally, phytochemicals (plant secondary metabolites) present several advantages over synthetic molecules, including green status and different mechanisms of action from antibiotics which could help to overcome the resistance problem. In this study, an overview of the main classes of phytochemicals with antimicrobial properties and their mode of action is presented. A revision about the application of phytochemicals for biofilm prevention and control is also done. Moreover, the use of phytochemicals as scaffolds of new functional molecules to expand the antibiotics pipeline is reviewed.