ERIC Educational Resources Information Center
Gogtay, Nitin; Thompson, Paul M.
2010-01-01
Recent studies with brain magnetic resonance imaging (MRI) have scanned large numbers of children and adolescents repeatedly over time, as their brains develop, tracking volumetric changes in gray and white matter in remarkable detail. Focusing on gray matter changes specifically, here we explain how earlier studies using lobar volumes of specific…
ERIC Educational Resources Information Center
Cochran, Moncrieff
The major portion of this presentation describes research results and policy implications of the Family Matters Project, a longitudinal study of social contexts as they affect children and families during the period of transition from home to school. Also provided in this portion are highlights of what was learned from delivering to 160 families…
ERIC Educational Resources Information Center
Ciccia, Angela Hein; Meulenbroek, Peter; Turkstra, Lyn S.
2009-01-01
Adolescence is a time of significant physical, social, and emotional developments, accompanied by changes in cognitive and language skills. Underlying these are significant developments in brain structures and functions including changes in cortical and subcortical gray matter and white matter tracts. Among the brain regions that develop during…
We take a historic approach to explore how concepts of the chemical and physical nature of soil organic matter have evolved over time. We emphasize conceptual and analytical achievements in organic matter research over the last two decades and demonstrate how these developments h...
Development of the Adolescent Brain: Implications for Executive Function and Social Cognition
ERIC Educational Resources Information Center
Blakemore, Sarah-Jayne; Choudhury, Suparna
2006-01-01
Adolescence is a time of considerable development at the level of behaviour, cognition and the brain. This article reviews histological and brain imaging studies that have demonstrated specific changes in neural architecture during puberty and adolescence, outlining trajectories of grey and white matter development. The implications of brain…
Ladouceur, Cecile D.; Peper, Jiska S.; Crone, Eveline A.; Dahl, Ronald E.
2011-01-01
There have been rapid advances in understanding a broad range of changes in brain structure and function during adolescence, and a growing interest in identifying which of these neurodevelopmental changes are directly linked with pubertal maturation—at least in part because of their potential to provide insights into the numerous emotional and behavioral health problems that emerge during this developmental period. This review focuses on what is known about the influence of puberty on white matter development in adolescence. We focus on white matter because of its role in providing the structural architectural organization of the brain and as a structural correlate of communication within complex neural systems. We begin with a review of studies that report sex differences or sex by age interactions in white matter development as these findings can provide, although indirectly, information relevant to puberty-related changes. Studies are also critically reviewed based on methodological procedures used to assess pubertal maturation and relations with white matter changes. Findings are discussed in light of their implications for the development of neural systems underlying the regulation of emotion and behavior and how alterations in the development of these systems may mediate risk for affective disorders in vulnerable adolescents. PMID:22247751
ERIC Educational Resources Information Center
Warshaw, Jarrett B.; Toutkoushian, Robert K.; Choi, Hyejin
2017-01-01
For a future faculty member the choice of which graduate programme and institution to attend is considered to have important implications for securing academic employment, developing skills to succeed in academia, and yielding positive returns on investment of time and money in education. Yet does it matter where a faculty member attends graduate…
A Gift of Writing? Choreographer and Writer Collaborations in the University
ERIC Educational Resources Information Center
Pollard, Niki; Garrett, Natalie; Lee, Rosemary; Voris, Amy
2010-01-01
This paper investigates certain philosophical implications of asking a dance artist for an account of how she or he works. The research proposes the development of practices of collaborative writing by a dance artist and researcher-observer (alert to the motivated and implicated positions of each) that are capable of articulating what matters to…
USDA-ARS?s Scientific Manuscript database
Chemical properties of whole organic matter (OM) and its dissolved organic matter (DOM) fraction from six dominant macrophytes in Lake Dianchi were comparatively characterized, and their environmental implications were discussed. Significant differences in chemical composition of the OM samples were...
Particle Physics at the Cosmic, Intensity, and Energy Frontiers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Essig, Rouven
Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Searchmore » (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.« less
'White matter connectivity and Internet gaming disorder' and broader considerations in the field.
Tam, Philip G E
2017-01-01
This invited commentary on the paper 'White Matter Connectivity and Internet gaming disorder' by Jeong et al. (unpublished) looks at the implications and importance of the MRI findings in the present study-one of the largest to date-and also considers the broader developments of neuroimaging within the complex, emerging field of 'Internet psychology' and problematic Internet usage. © 2015 Society for the Study of Addiction.
Dark-matter particles without weak-scale masses or weak interactions.
Feng, Jonathan L; Kumar, Jason
2008-12-05
We propose that dark matter is composed of particles that naturally have the correct thermal relic density, but have neither weak-scale masses nor weak interactions. These models emerge naturally from gauge-mediated supersymmetry breaking, where they elegantly solve the dark-matter problem. The framework accommodates single or multiple component dark matter, dark-matter masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to strong. These candidates enhance many direct and indirect signals relative to weakly interacting massive particles and have qualitatively new implications for dark-matter searches and cosmological implications for colliders.
Brain Growth Rate Abnormalities Visualized in Adolescents with Autism
Hua, Xue; Thompson, Paul M.; Leow, Alex D.; Madsen, Sarah K.; Caplan, Rochelle; Alger, Jeffry R.; O’Neill, Joseph; Joshi, Kishori; Smalley, Susan L.; Toga, Arthur W.; Levitt, Jennifer G.
2014-01-01
Autism spectrum disorder (ASD) is a heterogeneous disorder of brain development with wide-ranging cognitive deficits. Typically diagnosed before age 3, ASD is behaviorally defined but patients are thought to have protracted alterations in brain maturation. With longitudinal magnetic resonance imaging (MRI), we mapped an anomalous developmental trajectory of the brains of autistic compared to those of typically developing children and adolescents. Using tensor-based morphometry (TBM), we created 3D maps visualizing regional tissue growth rates based on longitudinal brain MRI scans of 13 autistic and 7 typically developing boys (mean age/inter-scan interval: autism 12.0 ± 2.3 years/2.9 ± 0.9 years; control 12.3 ± 2.4/2.8 ± 0.8). The typically developing boys demonstrated strong whole-brain white matter growth during this period, but the autistic boys showed abnormally slowed white matter development (p = 0.03, corrected), especially in the parietal (p = 0.008), temporal (p = 0.03) and occipital lobes (p =0.02). We also visualized abnormal overgrowth in autism in some gray matter structures, such as the putamen and anterior cingulate cortex. Our findings reveal aberrant growth rates in brain regions implicated in social impairment, communication deficits and repetitive behaviors in autism, suggesting that growth rate abnormalities persist into adolescence. TBM revealed persisting growth rate anomalies long after diagnosis, which has implications for evaluation of therapeutic effects. PMID:22021093
Brain growth rate abnormalities visualized in adolescents with autism.
Hua, Xue; Thompson, Paul M; Leow, Alex D; Madsen, Sarah K; Caplan, Rochelle; Alger, Jeffry R; O'Neill, Joseph; Joshi, Kishori; Smalley, Susan L; Toga, Arthur W; Levitt, Jennifer G
2013-02-01
Autism spectrum disorder is a heterogeneous disorder of brain development with wide ranging cognitive deficits. Typically diagnosed before age 3, autism spectrum disorder is behaviorally defined but patients are thought to have protracted alterations in brain maturation. With longitudinal magnetic resonance imaging (MRI), we mapped an anomalous developmental trajectory of the brains of autistic compared with those of typically developing children and adolescents. Using tensor-based morphometry, we created 3D maps visualizing regional tissue growth rates based on longitudinal brain MRI scans of 13 autistic and seven typically developing boys (mean age/interscan interval: autism 12.0 ± 2.3 years/2.9 ± 0.9 years; control 12.3 ± 2.4/2.8 ± 0.8). The typically developing boys demonstrated strong whole brain white matter growth during this period, but the autistic boys showed abnormally slowed white matter development (P = 0.03, corrected), especially in the parietal (P = 0.008), temporal (P = 0.03), and occipital lobes (P = 0.02). We also visualized abnormal overgrowth in autism in gray matter structures such as the putamen and anterior cingulate cortex. Our findings reveal aberrant growth rates in brain regions implicated in social impairment, communication deficits and repetitive behaviors in autism, suggesting that growth rate abnormalities persist into adolescence. Tensor-based morphometry revealed persisting growth rate anomalies long after diagnosis, which has implications for evaluation of therapeutic effects. Copyright © 2011 Wiley Periodicals, Inc.
ERIC Educational Resources Information Center
Lanki, Jari
2006-01-01
This article looks at the ethical implications of the use of information and communications technology (ICT) in bringing about development in developing societies. Any proposed means to enhance development has costs as well as benefits. Hence, the evaluation of a given means to development should always be a matter of "applied ethics".…
Structural changes in white matter are uniquely related to children’s reading development
Myers, Chelsea A.; Vandermosten, Maaike; Farris, Emily A.; Hancock, Roeland; Gimenez, Paul; Black, Jessica M.; Casto, Brandi; Drahos, Miroslav; Tumber, Mandeep; Hendren, Robert L.; Hulme, Charles; Hoeft, Fumiko
2014-01-01
This study examined whether variations in brain development between kindergarten and Grade 3 predicted individual differences in reading ability at the latter time point. Structural MRI measurements indicated that increases in volume of two left temporo-parietal white matter clusters are unique predictors of reading outcome at Grade 3. Using diffusion MRI, the larger of these two clusters was identified as a location where fibers of the long segment of arcuate fasciculus and superior corona radiata intersect, and the smaller cluster as the posterior arcuate fasciculus. Bias-free regression analyses using regions-of-interest from prior literature revealed white matter volume changes in temporo-parietal white matter, together with preliteracy measures, predicted 56% of the variance in reading outcomes. Our findings demonstrate the important contribution of developmental differences in areas of left dorsal white matter, often implicated in phonological processing, as a sensitive early biomarker for later reading abilities, and by extension, reading difficulties. PMID:25212581
Why Free Software Matters for Literacy Educators.
ERIC Educational Resources Information Center
Brunelle, Michael D.; Bruce, Bertram C.
2002-01-01
Notes that understanding what "free software" means and its implications for access and use of new technologies is an important component of the new literacies. Concludes that if free speech and free press are essential to the development of a general literacy, then free software can promote the development of computer literacy. (SG)
Investigating the Microstructural Correlation of White Matter in Autism Spectrum Disorder.
Dean, Douglas C; Travers, Brittany G; Adluru, Nagesh; Tromp, Do P M; Destiche, Daniel J; Samsin, Danica; Prigge, Molly B; Zielinski, Brandon A; Fletcher, P Thomas; Anderson, Jeffrey S; Froehlich, Alyson L; Bigler, Erin D; Lange, Nicholas; Lainhart, Janet E; Alexander, Andrew L
2016-06-01
White matter microstructure forms a complex and dynamical system that is critical for efficient and synchronized brain function. Neuroimaging findings in children with autism spectrum disorder (ASD) suggest this condition is associated with altered white matter microstructure, which may lead to atypical macroscale brain connectivity. In this study, we used diffusion tensor imaging measures to examine the extent that white matter tracts are interrelated within ASD and typical development. We assessed the strength of inter-regional white matter correlations between typically developing and ASD diagnosed individuals. Using hierarchical clustering analysis, clustering patterns of the pairwise white matter correlations were constructed and revealed to be different between the two groups. Additionally, we explored the use of graph theory analysis to examine the characteristics of the patterns formed by inter-regional white matter correlations and compared these properties between ASD and typical development. We demonstrate that the ASD sample has significantly less coherence in white matter microstructure across the brain compared to that in the typical development sample. The ASD group also presented altered topological characteristics, which may implicate less efficient brain networking in ASD. These findings highlight the potential of graph theory based network characteristics to describe the underlying networks as measured by diffusion magnetic resonance imaging and furthermore indicates that ASD may be associated with altered brain network characteristics. Our findings are consistent with those of a growing number of studies and hypotheses that have suggested disrupted brain connectivity in ASD.
Investigating the Microstructural Correlation of White Matter in Autism Spectrum Disorder
Travers, Brittany G.; Adluru, Nagesh; Tromp, Do P.M.; Destiche, Daniel J.; Samsin, Danica; Prigge, Molly B.; Zielinski, Brandon A.; Fletcher, P. Thomas; Anderson, Jeffrey S.; Froehlich, Alyson L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.; Alexander, Andrew L.
2016-01-01
Abstract White matter microstructure forms a complex and dynamical system that is critical for efficient and synchronized brain function. Neuroimaging findings in children with autism spectrum disorder (ASD) suggest this condition is associated with altered white matter microstructure, which may lead to atypical macroscale brain connectivity. In this study, we used diffusion tensor imaging measures to examine the extent that white matter tracts are interrelated within ASD and typical development. We assessed the strength of inter-regional white matter correlations between typically developing and ASD diagnosed individuals. Using hierarchical clustering analysis, clustering patterns of the pairwise white matter correlations were constructed and revealed to be different between the two groups. Additionally, we explored the use of graph theory analysis to examine the characteristics of the patterns formed by inter-regional white matter correlations and compared these properties between ASD and typical development. We demonstrate that the ASD sample has significantly less coherence in white matter microstructure across the brain compared to that in the typical development sample. The ASD group also presented altered topological characteristics, which may implicate less efficient brain networking in ASD. These findings highlight the potential of graph theory based network characteristics to describe the underlying networks as measured by diffusion magnetic resonance imaging and furthermore indicates that ASD may be associated with altered brain network characteristics. Our findings are consistent with those of a growing number of studies and hypotheses that have suggested disrupted brain connectivity in ASD. PMID:27021440
White Matter Integrity and Pictorial Reasoning in High-Functioning Children with Autism
Sahyoun, Chérif P.; Belliveau, John W.; Mody, Maria
2010-01-01
The current study investigated the neurobiological role of white matter in visuospatial versus linguistic processing abilities in autism using diffusion tensor imaging. We examined differences in white matter integrity between high-functioning children with autism (HFA) and typically developing controls (CTRL), in relation to the groups’ response times (RT) on a pictorial reasoning task under three conditions: visuospatial, V, semantic, S, and V+S, a hybrid condition allowing language use to facilitate visuospatial transformations. Diffusion-weighted images were collected from HFA and CTRL participants, matched on age and IQ, and significance maps were computed for group differences in fractional anisotropy (FA) and in RT-FA association for each condition. Typically developing children showed increased FA within frontal white matter and the superior longitudinal fasciculus (SLF). HFA showed increased FA within peripheral white matter, including the ventral temporal lobe. Additionally, RT-FA relationships in the semantic condition (S) implicated white matter near the STG and in the SLF within the temporal and frontal lobes to a greater extent in CTRL. Performance in visuospatial reasoning (V, V+S), in comparison, was related to peripheral parietal and superior precentral white matter in HFA, but to the SLF, callosal, and frontal white matter in CTRL. Our results appear to support a preferential use of linguistically-mediated pathways in reasoning by typically-developing children, whereas autistic cognition may rely more on visuospatial processing networks. PMID:20542370
Equality Matters: The Critical Implications of Precisely Defining Equality
ERIC Educational Resources Information Center
Faulkner, Valerie; Walkowiak, Temple; Cain, Chris; Lee, Carrie
2016-01-01
Equality is such an important concept for children to develop. In this article it is argued that a precise definition is needed to ensure that students are provided with a consistent "picture" of what it is that equality really means.
Tan, Geoffrey C.Y.; Doke, Thomas F.; Ashburner, John; Wood, Nicholas W.; Frackowiak, Richard S.J.
2010-01-01
Recent genetic studies have implicated a number of candidate genes in the pathogenesis of Autism Spectrum Disorder (ASD). Polymorphisms of CNTNAP2 (contactin-associated like protein-2), a member of the neurexin family, have already been implicated as a susceptibility gene for autism by at least 3 separate studies. We investigated variation in white and grey matter morphology using structural MRI and diffusion tensor imaging. We compared volumetric differences in white and grey matter and fractional anisotropy values in control subjects characterised by genotype at rs7794745, a single nucleotide polymorphism in CNTNAP2. Homozygotes for the risk allele showed significant reductions in grey and white matter volume and fractional anisotropy in several regions that have already been implicated in ASD, including the cerebellum, fusiform gyrus, occipital and frontal cortices. Male homozygotes for the risk alleles showed greater reductions in grey matter in the right frontal pole and in FA in the right rostral fronto-occipital fasciculus compared to their female counterparts who showed greater reductions in FA of the anterior thalamic radiation. Thus a risk allele for autism results in significant cerebral morphological variation, despite the absence of overt symptoms or behavioural abnormalities. The results are consistent with accumulating evidence of CNTNAP2's function in neuronal development. The finding suggests the possibility that the heterogeneous manifestations of ASD can be aetiologically characterised into distinct subtypes through genetic-morphological analysis. PMID:20176116
Dipolar dark matter with massive bigravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blanchet, Luc; Heisenberg, Lavinia; Department of Physics & The Oskar Klein Centre, AlbaNova University Centre,Roslagstullsbacken 21, 10691 Stockholm
2015-12-14
Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the twomore » metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.« less
Dipolar dark matter with massive bigravity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blanchet, Luc; Heisenberg, Lavinia, E-mail: blanchet@iap.fr, E-mail: laviniah@kth.se
2015-12-01
Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the twomore » metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.« less
Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Hedman, Anna M; van den Heuvel, Martijn P; van Haren, Neeltje E M; Kahn, René S; Hulshoff Pol, Hilleke E
2016-01-01
Intelligence is associated with a network of distributed gray matter areas including the frontal and parietal higher association cortices and primary processing areas of the temporal and occipital lobes. Efficient information transfer between gray matter regions implicated in intelligence is thought to be critical for this trait to emerge. Genetic factors implicated in intelligence and gray matter may promote a high capacity for information transfer. Whether these genetic factors act globally or on local gray matter areas separately is not known. Brain maps of phenotypic and genetic associations between gray matter volume and intelligence were made using structural equation modeling of 3T MRI T1-weighted scans acquired in 167 adult twins of the newly acquired U-TWIN cohort. Subsequently, structural connectivity analyses (DTI) were performed to test the hypothesis that gray matter regions associated with intellectual ability form a densely connected core. Gray matter regions associated with intellectual ability were situated in the right prefrontal, bilateral temporal, bilateral parietal, right occipital and subcortical regions. Regions implicated in intelligence had high structural connectivity density compared to 10,000 reference networks (p=0.031). The genetic association with intelligence was for 39% explained by a genetic source unique to these regions (independent of total brain volume), this source specifically implicated the right supramarginal gyrus. Using a twin design, we show that intelligence is genetically represented in a spatially distributed and densely connected network of gray matter regions providing a high capacity infrastructure. Although genes for intelligence have overlap with those for total brain volume, we present evidence that there are genes for intelligence that act specifically on the subset of brain areas that form an efficient brain network. Copyright © 2015 Elsevier Inc. All rights reserved.
Dark matter effective field theory scattering in direct detection experiments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schneck, K.; Cabrera, B.; Cerdeño, D. G.
2015-05-18
We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. Here. we demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. In conclusion, we discussmore » the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.« less
NASA Astrophysics Data System (ADS)
Lezon, Timothy R.; Banavar, Jayanth R.; Maritan, Amos
2006-01-01
All living organisms rely upon networks of molecular interactions to carry out their vital processes. In order for a molecular system to display the properties of life, its constituent molecules must themselves be endowed with several features: stability, specificity, self-organization, functionality, sensitivity, robustness, diversity and adaptability. We argue that these are the emergent properties of a unique phase of matter, and we demonstrate that proteins, the functional molecules of terrestrial life, are perfectly suited to this phase. We explore, through an understanding of this phase of matter, the physical principles that govern the operation of living matter. Our work has implications for the design of functionally useful nanoscale devices and the ultimate development of physically based artificial life.
ERIC Educational Resources Information Center
Fletcher, Wallace J.; And Others
The goals of the Information System for Vocational Decisions (ISVD), a computerized vocational development program which emphasized goal setting and purposeful action, are related to a tentative curriculum context called a Career Development Program. This Program is learner centered with process and subject matter a function of individual…
Stellar Wakes from Dark Matter Subhalos
NASA Astrophysics Data System (ADS)
Buschmann, Malte; Kopp, Joachim; Safdi, Benjamin R.; Wu, Chih-Liang
2018-05-01
We propose a novel method utilizing stellar kinematic data to detect low-mass substructure in the Milky Way's dark matter halo. By probing characteristic wakes that a passing dark matter subhalo leaves in the phase-space distribution of ambient halo stars, we estimate sensitivities down to subhalo masses of ˜107 M⊙ or below. The detection of such subhalos would have implications for dark matter and cosmological models that predict modifications to the halo-mass function at low halo masses. We develop an analytic formalism for describing the perturbed stellar phase-space distributions, and we demonstrate through idealized simulations the ability to detect subhalos using the phase-space model and a likelihood framework. Our method complements existing methods for low-mass subhalo searches, such as searches for gaps in stellar streams, in that we can localize the positions and velocities of the subhalos today.
SENSEI: First Direct-Detection Constraints on sub-GeV Dark Matter from a Surface Run
DOE Office of Scientific and Technical Information (OSTI.GOV)
Crisler, Michael; Essig, Rouven; Estrada, Juan
The Sub-Electron-Noise Skipper CCD Experimental Instrument (SENSEI) uses the recently developed Skipper-CCD technology to search for electron recoils from the interaction of sub-GeV dark matter particles with electrons in silicon. We report first results from a prototype SENSEI detector, which collected 0.019 gram-days of commissioning data above ground at Fermi National Accelerator Laboratory. These commissioning data are sufficient to set new direct-detection constraints for dark matter particles with masses between ~500 keV and 4 MeV. Moreover, since these data were taken on the surface, they disfavor previously allowed strongly interacting dark matter particles with masses between ~500 keV and amore » few hundred MeV. We discuss the implications of these data for several dark matter candidates, including one model proposed to explain the anomalously large 21-cm signal observed by the EDGES Collaboration. SENSEI is the first experiment dedicated to the search for electron recoils from dark matter, and these results demonstrate the power of the Skipper-CCD technology for dark matter searches.« less
Anterior Cortical Development During Adolescence in Bipolar Disorder
Najt, Pablo; Wang, Fei; Spencer, Linda; Johnston, Jennifer A.Y.; Cox Lippard, Elizabeth T.; Pittman, Brian P.; Lacadie, Cheryl; Staib, Lawrence H.; Papademetris, Xenophon; Blumberg, Hilary P.
2015-01-01
Background Increasing evidence supports a neurodevelopmental model for bipolar disorder (BD), with adolescence as a critical period in its development. Developmental abnormalities of anterior paralimbic and heteromodal frontal cortices, key structures in emotional regulation processes and central in BD, are implicated. However, few longitudinal studies have been conducted, limiting understanding of trajectory alterations in BD. In this study, we performed longitudinal neuroimaging of adolescents with and without BD and assessed volume changes over time, including changes in tissue overall and within gray and white matter. Larger decreases over time in anterior cortical volumes in the adolescents with BD were hypothesized. Gray matter decreases and white matter increases are typically observed during adolescence in anterior cortices. It was hypothesized that volume decreases over time in BD would reflect alterations in those processes, showing larger gray matter contraction and decreased white matter expansion. Methods Two high-resolution magnetic resonance imaging scans were obtained approximately two-years apart for 35 adolescents with BDI and 37 healthy adolescents. Differences over time between groups were investigated for volume overall and specifically for gray and white matter. Results Relative to healthy adolescents, adolescents with BDI showed greater volume contraction over time in a region including insula, and orbitofrontal, rostral and dorsolateral prefrontal cortices (P<.05, corrected), including greater gray matter contraction and decreased white matter expansion over time, in the BD compared to the healthy group. Conclusions: The findings support neurodevelopmental abnormalities during adolescence in BDI in anterior cortices, include altered developmental trajectories of anterior gray and white matter. PMID:26033826
A Review of the Capability Options Development and Analysis System and the Role of Risk Management
2006-08-01
Development Plan OF Objective Force SME Subject Matter Expertise S&T Science & Technology SWOT strengths, weaknesses, opportunities and threats...aircraft, or armoured vehicles. Rather it is the combination of people, organisation, equipment, systems and facilities to achieve a desired...Defence policy or Joint Service implications. They include ships, tanks, missile systems, armoured personnel carriers, major electronic systems, and
IMatter: validation of the NHS Scotland Employee Engagement Index.
Snowden, Austyn; MacArthur, Ewan
2014-11-08
Employee engagement is a fundamental component of quality healthcare. In order to provide empirical data of engagement in NHS Scotland an Employee Engagement Index was co-constructed with staff. 'iMatter' consists of 25 Likert questions developed iteratively from the literature and a series of validation events with NHS Scotland staff. The aim of this study was to test the face, content and construct validity of iMatter. Cross sectional survey of NHS Scotland staff. In January 2013 iMatter was sent to 2300 staff across all disciplines in NHS Scotland. 1280 staff completed it. Demographic data were collected. Internal consistency of the scale was calculated. Construct validity consisted of concurrent application of factor analysis and Rasch analysis. Face and content validity were checked using 3 focus groups. The sample was representative of the NHSScotland population. iMatter showed very strong reliability (α = 0.958). Factor analysis revealed a four-factor structure consistent with the following interpretation: iMatter showed evidence of high reliability and validity. It is a popular measure of staff engagement in NHS Scotland. Implications for practice focus on the importance of coproduction in psychometric development.
Dark matter and the equivalence principle
NASA Technical Reports Server (NTRS)
Frieman, Joshua A.; Gradwohl, Ben-Ami
1991-01-01
If the dark matter in galaxies and clusters is nonbaryonic, it can interact with additional long-range fields that are invisible to experimental tests of the equivalence principle. The astrophysical and cosmological implications of a long-range force coupled only to the dark matter are discussed and rather tight constraints on its strength are found. If the force is repulsive (attractive), the masses of galaxy groups and clusters (and the mean density of the universe inferred from them) have been systematically underestimated (overestimated). Such an interaction also has unusual implications for the growth of large-scale structure.
ERIC Educational Resources Information Center
Wong, Frank Y.; Chng, Chwee Lye
1998-01-01
Argues that all children have the right to a safe environment in which to learn, and the right to achieve their full human potential, no matter what their sexual orientation. Highlights needs of gay, lesbian, and bisexual students in schools. Examines challenges in personnel, curriculum, policies, and parental involvement facing…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-30
... cause review, a Safety Culture Implications Review, organizational and process changes in response to... of the assessment. d. NFS agrees to develop and implement an appropriate safety culture improvement plan to address the findings identified in the second Safety Culture Assessment report that was...
Writing Matters: Back to the Future with Rhetoric
ERIC Educational Resources Information Center
Pare, Anthony
2009-01-01
The past four decades have seen dramatic developments in the study and teaching of writing. The result is a body of knowledge about writing that has profound practical and pedagogical implications for teaching, thinking, and learning across the curriculum. This article discusses five things about writing that can have an effect across the…
The US EPA National Exposure Research Laboratory (NERL) has developed a population exposure model for particulate matter (PM), called the Stochastic Human Exposure and Dose Simulation (SHEDS-PM) model. The SHEDS-PM model estimates the population distribution of PM exposures by...
Materials Technology; 200 Years and the Future.
ERIC Educational Resources Information Center
Yadon, James N.; Steeb, Ralph V.
Focus in this paper is on the importance of materials technology, the matter and energy crises, and the interrelatedness of our increasing need for materials, and the implications for education. Following a short history of what materials have done for man and what man has done with materials, particularly in the development of various metals and…
Implications of two-component dark matter induced by forbidden channels and thermal freeze-out
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aoki, Mayumi; Toma, Takashi, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@tum.de
2017-01-01
We consider a model of two-component dark matter based on a hidden U(1) {sub D} symmetry, in which relic densities of the dark matter are determined by forbidden channels and thermal freeze-out. The hidden U(1) {sub D} symmetry is spontaneously broken to a residual Z{sub 4} symmetry, and the lightest Z{sub 4} charged particle can be a dark matter candidate. Moreover, depending on the mass hierarchy in the dark sector, we have two-component dark matter. We show that the relic density of the lighter dark matter component can be determined by forbidden annihilation channels which require larger couplings compared tomore » the normal freeze-out mechanism. As a result, a large self-interaction of the lighter dark matter component can be induced, which may solve small scale problems of ΛCDM model. On the other hand, the heavier dark matter component is produced by normal freeze-out mechanism. We find that interesting implications emerge between the two dark matter components in this framework. We explore detectabilities of these dark matter particles and show some parameter space can be tested by the SHiP experiment.« less
Stellar Wakes from Dark Matter Subhalos.
Buschmann, Malte; Kopp, Joachim; Safdi, Benjamin R; Wu, Chih-Liang
2018-05-25
We propose a novel method utilizing stellar kinematic data to detect low-mass substructure in the Milky Way's dark matter halo. By probing characteristic wakes that a passing dark matter subhalo leaves in the phase-space distribution of ambient halo stars, we estimate sensitivities down to subhalo masses of ∼10^{7} M_{⊙} or below. The detection of such subhalos would have implications for dark matter and cosmological models that predict modifications to the halo-mass function at low halo masses. We develop an analytic formalism for describing the perturbed stellar phase-space distributions, and we demonstrate through idealized simulations the ability to detect subhalos using the phase-space model and a likelihood framework. Our method complements existing methods for low-mass subhalo searches, such as searches for gaps in stellar streams, in that we can localize the positions and velocities of the subhalos today.
Anterior Cortical Development During Adolescence in Bipolar Disorder.
Najt, Pablo; Wang, Fei; Spencer, Linda; Johnston, Jennifer A Y; Cox Lippard, Elizabeth T; Pittman, Brian P; Lacadie, Cheryl; Staib, Lawrence H; Papademetris, Xenophon; Blumberg, Hilary P
2016-02-15
Increasing evidence supports a neurodevelopmental model for bipolar disorder (BD), with adolescence as a critical period in its development. Developmental abnormalities of anterior paralimbic and heteromodal frontal cortices, key structures in emotional regulation processes and central in BD, are implicated. However, few longitudinal studies have been conducted, limiting understanding of trajectory alterations in BD. In this study, we performed longitudinal neuroimaging of adolescents with and without BD and assessed volume changes over time, including changes in tissue overall and within gray and white matter. Larger decreases over time in anterior cortical volumes in the adolescents with BD were hypothesized. Gray matter decreases and white matter increases are typically observed during adolescence in anterior cortices. It was hypothesized that volume decreases over time in BD would reflect alterations in those processes, showing larger gray matter contraction and decreased white matter expansion. Two high-resolution magnetic resonance imaging scans were obtained approximately 2 years apart for 35 adolescents with bipolar I disorder (BDI) and 37 healthy adolescents. Differences over time between groups were investigated for volume overall and specifically for gray and white matter. Relative to healthy adolescents, adolescents with BDI showed greater volume contraction over time in a region including insula and orbitofrontal, rostral, and dorsolateral prefrontal cortices (p < .05, corrected), including greater gray matter contraction and decreased white matter expansion over time, in the BD compared with the healthy group. The findings support neurodevelopmental abnormalities during adolescence in BDI in anterior cortices, including altered developmental trajectories of anterior gray and white matter. Published by Elsevier Inc.
The shadow world of superstring theories
NASA Technical Reports Server (NTRS)
Kolb, E. W.; Turner, M. S.; Seckel, D.
1985-01-01
Some possible astrophysical and cosmological implications of 'shadow matter', a form of matter which only interacts gravitationally with ordinary matter and which may or may not be identical in its properties to ordinary matter, are considered. The possible existence, amount, and location of shadow matter in the solar system are discussed, and the significance of shadow matter for primordial nucleosynthesis, macroscopic asymmetry, baryogenesis, double-bubble inflation, and asymmetric microphysics is addressed. Massive shadow states are discussed.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-27
..., who do not routinely encounter claims that implicate the abstract idea exception. Under the principles... principles: Laws of nature, physical phenomena, and abstract ideas. See id. The Office has been using the so... marketing a product, comprising: Developing a shared marketing force, said shared marketing force including...
Rebecca E. Hewitt; Alec P. Bennett; Amy L. Breen; Teresa N. Hollingsworth; D. Lee Taylor; F. Stuart Chapin; T. Scott Rupp
2016-01-01
Context  Forecasting the expansion of forest into Alaska tundra is critical to predicting regional ecosystem services, including climate feedbacks such as carbon storage. Controls over seedling establishment govern forest development and migration potential. Ectomycorrhizal fungi (EMF), obligate symbionts of all Alaskan tree species, are...
Threats to Autonomy in Consumer Societies and Their Implications for Education
ERIC Educational Resources Information Center
Schinkel, Anders; de Ruyter, Doret; Steutel, Jan
2010-01-01
The development of autonomy in children is a central concern of liberal philosophers of education. We endorse the liberal intuition that autonomy matters and that it is an appropriate aim of education. However, we divert from autonomy liberals, who defend a rather limited and demanding conception of autonomy that is closely connected with skills…
ERIC Educational Resources Information Center
Walker, B. M.; Kushner, S.
Recent research has begun to examine heterosexual male behavior and the early experiences of masculinity. This pilot research project used naturalistic inquiry methodologies to investigate the experience and education of boys/young men in relation to matters of sexual health and masculinity and to develop an understanding of the relationship among…
Autism, the superior temporal sulcus and social perception.
Zilbovicius, Monica; Meresse, Isabelle; Chabane, Nadia; Brunelle, Francis; Samson, Yves; Boddaert, Nathalie
2006-07-01
The most common clinical sign of autism spectrum disorders (ASD) is social interaction impairment, which is associated with communication deficits and stereotyped behaviors. Based on recent brain-imaging results, our hypothesis is that abnormalities in the superior temporal sulcus (STS) are highly implicated in ASD. STS abnormalities are characterized by decreased gray matter concentration, rest hypoperfusion and abnormal activation during social tasks. STS anatomical and functional anomalies occurring during early brain development could constitute the first step in the cascade of neural dysfunction underlying ASD. We will focus this review on the STS, which has been highly implicated in social cognition. We will review recent data on the contribution of the STS to normal social cognition and review brain-imaging data implicating this area in ASD. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).
Life Support Filtration System Trade Study for Deep Space Missions
NASA Technical Reports Server (NTRS)
Agui, Juan H.; Perry, Jay L.
2017-01-01
The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.
Impact of breast milk on IQ, brain size and white matter development
Isaacs, Elizabeth B.; Fischl, Bruce R.; Quinn, Brian T.; Chong, Wui K.; Gadian, David G.; Lucas, Alan
2010-01-01
Although observational findings linking breast milk to higher scores on cognitive tests may be confounded by factors associated with mothers’ choice to breastfeed, it has been suggested that one or more constituents of breast milk facilitate cognitive development, particularly in preterms. Because cognitive scores are related to head size, we hypothesised that breast milk mediates cognitive effects by affecting brain growth. We used detailed data from a randomized feeding trial to calculate percentage of breast milk (%EBM) in the infant diet of 50 adolescents. MRI scans were obtained (mean age=15y9m), allowing volumes of total brain (TBV), white and grey matter (WMV, GMV) to be calculated. In the total group %EBM correlated significantly with Verbal IQ (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with grey matter. These data support the hypothesis that breast milk promotes brain development, particularly white matter growth. The selective effect in males accords with animal and human evidence regarding gender effects of early diet. Our data have important neurobiological and public health implications and identify areas for future mechanistic study. PMID:20035247
Impact of breast milk on intelligence quotient, brain size, and white matter development.
Isaacs, Elizabeth B; Fischl, Bruce R; Quinn, Brian T; Chong, Wui K; Gadian, David G; Lucas, Alan
2010-04-01
Although observational findings linking breast milk to higher scores on cognitive tests may be confounded by factors associated with mothers' choice to breastfeed, it has been suggested that one or more constituents of breast milk facilitate cognitive development, particularly in preterms. Because cognitive scores are related to head size, we hypothesized that breast milk mediates cognitive effects by affecting brain growth. We used detailed data from a randomized feeding trial to calculate percentage of expressed maternal breast milk (%EBM) in the infant diet of 50 adolescents. MRI scans were obtained (mean age=15 y 9 mo), allowing volumes of total brain (TBV) and white and gray matter (WMV, GMV) to be calculated. In the total group, %EBM correlated significantly with verbal intelligence quotient (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with gray matter. These data support the hypothesis that breast milk promotes brain development, particularly white matter growth. The selective effect in males accords with animal and human evidence regarding gender effects of early diet. Our data have important neurobiological and public health implications and identify areas for future mechanistic study.
Wang, Yihan; Matz-Costa, Christina
2018-05-16
This study explores the effect of positive and negative social support, social reciprocity, and subjective social status on the retirement satisfaction and health of retirees and gender differences therein. Using cross-sectional data from the 2010 and 2012 waves of the Health and Retirement Study (HRS), we found that social support seems to matter more for the retirement satisfaction and health of women, while social reciprocity matters more for the health of men and subjective social status for the retirement satisfaction of men. Implications for the development of social programs and policies over the life course are discussed.
"Music Matters": A Philosophical Foundation for a Sociology of Music Education.
ERIC Educational Resources Information Center
McCarthy, Marie
2000-01-01
Focuses on the book, "Music Matters" (David Elliott). Identifies the social foundations present within the volume. Explores the implications of "Music Matters" in terms of three areas of music education: (1) music teacher education; (2) music in classrooms; and (3) the relationship of school and community music. (CMK)
Exciton-photon correlations in bosonic condensates of exciton-polaritons
Kavokin, Alexey V.; Sheremet, Alexandra S.; Shelykh, Ivan A.; Lagoudakis, Pavlos G.; Rubo, Yuri G.
2015-01-01
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitted by polariton lasers. PMID:26153979
Exciton-photon correlations in bosonic condensates of exciton-polaritons.
Kavokin, Alexey V; Sheremet, Alexandra S; Shelykh, Ivan A; Lagoudakis, Pavlos G; Rubo, Yuri G
2015-07-08
Exciton-polaritons are mixed light-matter quasiparticles. We have developed a statistical model describing stochastic exciton-photon transitions within a condensate of exciton polaritons. We show that the exciton-photon correlator depends on the rate of incoherent exciton-photon transformations in the condensate. We discuss implications of this effect for the quantum statistics of photons emitted by polariton lasers.
ERIC Educational Resources Information Center
Mufwene, Salikoko S.
2010-01-01
During the past two decades, field linguists have expressed serious concerns over the unprecedented rapid loss of "indigenous languages", the endangerment of many others, and the implications of these processes for the education and economic development of "indigenous populations", among other matters. The book to which this article responds is a…
ERIC Educational Resources Information Center
Hoge, Robert Joaquin
2010-01-01
Within the sphere of education, navigating throughout a digital world has become a matter of necessity for the developing professional, as with the advent of Document Camera Technology (DCT). This study explores the pedagogical implications of implementing DCT; to see if there is a relationship between teachers' comfort with DCT and to the…
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-02
... effect of Hurricane Sandy and its implications for the Committee 5. Identifying key issues to be addressed by the Committee 6. Future Committee activities, meeting schedule, work plan 7. Public comment and... development of a reuse plan and on matters relating to future uses of certain buildings at Fort Hancock within...
Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer
2016-06-01
Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.
NASA Astrophysics Data System (ADS)
Chala, Mikael; Gröber, Ramona; Spannowsky, Michael
2018-03-01
Many composite Higgs models predict the existence of vector-like quarks with masses outside the reach of the LHC, e.g. m Q ≳ 2 TeV, in particular if these models contain a dark matter candidate. In such models the mass of the new resonances is bounded from above to satisfy the constraint from the observed relic density. We therefore develop new strategies to search for vector-like quarks at a future 100 TeV collider and evaluate what masses and interactions can be probed. We find that masses as large as ˜ 6.4 (˜9) TeV can be tested if the fermionic resonances decay into Standard Model (dark matter) particles. We also discuss the complementarity of dark matter searches, showing that most of the parameter space can be closed. On balance, this study motivates further the consideration of a higher-energy hadron collider for a next generation of facilities.
Paquola, Casey; Bennett, Maxwell; Lagopoulos, Jim
2018-05-15
Structural covariance networks (SCNs) may offer unique insights into the developmental impact of childhood maltreatment because they are thought to reflect coordinated maturation of distinct grey matter regions. T1-weighted magnetic resonance images were acquired from 121 young people with emerging mental illness. Diffusion weighted and resting state functional imaging was also acquired from a random subset of the participants (n=62). Ten study-specific SCNs were identified using a whole brain grey matter independent component analysis. The effects of childhood maltreatment and age on average grey matter density and the expression of each SCN were calculated. Childhood maltreatment was linked to age-related decreases in grey matter density across a SCN that overlapped with the default mode and fronto-parietal networks. Resting state functional connectivity and structural connectivity were calculated in the study-specific SCN and across the whole brain. Grey matter covariance was significantly correlated with rsFC across the SCN, and rsFC fully mediated the relationship between grey matter covariance and structural connectivity in the non-maltreated group. A unique association of grey matter covariance with structural connectivity was detected amongst individuals with a history of childhood maltreatment. Perturbation of grey matter development across the default mode and fronto-parietal networks following childhood maltreatment may have significant implications for mental well-being, given the networks' roles in self-referential activity. Cross-modal comparisons suggest reduced grey matter following childhood maltreatment could arise from deficient functional activity earlier in life.
NASA Technical Reports Server (NTRS)
Silk, Joseph; Stebbins, Albert
1993-01-01
A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.
Simulated Milky Way analogues: implications for dark matter direct searches
NASA Astrophysics Data System (ADS)
Bozorgnia, Nassim; Calore, Francesca; Schaller, Matthieu; Lovell, Mark; Bertone, Gianfranco; Frenk, Carlos S.; Crain, Robert A.; Navarro, Julio F.; Schaye, Joop; Theuns, Tom
2016-05-01
We study the implications of galaxy formation on dark matter direct detection using high resolution hydrodynamic simulations of Milky Way-like galaxies simulated within the EAGLE and APOSTLE projects. We identify Milky Way analogues that satisfy observational constraints on the Milky Way rotation curve and total stellar mass. We then extract the dark matter density and velocity distribution in the Solar neighbourhood for this set of Milky Way analogues, and use them to analyse the results of current direct detection experiments. For most Milky Way analogues, the event rates in direct detection experiments obtained from the best fit Maxwellian distribution (with peak speed of 223-289 km/s) are similar to those obtained directly from the simulations. As a consequence, the allowed regions and exclusion limits set by direct detection experiments in the dark matter mass and spin-independent cross section plane shift by a few GeV compared to the Standard Halo Model, at low dark matter masses. For each dark matter mass, the halo-to-halo variation of the local dark matter density results in an overall shift of the allowed regions and exclusion limits for the cross section. However, the compatibility of the possible hints for a dark matter signal from DAMA and CDMS-Si and null results from LUX and SuperCDMS is not improved.
NASA Astrophysics Data System (ADS)
Robertson, Amy D.; Daane, Abigail R.
2017-12-01
Promoting positive attitudes about science among teachers has important implications for teachers' classroom practice and for their relationship to science as a discipline. In this paper, we report positive shifts in teachers' attitudes about science, as measured by the Colorado Learning Attitudes about Science (CLASS) survey, over the course of their participation in a professional development course that emphasized the flexible use of energy representations to understand real world scenarios. Our work contributes to the larger effort to make the case that professional development matters for teacher learning and attitudes.
ERIC Educational Resources Information Center
Ryan, Rebecca M.; Claessens, Amy
2013-01-01
Most children in the U.S. today will experience one or more changes in family structure. The present study explores the implications of this trend for child development by investigating the conditions under which family structure changes matter most to child well-being. Using data from the Maternal and Child Supplement of the National Longitudinal…
ERIC Educational Resources Information Center
Cummings, Mark E.; Goeke-Morey, Marcie C.; Schermerhorn, Alice C.; Merrilees, Christine E.; Cairns, Ed
2009-01-01
The effects on children of political violence are matters of international concern, with many negative effects well-documented. At the same time, relations between war, terrorism, or other forms of political violence and child development do not occur in a vacuum. The impact can be understood as related to changes in the communities, families and…
Robinson, Shenandoah; Mikolaenko, Irina; Thompson, Ian; Cohen, Mark L.; Goyal, Monisha
2011-01-01
Epilepsy associated with preterm birth is often refractory to anticonvulsants. Children who are born preterm are also prone to cognitive delay and behavioral problems. Brains from these children often show diffuse abnormalities in cerebral circuitry that is likely caused by disrupted development during critical stages of cortical formation. To test the hypothesis that prenatal injury impairs the developmental switch of γ-amino butyric acid (GABA)ergic synapses from excitatory to inhibitory, thereby disrupting cortical circuit formation and predisposing to epilepsy, we used immunohistochemistry to compare the expression of cation-chloride transporters that developmentally regulate postsynaptic GABAergic discharges in postmortem cerebral samples from infants born preterm with known white matter injury (n = 11) with that of controls with minimal white matter gliosis (n = 7). Controls showed the expected developmental expression of cation-chloride transporters NKCC1 and KCC2 and of calretinin, a marker of a GABAergic neuronal subpopulation. Samples from infants with white matter damage showed a significant loss of expression of both NKCC1 and KCC2 in subplate and white matter. By contrast, there were no significant differences in total cell number or glutamate transporter VGLUT1 expression. Together, these novel findings suggest a molecular mechanism involved in the disruption of a critical stage of cerebral circuit development after brain injury from preterm birth that may predispose to epilepsy. PMID:20467335
Fundamental tests of galaxy formation theory
NASA Technical Reports Server (NTRS)
Silk, J.
1982-01-01
The structure of the universe as an environment where traces exist of the seed fluctuations from which galaxies formed is studied. The evolution of the density fluctuation modes that led to the eventual formation of matter inhomogeneities is reviewed, How the resulting clumps developed into galaxies and galaxy clusters acquiring characteristic masses, velocity dispersions, and metallicities, is discussed. Tests are described that utilize the large scale structure of the universe, including the dynamics of the local supercluster, the large scale matter distribution, and the anisotropy of the cosmic background radiation, to probe the earliest accessible stages of evolution. Finally, the role of particle physics is described with regard to its observable implications for galaxy formation.
Ensuring Every Child Matters: Issues and Implications for School Leadership
ERIC Educational Resources Information Center
Harris, Alma; Allen, Tracey
2009-01-01
This article considers the challenges and issues facing school leaders in the implementation of Every Child Matters. It outlines the factors that contribute to the effective delivery of Every Child Matters and outlines some of the barriers that make the delivery of this agenda more difficult. The article concludes that school leaders play a…
Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment
Aprile, E.; Agostini, F.; Alfonsi, M.; ...
2015-11-23
The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, wemore » detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.« less
Broader Societal Issues of Nanotechnology
NASA Astrophysics Data System (ADS)
Roco, M. C.
2003-08-01
Nanoscale science and engineering are providing unprecedented understanding and control over the basic building blocks of matter, leading to increased coherence in knowledge, technology, and education. The main reason for developing nanotechnology is to advance broad societal goals such as improved comprehension of nature, increased productivity, better healthcare, and extending the limits of sustainable development and of human potential. This paper outlines societal implication activities in nanotechnology R&D programs. The US National Nanotechnology Initiative annual investment in research with educational and societal implications is estimated at about 30 million (of which National Science Foundation (NSF) awards about 23 million including contributions to student fellowships), and in nanoscale research with relevance to environment at about 50 million (of which NSF awards about 30 million and EPA about 6 million). An appeal is made to researchers and funding organizations worldwide to take timely and responsible advantage of the new technology for economic and sustainable development, to initiate societal implications studies from the beginning of the nanotechnology programs, and to communicate effectively the goals and potential risks with research users and the public.
What is special about the adolescent (JME) brain?
Craiu, Dana
2013-07-01
Juvenile myoclonic epilepsy (JME) involves cortico-thalamo-cortical networks. Thalamic, frontal gray matter, connectivity, and neurotransmitter disturbances have been demonstrated by structural/functional imaging studies. Few patients with JME show mutations in genes coding ion channels or GABAA (gamma-aminobutyric acid) receptor subunits. Recent research points to EFHC1 gene mutations leading to microdysgenesis and possible aberrant circuitry. Imaging studies have shown massive structural/functional changes of normally developing adolescent brain structures maturing at strikingly different rates and times. Gray matter (GM) volume diminishes in cortical areas (frontal and parietal) and deep structures (anterior thalamus, putamen, and caudate). Diffusion tensor imaging (DTI) findings support continued microstructural change in WM (white matter) during late adolescence with robust developmental changes in thalamocortical connectivity. The GABAA receptor distribution and specific receptor subunits' expression patterns change with age from neonate to adolescent/adult, contributing to age-related changes in brain excitability. Hormonal influence on brain structure development during adolescence is presented. Possible implications of brain changes during adolescence on the course of JME are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.
The density of dark matter in the Galactic bulge and implications for indirect detection
Hooper, Dan
2016-11-29
A recent study, making use of the number of horizontal branch stars observed in infrared photometric surveys and kinematic measurements of M-giant stars from the BRAVA survey, combined with N-body simulations of stellar populations, has presented a new determination of the dark matter mass within the bulge-bar region of the Milky Way. That study constrains the total mass within themore » $$\\pm 2.2 \\times \\pm 1.4 \\times \\pm 1.2$$ kpc volume of the bulge-bar region to be ($$1.84 \\pm 0.07) \\times 10^{10} \\, M_{\\odot}$$, of which 9-30% is made up of dark matter. Here, we use this result to constrain the the Milky Way's dark matter density profile, and discuss the implications for indirect dark matter searches. Furthermore uncertainties remain significant, these results favor dark matter distributions with a cusped density profile. For example, for a scale radius of 20 kpc and a local dark matter density of 0.4 GeV/cm$^3$, density profiles with an inner slope of 0.69 to 1.40 are favored, approximately centered around the standard NFW value. In contrast, profiles with large flat-density cores are disfavored by this information.« less
WIMP-less dark matter and meson decays with missing energy
DOE Office of Scientific and Technical Information (OSTI.GOV)
McKeen, David
2009-06-01
WIMP-less dark matter [J. L. Feng and J. Kumar, Phys. Rev. Lett. 101, 231301 (2008).] offers an attractive framework in which dark matter can be very light. We investigate the implications of such scenarios on invisible decays of bottomonium states for dark matter with a mass less than around 5 GeV. We relate these decays to measurements of nucleon-dark matter elastic scattering. We also investigate the effect that a coupling to s quarks has on flavor changing b{yields}s processes involving missing energy.
Implications of tachyon-like matter for superdense stars.
NASA Technical Reports Server (NTRS)
Bhatia, M. S.; Pande, L. K.
1972-01-01
Derivation of a new equation of state of superdense matter by treating superdense matter as a perfect, degenerate tachyon gas. Model calculations for superdense stars based on this equation of state are presented. By appropriately choosing a certain parameter, dynamical stability can be achieved for arbitrarily large central densities. Also, a somewhat larger than usual value for the maximum mass is obtained.
The estuarine mixing zone is an effective trap for particulate and dissolved organic matter From many sources, and thus greatly affects transport and deposition of organic matter between the land and ocean. This study examined sedimentary distributions of various fatty acids and ...
Simulated Milky Way analogues: implications for dark matter direct searches
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bozorgnia, Nassim; Calore, Francesca; Lovell, Mark
2016-05-01
We study the implications of galaxy formation on dark matter direct detection using high resolution hydrodynamic simulations of Milky Way-like galaxies simulated within the EAGLE and APOSTLE projects. We identify Milky Way analogues that satisfy observational constraints on the Milky Way rotation curve and total stellar mass. We then extract the dark matter density and velocity distribution in the Solar neighbourhood for this set of Milky Way analogues, and use them to analyse the results of current direct detection experiments. For most Milky Way analogues, the event rates in direct detection experiments obtained from the best fit Maxwellian distribution (withmore » peak speed of 223–289 km/s) are similar to those obtained directly from the simulations. As a consequence, the allowed regions and exclusion limits set by direct detection experiments in the dark matter mass and spin-independent cross section plane shift by a few GeV compared to the Standard Halo Model, at low dark matter masses. For each dark matter mass, the halo-to-halo variation of the local dark matter density results in an overall shift of the allowed regions and exclusion limits for the cross section. However, the compatibility of the possible hints for a dark matter signal from DAMA and CDMS-Si and null results from LUX and SuperCDMS is not improved.« less
Axon-glia Synapses Are Highly Vulnerable to White Matter Injury in the Developing Brain
Shen, Yan; Liu, Xiao-Bo; Pleasure, David E.; Deng, Wenbin
2011-01-01
The biology of cerebral white matter injury is woefully understudied, in part due to the difficulty to reliably model this type of injury in rodents. Periventricular leukomalacia (PVL) is the predominant form of brain injury and the most common cause of cerebral palsy in premature infants. PVL is characterized by predominant white matter injury. No specific therapy for PVL is presently available because the pathogenesis is not well understood. Here we report that two types of mouse PVL models have been created by hypoxia-ischemia with or without systemic co-administration of lipopolysaccharide (LPS). LPS co-administration exacerbated hypoxic-ischemic white matter injury and led to enhanced microglial activation and astrogliosis. Drug trials with the anti-inflammatory agent minocycline, the anti-excitotoxic agent NBQX and the antioxidant agent edaravone showed various degrees of protection in the two models, indicating that excitotoxic, oxidative and inflammatory forms of injury are involved in the pathogenesis of injury to immature white matter. We then applied immune-electron microscopy to reveal fine structural changes in the injured white matter, and found that synapses between axons and oligodendroglial precursor cells (OPCs) are quickly and profoundly damaged. Hypoxia-ischemia caused a drastic decrease in the number of postsynaptic densities associated with the glutamatergic axon-OPC synapses defined by the expression of vesicular glutamate transporters, vGluT1 and vGluT2, on axon terminals that formed contacts with OPCs in the periventricular white matter, resulted in selective shrinkage of the postsynaptic OPCs contacted by vGluT2 labeled synapses, and led to excitotoxicity mediated by GluR2-lacking, Ca2+-permeable AMPA receptors. Taken together, the present study provides novel mechanistic insights into the pathogenesis of PVL, and reveals that axon-glia synapses are highly vulnerable to white matter injury in the developing brain. More broadly, the study of white matter development and injury has general implications for a variety of neurological diseases including PVL, stroke, spinal cord injury and multiple sclerosis. PMID:21812016
Noumbissi, Midrelle E; Galasso, Bianca; Stins, Monique F
2018-04-23
The vertebrate blood-brain barrier (BBB) is composed of cerebral microvascular endothelial cells (CEC). The BBB acts as a semi-permeable cellular interface that tightly regulates bidirectional molecular transport between blood and the brain parenchyma in order to maintain cerebral homeostasis. The CEC phenotype is regulated by a variety of factors, including cells in its immediate environment and within functional neurovascular units. The cellular composition of the brain parenchyma surrounding the CEC varies between different brain regions; this difference is clearly visible in grey versus white matter. In this review, we discuss evidence for the existence of brain vascular heterogeneity, focusing on differences between the vessels of the grey and white matter. The region-specific differences in the vasculature of the brain are reflective of specific functions of those particular brain areas. This BBB-endothelial heterogeneity may have implications for the course of pathogenesis of cerebrovascular diseases and neurological disorders involving vascular activation and dysfunction. This heterogeneity should be taken into account when developing BBB-neuro-disease models representative of specific brain areas.
Recent personal exposure panel studies and monitoring programs addressing fine particulate matter (PM) and associated co-pollutants have elucidated the physical and statistical relationships between personal exposures, residential indoor concentrations (and sources), concentratio...
White matter structural connectivity and episodic memory in early childhood.
Ngo, Chi T; Alm, Kylie H; Metoki, Athanasia; Hampton, William; Riggins, Tracy; Newcombe, Nora S; Olson, Ingrid R
2017-12-01
Episodic memory undergoes dramatic improvement in early childhood; the reason for this is poorly understood. In adults, episodic memory relies on a distributed neural network. Key brain regions that supporting these processes include the hippocampus, portions of the parietal cortex, and portions of prefrontal cortex, each of which shows different developmental profiles. Here we asked whether developmental differences in the axonal pathways connecting these regions may account for the robust gains in episodic memory in young children. Using diffusion weighted imaging, we examined whether white matter connectivity between brain regions implicated in episodic memory differed with age, and were associated with memory performance differences in 4- and 6-year-old children. Results revealed that white matter connecting the hippocampus to the inferior parietal lobule significantly predicted children's performance on episodic memory tasks. In contrast, variation in the white matter connecting the hippocampus to the medial prefrontal cortex did not relate to memory performance. These findings suggest that structural connectivity between the hippocampus and lateral parietal regions is relevant to the development of episodic memory. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
White Matter Structural Connectivity and Episodic Memory in Early Childhood
Ngo, Chi T.; Alm, Kylie H.; Metoki, Athanasia; Hampton, William; Riggins, Tracy; Newcombe, Nora S.; Olson, Ingrid R.
2018-01-01
Episodic memory undergoes dramatic improvement in early childhood; the reason for this is poorly understood. In adults, episodic memory relies on a distributed neural network. Key brain regions that supporting these processes include the hippocampus, portions of the parietal cortex, and portions of prefrontal cortex, each of which shows different developmental profiles. Here we asked whether developmental differences in the axonal pathways connecting these regions may account for the robust gains in episodic memory in young children. Using diffusion weighted imaging, we examined whether white matter connectivity between brain regions implicated in episodic memory differed with age, and were associated with memory performance differences in 4- and 6-year-old children. Results revealed that white matter connecting the hippocampus to the inferior parietal lobule significantly predicted children’s performance on episodic memory tasks. In contrast, variation in the white matter connecting the hippocampus to the medial prefrontal cortex did not relate to memory performance. These findings suggest that structural connectivity between the hippocampus and lateral parietal regions is relevant to the development of episodic memory PMID:29175538
Insight and white matter fractional anisotropy in first-episode schizophrenia.
Asmal, Laila; du Plessis, Stefan; Vink, Matthijs; Fouche, Jean-Paul; Chiliza, Bonginkosi; Emsley, Robin
2017-05-01
Impaired insight is a hallmark feature of schizophrenia. Structural studies implicate predominantly prefrontal, cingulate, cuneus/precuneus, and inferior temporal brain regions. The cortical midline structures (CMS) are also implicated in functional studies primarily through self-reflective processing tasks. However, few studies have explored the relationship between white matter tracts and insight in schizophrenia, and none in first-episode schizophrenia (FES). Here, we examined for fractional anisotropy (FA) differences in 89 minimally treated FES patients and 98 matched controls, and identified those FA differences associated with impaired clinical insight in patients. We found widespread FA reduction in FES patients compared to controls. Poorer insight in patients was predicted by lower FA values in a number of white matter tracts with a predilection for tracts associated with cortical midline structures (fronto-occipital, cingulate, cingulate hippocampus, uncinate, anterior corona radiata), and more severe depressive symptoms. The association between FA abnormalities and insight was most robust for the awareness of symptoms and illness awareness domains. Our study implicates a network of tracts involved in impaired insight in schizophrenia with a predilection for the CMS. This study is a first step in delineating the white matter tracts involved in insight impairment in schizophrenia prior to chronicity. Copyright © 2016. Published by Elsevier B.V.
Ultimate energy density of observable cold baryonic matter.
Lattimer, James M; Prakash, Madappa
2005-03-25
We demonstrate that the largest measured mass of a neutron star establishes an upper bound to the energy density of observable cold baryonic matter. An equation of state-independent expression satisfied by both normal neutron stars and self-bound quark matter stars is derived for the largest energy density of matter inside stars as a function of their masses. The largest observed mass sets the lowest upper limit to the density. Implications from existing and future neutron star mass measurements are discussed.
Solar test of Dirac's large number hypothesis. [multiplicative creation model for solar evolution
NASA Technical Reports Server (NTRS)
Chin, C.-W.; Stothers, R.
1975-01-01
An investigation is conducted regarding the implications of Dirac's theories (1973, 1974) concerning the creation of new matter. It is found that Dirac's theory of multiplicative creation, but not his theory of additive creation, is not in contradiction with known facts about the sun. According to the theory of additive creation, matter is formed uniformly throughout space. The concept of multiplicative creation implies that existing matter multiplies itself in proportion to the amount of matter already present.
Neurocognitive Correlates of White Matter Quality in Adolescent Substance Users
ERIC Educational Resources Information Center
Bava, Sunita; Jacobus, Joanna; Mahmood, Omar; Yang, Tony T.; Tapert, Susan F.
2010-01-01
Background: Progressive myelination during adolescence implicates an increased vulnerability to neurotoxic substances and enduring neurocognitive consequences. This study examined the cognitive manifestations of altered white matter microstructure in chronic marijuana and alcohol-using (MJ + ALC) adolescents. Methods: Thirty-six MJ + ALC…
ERIC Educational Resources Information Center
Aydeniz, Mehmet; Kotowski, Erin Leigh
2012-01-01
This study explores middle and high school students' understanding of the particulate nature of matter after they were taught the concept. A total of 87 students (41 high school and 46 middle school) participated in the study. Findings suggest that students held misconceptions about the law of conservation of matter, chemical composition of matter…
Subcortical grey matter changes in untreated, early stage Parkinson's disease without dementia.
Lee, Hye Mi; Kwon, Kyum-Yil; Kim, Min-Jik; Jang, Ji-Wan; Suh, Sang-Il; Koh, Seong-Beom; Kim, Ji Hyun
2014-06-01
Previous MRI studies have investigated cortical or subcortical grey matter changes in patients with Parkinson's disease (PD), yielding inconsistent findings between the studies. We therefore sought to determine whether focal cortical or subcortical grey matter changes may be present from the early disease stage. We recruited 49 untreated, early stage PD patients without dementia and 53 control subjects. Voxel-based morphometry was used to evaluate cortical grey matter changes, and automated volumetry and shape analysis were used to assess volume changes and shape deformation of the subcortical grey matter structures, respectively. Voxel-based morphometry showed neither reductions nor increases in grey matter volume in patients compared to controls. Compared to controls, PD patients had significant reductions in adjusted volumes of putamen, nucleus accumbens, and hippocampus (corrected p < 0.05). Vertex-based shape analysis showed regionally contracted area on the posterolateral and ventromedial putamen bilaterally in PD patients (corrected p < 0.05). No correlations were found between cortical and subcortical grey matter and clinical variables representing disease duration and severity. Our results suggest that untreated, early stage PD without dementia is associated with volume reduction and shape deformation of subcortical grey matter, but not with cortical grey matter reduction. Our findings of structural changes in the posterolateral putamen and ventromedial putamen/nucleus accumbens could provide neuroanatomical basis for the involvement of motor and limbic striatum, further implicating motor and non-motor symptoms in PD, respectively. Early hippocampal involvement might be related to the risk for developing dementia in PD patients. Copyright © 2014 Elsevier Ltd. All rights reserved.
2008-08-18
Operations Concept Rules of engagement Reconnaissance, surveillance, and target acquisition Subject matter experts Technology readiness level Tactics...might call for the notification of an additional ASW platform, a pouncer, to reacquire, follow, and/or kill the transiter depending on the rules of...Naval Research Laboratory (E. Franchi , F. Erskine) 2 Naval Sea Systems Command (PEO-C4I and Space - D. Bauman, PEO-IWS - Technical Director, PEO-IWS5
Introducing 12 year-olds to elementary particles
NASA Astrophysics Data System (ADS)
Wiener, Gerfried J.; Schmeling, Sascha M.; Hopf, Martin
2017-07-01
We present a new learning unit, which introduces 12 year-olds to the subatomic structure of matter. The learning unit was iteratively developed as a design-based research project using the technique of probing acceptance. We give a brief overview of the unit’s final version, discuss its key ideas and main concepts, and conclude by highlighting the main implications of our research, which we consider to be most promising for use in the physics classroom.
Detecting the Disruption of Dark-Matter Halos with Stellar Streams.
Bovy, Jo
2016-03-25
Narrow stellar streams in the Milky Way halo are uniquely sensitive to dark-matter subhalos, but many of these subhalos may be tidally disrupted. I calculate the interaction between stellar and dark-matter streams using analytical and N-body calculations, showing that disrupting objects can be detected as low-concentration subhalos. Through this effect, we can constrain the lumpiness of the halo as well as the orbit and present position of individual dark-matter streams. This will have profound implications for the formation of halos and for direct- and indirect-detection dark-matter searches.
The contentious nature of soil organic matter.
Lehmann, Johannes; Kleber, Markus
2015-12-03
The exchange of nutrients, energy and carbon between soil organic matter, the soil environment, aquatic systems and the atmosphere is important for agricultural productivity, water quality and climate. Long-standing theory suggests that soil organic matter is composed of inherently stable and chemically unique compounds. Here we argue that the available evidence does not support the formation of large-molecular-size and persistent 'humic substances' in soils. Instead, soil organic matter is a continuum of progressively decomposing organic compounds. We discuss implications of this view of the nature of soil organic matter for aquatic health, soil carbon-climate interactions and land management.
This presentation will describe the following items: important epidemiologic data establishing the need for new particulate matter standards, the size distribution of suspended particulate matter, epidemiologic data demonstrating the need for a fine particle standard, indicator a...
Dairy manure applications and soil health implications
USDA-ARS?s Scientific Manuscript database
Dairy manure applications can potentially improve soil health by adding organic matter (OM) to the soil. However, intensive dairy manure applications can cause salt accumulations on arid, irrigated soils, impairing soil health, which can reduce crop growth and yield. Soil organic matter, a major c...
The implications of spatially variable pre‐emergence herbicide efficacy for weed management
Milne, Alice E; Hull, Richard; Murdoch, Alistair J; Storkey, Jonathan
2017-01-01
Abstract BACKGROUND The efficacy of pre‐emergence herbicides within fields is spatially variable as a consequence of soil heterogeneity. We quantified the effect of soil organic matter on the efficacy of two pre‐emergence herbicides, flufenacet and pendimethalin, against Alopecurus myosuroides and investigated the implications of variation in organic matter for weed management using a crop–weed competition model. RESULTS Soil organic matter played a critical role in determining the level of control achieved. The high organic matter soil had more surviving weeds with higher biomass than the low organic matter soil. In the absence of competition, surviving plants recovered to produce the same amount of seed as if no herbicide had been applied. The competition model predicted that weeds surviving pre‐emergence herbicides could compensate for sublethal effects even when competing with the crop. The ED50 (median effective dose) was higher for weed seed production than seedling mortality or biomass. This difference was greatest on high organic matter soil. CONCLUSION These results show that the application rate of herbicides should be adjusted to account for within‐field variation in soil organic matter. The results from the modelling emphasised the importance of crop competition in limiting the capacity of weeds surviving pre‐emergence herbicides to compensate and replenish the seedbank. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:29095563
Abnormal white matter properties in adolescent girls with anorexia nervosa
Travis, Katherine E.; Golden, Neville H.; Feldman, Heidi M.; Solomon, Murray; Nguyen, Jenny; Mezer, Aviv; Yeatman, Jason D.; Dougherty, Robert F.
2015-01-01
Anorexia nervosa (AN) is a serious eating disorder that typically emerges during adolescence and occurs most frequently in females. To date, very few studies have investigated the possible impact of AN on white matter tissue properties during adolescence, when white matter is still developing. The present study evaluated white matter tissue properties in adolescent girls with AN using diffusion MRI with tractography and T1 relaxometry to measure R1 (1/T1), an index of myelin content. Fifteen adolescent girls with AN (mean age = 16.6 years ± 1.4) were compared to fifteen age-matched girls with normal weight and eating behaviors (mean age = 17.1 years ± 1.3). We identified and segmented 9 bilateral cerebral tracts (18) and 8 callosal fiber tracts in each participant's brain (26 total). Tract profiles were generated by computing measures for fractional anisotropy (FA) and R1 along the trajectory of each tract. Compared to controls, FA in the AN group was significantly decreased in 4 of 26 white matter tracts and significantly increased in 2 of 26 white matter tracts. R1 was significantly decreased in the AN group compared to controls in 11 of 26 white matter tracts. Reduced FA in combination with reduced R1 suggests that the observed white matter differences in AN are likely due to reductions in myelin content. For the majority of tracts, group differences in FA and R1 did not occur within the same tract. The present findings have important implications for understanding the neurobiological factors underlying white matter changes associated with AN and invite further investigations examining associations between white matter properties and specific physiological, cognitive, social, or emotional functions affected in AN. PMID:26740918
Anomalous White Matter Morphology in Adults Who Stutter
ERIC Educational Resources Information Center
Cieslak, Matthew; Ingham, Rojer J.; Ingham, Janis C.; Grafton, Scott T.
2015-01-01
Aims: Developmental stuttering is now generally considered to arise from genetic determinants interacting with neurologic function. Changes within speech-motor white matter (WM) connections may also be implicated. These connections can now be studied in great detail by high-angular-resolution diffusion magnetic resonance imaging. Therefore,…
Particulate matter (PM) in the air is known to cause adverse health effects, particularly in elderly subjects with respiratory and cardiopulmonary disease. Although observed health effects are likely caused by multiple factors, the respiratory dose is one factor of particular con...
Semi-volatile compounds present special analytical challenges not met by conventional methods for analysis of ambient particulate matter (PM). Accurate quantification of PM-associated organic compounds requires validation of the laboratory procedures for recovery over a wide v...
Novel white matter tract integrity metrics sensitive to Alzheimer disease progression.
Fieremans, E; Benitez, A; Jensen, J H; Falangola, M F; Tabesh, A; Deardorff, R L; Spampinato, M V S; Babb, J S; Novikov, D S; Ferris, S H; Helpern, J A
2013-01-01
Along with cortical abnormalities, white matter microstructural changes such as axonal loss and myelin breakdown are implicated in the pathogenesis of Alzheimer disease. Recently, a white matter model was introduced that relates non-Gaussian diffusional kurtosis imaging metrics to characteristics of white matter tract integrity, including the axonal water fraction, the intra-axonal diffusivity, and the extra-axonal axial and radial diffusivities. This study reports these white matter tract integrity metrics in subjects with amnestic mild cognitive impairment (n = 12), Alzheimer disease (n = 14), and age-matched healthy controls (n = 15) in an effort to investigate their sensitivity, diagnostic accuracy, and associations with white matter changes through the course of Alzheimer disease. With tract-based spatial statistics and region-of-interest analyses, increased diffusivity in the extra-axonal space (extra-axonal axial and radial diffusivities) in several white matter tracts sensitively and accurately discriminated healthy controls from those with amnestic mild cognitive impairment (area under the receiver operating characteristic curve = 0.82-0.95), while widespread decreased axonal water fraction discriminated amnestic mild cognitive impairment from Alzheimer disease (area under the receiver operating characteristic curve = 0.84). Additionally, these white matter tract integrity metrics in the body of the corpus callosum were strongly correlated with processing speed in amnestic mild cognitive impairment (r = |0.80-0.82|, P < .001). These findings have implications for the course and spatial progression of white matter degeneration in Alzheimer disease, suggest the mechanisms by which these changes occur, and demonstrate the viability of these white matter tract integrity metrics as potential neuroimaging biomarkers of the earliest stages of Alzheimer disease and disease progression.
NASA Astrophysics Data System (ADS)
Shields, Emily Kathryn
Ample evidence has been gathered demonstrating that the majority of the mass in the universe is composed of non-luminous, non-baryonic matter. Though the evidence for dark matter is unassailable, its nature and properties remain unknown. A broad effort has been undertaken by the physics community to detect dark-matter particles through direct-detection techniques. For over a decade, the DAMA/LIBRA experiment has observed a highly significant (9.3sigma) modulation in the scintillation event rate in their highly pure NaI(Tl) detectors, which they use as the basis of a claim for the discovery of dark-matter particles. However, the dark-matter interpretation of the DAMA/LIBRA modulation remains unverified. While there have been some recent hints of dark matter in the form of a light Weakly-Interacting Massive Particle (WIMP) from the CoGeNT and CDMS-Si experiments, when assuming a WIMP dark-matter model, several other experiments, including the LUX and XENON noble-liquid experiments, the KIMS CsI(Tl) experiment, and several bubble chamber experiments, conflict with DAMA/LIBRA. However, these experiments use different dark-matter targets and cannot be compared with DAMA/LIBRA in a model-independent way. The uncertainty surrounding the dark-matter model, astrophysical model, and nuclear-physics effects makes it necessary for a new NaI(Tl) experiment to directly test the DAMA/LIBRA result. The Sodium-iodide with Active Background REjection (SABRE) experiment seeks to provide a much-needed model-independent test of the DAMA/LIBRA modulation by developing highly pure crystal detectors with very low radioactivity and deploying them in an active veto detector that can reject key backgrounds in a dark-matter measurement. This work focuses on the efforts put forward by the SABRE collaboration in developing low-background, low-threshold crystal detectors, designing and fabricating a liquid-scintillator veto detector, and simulating the predicted background spectrum for a dark-matter measurement. In addition, recent controversy surrounding the value of an important parameter for direct detection---the nuclear quenching factor---prompted SABRE to perform a measurement of the quenching factor in sodium. The measurement, its results, and the implications for DAMA/LIBRA and dark matter are also described.
Klosinski, Lauren P; Yao, Jia; Yin, Fei; Fonteh, Alfred N; Harrington, Michael G; Christensen, Trace A; Trushina, Eugenia; Brinton, Roberta Diaz
2015-12-01
White matter degeneration is a pathological hallmark of neurodegenerative diseases including Alzheimer's. Age remains the greatest risk factor for Alzheimer's and the prevalence of age-related late onset Alzheimer's is greatest in females. We investigated mechanisms underlying white matter degeneration in an animal model consistent with the sex at greatest Alzheimer's risk. Results of these analyses demonstrated decline in mitochondrial respiration, increased mitochondrial hydrogen peroxide production and cytosolic-phospholipase-A2 sphingomyelinase pathway activation during female brain aging. Electron microscopic and lipidomic analyses confirmed myelin degeneration. An increase in fatty acids and mitochondrial fatty acid metabolism machinery was coincident with a rise in brain ketone bodies and decline in plasma ketone bodies. This mechanistic pathway and its chronologically phased activation, links mitochondrial dysfunction early in aging with later age development of white matter degeneration. The catabolism of myelin lipids to generate ketone bodies can be viewed as a systems level adaptive response to address brain fuel and energy demand. Elucidation of the initiating factors and the mechanistic pathway leading to white matter catabolism in the aging female brain provides potential therapeutic targets to prevent and treat demyelinating diseases such as Alzheimer's and multiple sclerosis. Targeting stages of disease and associated mechanisms will be critical.
Klosinski, Lauren P.; Yao, Jia; Yin, Fei; Fonteh, Alfred N.; Harrington, Michael G.; Christensen, Trace A.; Trushina, Eugenia; Brinton, Roberta Diaz
2015-01-01
White matter degeneration is a pathological hallmark of neurodegenerative diseases including Alzheimer's. Age remains the greatest risk factor for Alzheimer's and the prevalence of age-related late onset Alzheimer's is greatest in females. We investigated mechanisms underlying white matter degeneration in an animal model consistent with the sex at greatest Alzheimer's risk. Results of these analyses demonstrated decline in mitochondrial respiration, increased mitochondrial hydrogen peroxide production and cytosolic-phospholipase-A2 sphingomyelinase pathway activation during female brain aging. Electron microscopic and lipidomic analyses confirmed myelin degeneration. An increase in fatty acids and mitochondrial fatty acid metabolism machinery was coincident with a rise in brain ketone bodies and decline in plasma ketone bodies. This mechanistic pathway and its chronologically phased activation, links mitochondrial dysfunction early in aging with later age development of white matter degeneration. The catabolism of myelin lipids to generate ketone bodies can be viewed as a systems level adaptive response to address brain fuel and energy demand. Elucidation of the initiating factors and the mechanistic pathway leading to white matter catabolism in the aging female brain provides potential therapeutic targets to prevent and treat demyelinating diseases such as Alzheimer's and multiple sclerosis. Targeting stages of disease and associated mechanisms will be critical. PMID:26844268
Conti, Rena M; Padula, William V; Larson, Richard A
2015-04-01
Imatinib is an oral tyrosine kinase inhibitor and considered to be the most successful targeted anti-cancer agent yet developed given its substantial efficacy in treating chronic myeloid leukemia (CML) and other malignant diseases. In the USA and the European Union (EU), Novartis' composition of matter patent on imatinib will expire in 2016. The potential impact on health system spending levels for CML after generic imatinib becomes available is the subject of significant interest among stakeholders. The extent of the potential savings largely depends on whether and to what extent prices decline and use stays the same or even increases. These are also empirical questions since the likely spending implications following generic imatinib's availability are predicated on multiple factors: physicians' willingness to prescribe generic imatinib, molecule characteristics, and health system priorities. This article discusses each of these issues in turn. We then review their implications for the development of country-specific cost-effectiveness models to predict the implications for cost and quality of care from generic imatinib.
Padula, William V.; Larson, Richard A.
2015-01-01
Imatinib is an oral tyrosine kinase inhibitor and considered to be the most successful targeted anti-cancer agent yet developed given its substantial efficacy in treating chronic myeloid leukemia (CML) and other malignant diseases. In the USA and the European Union (EU), Novartis’ composition of matter patent on imatinib will expire in 2016. The potential impact on health system spending levels for CML after generic imatinib becomes available is the subject of significant interest among stakeholders. The extent of the potential savings largely depends on whether and to what extent prices decline and use stays the same or even increases. These are also empirical questions since the likely spending implications following generic imatinib’s availability are predicated on multiple factors: physicians’ willingness to prescribe generic imatinib, molecule characteristics, and health system priorities. This article discusses each of these issues in turn. We then review their implications for the development of country-specific cost-effectiveness models to predict the implications for cost and quality of care from generic imatinib. PMID:25814091
While the association between exposure to ambient fine particulate matter mass (PM2.5) and human mortality is well established, the most responsible particle types/sources are not yet certain. In May 2003, the U.S. Environmental Protection Agency's Particulate Matter Centers Prog...
Dissolved organic matter (DOM) has been implicated as an important complexing agent for Hg that can affect its mobility and bioavailability in aquatic ecosystems. However, binding constants for natural Hg-DOM complexes are not well known. We employed a competitive ligand appro...
Exposure to air pollution-derived particulate matter (PM) causes adverse cardiovascular health outcomes, with increasing evidence implicating soluble components of PM; however, the enormous number of unique PM samples from different air sheds far exceeds the capacity of conventio...
Post-stroke dementia: the contribution of thalamus and basal ganglia changes.
Lopes, Marcos Antonio; Firbank, Michael J; Widdrington, Michelle; Blamire, Andrew M; Kalaria, Raj N; O'Brien, John T
2012-04-01
The neurobiological basis of increased risk of dementia in stroke patients is unclear, though there are several related pathological changes, including white matter hyperintensities (WMH), and medial temporal atrophy. Subcortical gray matter structures have also been implicated in dementia resulting from vascular pathology, particularly vascular dementia. This study aimed to investigate the contribution of changes in subcortical gray matter structures to post-stroke dementia (PSD). T1- and T2-weighted images and T2-weighted fluid-attenuated inversion recovery (FLAIR) images were obtained on a 3-Tesla magnetic resonance (MR) system, in four groups aged over 75 years: post-stroke with dementia (PSD; 8), post-stroke no dementia (PSnoD; 33), Alzheimer's disease (AD; 26) and controls (30). Automated software was used to measure the volume of thalamus, putamen, caudate nucleus, and hippocampus as well as total WMH volume. The number of subcortical lacunes was also counted. The number of caudate lacunes was higher in the PSnoD group, compared with AD (p = 0.029) and controls (p = 0.019). The putamen volume was smaller in the stroke and AD groups, when compared with controls. In the whole stroke group, putamen lacunes were correlated with impairment in memory (Rey test; ρ = -0.365; p = 0.031), while WMH and hippocampal volume both correlated with global dysfunction. Our findings implicate a variety of neurobiological substrates of dementia, such as small vessel disease and Alzheimer pathology, which develop after stroke in an old older population, with a contribution from subcortical brain structures.
Jardine, Timothy D; Kidd, Karen A; Rasmussen, Joseph B
2012-04-01
The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whether Hg concentrations in fish and their prey were related to these energy sources. Taxa varied in their use of the two sources, with grazing mayflies (Heptageniidae), predatory stoneflies (Perlidae), one species of water strider (Metrobates hesperius), and the fish blacknose dace (Rhinichthys atratulus) showing strong connections to aquatic sources, while Aquarius remigis water striders and brook trout (Salvelinus fontinalis) showed a weak link to in-stream production. The aquatic food source for consumers, periphyton, had higher Hg concentrations in low-pH waters, and pH was a much better predictor of Hg in predatory invertebrates that relied mainly on this food source vs. those that used terrestrial C. These findings suggest that stream biota relying mainly on dietary inputs from the riparian zone will be partially insulated from the effects of water chemistry on Hg availability. This has implications for the development of a whole-system understanding of nutrient and material cycling in streams, the choice of taxa in contaminant monitoring studies, and in understanding the fate of Hg in stream food webs.
Simultaneous Chiral Symmetry Restoration and Deconfinement Consequences for the QCD Phase Diagram
NASA Astrophysics Data System (ADS)
Klähn, Thomas; Fischer, Tobias; Hempel, Matthias
2017-02-01
For studies of quark matter in astrophysical scenarios, the thermodynamic bag model is commonly employed. Although successful, it does not account for dynamical chiral symmetry breaking and repulsions due to the vector interaction which is crucial to explain recent observations of massive, two solar mass neutron stars. In Klähn & Fischer we developed the novel vBag quark matter model which takes these effects into account. This article extends vBag to finite temperatures and isospin asymmetry. Another particular feature of vBag is the determination of the deconfinement bag constant {B}{dc} from a given hadronic equation of state in order to ensure that chiral and deconfinement transitions coincide. We discuss consequences of this novel approach for the phase transition construction, the phase diagram, and implications for protoneutron stars.
Flooded Dark Matter and S level rise
NASA Astrophysics Data System (ADS)
Randall, Lisa; Scholtz, Jakub; Unwin, James
2016-03-01
Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as "Maximum Baroqueness". We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant non-thermal leptogenesis implementation in which decays of a heavy right-handed neutrino lead to late time reheating of the Standard Model degrees of freedom and provide suitable conditions for creation of a lepton asymmetry.
Tying dark matter to baryons with self-interactions.
Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo
2014-07-11
Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.
Diffusion Tensor Imaging of Pedophilia.
Cantor, James M; Lafaille, Sophie; Soh, Debra W; Moayedi, Massieh; Mikulis, David J; Girard, Todd A
2015-11-01
Pedophilia is a principal motivator of child molestation, incurring great emotional and financial burdens on victims and society. Even among pedophiles who never commit any offense,the condition requires lifelong suppression and control. Previous comparison using voxel-based morphometry (VBM)of MR images from a large sample of pedophiles and controls revealed group differences in white matter. The present study therefore sought to verify and characterize white matter involvement using diffusion tensor imaging (DTI), which better captures the microstructure of white matter than does VBM. Pedophilics ex offenders (n=24) were compared with healthy, age-matched controls with no criminal record and no indication of pedophilia (n=32). White matter microstructure was analyzed with Tract-Based Spatial Statistics, and the trajectories of implicated fiber bundles were identified by probabilistic tractography. Groups showed significant, highly focused differences in DTI parameters which related to participants’ genital responses to sexual depictions of children, but not to measures of psychopathy or to childhood histories of physical abuse, sexual abuse, or neglect. Some previously reported gray matter differences were suggested under highly liberal statistical conditions (p(uncorrected)<.005), but did not survive ordinary statistical correction (whole brain per voxel false discovery rate of 5%). These results confirm that pedophilia is characterized by neuroanatomical differences in white matter microstructure, over and above any neural characteristics attributable to psychopathy and childhood adversity, which show neuroanatomic footprints of their own. Although some gray matter structures were implicated previously, only few have emerged reliably.
Nuclear pasta in hot dense matter and its implications for neutrino scattering
NASA Astrophysics Data System (ADS)
Roggero, Alessandro; Margueron, Jérôme; Roberts, Luke F.; Reddy, Sanjay
2018-04-01
The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Ye>0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T =0 , dissolve at a relatively low temperature Tu as protons leak out of nuclei and pasta. For matter at β equilibrium with a negligible neutrino chemical potential we find that Tuβ≃4 ±1 MeV for realistic equations of state. This is lower than the maximum temperature Tmaxβ≃9 ±1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Implications for neutrino signals from galactic supernovas are briefly discussed.
One indicator of health in estuarine and coastal ecosystems is the ability of local waters to transmit sunlight to planktonic, macrophytic, and other submerged vegetation for photosynthesis. The concentration of coloured dissolved organic matter (CDOM) is a primary factor affecti...
Educational Content of Basal Reading Texts: Implications for Comprehension Instruction.
ERIC Educational Resources Information Center
Schmidt, William H.; And Others
To explore the issue of educational content in basal readers, a study analyzed 34 basal reading textbooks, representing eight of the most commonly used series in American elementary education. Educational content was defined and categorized along three dimensions: subject matter, function, and ethos. The subject matter component covered theories,…
A number of studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden particulate matter inhibits protein tyrosine phosphatase activity in HAEC and leads to Src-dependent activation of EGFR sign...
Increased White Matter Gyral Depth in Dyslexia: Implications for Corticocortical Connectivity
ERIC Educational Resources Information Center
Casanova, Manuel F.; El-Baz, Ayman S.; Giedd, Jay; Rumsey, Judith M.; Switala, Andrew E.
2010-01-01
Recent studies provide credence to the minicolumnar origin of several developmental conditions, including dyslexia. Characteristics of minicolumnopathies include abnormalities in how the cortex expands and folds. This study examines the depth of the gyral white matter measured in an MRI series of 15 dyslexic adult men and eleven age-matched…
ERIC Educational Resources Information Center
Abd-El-Khalick, Fouad
2006-01-01
This study aimed to describe preservice and experienced secondary biology teachers' global and specific subject matter structures (SMSs) and elucidate the relationship between these structures and teaching experience. Teachers' global and specific SMSs respectively designate their conceptions and/or organization of their disciplines and of…
New Views on Dark Matter from Emergent Gravity
NASA Astrophysics Data System (ADS)
Sun, Sichun; Zhang, Yun-Long
2018-01-01
We discuss a scenario that apparent dark matter comes from the induced gravity in the (3+1)- dimensional spacetime, which can be embedded into one higher dimensional flat spacetime. The stress tensor of dark energy and dark matter is identified with the Brown-York stress tensor on the hypersurface, and we find an interesting constraint relation between the dark matter and dark energy density parameter and baryonic density parameter. Our approach may show a new understanding for Verlinde's emergent gravity from higher dimensions. We also comment on some phenomenological implications, including gravitational wave solutions and MOND limit.
Heavy Higgs boson production at colliders in the singlet-triplet scotogenic dark matter model
NASA Astrophysics Data System (ADS)
Díaz, Marco Aurelio; Rojas, Nicolás; Urrutia-Quiroga, Sebastián; Valle, José W. F.
2017-08-01
We consider the possibility that the dark matter particle is a scalar WIMP messenger associated to neutrino mass generation, made stable by the same symmetry responsible for the radiative origin of neutrino mass. We focus on some of the implications of this proposal as realized within the singlet-triplet scotogenic dark matter model. We identify parameter sets consistent both with neutrino mass and the observed dark matter abundance. Finally we characterize the expected phenomenological profile of heavy Higgs boson physics at the LHC as well as at future linear Colliders.
Power, politics, and top management team characteristics: do they matter?
Gerowitz, M B
1998-01-01
This study assesses the contributions of the leader power and top management team characteristics to perceived strategic capability. Low age heterogeneity and low tenure heterogeneity were found to have a positive association with perceived adaptability. High diversity in educational specialization was also found to be positively associated with adaptability. Top management perceptions of CEO power were, however, lower among high adaptors. Implications for leadership research, senior management recruitment, and the design of management development for top management teams are discussed.
Developmental differences in white matter architecture between boys and girls.
Schmithorst, Vincent J; Holland, Scott K; Dardzinski, Bernard J
2008-06-01
Previous studies have found developmental differences between males and females in brain structure. During childhood and adolescence, relative white matter volume increases faster in boys than in girls. Sex differences in the development of white matter microstructure were investigated in a cohort of normal children ages 5-18 in a cross-sectional diffusion tensor imaging (DTI) study. Greater fractional anisotropy (FA) in boys was shown in associative white matter regions (including the frontal lobes), while greater FA in girls was shown in the splenium of the corpus callosum. Greater mean diffusivity (MD) in boys was shown in the corticospinal tract and in frontal white matter in the right hemisphere; greater MD in girls was shown in occipito-parietal regions and the most superior aspect of the corticospinal tract in the right hemisphere. Significant sex-age interactions on FA and MD were also shown. Girls displayed a greater rate of fiber density increase with age when compared with boys in associative regions (reflected in MD values). However, girls displayed a trend toward increased organization with age (reflected in FA values) only in the right hemisphere, while boys displayed this trend only in the left hemisphere. These results indicate differing developmental trajectories in white matter for boys and girls and the importance of taking sex into account in developmental DTI studies. The results also may have implications for the study of the relationship of brain architecture with intelligence. Copyright 2007 Wiley-Liss, Inc.
Neuregulin-1 genotype is associated with structural differences in the normal human brain.
Barnes, Anna; Isohanni, Matti; Barnett, Jennifer H; Pietiläinen, Olli; Veijola, Juha; Miettunen, Jouko; Paunio, Tiina; Tanskanen, Päivikki; Ridler, Khanum; Suckling, John; Bullmore, Edward T; Jones, Peter B; Murray, Graham K
2012-02-01
The human neuregulin-1 (NRG-1) gene is highly expressed in the brain, is implicated in numerous functions associated with neuronal development, and is a leading candidate gene for schizophrenia. The T allele of SNP8NRG243177, part of a risk haplotype for schizophrenia, has been previously associated with decreases in white matter in the right anterior internal capsule and the left anterior thalamic radiation. To our knowledge no studies have described the effects of SNP8NRG243177 on grey matter volume at a voxelwise level. We assessed associations between this SNP and brain structure in 79 general population volunteers from the Northern Finland 1966 Birth Cohort (NFBC 1966). We show, for the first time, that genetic variation in SNP8NRG243177 is associated with variation in frontal brain structure in both grey and white matter. T allele carriers showed decreased grey matter volume in several frontal gyri, including inferior, middle and superior frontal gyri and the anterior cingulate gyrus, as well as decreased white matter volume in the regions of the genu and body of the corpus callosum, anterior and superior corona radiata, anterior limb of the internal capsule and external capsule regions traversed by major white matter tracts of the anterior thalamic radiation, and the inferior fronto-occipital fasciculus. These results suggest that this genetic variant may mediate risk for schizophrenia, in part, through its effect on brain structure in these regions. Copyright © 2011 Elsevier Inc. All rights reserved.
Papageorgiou, Alexandros; Stylianou, Stylianos K; Kaffes, Pavlos; Zouboulis, Anastasios I; Voutsa, Dimitra
2017-03-01
The aim of this study was to investigate possible implications of natural and wastewater derived organic matter in river water that is subsequently used following treatment for drinking purposes. River water was subjected to lab-scale ozonation experiments under different ozone doses (0.1, 0.4, 0.8, 1.0 and 2.0 mgO 3 /mgC) and contact times (1, 3, 5, 8 and 10 min). Mixtures of river water with humic acids or wastewaters (sewage wastewater and secondary effluents) at different proportions were also ozonated. Dissolved organic carbon and biodegradable dissolved organic carbon concentrations as well as spectroscopic characteristics (UV absorbance and fluorescence intensities) of different types of dissolved organic matter and possible changes due to the ozonation treatment are presented. River water, humic substances and wastewater exhibited distinct spectroscopic characteristics that could serve for pollution source tracing. Wastewater impacted surface water results in higher formation of carbonyl compounds. However, the formation yield (μg/mgC) of wastewaters was lower than that of surface water possibly due to different composition of wastewater derived organic matter and the presence of scavengers, which may limit the oxidative efficiency of ozone. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Kroupa, P.
2014-05-01
The existence of dark matter particles is a key hypothesis in present-day cosmology and galactic dynamics. The validity of this hypothesis is challenged significantly by two independent arguments. 1) The dual dwarf galaxy theorem must be true in any realistic cosmological model. But it is found to be falsified when the dark-matter-based model is applied to the observational data. A consistency check of this conclusion comes from the observed significantly disk-like distributions of satellite populations which orbit in the same direction around their hosting galaxy and which cannot be derived from dark-matter models. 2) The action of dynamical friction due to expansive and massive dark matter halos must be evident in the galaxy population. The evidence however for dynamical friction is void or meagre at best. The M81 group fo galaxies already appears to rule out the existence of dynamical friction through dark matter halos, and the Milky Way satellite galaxies have been shown to challenge dark-matter-induced dynamical friction. The implication of this deduction for fundamental physics would be that exotic dark matter particles do not exist and that consequently gravitational physics on the scales of galaxies and beyond ought to be non-Newtonian/Einsteinian. An analysis of the kinematical data in galaxies shows them to be described excellently by scale-invariant dynamics, as discovered by Milgrom. This leads to a natural emergence of laws that galaxies are observed to obey. Such success has not been forthcoming in the dark-matter-based models. A consequence of this novel understanding of galactic astrophysics is that most dwarf satellite galaxies are formed as tidal dwarf galaxies in galaxy-galaxy encounters and that galactic mergers are rare.
Understanding Music's Therapeutic Efficacy with Implications for Why Music Matters
ERIC Educational Resources Information Center
Thram, Diane
2015-01-01
In this essay, I focus on how attention to music's therapeutic efficacy is important to the praxial music education philosophy espoused by Elliott and Silverman. I note, despite the use of the term praxis from Aristotle's philosophy dating back to antiquity, there is no mention in Music Matters 2 of what historical evidence tells us about how…
ERIC Educational Resources Information Center
Liu, Xiufeng
2006-01-01
Using the US national sample from the 1995 Third International Mathematics and Science Study (TIMSS), this study examined students' competence levels in understanding the matter concept at grades 3, 4, 7, 8 and high school graduation, and compared them to the expectations in the US national science education standards. It was found that…
Emma P. McCorkle; Asmeret Asefaw Berhe; Carolyn T. Hunsaker; Dale W. Johnson; Karis J. McFarlane; Marilyn L. Fogel; Stephen C. Hart
2016-01-01
Soil erosion continuously redistributes soil and associated soil organic matter (SOM) on the Earth's surface, with important implications for biogeochemical cycling of essential elements and terrestrial carbon sequestration. Despite the importance of soil erosion, surprisingly few studies have evaluated the sources of eroded carbon (C). We used natural abundance...
ERIC Educational Resources Information Center
Powers, Anne S.; Myers, Jane E.; Tingle, Lynne R.; Powers, John C.
2004-01-01
Numerous studies document that medical education is demanding and stressful, yet few studies have examined the effects of medical training on spouses and medical marriages. Eighty-three individuals (42 couples) living in medical marriages completed questionnaires measuring marital satisfaction, perceived stress, general mattering, and wellness.…
ERIC Educational Resources Information Center
Bown, Kathryn; Sumsion, Jennifer; Press, Frances
2011-01-01
The article reports on a study investigating influences on Australian politicians' decision making for early childhood education and care (ECEC) policy. The astronomical concept of dark matter is utilised as a metaphor for considering normalising, and therefore frequently difficult to detect and disrupt, influences implicated in politicians'…
Gravity and count probabilities in an expanding universe
NASA Technical Reports Server (NTRS)
Bouchet, Francois R.; Hernquist, Lars
1992-01-01
The time evolution of nonlinear clustering on large scales in cold dark matter, hot dark matter, and white noise models of the universe is investigated using N-body simulations performed with a tree code. Count probabilities in cubic cells are determined as functions of the cell size and the clustering state (redshift), and comparisons are made with various theoretical models. We isolate the features that appear to be the result of gravitational instability, those that depend on the initial conditions, and those that are likely a consequence of numerical limitations. More specifically, we study the development of skewness, kurtosis, and the fifth moment in relation to variance, the dependence of the void probability on time as well as on sparseness of sampling, and the overall shape of the count probability distribution. Implications of our results for theoretical and observational studies are discussed.
NASA Astrophysics Data System (ADS)
Herzog-Arbeitman, Jonah; Lisanti, Mariangela; Necib, Lina
2018-04-01
The local velocity distribution of dark matter plays an integral role in interpreting the results from direct detection experiments. We previously showed that metal-poor halo stars serve as excellent tracers of the virialized dark matter velocity distribution using a high-resolution hydrodynamic simulation of a Milky Way-like halo. In this paper, we take advantage of the first Gaia data release, coupled with spectroscopic measurements from the RAdial Velocity Experiment (RAVE), to study the kinematics of stars belonging to the metal-poor halo within an average distance of ~5 kpc of the Sun. We study stars with iron abundances [Fe/H] < ‑1.5 and ‑1.8 that are located more than 1.5 kpc from the Galactic plane. Using a Gaussian mixture model analysis, we identify the stars that belong to the halo population, as well as some kinematic outliers. We find that both metallicity samples have similar velocity distributions for the halo component, within uncertainties. Assuming that the stellar halo velocities adequately trace the virialized dark matter, we study the implications for direct detection experiments. The Standard Halo Model, which is typically assumed for dark matter, is discrepant with the empirical distribution by ~6σ, predicts fewer high-speed particles, and is anisotropic. As a result, the Standard Halo Model overpredicts the nuclear scattering rate for dark matter masses below ~10 GeV. The kinematic outliers that we identify may potentially be correlated with dark matter substructure, though further study is needed to establish this correspondence.
NASA Astrophysics Data System (ADS)
Mayer, D. P.; Kite, E. S.
2016-12-01
Sandblasting, aeolian infilling, and wind deflation all obliterate impact craters on Mars, complicating the use of crater counts for chronology, particularly on sedimentary rock surfaces. However, crater counts on sedimentary rocks can be exploited to constrain wind erosion rates. Relatively small, shallow craters are preferentially obliterated as a landscape undergoes erosion, so the size-frequency distribution of impact craters in a landscape undergoing steady exhumation will develop a shallower power-law slope than a simple production function. Estimating erosion rates is important for several reasons: (1) Wind erosion is a source of mass for the global dust cycle, so the global dust reservoir will disproportionately sample fast-eroding regions; (2) The pace and pattern of recent wind erosion is a sorely-needed constraint on models of the sculpting of Mars' sedimentary-rock mounds; (3) Near-surface complex organic matter on Mars is destroyed by radiation in <108 years, so high rates of surface exhumation are required for preservation of near-surface organic matter. We use crater counts from 18 HiRISE images over sedimentary rock deposits as the basis for estimating erosion rates. Each image was counted by ≥3 analysts and only features agreed on by ≥2 analysts were included in the erosion rate estimation. Erosion rates range from 0.1-0.2 {μ }m/yr across all images. These rates represent an upper limit on surface erosion by landscape lowering. At the conference we will discuss the within and between-image variability of erosion rates and their implications for recent geological processes on Mars.
Noble, Kimberly G; Korgaonkar, Mayuresh S; Grieve, Stuart M; Brickman, Adam M
2013-09-01
Socioeconomic status is an important predictor of cognitive development and academic achievement. Late adolescence provides a unique opportunity to study how the attainment of socioeconomic status (in the form of years of education) relates to cognitive and neural development, during a time when age-related cognitive and neural development is ongoing. During late adolescence it is possible to disambiguate age- and education-related effects on the development of these processes. Here we assessed the degree to which higher educational attainment was related to performance on a cognitive control task, controlling for age. We then used diffusion tensor imaging (DTI) to assess the degree to which white matter microstructure might mediate this relationship. When covarying age, significant associations were found between educational attainment and fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and cingulum bundle (CB). Further, when covarying age, FA in these regions was associated with cognitive control. Finally, mediation analyses revealed that the age-independent association between educational attainment and cognitive control was completely accounted for by FA in these regions. The uncinate fasciculus, a late-myelinated control region not implicated in cognitive control, did not mediate this effect. © 2013 John Wiley & Sons Ltd.
Nuclear pasta in hot dense matter and its implications for neutrino scattering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roggero, Alessandro; Margueron, Jerome; Roberts, Luke F.
The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Y e > 0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T = 0 , dissolve at a relatively low temperature T u as protons leak out of nuclei and pasta. For matter at β-equilibrium with a negligible neutrino chemical potential we find that Tmore » $$β\\atop{u}$$ ≃ 4 ± 1 MeV for realistic equations of state. This is lower than the maximum temperature T$$β\\atop{max}$$ ≃ 9 ± 1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Lastly, implications for neutrino signals from galactic supernovas are briefly discussed.« less
Nuclear pasta in hot dense matter and its implications for neutrino scattering
Roggero, Alessandro; Margueron, Jerome; Roberts, Luke F.; ...
2018-04-16
The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Y e > 0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T = 0 , dissolve at a relatively low temperature T u as protons leak out of nuclei and pasta. For matter at β-equilibrium with a negligible neutrino chemical potential we find that Tmore » $$β\\atop{u}$$ ≃ 4 ± 1 MeV for realistic equations of state. This is lower than the maximum temperature T$$β\\atop{max}$$ ≃ 9 ± 1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Lastly, implications for neutrino signals from galactic supernovas are briefly discussed.« less
Fermi large area telescope search for photon lines from 30 to 200 GeV and dark matter implications.
Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Bloom, E D; Bonamente, E; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Carrigan, S; Casandjian, J M; Cecchi, C; Celik, O; Chekhtman, A; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; do Couto E Silva, E; Drell, P S; Drlica-Wagner, A; Dubois, R; Dumora, D; Edmonds, Y; Essig, R; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guillemot, L; Guiriec, S; Gustafsson, M; Hadasch, D; Harding, A K; Horan, D; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Llena Garde, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Makeev, A; Mazziotta, M N; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ripken, J; Ritz, S; Rodriguez, A Y; Roth, M; Sadrozinski, H F-W; Sander, A; Parkinson, P M Saz; Scargle, J D; Schalk, T L; Sellerholm, A; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J B; Thayer, J G; Tibaldo, L; Torres, D F; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M
2010-03-05
Dark matter (DM) particle annihilation or decay can produce monochromatic gamma rays readily distinguishable from astrophysical sources. gamma-ray line limits from 30 to 200 GeV obtained from 11 months of Fermi Large Area Space Telescope data from 20-300 GeV are presented using a selection based on requirements for a gamma-ray line analysis, and integrated over most of the sky. We obtain gamma-ray line flux upper limits in the range 0.6-4.5x10{-9} cm{-2} s{-1}, and give corresponding DM annihilation cross-section and decay lifetime limits. Theoretical implications are briefly discussed.
Unbound particles in dark matter halos
DOE Office of Scientific and Technical Information (OSTI.GOV)
Behroozi, Peter S.; Wechsler, Risa H.; Loeb, Abraham, E-mail: behroozi@stanford.edu, E-mail: aloeb@cfa.harvard.edu, E-mail: rwechsler@stanford.edu
2013-06-01
We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches formore » intergalactic supernovae.« less
Unbound particles in dark matter halos
DOE Office of Scientific and Technical Information (OSTI.GOV)
Behroozi, Peter S.; Loeb, Abraham; Wechsler, Risa H.
2013-06-13
We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches formore » intergalactic supernovae.« less
Baryogenesis and dark matter through a Higgs asymmetry.
Servant, Géraldine; Tulin, Sean
2013-10-11
In addition to explaining the masses of elementary particles, the Higgs boson may have far-reaching implications for the generation of the matter content in the Universe. For instance, the Higgs boson plays a key role in two main theories of baryogenesis, namely, electroweak baryogenesis and leptogenesis. In this Letter, we propose a new cosmological scenario where the Higgs chemical potential mediates asymmetries between visible and dark matter sectors, either generating a baryon asymmetry from a dark matter asymmetry or vice versa. We illustrate this mechanism with a simple model with two new fermions coupled to the Higgs boson and discuss the associated signatures.
Cosmic matter-antimatter asymmetry and gravitational force
NASA Technical Reports Server (NTRS)
Hsu, J. P.
1980-01-01
Cosmic matter-antimatter asymmetry due to the gravitational interaction alone is discussed, considering the gravitational coupling of fermion matter related to the Yang-Mills (1954) gauge symmetry with the unique generalization of the four-dimensional Poincare group. Attention is given to the case of weak static fields which determines the space-time metric where only large source terms are retained. In addition, considering lowest-order Feynman diagrams, there are presented gravitational potential energies between fermions, between antifermions, and between a fermion and an antifermion. It is concluded that the gravitational force between matter is different from that between antimatter; implications from this concerning the evolution of the universe are discussed.
The Symposium Proceedings of the 1998 Air Transport Research Group (ATRG). Volume 3
NASA Technical Reports Server (NTRS)
Reynolds-Feighan, Aisling (Editor); Bowen, Brent D. (Editor)
1998-01-01
Contents include the following: airline deregulation in Australia: a medium term assessment; why can't Japan deregulate the airline industry and open the sky immediately?; toward a market-oriented air transport system?: present developments in Russian civil aviation performance and policy; the asian economic crisis and its implications for aviation policy in asia pacific: industry outlook approaching the next millennium; a tale of two airlines: the post privatization performance of two caribbean airlines: the role of capital productivity in British Airways' financial recovery; airline privatization: does it matter?; airfright demand: responding to new developments in logistics; and air cargo business relationships.
ERIC Educational Resources Information Center
Doménech-Betoret, Fernando; Fortea-Bagán, Miguel Angel
2015-01-01
Introduction: Education research has clearly verified that a student's perception of the system to evaluate the subject matter will play a fundamental role in his/her implication (deep approach vs. surface approach) in the teaching/learning process of the subject matter. The present work aims to examine the factorial validity and reliability of a…
Susan E. Crow; Kate Lajtha; Timothy R. Filley; Chris Swanston; Richard D. Bowden; Bruce A. Caldwell
2009-01-01
Alterations in forest productivity and changes in the relative proportion of above- and belowground biomass may have nonlinear effects on soil organic matter (SOM) storage. To study the influence of plant litter inputs on SOM accumulation, the Detritus Input Removal and Transfer (DIRT) Experiment continuously alters above- and belowground plant inputs to soil by a...
Stability of disformally coupled accretion disks
NASA Astrophysics Data System (ADS)
Koivisto, Tomi S.; Nyrhinen, Hannu J.
2017-10-01
The no-hair theorem postulates that the only externally observable properties of a black hole are its mass, its electric charge, and its angular momentum. In scalar-tensor theories of gravity, a matter distribution around a black hole can lead to the so called ‘spontaneous scalarisation’ instability that triggers the development of scalar hair. In the Brans-Dicke type theories, this effect can be understood as a result of tachyonic effective mass of the scalar field. Here we consider the instability in the generalised class of scalar-theories that feature non-conformal, i.e. ‘disformal’, couplings to matter. Such theories have gained considerable interest in the recent years and have been studied in a wide variety of systems, both cosmological and astrophysical. In view of the prospects of gravitational wave astronomy, it is relevant to explore the implications of the theories in the strong-gravity regime. In this article, we concentrate on the spontaneous scalarisation of matter configurations around Schwarzschild and Kerr black holes. We find that in the more generic scalar-tensor theories, the instability of the Brans-Dicke theory can be enhanced, suggesting violations of the no-hair theorem. On the other hand, we find that, especially if the coupling is very strong, or if the gradients in the matter distribution are negligible, the disformal coupling tends to stabilise the system.
The global distribution and dynamics of chromophoric dissolved organic matter.
Nelson, Norman B; Siegel, David A
2013-01-01
Chromophoric dissolved organic matter (CDOM) is a ubiquitous component of the open ocean dissolved matter pool, and is important owing to its influence on the optical properties of the water column, its role in photochemistry and photobiology, and its utility as a tracer of deep ocean biogeochemical processes and circulation. In this review, we discuss the global distribution and dynamics of CDOM in the ocean, concentrating on developments in the past 10 years and restricting our discussion to open ocean and deep ocean (below the main thermocline) environments. CDOM has been demonstrated to exert primary control on ocean color by its absorption of light energy, which matches or exceeds that of phytoplankton pigments in most cases. This has important implications for assessing the ocean biosphere via ocean color-based remote sensing and the evaluation of ocean photochemical and photobiological processes. The general distribution of CDOM in the global ocean is controlled by a balance between production (primarily microbial remineralization of organic matter) and photolysis, with vertical ventilation circulation playing an important role in transporting CDOM to and from intermediate water masses. Significant decadal-scale fluctuations in the abundance of global surface ocean CDOM have been observed using remote sensing, indicating a potentially important role for CDOM in ocean-climate connections through its impact on photochemistry and photobiology.
Vijayakumar, Nandita; Bartholomeusz, Cali; Whitford, Thomas; Hermens, Daniel F; Nelson, Barnaby; Rice, Simon; Whittle, Sarah; Pantelis, Christos; McGorry, Patrick; Schäfer, Miriam R; Amminger, G Paul
2016-08-11
Schizophrenia is thought to be a neurodevelopmental disorder with pathophysiological processes beginning in the brain prior to the emergence of clinical symptoms. Recent evidence from neuroimaging studies using techniques such as diffusion tensor imaging has identified white matter abnormalities that are suggestive of disrupted brain myelination and neuronal connectivity. Identifying whether such effects exist in individuals at high risk for developing psychosis may help with prevention and early intervention strategies. In addition, there is preliminary evidence for a role of lipid biology in the onset of psychosis, along with well-established evidence of its role in myelination of white matter tracts. As such, this article synthesises the literature on polyunsaturated fatty acids (PUFAs) in myelination and schizophrenia, hypothesizing that white matter abnormalities may potentially mediate the relationship between PUFAs and schizophrenia. Diffusion tensor imaging studies were identified through a systematic search of existing literature. Studies examined white matter integrity in ultra-high risk (UHR) samples, as assessed using structured diagnostic interviews. Data was extracted and summarised as a narrative review. Twelve studies met inclusion criteria, and findings identified reduced fractional anisotropy and higher diffusivity. Although the exact location of abnormalities remains uncertain, fronto-temporal and fronto-limbic connections, including the superior longitudinal and uncinate fasiculus, cingulum, and corpus callosum appear to be implicated. Because of preliminary evidence suggesting lipid biology may be relevant for the onset of psychosis, a discussion is provided of the role of polyunsaturated fatty acids (PUFAs) in myelination and risk for psychosis. While the function of PUFAs in myelination is well-established, there is growing evidence of reduced PUFA concentration in UHR samples, highlighting the need for research to examine the relationship between PUFA and white matter integrity in high-risk samples and age-matched healthy controls. Such investigations will help to better understand the pathophysiology of the disorder, and potentially assist in the development of novel treatment and early intervention strategies.
Sulik, Gayle A; Cameron, Carrie; Chamberlain, Robert M
2012-05-01
In considering the role of the cancer prevention workforce in meeting the nation's future health care needs, it is vital to address the considerable gaps in information, communication, training, professional development, roles, and levels of collaboration among diverse disciplines, stakeholders, and constituencies. As part of an October 2009 symposium at The University of Texas MD Anderson Cancer Center entitled "Future Directions in Cancer Prevention and Control: Workforce Implications for Training, Practice, and Policy," the Health Policy and Advocacy Working Group was convened to discuss barriers to closing these gaps. Three major themes emerged from the group's deliberations and are discussed here: (1) the role of critical health literacy and evidence-based collaborations in cancer prevention education, research, and practice; (2) the implications of health advocacy for policy development and clinical and public health practice; and (3) culturally and linguistically appropriate cancer prevention programs and information within advocacy/workforce collaborations. Mechanisms for addressing these gaps are presented.
NASA Astrophysics Data System (ADS)
Avelino, P. P.; Azevedo, R. P. L.
2018-03-01
In this paper we show that the on-shell Lagrangian of a perfect fluid depends on microscopic properties of the fluid, giving specific examples of perfect fluids with different on-shell Lagrangians but with the same energy-momentum tensor. We demonstrate that if the fluid is constituted by localized concentrations of energy with fixed rest mass and structure (solitons) then the average on-shell Lagrangian of a perfect fluid is given by Lm=T , where T is the trace of the energy-momentum tensor. We show that our results have profound implications for theories of gravity where the matter Lagrangian appears explicitly in the equations of motion of the gravitational and matter fields, potentially leading to observable deviations from a nearly perfect cosmic microwave background black body spectrum: n -type spectral distortions, affecting the normalization of the spectral energy density. Finally, we put stringent constraints on f (R ,Lm) theories of gravity using the COBE-FIRAS measurement of the spectral radiance of the cosmic microwave background.
Higgs enhancement for the dark matter relic density
NASA Astrophysics Data System (ADS)
Harz, Julia; Petraki, Kalliopi
2018-04-01
We consider the long-range effect of the Higgs on the density of thermal-relic dark matter. While the electroweak gauge boson and gluon exchange have been previously studied, the Higgs is typically thought to mediate only contact interactions. We show that the Sommerfeld enhancement due to a 125 GeV Higgs can deplete TeV-scale dark matter significantly and describe how the interplay between the Higgs and other mediators influences this effect. We discuss the importance of the Higgs enhancement in the minimal supersymmetric standard model and its implications for experiments.
Cognitive Implications of Deep Gray Matter Iron in Multiple Sclerosis.
Fujiwara, E; Kmech, J A; Cobzas, D; Sun, H; Seres, P; Blevins, G; Wilman, A H
2017-05-01
Deep gray matter iron accumulation is increasingly recognized in association with multiple sclerosis and can be measured in vivo with MR imaging. The cognitive implications of this pathology are not well-understood, especially vis-à-vis deep gray matter atrophy. Our aim was to investigate the relationships between cognition and deep gray matter iron in MS by using 2 MR imaging-based iron-susceptibility measures. Forty patients with multiple sclerosis (relapsing-remitting, n = 16; progressive, n = 24) and 27 healthy controls were imaged at 4.7T by using the transverse relaxation rate and quantitative susceptibility mapping. The transverse relaxation rate and quantitative susceptibility mapping values and volumes (atrophy) of the caudate, putamen, globus pallidus, and thalamus were determined by multiatlas segmentation. Cognition was assessed with the Brief Repeatable Battery of Neuropsychological Tests. Relationships between cognition and deep gray matter iron were examined by hierarchic regressions. Compared with controls, patients showed reduced memory ( P < .001) and processing speed ( P = .02) and smaller putamen ( P < .001), globus pallidus ( P = .002), and thalamic volumes ( P < .001). Quantitative susceptibility mapping values were increased in patients compared with controls in the putamen ( P = .003) and globus pallidus ( P = .003). In patients only, thalamus ( P < .001) and putamen ( P = .04) volumes were related to cognitive performance. After we controlled for volume effects, quantitative susceptibility mapping values in the globus pallidus ( P = .03; trend for transverse relaxation rate, P = .10) were still related to cognition. Quantitative susceptibility mapping was more sensitive compared with the transverse relaxation rate in detecting deep gray matter iron accumulation in the current multiple sclerosis cohort. Atrophy and iron accumulation in deep gray matter both have negative but separable relationships to cognition in multiple sclerosis. © 2017 by American Journal of Neuroradiology.
1988-01-01
crystal and in a mixed crystal. The mixed crystal data was taken with resonance enhancement by the pentacene .. ... 7 Accesiw, r)re 0IE r)) NiS cR4~ IE~) D...observations as well as their implications about the nature of the coupling of a localized defect to the bulk modes of the crystal have been analyzed [7...matter systems, in addition to phonon induced fluctuations of local mechanical properties, there can be much slower timescale structural evolution
Frustration in Condensed Matter and Protein Folding
NASA Astrophysics Data System (ADS)
Lorelli, S.; Cabot, A.; Sundarprasad, N.; Boekema, C.
Using computer modeling we study frustration in condensed matter and protein folding. Frustration is due to random and/or competing interactions. One definition of frustration is the sum of squares of the differences between actual and expected distances between characters. If this sum is non-zero, then the system is said to have frustration. A simulation tracks the movement of characters to lower their frustration. Our research is conducted on frustration as a function of temperature using a logarithmic scale. At absolute zero, the relaxation for frustration is a power function for randomly assigned patterns or an exponential function for regular patterns like Thomson figures. These findings have implications for protein folding; we attempt to apply our frustration modeling to protein folding and dynamics. We use coding in Python to simulate different ways a protein can fold. An algorithm is being developed to find the lowest frustration (and thus energy) states possible. Research supported by SJSU & AFC.
Dark matter, long-range forces, and large-scale structure
NASA Technical Reports Server (NTRS)
Gradwohl, Ben-Ami; Frieman, Joshua A.
1992-01-01
If the dark matter in galaxies and clusters is nonbaryonic, it can interact with additional long-range fields that are invisible to experimental tests of the equivalence principle. We discuss the astrophysical and cosmological implications of a long-range force coupled only to the dark matter and find rather tight constraints on its strength. If the force is repulsive (attractive), the masses of galaxy groups and clusters (and the mean density of the universe inferred from them) have been systematically underestimated (overestimated). We explore the consequent effects on the two-point correlation function, large-scale velocity flows, and microwave background anisotropies, for models with initial scale-invariant adiabatic perturbations and cold dark matter.
Equations of state for neutron stars and core-collapse supernovae
NASA Astrophysics Data System (ADS)
Oertel, Micaela; Providência, Constança
2018-04-01
Modelling compact stars is a complex task which depends on many ingredients, among others the properties of dense matter. In this contribution models for the equation of state (EoS) of dense matter will be discussed, relevant for the description of core-collapse supernovae, compact stars and compact star mergers. Such EoS models have to cover large ranges in baryon number density, temperature and isospin asymmetry. The characteristics of matter change dramatically within these ranges, from a mixture of nucleons, nuclei, and electrons to uniform, strongly interacting matter containing nucleons, and possibly other particles such as hyperons or quarks. Some implications for compact star astrophysics will be highlighted, too.
Cosmic Ray Experiments and the Implications for Indirect Detection of Dark Matter
NASA Technical Reports Server (NTRS)
Mitchell, John W.; Ormes, Jonathan F.; Streitmatter, Robert E.
2013-01-01
Detection of cosmic-ray antiprotons was first reported by Golden et al. in 1979 and their existence was firmly established by the BESS and IMAX collaborations in the early 1990s. Increasingly precise measurements of the antiproton spectrum, most recently from BESS-Polar and PAMELA, have made it an important tool for investigating cosmic-ray transport in the galaxy and heliosphere and for constraining dark-matter models. The history of antiproton measurements will be briefly reviewed. The current status will be discussed, focusing on the results of BESS-Polar II and their implications for the possibility of antiprotons from primordial black hole evaporation. The current results of the BESS-Polar II antihelium search are also presented.
Cerebral White Matter Integrity and Cognitive Aging: Contributions from Diffusion Tensor Imaging
Madden, David J.; Bennett, Ilana J.; Song, Allen W.
2009-01-01
The integrity of cerebral white matter is critical for efficient cognitive functioning, but little is known regarding the role of white matter integrity in age-related differences in cognition. Diffusion tensor imaging (DTI) measures the directional displacement of molecular water and as a result can characterize the properties of white matter that combine to restrict diffusivity in a spatially coherent manner. This review considers DTI studies of aging and their implications for understanding adult age differences in cognitive performance. Decline in white matter integrity contributes to a disconnection among distributed neural systems, with a consistent effect on perceptual speed and executive functioning. The relation between white matter integrity and cognition varies across brain regions, with some evidence suggesting that age-related effects exhibit an anterior-posterior gradient. With continued improvements in spatial resolution and integration with functional brain imaging, DTI holds considerable promise, both for theories of cognitive aging and for translational application. PMID:19705281
Mancke, Falk; Schmitt, Ruth; Winter, Dorina; Niedtfeld, Inga; Herpertz, Sabine C; Schmahl, Christian
2017-12-13
There is increasing evidence that psychotherapy can alter the function of the brain of patients with borderline personality disorder (BPD). However, it is not known whether psychotherapy can also modify the brain structure of patients with BPD. We used structural MRI data of female patients with BPD before and after participation in 12 weeks of residential dialectical behavioural therapy (DBT) and compared them to data from female patients with BPD who received treatment as usual (TAU). We applied voxel-based morphometry to study voxel-wise changes in grey matter volume over time. We included 31 patients in the DBT group and 17 in the TAU group. Patients receiving DBT showed an increase of grey matter volume in the anterior cingulate cortex, inferior frontal gyrus and superior temporal gyrus together with an alteration of grey matter volume in the angular gyrus and supramarginal gyrus compared with patients receiving TAU. Furthermore, therapy response correlated with increase of grey matter volume in the angular gyrus. Only women were investigated, and groups differed in size, medication (controlled for) and intensity of the treatment condition. We found that DBT increased grey matter volume of brain regions that are critically implicated in emotion regulation and higher-order functions, such as mentalizing. The role of the angular gyrus for treatment response may reside in its cross-modal integrative function. These findings enhance our understanding of psychotherapy mechanisms of change and may foster the development of neurobiologically informed therapeutic interventions.
Defining organic matter quality in sediment systems: a suggested classification scheme
NASA Astrophysics Data System (ADS)
Alderson, Danielle; Evans, Martin; Rothwell, James; Boult, Stephen
2015-04-01
The quantity and quality of the mineral component of sediments is a core focus of sedimentological investigation in terrestrial systems. This is not to say that the organic component of collected sediments is simply ignored; the organic component is often scrutinised, but in some fields in a restricted manner, limited to basic characteristics such as the ratio of organic to mineral content derived from loss on ignition. There is no doubt that this information is useful; however, these types of analysis indicate the quantity of organic matter relative to a particular temporal scale or volume, rather than treating the organic fraction as a separate entity worthy of substantial investigation. The quality of the organic component is being increasingly considered in a number of fields, with molecular, thermal, spectroscopic and bulk methods being used. However, models and theories on organic matter processing in a variety of environmental systems, have been developed without clearly defining organic matter quality, because most results do not depend on an outright measure of quality (Bosatta and Agren, 1999). With approaches and techniques varying between fields, there is a need to consider a more systematic approach to the analysis and definition of organic matter quality. The disparities in the definition of the quality of organic matter, and thus how it may be measured have vital implications for the study of carbon cycling, biogeochemical processing, and ultimately ecosystem structure and function. The quality and quantity of organic matter have an influence on the chemistry and biology of systems and may reveal a wealth of past or contemporary environmental information. In this paper we provide a classification of organic matter quality and examples of potential applications and suitable techniques for the analysis of the main classes of organic matter character. A more consistent approach to organic matter characterisation has the potential to aid understanding of soils and sediments through consideration of decomposition dynamics; accounting for organic matter variety in carbon cycling and budgeting; use of organic proxies of source determination; and investigations into palaeovegetation and palaeoclimate.
Early deprivation, atypical brain development, and internalizing symptoms in late childhood
Bick, Johanna; Fox, Nathan; Zeanah, Charles; Nelson, Charles A.
2015-01-01
Children exposed to extreme early life neglect such as in institutional rearing are at heightened risk for developing depression and anxiety disorders, and internalizing problems more broadly. These outcomes are believed to be due to alterations in the development of neural circuitry that supports emotion regulation. The specific neurodevelopmental changes that contribute to these difficulties are largely unknown. This study examined whether microstructural alterations in white matter pathways predicted long term risk for internalizing problems in institutionally reared children. Data from 69 children were drawn from the Bucharest Early Intervention Project, a randomized clinical trial of foster care for institutionally reared children. White matter was assessed using Diffusion Tensor Imaging (DTI) when children were between 8 and 10 years of age. Internalizing symptoms were assessed at the time of the MRI scan, and once children reached 12 to 14 years of age. Results indicated that neglect-associated alterations in the external capsule and corpus callosum partially explained links between institutional rearing status and internalizing symptoms in middle childhood and early adolescence. Findings shed light on neural mechanisms contributing to increased risk for emotional difficulties among children reared in adverse conditions and have implications for prevention and intervention. PMID:26384960
White matter changes in Alzheimer's disease: a focus on myelin and oligodendrocytes.
Nasrabady, Sara E; Rizvi, Batool; Goldman, James E; Brickman, Adam M
2018-03-02
Alzheimer's disease (AD) is conceptualized as a progressive consequence of two hallmark pathological changes in grey matter: extracellular amyloid plaques and neurofibrillary tangles. However, over the past several years, neuroimaging studies have implicated micro- and macrostructural abnormalities in white matter in the risk and progression of AD, suggesting that in addition to the neuronal pathology characteristic of the disease, white matter degeneration and demyelination may be also important pathophysiological features. Here we review the evidence for white matter abnormalities in AD with a focus on myelin and oligodendrocytes, the only source of myelination in the central nervous system, and discuss the relationship between white matter changes and the hallmarks of Alzheimer's disease. We review several mechanisms such as ischemia, oxidative stress, excitotoxicity, iron overload, Aβ toxicity and tauopathy, which could affect oligodendrocytes. We conclude that white matter abnormalities, and in particular myelin and oligodendrocytes, could be mechanistically important in AD pathology and could be potential treatment targets.
NASA Astrophysics Data System (ADS)
Wiebke, Heidi Lynn
This study employed an embedded mixed methods multi-case study design (Creswell, 2014) with six early childhood (grades K-2) teachers to examine a) what changes occurred to their subject matter knowledge (SMK) and pedagogical content knowledge (PCK) for teaching scientific explanations while participating in a professional development program, b) how they planned for and implemented scientific explanation instruction within a teacher developed unit on properties of matter, and c) what affordances their instruction of scientific explanations had on fostering their students' abilities to generate explanations in science. Several quantitative and qualitative measures were collected and analyzed in accordance to this studies conceptual framework, which consisted of ten instructional practices teachers should consider assimilating or accommodating into their knowledge base (i.e., SMK & PCK) for teaching scientific explanations. Results of this study indicate there was little to no positive change in the teachers' substantive and syntactic SMK. However, all six teachers did make significant changes to all five components of their PCK for teaching explanations in science. While planning for scientific explanation instruction, all six teachers' contributed some ideas for how to incorporate seven of the ten instructional practices for scientific explanations within the properties of matter unit they co-developed. When enacting the unit, the six teachers' employed seven to nine of the instructional practices to varying levels of effectiveness, as measured by researcher developed rubrics. Given the six teachers' scientific explanation instruction, many students did show improvement in their ability to formulate a scientific explanation, particularly their ability to provide multiple pieces of evidence. Implications for professional developers, teacher educators, researchers, policy makers, and elementary teachers regarding how to prepare teachers for and support students' construction of scientific explanations are discussed.
Kulas, Joshua A; Hettwer, Jordan V; Sohrabi, Mona; Melvin, Justine E; Manocha, Gunjan D; Puig, Kendra L; Gorr, Matthew W; Tanwar, Vineeta; McDonald, Michael P; Wold, Loren E; Combs, Colin K
2018-05-22
Environmental exposure to air pollution has been linked to a number of health problems including organ rejection, lung damage and inflammation. While the deleterious effects of air pollution in adult animals are well documented, the long-term consequences of particulate matter (PM) exposure during animal development are uncertain. In this study we tested the hypothesis that environmental exposure to PM 2.5 μm in diameter in utero promotes long term inflammation and neurodegeneration. We evaluated the behavior of PM exposed animals using several tests and observed deficits in spatial memory without robust changes in anxiety-like behavior. We then examined how this affects the brains of adult animals by examining proteins implicated in neurodegeneration, synapse formation and inflammation by western blot, ELISA and immunohistochemistry. These tests revealed significantly increased levels of COX2 protein in PM2.5 exposed animal brains in addition to changes in synaptophysin and Arg1 proteins. Exposure to PM2.5 also increased the immunoreactivity for GFAP, a marker of activated astrocytes. Cytokine concentrations in the brain and spleen were also altered by PM2.5 exposure. These findings indicate that in utero exposure to particulate matter has long term consequences which may affect the development of both the brain and the immune system in addition to promoting inflammatory change in adult animals. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
78 FR 8160 - President's National Security Telecommunications Advisory Committee
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-05
... matters related to national security and emergency preparedness telecommunications policy. Agenda: The... and Emergency Preparedness Implications of a Nationwide Public Safety Broadband Network. The report...
Implications of neutron star properties for the existence of light dark matter
NASA Astrophysics Data System (ADS)
Motta, T. F.; Guichon, P. A. M.; Thomas, A. W.
2018-05-01
It was recently suggested that the discrepancy between two methods of measuring the lifetime of the neutron may be a result of an unseen decay mode into a dark matter particle which is almost degenerate with the neutron. We explore the consequences of this for the properties of neutron stars, finding that their known properties are in conflict with the existence of such a particle.
Phase transitions in neutron star equation of state induced by the delta resonances matter
NASA Astrophysics Data System (ADS)
T, Oliveira J. C.; Rodrigues, H.; Duarte, S. B.
2016-04-01
In the present work we determine the equation of state and the population of baryons and leptons, and also we discuss the implication of changes in the baryon-meson coupling constants to the formation of delta matter in the stellar medium. And also in this work the phase transition is explored with respect to the domain of the delta-mesons coupling constants.
NASA Technical Reports Server (NTRS)
Stecker, F. W.; Tylka, A. J.
1989-01-01
The spectrum of antiprotons from dark matter annihilation are calculated using the Lund Monte Carlo program, and simple analytic expressions for the spectrum and low-energy antiproton/proton ratio are derived. Comparing the results with recent upper limits on low energy antiprotons, it is concluded that the reported 4-13 GeV antiproton flux cannot be accounted for by dark matter annihilation. The new upper limits do not provide useful constraints on dark matter particles. They restrict the annihilation rate and imply that annihilation gamma ray and e(+) fluxes would be far below the fluxes produced by cosmic-ray collisions. It may be possible to look for a dark matter halo annihilation signal at antiprotons energies below 0.5 GeV, where the flux from cosmic-ray collisions is expected to be negligible.
Anatürk, M; Demnitz, N; Ebmeier, K P; Sexton, C E
2018-06-22
Population aging has prompted considerable interest in identifying modifiable factors that may help protect the brain and its functions. Collectively, epidemiological studies show that leisure activities with high mental and social demands are linked with better cognition in old age. The extent to which socio-intellectual activities relate to the brain's structure is, however, not yet fully understood. This systematic review and meta-analysis summarizes magnetic resonance imaging studies that have investigated whether cognitive and social activities correlate with measures of gray and white matter volume, white matter microstructure and white matter lesions. Across eighteen included studies (total n = 8429), activity levels were associated with whole-brain white matter volume, white matter lesions and regional gray matter volume, although effect sizes were small. No associations were found for global gray matter volume and the evidence concerning white matter microstructure was inconclusive. While the causality of the reviewed associations needs to be established, our findings implicate socio-intellectual activity levels as promising targets for interventions aimed at promoting healthy brain aging. Copyright © 2018. Published by Elsevier Ltd.
NASA Astrophysics Data System (ADS)
Sephton, Mark A.; Lewis, James M. T.; Watson, Jonathan S.; Montgomery, Wren; Garnier, Carole
2014-11-01
Instruments on the Viking landers and Curiosity rover analyzed samples of Mars and detected carbon dioxide and organic compounds of uncertain origin. Mineral-assisted reactions are leading to uncertainty, particularly those involving perchlorate minerals which thermally decompose to produce chlorine and oxygen which can then react with organic matter to generate organochlorine compounds and carbon dioxide. Although generally considered a problem for interpretation, the release profiles of generated gases can indicate the type of organic matter present. We have performed a set of experiments with perchlorate and organic matter of variable molecular weights. Results indicate that organic susceptibility to thermal degradation and mineral-assisted reactions is related to molecular weight. Low molecular weight organic matter reacts at lower temperatures than its high molecular weight counterparts. The natural occurrence and association of organic matter with differing molecular weights helps to discriminate between contamination (usually low molecular weight organic matter only) and indigenous carbon (commonly low and high molecular weight organic matter together). Our results can be used to provide insights into data returning from Mars.
The emergence and policy implications of converging new technologies integrated from the nanoscale
NASA Astrophysics Data System (ADS)
Roco, M. C.
2005-06-01
Science based on the unified concepts on matter at the nanoscale provides a new foundation for knowledge creation, innovation, and technology integration. Convergent new technologies refers to the synergistic combination of nanotechnology, biotechnology, information technology and cognitive sciences (NBIC), each of which is currently progressing at a rapid rate, experiencing qualitative advancements, and interacting with the more established fields such as mathematics and environmental technologies (Roco & Bainbridge, 2002). It is expected that converging technologies will bring about tremendous improvements in transforming tools, new products and services, enable human personal abilities and social achievements, and reshape societal relationships. After a brief overview of the general implications of converging new technologies, this paper focuses on its effects on R&D policies and business models as part of changing societal relationships. These R&D policies will have implications on investments in research and industry, with the main goal of taking advantage of the transformative development of NBIC. Introduction of converging technologies must be done with respect of immediate concerns (privacy, toxicity of new materials, etc.) and longer-term concerns including human integrity, dignity and welfare. The efficient introduction and development of converging new technologies will require new organizations and business models, as well as solutions for preparing the economy, such as multifunctional research facilities, integrative technology platforms, and global risk governance.
Bick, Johanna; Zhu, Tong; Stamoulis, Catherine; Fox, Nathan A; Zeanah, Charles; Nelson, Charles A
2015-03-01
Severe neglect in early life is associated with compromises in brain development and associated behavioral functioning. Although early intervention has been shown to support more normative trajectories of brain development, specific improvements in the white matter pathways that underlie emotional and cognitive development are unknown. To examine associations among neglect in early life, early intervention, and the microstructural integrity of white matter pathways in middle childhood. The Bucharest Early Intervention Project is a randomized clinical trial of high-quality foster care as an intervention for institutionally reared children in Bucharest, Romania, from 2000 through the present. During infancy, children were randomly selected to remain in an institution or to be placed in foster care. Those who remained in institutions experienced neglect, including social, emotional, linguistic, and cognitive impoverishment. Developmental trajectories of these children were compared with a group of sociodemographically matched children reared in biological families at baseline and several points throughout development. At approximately 8 years of age, 69 of the original 136 children underwent structural magnetic resonance imaging scans. Four estimates of white matter integrity (fractional anisotropy [FA] and mean [MD], radial [RD], and axial [AD] diffusivity) for 48 white matter tracts throughout the brain were obtained through diffusion tensor imaging. Significant associations emerged between neglect in early life and microstructural integrity of the body of the corpus callosum (FA, β = 0.01 [P = .01]; RD, β = -0.02 [P = .005]; MD, β = -0.01 [P = .02]) and tracts involved in limbic circuitry (fornix crus [AD, β = 0.02 (P = .046)] and cingulum [RD, β = -0.01 (P = .02); MD, β = -0.01 (P = .049)]), frontostriatal circuitry (anterior [AD, β = -0.01 (P = .02)] and superior [AD, β = -0.02 (P = .02); MD, β = -0.01 (P = .03)] corona radiata and external capsule [right FA, β = 0.01 (P = .03); left FA, β = 0.01 (P = .03); RD, β = -0.01 (P = .01); MD, β = -0.01 (P = .03)]), and sensory processing (medial lemniscus [AD, β = -0.02 (P = .045); MD, β = -0.01 (P = .04)] and retrolenticular internal capsule [FA, β = -0.01 (P = .002); RD, β = 0.01 (P = .003); MD, β = 0.01 (P = .04)]). Follow-up analyses revealed that early intervention promoted more normative white matter development among previously neglected children who entered foster care. Results suggest that removal from conditions of neglect in early life and entry into a high-quality family environment can support more normative trajectories of white matter growth. Our findings have implications for public health and policy efforts designed to promote normative brain development among vulnerable children. clinicaltrials.gov Identifier: NCT00747396.
Long-lived light mediator to dark matter and primordial small scale spectrum
Zhang, Yue
2015-05-01
We calculate the early universe evolution of perturbations in the dark matter energy density in the context of simple dark sector models containing a GeV scale light mediator. We consider the case that the mediator is long-lived, with lifetime up to a second, and before decaying it temporarily dominates the energy density of the universe. We show that for primordial perturbations that enter the horizon around this period, the interplay between linear growth during matter domination and collisional damping can generically lead to a sharp peak in the spectrum of dark matter density perturbation. Finally, as a result, the populationmore » of the smallest DM halos gets enhanced. Possible implications of this scenario are discussed.« less
NASA Astrophysics Data System (ADS)
Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; Beiser, E.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Edsjö, J.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Gier, D.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Góra, D.; Grant, D.; Griffith, Z.; Groß, A.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, B.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Jurkovic, M.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kiryluk, J.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, G.; Kroll, M.; Krückl, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mandelartz, M.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Richter, S.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Sabbatini, L.; Sander, H.-G.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Savage, C.; Schatto, K.; Schimp, M.; Schlunder, P.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schulte, L.; Schumacher, L.; Scott, P.; Seckel, D.; Seunarine, S.; Silverwood, H.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stamatikos, M.; Stanev, T.; Stasik, A.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Ter-Antonyan, S.; Terliuk, A.; Te{š}ić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Turcati, A.; Unger, E.; Usner, M.; Vallecorsa, S.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Santen, J.; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.
2016-04-01
We present an improved event-level likelihood formalism for including neutrino telescope data in global fits to new physics. We derive limits on spin-dependent dark matter-proton scattering by employing the new formalism in a re-analysis of data from the 79-string IceCube search for dark matter annihilation in the Sun, including explicit energy information for each event. The new analysis excludes a number of models in the weak-scale minimal supersymmetric standard model (MSSM) for the first time. This work is accompanied by the public release of the 79-string IceCube data, as well as an associated computer code for applying the new likelihood to arbitrary dark matter models.
Blumen, Helena M; Brown, Lucy L; Habeck, Christian; Allali, Gilles; Ayers, Emmeline; Beauchet, Olivier; Callisaya, Michele; Lipton, Richard B; Mathuranath, P S; Phan, Thanh G; Pradeep Kumar, V G; Srikanth, Velandai; Verghese, Joe
2018-04-09
Accelerated gait decline in aging is associated with many adverse outcomes, including an increased risk for falls, cognitive decline, and dementia. Yet, the brain structures associated with gait speed, and how they relate to specific cognitive domains, are not well-understood. We examined structural brain correlates of gait speed, and how they relate to processing speed, executive function, and episodic memory in three non-demented and community-dwelling older adult cohorts (Overall N = 352), using voxel-based morphometry and multivariate covariance-based statistics. In all three cohorts, we identified gray matter volume covariance patterns associated with gait speed that included brain stem, precuneus, fusiform, motor, supplementary motor, and prefrontal (particularly ventrolateral prefrontal) cortex regions. Greater expression of these gray matter volume covariance patterns linked to gait speed were associated with better processing speed in all three cohorts, and with better executive function in one cohort. These gray matter covariance patterns linked to gait speed were not associated with episodic memory in any of the cohorts. These findings suggest that gait speed, processing speed (and to some extent executive functions) rely on shared neural systems that are subject to age-related and dementia-related change. The implications of these findings are discussed within the context of the development of interventions to compensate for age-related gait and cognitive decline.
NASA Astrophysics Data System (ADS)
Wright, E. L.
1992-12-01
The COBE() DMR observation of large scale anisotropy of the CMBR allows one to compare the gravitational potential measured using Delta T to the gravitational forces required to produce the observed clustering of galaxies. This comparison helps to define the allowed range of cosmological models. As shown by Wright etal 1992, the COBE Delta T agrees quite well with the bulk flow velocity measured by Bertschinger etal 1990 in a window of radius 6000 km/sec. This is the best evidence that the initial perturbation spectrum in fact followed the Harrison-Zeldovich (and inflationary) prediction that P(k) ~ k(n) with n = 1. Assuming that n ~ 1, one can deduce information about the nature of the matter in the Universe: the first conclusion is that a large amount of non-baryonic dark matter is required. The second conclusion is that a linearly evolving model dominated by Cold Dark Matter produces too little structure on 2500 km/sec scales. However, mixed Cold Plus Hot Dark Matter models, vacuum dominated models, or the Couchman & Carlberg (1992) non-linear recipe for making galaxies out of CDM all seem to reproduce the observed structures on scales from 500-6,000 km/sec while connecting to the COBE results with the expected n ~ 1 slope. () COBE is supported by NASA's Astrophysics Division. Goddard Space Flight Center (GSFC), under the scientific guidance of the COBE Science Working Group, is responsible for the development and operation of COBE.
Cunningham, Anne E; Perry, Kathryn E; Stanovich, Keith E; Stanovich, Paula J
2004-06-01
Recently, investigators have begun to pay increasing attention to the role of teachers' domain specific knowledge in the area of reading, and its implications for both classroom practice and student learning. The aims of the present study were to assess kindergarten to third-grade teachers' actual and perceived reading-related subject matter knowledge, and to investigate the extent to which teachers calibrate their reading related subject matter knowledge by examining relationships between actual and perceived knowledge. Results indicated that while teachers demonstrated limited knowledge of children's literature, phoneme awareness, and phonics, the majority of these same teachers evaluated their knowledge levels quite positively. Teachers demonstrated some ability to calibrate their own knowledge levels in the area of children's literature, yet they were poorly calibrated in the domains of phoneme awareness and phonics. These findings suggest that teachers tend to overestimate their reading related subject matter knowledge and are often unaware of what they know and do not know. Implications for the design of teacher education at both the preservice and inservice levels are discussed.
Information technology law and health systems in the European Union.
Mossialos, Elias; Thomson, Sarah; Ter Linden, Annemarie
2004-01-01
This study aims to examine the impact of European Union (EU) law relating to information technology (IT) on health systems. The study identifies EU directives relating to IT, analyzes them in terms of their impact on the use of IT in health systems, and outlines their implications for health technology assessment (HTA). Analysis is based on a review of literature identified through relevant databases and Internet searches. Developments in IT have serious implications for EU health systems, presenting policy makers with new challenges. The European Commission has adopted a range of legal measures to protect consumers in the "information society" However, as few of them are health-specific, it is not evident that they have implications for health, health systems, or HTA, and they may not be effective in protecting consumers in the health sector. In light of the growing importance of IT in the health sector, legal and nonlegal measures need to be further developed at EU and international level. Where possible, future initiatives should pay attention to the particular characteristics of health goods and services and health systems. Although definitions of HTA usually recognize the importance of evaluating both the indirect, unintended consequences of health technologies and the legal aspects of their application, it seems that, in practice, HTA often overlooks or underestimates legislative matters. Those involved in HTA should be aware of the legal implications of using IT to provide health goods and services and compile, store, transfer, and disseminate health information electronically.
Commentary: Epidemiology in the era of big data.
Mooney, Stephen J; Westreich, Daniel J; El-Sayed, Abdulrahman M
2015-05-01
Big Data has increasingly been promoted as a revolutionary development in the future of science, including epidemiology. However, the definition and implications of Big Data for epidemiology remain unclear. We here provide a working definition of Big Data predicated on the so-called "three V's": variety, volume, and velocity. From this definition, we argue that Big Data has evolutionary and revolutionary implications for identifying and intervening on the determinants of population health. We suggest that as more sources of diverse data become publicly available, the ability to combine and refine these data to yield valid answers to epidemiologic questions will be invaluable. We conclude that while epidemiology as practiced today will continue to be practiced in the Big Data future, a component of our field's future value lies in integrating subject matter knowledge with increased technical savvy. Our training programs and our visions for future public health interventions should reflect this future.
Epidemiology in the Era of Big Data
Mooney, Stephen J; Westreich, Daniel J; El-Sayed, Abdulrahman M
2015-01-01
Big Data has increasingly been promoted as a revolutionary development in the future of science, including epidemiology. However, the definition and implications of Big Data for epidemiology remain unclear. We here provide a working definition of Big Data predicated on the so-called ‘3 Vs’: variety, volume, and velocity. From this definition, we argue that Big Data has evolutionary and revolutionary implications for identifying and intervening on the determinants of population health. We suggest that as more sources of diverse data become publicly available, the ability to combine and refine these data to yield valid answers to epidemiologic questions will be invaluable. We conclude that, while epidemiology as practiced today will continue to be practiced in the Big Data future, a component of our field’s future value lies in integrating subject matter knowledge with increased technical savvy. Our training programs and our visions for future public health interventions should reflect this future. PMID:25756221
Size does matter - span of control in hospitals.
Holm-Petersen, Christina; Østergaard, Sussanne; Andersen, Per Bo Noergaard
2017-04-10
Purpose Centralization, mergers and cost reductions have generally led to increasing levels of span of control (SOC), and thus potentially to lower leadership capacity. The purpose of this paper is to explore how a large SOC impacts hospital staff and their leaders. Design/methodology/approach The study is based on a qualitative explorative case study of three large inpatient wards. Findings The study finds that the nursing staff and their frontline leaders experience challenges in regard to visibility and role of the leader, e.g., in creating overview, coordination, setting-up clear goals, following up and being in touch. However, large wards also provide flexibility and development possibilities. Practical implications The authors discuss the implications of these findings for decision makers in deciding future SOC and for future SOC research. Originality/value Only few studies have qualitatively explored the consequences of large SOC in hospitals.
Dissipationless Hall current in dense quark matter in a magnetic field
Ferrer, Efrain J.; de la Incera, V.
2017-03-29
Here, we show the realization of axion electrodynamics within the Dual Chiral Density Wave phase of dense quark matter in the presence of a magnetic field. This system exhibits an anomalous dissipationless Hall current perpendicular to the magnetic field and an anomalous electric charge density. This connection to topological insulators and 3D optical lattices, as well as possible implications for heavy-ion collisions and neutron stars are outlined.
New Developments in Insomnia Medications of Relevance to Mental Health Disorders.
Krystal, Andrew D
2015-12-01
Many insomnia medications with high specificity have become available recently. They provide a window into the clinical effects of modulating specific brain systems and establish a new guiding principal for conceptualizing insomnia medications: "mechanism matters." A new paradigm for insomnia therapy in which specific drugs are selected to target the specific type of sleep difficulty for each patient includes administering specific treatments for patients with insomnia comorbid with particular psychiatric disorders. This article reviews insomnia medications and discusses the implications for optimizing the treatment of insomnia occurring comorbid with psychiatric conditions. Copyright © 2015 Elsevier Inc. All rights reserved.
Atomic dark matter with hyperfine interactions
NASA Astrophysics Data System (ADS)
Boddy, Kimberly K.; Kaplinghat, Manoj; Kwa, Anna; Peter, Annika H. G.
2017-11-01
We consider dark matter as an analog of hydrogen in a secluded sector and study its astrophysical implications. The self interactions between dark matter particles include elastic scatterings as well as inelastic processes from hyperfine transitions. We show that for a dark hydrogen mass in the 10-100 GeV range and a dark fine-structure constant larger than 0.01, the self-interaction cross section has the right magnitude and velocity dependence to explain the low dark matter density cores seen in small galaxies while being consistent with all constraints from observations of galaxy clusters. Excitations to the hyperfine state and subsequent decays, however, may cause significant cooling losses and affect the evolution of low-mass halos. We also find minimum halo masses in the range of 103.5-107 M⊙, which are significantly larger than the typical predictions for weakly interacting dark matter models. This pattern of observables in structure formation is unique to this model, making it possible to determine the viability of hidden-sector hydrogen as a dark matter candidate.
NASA Astrophysics Data System (ADS)
de Martino, Ivan; Broadhurst, Tom; Tye, S.-H. Henry; Chiueh, Tzihong; Shive, Hsi-Yu; Lazkoz, Ruth
2018-01-01
The cold dark matter (CDM) paradigm successfully explains the cosmic structure over an enormous span of redshifts. However, it fails when probing the innermost regions of dark matter halos and the properties of the Milky Way's dwarf galaxy satellites. Moreover, the lack of experimental detection of Weakly Interacting Massive Particle (WIMP) favors alternative candidates such as light axionic dark matter that naturally arise in string theory. Cosmological N-body simulations have shown that axionic dark matter forms a solitonic core of size of ≃ 150 pc in the innermost region of the galactic halos. The oscillating scalar field associated to the axionic dark matter halo produces an oscillating gravitational potential that induces a time dilation of the pulse arrival time of ≃ 400 ns/(m_B/10^{-22} eV) for pulsar within such a solitonic core. Over the whole galaxy, the averaged predicted signal may be detectable with current and forthcoming pulsar timing array telescopes.
Samanez-Larkin, Gregory R; Levens, Sara M; Perry, Lee M; Dougherty, Robert F; Knutson, Brian
2012-04-11
Frontostriatal circuits have been implicated in reward learning, and emerging findings suggest that frontal white matter structural integrity and probabilistic reward learning are reduced in older age. This cross-sectional study examined whether age differences in frontostriatal white matter integrity could account for age differences in reward learning in a community life span sample of human adults. By combining diffusion tensor imaging with a probabilistic reward learning task, we found that older age was associated with decreased reward learning and decreased white matter integrity in specific pathways running from the thalamus to the medial prefrontal cortex and from the medial prefrontal cortex to the ventral striatum. Further, white matter integrity in these thalamocorticostriatal paths could statistically account for age differences in learning. These findings suggest that the integrity of frontostriatal white matter pathways critically supports reward learning. The findings also raise the possibility that interventions that bolster frontostriatal integrity might improve reward learning and decision making.
Schmitt, Ruth; Winter, Dorina; Niedtfeld, Inga; Herpertz, Sabine C.; Schmahl, Christian
2018-01-01
Background There is increasing evidence that psychotherapy can alter the function of the brain of patients with borderline personality disorder (BPD). However, it is not known whether psychotherapy can also modify the brain structure of patients with BPD. Methods We used structural MRI data of female patients with BPD before and after participation in 12 weeks of residential dialectical behavioural therapy (DBT) and compared them to data from female patients with BPD who received treatment as usual (TAU). We applied voxel-based morphometry to study voxel-wise changes in grey matter volume over time. Results We included 31 patients in the DBT group and 17 in the TAU group. Patients receiving DBT showed an increase of grey matter volume in the anterior cingulate cortex, inferior frontal gyrus and superior temporal gyrus together with an alteration of grey matter volume in the angular gyrus and supramarginal gyrus compared with patients receiving TAU. Furthermore, therapy response correlated with increase of grey matter volume in the angular gyrus. Limitations Only women were investigated, and groups differed in size, medication (controlled for) and intensity of the treatment condition. Conclusion We found that DBT increased grey matter volume of brain regions that are critically implicated in emotion regulation and higher-order functions, such as mentalizing. The role of the angular gyrus for treatment response may reside in its cross-modal integrative function. These findings enhance our understanding of psychotherapy mechanisms of change and may foster the development of neurobiologically informed therapeutic interventions. PMID:29688873
Johnston, Jennifer A Y; Wang, Fei; Liu, Jie; Blond, Benjamin N; Wallace, Amanda; Liu, Jiacheng; Spencer, Linda; Cox Lippard, Elizabeth T; Purves, Kirstin L; Landeros-Weisenberger, Angeli; Hermes, Eric; Pittman, Brian; Zhang, Sheng; King, Robert; Martin, Andrés; Oquendo, Maria A; Blumberg, Hilary P
2017-07-01
Bipolar disorder is associated with high risk for suicidal behavior that often develops in adolescence and young adulthood. Elucidation of involved neural systems is critical for prevention. This study of adolescents and young adults with bipolar disorder with and without a history of suicide attempts combines structural, diffusion tensor, and functional MR imaging methods to investigate implicated abnormalities in the morphology and structural and functional connectivity within frontolimbic systems. The study had 26 participants with bipolar disorder who had a prior suicide attempt (the attempter group) and 42 participants with bipolar disorder without a suicide attempt (the nonattempter group). Regional gray matter volume, white matter integrity, and functional connectivity during processing of emotional stimuli were compared between groups, and differences were explored for relationships between imaging modalities and associations with suicide-related symptoms and behaviors. Compared with the nonattempter group, the attempter group showed significant reductions in gray matter volume in the orbitofrontal cortex, hippocampus, and cerebellum; white matter integrity in the uncinate fasciculus, ventral frontal, and right cerebellum regions; and amygdala functional connectivity to the left ventral and right rostral prefrontal cortex. In exploratory analyses, among attempters, there was a significant negative correlation between right rostral prefrontal connectivity and suicidal ideation and between left ventral prefrontal connectivity and attempt lethality. Adolescent and young adult suicide attempters with bipolar disorder demonstrate less gray matter volume and decreased structural and functional connectivity in a ventral frontolimbic neural system subserving emotion regulation. Among attempters, reductions in amygdala-prefrontal functional connectivity may be associated with severity of suicidal ideation and attempt lethality.
Johnston, Jennifer A. Y.; Wang, Fei; Liu, Jie; Blond, Benjamin N.; Wallace, Amanda; Liu, Jiacheng; Spencer, Linda; Cox Lippard, Elizabeth T.; Purves, Kirstin L.; Landeros-Weisenberger, Angeli; Hermes, Eric; Pittman, Brian; Zhang, Sheng; King, Robert; Martin, Andrés; Oquendo, Maria A.; Blumberg, Hilary P.
2018-01-01
Objective Bipolar disorder is associated with high risk for suicide behavior that often develops in adolescence/young adulthood. Elucidation of involved neural systems is critical for prevention. This study of adolescents/young adults with bipolar disorder with and without history of suicide attempts combines structural, diffusion tensor and functional magnetic resonance imaging methods to investigate implicated abnormalities in structural and functional connectivity within fronto-limbic systems. Method Participants with bipolar disorder included 26 with a prior suicide attempt and 42 without attempts. Regional gray matter volume, white matter integrity and functional connectivity during processing of emotional stimuli were compared between groups and differences were explored for relationships between imaging modalities and associations with suicide-related symptoms and behaviors. Results Compared to the non-attempter group, the attempter group showed reductions in gray matter volume in orbitofrontal cortex, hippocampus and cerebellum; white matter integrity in uncinate fasciculus, ventral frontal and right cerebellum regions; and amygdala functional connectivity to left ventral and right rostral prefrontal cortex (p<0.05, corrected). In exploratory analyses, among attempters, right rostral prefrontal connectivity was negatively correlated with suicidal ideation (p<0.05), and left ventral prefrontal connectivity was negatively correlated with attempt lethality (p<0.05). Conclusions Adolescent/young adult suicide attempters with bipolar disorder demonstrate less gray matter volume and decreased structural and functional connectivity in a ventral fronto-limbic neural system subserving emotion regulation. Among suicide attempters, reductions in amygdala-prefrontal functional connectivity may be associated with severity of suicide ideation and attempt lethality. PMID:28135845
A cognitive perspective on medical expertise: theory and implication.
Schmidt, H G; Norman, G R; Boshuizen, H P
1990-10-01
A new theory of the development of expertise in medicine is outlined. Contrary to existing views, this theory assumes that expertise is not so much a matter of superior reasoning skills or in-depth knowledge of pathophysiological states as it is based on cognitive structures that describe the features of prototypical or even actual patients. These cognitive structures, referred to as "illness scripts," contain relatively little knowledge about pathophysiological causes of symptoms and complaints but a wealth of clinically relevant information about disease, its consequences, and the context under which illness develops. By contrast, intermediate-level students without clinical experience typically use pathophysiological, causal models of disease when solving problems. The authors review evidence supporting the theory and discuss its implications for the understanding of five phenomena extensively documented in the clinical-reasoning literature: (1) content specificity in diagnostic performance; (2) typical differences in data-gathering techniques between medical students and physicians; (3) difficulties involved in setting standards; (4) a decline in performance on certain measures of clinical reasoning with increasing expertise; and (5) a paradoxical association between errors and longer response times in visual diagnosis.
Micro-pigmentation: implications for patients and professionals.
Collingridge, Kim; Calcluth, Julie
In the UK, reconstructive breast surgery is routinely offered to patients undergoing surgery for breast cancer. The results can be excellent, but without a nipple-areola complex the patient can feel incomplete. In response to patient need, an innovative nurse-led micro-pigmentation service has been developed in the authors' NHS trust, which provides women (and men) an opportunity to complete their reconstruction process. With the use of coloured pigments, micro-pigmentation creates a permanent image of a nipple-areola complex, which improves the aesthetic appearance of the surgically-created breast. As with the development of any new nurse-led innovation, the micro-pigmentation service has professional and client implications. Breast cancer can be devastating and may induce many psychological concerns, not least about body image and sexuality. This article addresses these issues, along with professional matters, such as autonomous practice, role expansion and the blurring of clinical boundaries. These factors are considered in relation to the nursing management of the micro-pigmentation service, where patient autonomy is encouraged to promote acceptance of self-image and closure on the breast cancer experience.
Organic matter sources and rehabilitation of the Sacramento-San Joaquin Delta (California, USA)
Jassby, A.D.; Cloern, J.E.
2000-01-01
1. The Sacramento San Joaquin River Delta, a complex mosaic of tidal freshwater habitats in California, is the focus of a major ecosystem rehabilitation effort because of significant long-term changes in critical ecosystem functions. One of these functions is the production, transport and transformation of organic matter that constitutes the primary food supply, which may be sub-optimal at trophic levels supporting fish recruitment. A long historical data set is used to define the most important organic matter sources, the factors underlying their variability, and the implications of ecosystem rehabilitation actions for these sources. 2. Tributary-borne loading is the largest organic carbon source on an average annual Delta-wide basis; phytoplankton production and agricultural drainage are secondary; wastewater treatment plant discharge, tidal marsh drainage and possibly aquatic macrophyte production are tertiary; and benthic microalgal production, urban run-off and other sources are negligible. 3. Allochthonous dissolved organic carbon must be converted to particulate form - with losses due to hydraulic flushing and to heterotroph growth inefficiency - before it becomes available to the metazoan food web. When these losses are accounted for, phytoplankton production plays a much larger role than is evident from a simple accounting of bulk organic carbon sources, especially in seasons critical for larval development and recruitment success. Phytoplankton-derived organic matter is also an important component of particulate loading to the Delta. 4. The Delta is a net producer of organic matter in critically dry years but, because of water diversion from the Delta, transport of organic matter from the Delta to important, downstream nursery areas in San Francisco Bay is always less than transport into the Delta from upstream sources. 5. Of proposed rehabilitation measures, increased use of floodplains probably offers the biggest increase in organic matter sources. 6. An isolated diversion facility - channelling water from the Sacramento River around the Delta to the water projects - would result in substantial loading increases during winter and autumn, but little change in spring and summer when food availability probably matters most to developing organisms. 7. Flow and fish barriers in the channel could have significant effects, especially on phytoplankton sources and in dry years, by eliminating 'short-circuits' in the transport of organic matter to diversion points. 8. Finally, productivity of intentionally flooded islands probably would exceed that of adjacent channels because of lower turbidity and shallower mean depth, although vascular plants rather than phytoplankton could dominate if depths were too shallow. Copyright (C) 2000 John Wiley and Sons, Ltd.
NASA Astrophysics Data System (ADS)
Cullen, H. M.; Maibach, E.
2016-12-01
Most Americans view climate change as a threat that is distant in space (i.e., not here), time (i.e., not now), and species (i.e., not us). TV weathercasters are ideally positioned to educate Americans about the current and projected impacts of climate change in their community: they have tremendous reach, are trusted sources of climate information, and are highly skilled science communicators. In 2009, we learned that many weathercasters were potentially interested in reporting on climate change, but few actually were, citing significant barriers including a lack of time to prepare and air stories, and lack of access to high quality content. To test the premise that TV weathercasters can be effective climate educators - if supported with high quality localized climate communication content - in 2010 George Mason University, Climate Central and WLTX-TV (Columbia, SC) developed and pilot-tested Climate Matters, a series of short on-air (and online) segments about the local impacts of climate change, delivered by the station's chief meteorologist. During the first year, more than a dozen stories aired. To formally evaluate Climate Matters, we conducted pre- and post-test surveys of local TV news viewers in Columbia. After one year, WLTX viewers had developed a more science-based understanding of climate change than viewers of other local news stations, confirming our premise that when TV weathercasters report on the local implications of climate change, their viewers learn. Through a series of expansions, including the addition of important new partners - AMS, NASA, NOAA & Yale University - Climate Matters has become a comprehensive nationwide climate communication resource program for American TV weathercasters. As of March 2016, a network of 313 local weathercasters nationwide (at 202 stations in 111 media markets) are participating in the program, receiving new content on a weekly basis. This presentation will review the theoretical basis of the program, detail its development and national scale-up, and conclude with insights for how to develop climate communication initiatives for other professional communities of practice in the U.S. and other countries.
Simplified models vs. effective field theory approaches in dark matter searches
NASA Astrophysics Data System (ADS)
De Simone, Andrea; Jacques, Thomas
2016-07-01
In this review we discuss and compare the usage of simplified models and Effective Field Theory (EFT) approaches in dark matter searches. We provide a state of the art description on the subject of EFTs and simplified models, especially in the context of collider searches for dark matter, but also with implications for direct and indirect detection searches, with the aim of constituting a common language for future comparisons between different strategies. The material is presented in a form that is as self-contained as possible, so that it may serve as an introductory review for the newcomer as well as a reference guide for the practitioner.
Nonstandard Yukawa couplings and Higgs portal dark matter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bishara, Fady; Brod, Joachim; Uttayarat, Patipan
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less
Nonstandard Yukawa couplings and Higgs portal dark matter
Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; ...
2016-01-04
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less
Novel approaches to the study of particle dark matter in astrophysics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Argüelles, C. R., E-mail: carlos.arguelles@icranet.org; Ruffini, R., E-mail: ruffini@icra.it; Rueda, J. A., E-mail: jorge.rueda@icra.it
A deep understanding of the role of the dark matter in the different astrophysical scenarios of the local Universe such as galaxies, represent a crucial step to describe in a more consistent way the role of dark matter in cosmology. This kind of studies requires the interconnection between particle physics within and beyond the Standard Model, and fundamental physics such as thermodynamics and statistics, within a fully relativistic treatment of Gravity. After giving a comprehensive summary of the different types of dark matter and their role in astrophysics, we discuss the recent efforts in describing the distribution of dark mattermore » in the center and halo of galaxies from first principles such as gravitational interactions, quantum statistics and particle physics; and its implications with the observations.« less
Total Homocysteine Is Associated With White Matter Hyperintensity Volume
Wright, Clinton B.; Paik, Myunghee C.; Brown, Truman R.; Stabler, Sally P.; Allen, Robert H.; Sacco, Ralph L.; DeCarli, Charles
2005-01-01
Background Total homocysteine (tHcy) has been implicated as a risk factor for stroke and dementia, but the mechanism is unclear. White matter hyperintensities may be a risk factor for both, but studies of the relationship between tHcy and quantitative measures of white matter hyperintensity volume (WMHV) are lacking, especially in minority populations. Methods A community-based sample of 259 subjects with baseline tHcy levels underwent pixel-based quantitative measurement of WMHV. We examined the relationship between tHcy and WMHV adjusting for age, sociodemographics, vascular risk factors, and B12 deficiency. Results Higher levels of tHcy were associated with WMHV adjusting for sociodemographics and vascular risk factors. Conclusions These cross-sectional data provide evidence that tHcy is a risk factor for white matter damage. PMID:15879345
ERIC Educational Resources Information Center
Vavilis, Bob
The life work of both John Dewey and Lev Vygotsky and the implications for pedagogy that each of the theorist's work has generated is well known in the field of education. However, it is seldom that the theorists' works are juxtaposed for pedagogical considerations for specific subject matter. This is for at least three reasons: first, Dewey, of…
Three-Dimensional Anatomy of the White Matter Fibers of the Temporal Lobe: Surgical Implications.
Pescatori, Lorenzo; Tropeano, Maria Pia; Manfreda, Andrea; Delfini, Roberto; Santoro, Antonio
2017-04-01
The aim of this work is to describe in detail the complex 3-dimensional organization of the white matter of the temporal lobe and discuss the surgical implications of the approaches to lesions located into the mesial temporal region and within the temporal horn and the atrium of the lateral ventricles. Sixteen human cerebral hemispheres fixed in a 10% formalin solution for at least 40 days were studied. After removal of the arachnoid membrane, the hemispheres were frozen at -15°C for at least 14 days, and the Klingler technique, which consists of the microscopic dissection and progressive identification of white matter fibers, was performed. The dissection allowed us to appreciate the topographical organization of the white matter of the temporal lobe identifying the most important association, projection, and commissural fasciculi. The dissection from the lateral side allowed the progressive visualization of the superior longitudinal fasciculus and its components, the extreme and external capsule, the uncinate fasciculus, the inferior fronto-occipital fasciculus, the anterior commissure, the internal capsule, and the optic radiations. The dissection was completed from the inferior and medial side for identification of the cingulum and the fornix. The complex 3-dimensional organization of the white matter substance of the temporal lobe is characterized by 2 main systems of boundaries: the sagittal stratum and the temporal stem. Their knowledge is essential for the appropriate treatment of pathologies localized in this region as demonstrated by the 2 clinical cases presented in this work. Copyright © 2017 Elsevier Inc. All rights reserved.
Fertility preservation in young cancer patients--too little, too late?
Robbins, Helen Louise; Zahoor, Arooba; Jones, Kevin
2015-12-01
Fertility is an important concern for many younger women with cancer; however, evidence suggests that these matters are often inadequately addressed, potentially with long-term implications for quality of life. Increased confidence in discussing fertility-related matters and an emphasis on early discussion and referral are needed to improve current practice. Further work is needed to better assess current practice and to explore how barriers to discussion about fertility preservation may be best overcome.
Organic nitrogen storage in mineral soil: Implications for policy and management.
Bingham, Andrew H; Cotrufo, M Francesca
2016-05-01
Nitrogen is one of the most important ecosystem nutrients and often its availability limits net primary production as well as stabilization of soil organic matter. The long-term storage of nitrogen-containing organic matter in soils was classically attributed to chemical complexity of plant and microbial residues that retarded microbial degradation. Recent advances have revised this framework, with the understanding that persistent soil organic matter consists largely of chemically labile, microbially processed organic compounds. Chemical bonding to minerals and physical protection in aggregates are more important to long-term (i.e., centuries to millennia) preservation of these organic compounds that contain the bulk of soil nitrogen rather than molecular complexity, with the exception of nitrogen in pyrogenic organic matter. This review examines for the first time the factors and mechanisms at each stage of movement into long-term storage that influence the sequestration of organic nitrogen in the mineral soil of natural temperate ecosystems. Because the factors which govern persistence are different under this newly accepted paradigm we examine the policy and management implications that are altered, such as critical load considerations, nitrogen saturation and mitigation consequences. Finally, it emphasizes how essential it is for this important but underappreciated pool to be better quantified and incorporated into policy and management decisions, especially given the lack of evidence for many soils having a finite capacity to sequester nitrogen. Published by Elsevier B.V.
Search for right-handed neutrinos from dark matter annihilation with gamma-rays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Campos, Miguel D.; Queiroz, Farinaldo S.; Yaguna, Carlos E.
Several extensions of the Standard Model contain right-handed (sterile) neutrinos in the GeV-TeV mass range. Due to their mixing with the active neutrinos, they may give rise to novel effects in cosmology, neutrino physics, and collider searches. In addition, right-handed neutrinos can also appear as final states from dark matter annihilations, with important implications for dark matter indirect detection searches. In this paper, we use current data from the Fermi Large Area Telescope (6-year observation of dwarf spheroidal galaxies) and H.E.S.S. (10-year observation of the Galactic center) to constrain the annihilation of dark matter into right-handed neutrinos. We consider right-handedmore » neutrino with masses between 10 GeV and 1 TeV, including both two-body and three-body decays, to derive bounds on the dark matter annihilation rate, ( σ v ), as a function of the dark matter mass. Our results show, in particular, that the thermal dark matter annihilation cross section, 3× 10{sup −26} cm{sup 3} s {sup −1} , into right-handed neutrinos is excluded for dark matter masses smaller than 200 GeV.« less
Brain structural alterations associated with young women with subthreshold depression
Li, Haijiang; Wei, Dongtao; Sun, Jiangzhou; Chen, Qunlin; Zhang, Qinglin; Qiu, Jiang
2015-01-01
Neuroanatomical abnormalities in patients with major depression disorder (MDD) have been attracted great research attention. However, the structural alterations associated with subthreshold depression (StD) remain unclear and, therefore, require further investigation. In this study, 42 young women with StD, and 30 matched non-depressed controls (NCs) were identified based on two-time Beck Depression Inventory scores. Whole-brain voxel-based morphometry (VBM) and region of interest method were used to investigate altered gray matter volume (GMV) and white matter volume (WMV) among a non-clinical sample of young women with StD. VBM results indicated that young women with StD showed significantly decreased GMV in the right inferior parietal lobule than NCs; increased GMV in the amygdala, posterior cingulate cortex, and precuneus; and increased WMV in the posterior cingulate cortex and precuneus. Together, structural alterations in specific brain regions, which are known to be involved in the fronto-limbic circuits implicated in depression may precede the occurrence of depressive episodes and influence the development of MDD. PMID:25982857
Flavored dark matter beyond Minimal Flavor Violation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin
We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3) χ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter χ which transforms asmore » triplet under U(3) χ , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator Φ with a coupling λ. We identify a number of “flavor-safe” scenarios for the structure of λ which are beyond Minimal Flavor Violation. Also, for dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. Furthermore, the combined flavor and dark matter constraints on the parameter space of λ turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.« less
Flavored dark matter beyond Minimal Flavor Violation
Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin
2014-10-13
We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3) χ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter χ which transforms asmore » triplet under U(3) χ , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator Φ with a coupling λ. We identify a number of “flavor-safe” scenarios for the structure of λ which are beyond Minimal Flavor Violation. Also, for dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. Furthermore, the combined flavor and dark matter constraints on the parameter space of λ turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.« less
Janzen, J; van 't Ent, D; Lemstra, A W; Berendse, H W; Barkhof, F; Foncke, E M J
2012-01-01
Visual hallucinations (VH) are common in Parkinson's disease (PD) and lead to a poor quality of life. For a long time, dopaminergic therapy was considered to be the most important risk factor for the development of VH in PD. Recently, the cholinergic system, including the pedunculopontine nucleus (PPN), has been implicated in the pathophysiology of VH. The aim of the present study was to investigate grey matter density of the PPN region and one of its projection areas, the thalamus. Thirteen non-demented PD patients with VH were compared to 16 non-demented PD patients without VH, 13 demented PD patients (PDD) with VH and 11 patients with dementia with Lewy bodies (DLB). Isotropic 3-D T1-weighted MRI images (3T) were analysed using voxel-based morphometry (VBM) with the PPN region and thalamus as ROIs. PD and PDD patients with VH showed grey matter reductions of the PPN region and the thalamus compared to PD patients without VH. VH in PD(D) patients are associated with atrophy of the PPN region and its thalamic target area, suggesting that a cholinergic deficit may be involved in the development of VH in PD(D).
Differential distribution of neurons in the gyral white matter of the human cerebral cortex.
García-Marín, V; Blazquez-Llorca, L; Rodriguez, J R; Gonzalez-Soriano, J; DeFelipe, J
2010-12-01
The neurons in the cortical white matter (WM neurons) originate from the first set of postmitotic neurons that migrates from the ventricular zone. In particular, they arise in the subplate that contains the earliest cells generated in the telencephalon, prior to the appearance of neurons in gray matter cortical layers. These cortical WM neurons are very numerous during development, when they are thought to participate in transient synaptic networks, although many of these cells later die, and relatively few cells survive as WM neurons in the adult. We used light and electron microscopy to analyze the distribution and density of WM neurons in various areas of the adult human cerebral cortex. Furthermore, we examined the perisomatic innervation of these neurons and estimated the density of synapses in the white matter. Finally, we examined the distribution and neurochemical nature of interneurons that putatively innervate the somata of WM neurons. From the data obtained, we can draw three main conclusions: first, the density of WM neurons varies depending on the cortical areas; second, calretinin-immunoreactive neurons represent the major subpopulation of GABAergic WM neurons; and, third, the somata of WM neurons are surrounded by both glutamatergic and GABAergic axon terminals, although only symmetric axosomatic synapses were found. By contrast, both symmetric and asymmetric axodendritic synapses were observed in the neuropil. We discuss the possible functional implications of these findings in terms of cortical circuits. © 2010 Wiley-Liss, Inc.
Testing the Big Bang: Light elements, neutrinos, dark matter and large-scale structure
NASA Technical Reports Server (NTRS)
Schramm, David N.
1991-01-01
Several experimental and observational tests of the standard cosmological model are examined. In particular, a detailed discussion is presented regarding: (1) nucleosynthesis, the light element abundances, and neutrino counting; (2) the dark matter problems; and (3) the formation of galaxies and large-scale structure. Comments are made on the possible implications of the recent solar neutrino experimental results for cosmology. An appendix briefly discusses the 17 keV thing and the cosmological and astrophysical constraints on it.
Topology, Magnetic Field, and Strongly Interacting Matter
Kharzeev, Dmitri E.
2015-06-05
Gauge theories with compact symmetry groups possess topologically nontrivial configurations of gauge field. This characteristic has dramatic implications for the vacuum structure of quantum chromodynamics (QCD) and for the behavior of QCD plasma, as well as for condensed matter systems with chiral quasi-particles. Here, I review the current status of this problem with an emphasis both on the interplay between chirality and a background magnetic field and on the observable manifestations of topology in heavy-ion collisions, Dirac semimetals, neutron stars, and the early Universe.
Electroweak bremsstrahlung for wino-like Dark Matter annihilations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ciafaloni, Paolo; Comelli, Denis; Simone, Andrea De
2012-06-01
If the Dark Matter is the neutral Majorana component of a multiplet which is charged under the electroweak interactions of the Standard Model, its main annihilation channel is into W{sup +}W{sup −}, while the annihilation into light fermions is helicity suppressed. As pointed out recently, the radiation of gauge bosons from the initial state of the annihilation lifts the suppression and opens up an s-wave contribution to the cross section. We perform the full tree-level calculation of Dark Matter annihilations, including electroweak bremsstrahlung, in the context of an explicit model corresponding to the supersymmetric wino. We find that the fermionmore » channel can become as important as the di-boson one. This result has significant implications for the predictions of the fluxes of particles originating from Dark Matter annihilations.« less
Testing the Dark Matter Scenario for PeV Neutrinos Observed in IceCube.
Murase, Kohta; Laha, Ranjan; Ando, Shin'ichiro; Ahlers, Markus
2015-08-14
Late time decay of very heavy dark matter is considered as one of the possible explanations for diffuse PeV neutrinos observed in IceCube. We consider implications of multimessenger constraints, and show that proposed models are marginally consistent with the diffuse γ-ray background data. Critical tests are possible by a detailed analysis and identification of the sub-TeV isotropic diffuse γ-ray data observed by Fermi and future observations of sub-PeV γ rays by observatories like HAWC or Tibet AS+MD. In addition, with several-year observations by next-generation telescopes such as IceCube-Gen2, muon neutrino searches for nearby dark matter halos such as the Virgo cluster should allow us to rule out or support the dark matter models, independently of γ-ray and anisotropy tests.
NASA Astrophysics Data System (ADS)
Korsmeier, Michael; Donato, Fiorenza; Fornengo, Nicolao
2018-05-01
Cosmic rays are an important tool to study dark matter (DM) annihilation in our Galaxy. Recently, a possible hint for dark matter annihilation was found in the antiproton spectrum measured by AMS-02, even though the result might be affected by theoretical uncertainties. A complementary way to test its dark matter interpretation would be the observation of low-energy antinuclei in cosmic rays. We determine the chances to observe antideuterons with GAPS and AMS-02 and the implications for the ongoing AMS-02 antihelium searches. We find that the corresponding antideuteron signal is within the GAPS and AMS-02 detection potential. If, more conservatively, the putative signal was considered as an upper limit on DM annihilation, our results would indicate the highest possible fluxes for antideuterons and antihelium compatible with current antiproton data.
Irimia, Andrei; Torgerson, Carinna M.; Jacokes, Zachary J.; Van Horn, John D.
2017-01-01
Autism spectrum disorder (ASD) encompasses a set of neurodevelopmental conditions whose striking sex-related disparity (with an estimated male-to-female ratio of 4:1) remains unknown. Here we use magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) to identify the brain structure correlates of the sex-by-ASD diagnosis interaction in a carefully selected cohort of 110 ASD patients (55 females) and 83 typically-developing (TD) subjects (40 females). The interaction was found to be predicated primarily upon white matter connectivity density innervating, bilaterally, the lateral aspect of the temporal lobe, the temporo-parieto-occipital junction and the medial parietal lobe. By contrast, regional gray matter (GM) thickness and volume are not found to modulate this interaction significantly. When interpreted in the context of previous studies, our findings add considerable weight to three long-standing hypotheses according to which the sex disparity of ASD incidence is (A) due to WM connectivity rather than to GM differences, (B) modulated to a large extent by temporoparietal connectivity, and (C) accompanied by brain function differences driven by these effects. Our results contribute substantially to the task of unraveling the biological mechanisms giving rise to the sex disparity in ASD incidence, whose clinical implications are significant. PMID:28397802
McLeod, Pamela B.; van den Heuvel-Greve, Martine J.; Allen-King, Richelle M.; Luoma, Samuel N.; Luthy, Richard G.
2004-01-01
We investigated the bioavailability via diet of spiked benzo[a]pyrene (BaP) and 2,2‘,5,5‘-tetrachlorobiphenyl (PCB-52) from different carbonaceous (non-carbonate, carbon containing) particle types to clams (Macoma balthica) collected from San Francisco Bay. Our results reveal significant differences in absorption efficiency between compounds and among carbonaceous particle types. Absorption efficiency for PCB-52 was always greater than that for BaP bound to a given particle type. Among particles, absorption efficiency was highest from wood and diatoms and lowest from activated carbon. Large differences in absorption efficiency could not be simply explained by comparatively small differences in the particles' total organic carbon content. BaP and PCB-52 bound to activated carbon exhibited less than 2% absorption efficiency and were up to 60 times less available to clams than the same contaminants associated with other types of carbonaceous matter. These results suggest that variations in the amount and type of sediment particulate carbonaceous matter, whether naturally occurring or added as an amendment, will have a strong influence on the bioavailability of hydrophobic organic contaminants. This has important implications for environmental risk assessment, sediment management, and development of novel remediation techniques.
McLeod, Pamela B.; van den Heuvel-Greve, Martine J.; Allen-King, Richelle M.; Luoma, Samuel N.; Luthy, Richard G.
2004-01-01
We investigated the bioavailability via diet of spiked benzo[a]pyrene (BaP) and 2,2‘,5,5‘-tetrachlorobiphenyl (PCB-52) from different carbonaceous (non-carbonate, carbon containing) particle types to clams (Macoma balthica) collected from San Francisco Bay. Our results reveal significant differences in absorption efficiency between compounds and among carbonaceous particle types. Absorption efficiency for PCB-52 was always greater than that for BaP bound to a given particle type. Among particles, absorption efficiency was highest from wood and diatoms and lowest from activated carbon. Large differences in absorption efficiency could not be simply explained by comparatively small differences in the particles' total organic carbon content. BaP and PCB-52 bound to activated carbon exhibited less than 2% absorption efficiency and were up to 60 times less available to clams than the same contaminants associated with other types of carbonaceous matter. These results suggest that variations in the amount and type of sediment particulate carbonaceous matter, whether naturally occurring or added as an amendment, will have a strong influence on the bioavailability of hydrophobic organic contaminants. This has important implications for environmental risk assessment, sediment management, and development of novel remediation techniques.
NASA Astrophysics Data System (ADS)
Stange, P.; Bach, L. T.; Le Moigne, F. A. C.; Taucher, J.; Boxhammer, T.; Riebesell, U.
2017-01-01
The ocean's potential to export carbon to depth partly depends on the fraction of primary production (PP) sinking out of the euphotic zone (i.e., the e-ratio). Measurements of PP and export flux are often performed simultaneously in the field, although there is a temporal delay between those parameters. Thus, resulting e-ratio estimates often incorrectly assume an instantaneous downward export of PP to export flux. Evaluating results from four mesocosm studies, we find that peaks in organic matter sedimentation lag chlorophyll a peaks by 2 to 15 days. We discuss the implications of these time lags (TLs) for current e-ratio estimates and evaluate potential controls of TL. Our analysis reveals a strong correlation between TL and the duration of chlorophyll a buildup, indicating a dependency of TL on plankton food web dynamics. This study is one step further toward time-corrected e-ratio estimates.
Wu, Haipeng; Lai, Cui; Zeng, Guangming; Liang, Jie; Chen, Jin; Xu, Jijun; Dai, Juan; Li, Xiaodong; Liu, Junfeng; Chen, Ming; Lu, Lunhui; Hu, Liang; Wan, Jia
2017-09-01
Compost and biochar, used for the remediation of soil, are seen as attractive waste management options for the increasing volume of organic wastes being produced. This paper reviews the interaction of biochar and composting and its implication for soil amendment and pollution remediation. The interaction of biochar and composting affect each other's properties. Biochar could change the physico-chemical properties, microorganisms, degradation, humification and gas emission of composting, such as the increase of nutrients, cation exchange capacity (CEC), organic matter and microbial activities. The composting could also change the physico-chemical properties and facial functional groups of biochar, such as the improvement of nutrients, CEC, functional groups and organic matter. These changes would potentially improve the efficiency of the biochar and composting for soil amendment and pollution remediation. Based on the above review, this paper also discusses the future research required in this field.
Herrmann, Michael
2014-05-01
The greatest challenge today is to meet the needs of current and future generations, of a large and growing world population, without imposing catastrophic pressures on the natural environment. Meeting this challenge depends on decisive policy changes in three areas: more inclusive economic growth, greener economic growth, and population policies. This article focuses on efforts to address and harness demographic changes for sustainable development, which are largely outside the purview of the current debate. Efforts to this end must be based on the recognition that demographic changes are the cumulative result of individual choices and opportunities, and that demographic changes are best addressed through policies that enlarge these choices and opportunities, with a focus on ensuring unrestricted and universal access to sexual and reproductive health information and services, empowering women to fully participate in social, economic and political life, and investing in the education of the younger generation beyond the primary level. The article provides a strong argument for why the Programme of Action that was agreed at the International Conference on Population and Development (ICPD) 20 years ago continues to hold important implications and lessons for the formulation of the post-2015 development agenda, which is expected to supersede the Millennium Development Goals (MDGs). Copyright © 2014 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.
Why talk with children matters: clinical implications of infant- and child-directed speech research.
Ratner, Nan Bernstein
2013-11-01
This article reviews basic features of infant- or child-directed speech, with particular attention to those aspects of the register that have been shown to impact profiles of child language development. It then discusses concerns that arise when describing adult input to children with language delay or disorder, or children at risk for depressed language skills. The article concludes with some recommendations for parent counseling in such cases, as well as methods that speech-language pathologists can use to improve the quality and quantity of language input to language-learning children. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Proximal dentatothalamocortical tract involvement in posterior fossa syndrome
Phillips, Nicholas S.; Laningham, Fred H.; Patay, Zoltan; Gajjar, Amar; Wallace, Dana; Boop, Frederick; Sanford, Robert; Ness, Kirsten K.; Ogg, Robert J.
2009-01-01
Posterior fossa syndrome is characterized by cerebellar dysfunction, oromotor/oculomotor apraxia, emotional lability and mutism in patients after infratentorial injury. The underlying neuroanatomical substrates of posterior fossa syndrome are unknown, but dentatothalamocortical tracts have been implicated. We used pre- and postoperative neuroimaging to investigate proximal dentatothalamocortical tract involvement in childhood embryonal brain tumour patients who developed posterior fossa syndrome following tumour resection. Diagnostic imaging from a cohort of 26 paediatric patients previously operated on for an embryonal brain tumour (13 patients prospectively diagnosed with posterior fossa syndrome, and 13 non-affected patients) were evaluated. Preoperative magnetic resonance imaging was used to define relevant tumour features, including two potentially predictive measures. Postoperative magnetic resonance and diffusion tensor imaging were used to characterize operative injury and tract-based differences in anisotropy of water diffusion. In patients who developed posterior fossa syndrome, initial tumour resided higher in the 4th ventricle (P = 0.035). Postoperative magnetic resonance signal abnormalities within the superior cerebellar peduncles and midbrain were observed more often in patients with posterior fossa syndrome (P = 0.030 and 0.003, respectively). The fractional anisotropy of water was lower in the bilateral superior cerebellar peduncles, in the bilateral fornices, white matter region proximate to the right angular gyrus (Tailerach coordinates 35, –71, 19) and white matter region proximate to the left superior frontal gyrus (Tailerach coordinates –24, 57, 20). Our findings suggest that multiple bilateral injuries to the proximal dentatothalamocortical pathways may predispose the development of posterior fossa syndrome, that functional disruption of the white matter bundles containing efferent axons within the superior cerebellar peduncles is a critical underlying pathophysiological component of posterior fossa syndrome, and that decreased fractional anisotropy in the fornices and cerebral cortex may be related to the abnormal neurobehavioural symptoms of posterior fossa syndrome. PMID:19805491
Judson, Matthew C.; Burette, Alain C.; Shen, Mark D.; Rumple, Ashley M.; Del Cid, Wilmer A.; Paniagua, Beatriz
2017-01-01
Angelman syndrome (AS) is a debilitating neurodevelopmental disorder caused by loss of function of the maternally inherited UBE3A allele. It is currently unclear how the consequences of this genetic insult unfold to impair neurodevelopment. We reasoned that by elucidating the basis of microcephaly in AS, a highly penetrant syndromic feature with early postnatal onset, we would gain new insights into the mechanisms by which maternal UBE3A loss derails neurotypical brain growth and function. Detailed anatomical analysis of both male and female maternal Ube3a-null mice reveals that microcephaly in the AS mouse model is primarily driven by deficits in the growth of white matter tracts, which by adulthood are characterized by densely packed axons of disproportionately small caliber. Our results implicate impaired axon growth in the pathogenesis of AS and identify noninvasive structural neuroimaging as a potentially valuable tool for gauging therapeutic efficacy in the disorder. SIGNIFICANCE STATEMENT People who maternally inherit a deletion or nonfunctional copy of the UBE3A gene develop Angelman syndrome (AS), a severe neurodevelopmental disorder. To better understand how loss of maternal UBE3A function derails brain development, we analyzed brain structure in a maternal Ube3a knock-out mouse model of AS. We report that the volume of white matter (WM) is disproportionately reduced in AS mice, indicating that deficits in WM development are a major factor underlying impaired brain growth and microcephaly in the disorder. Notably, we find that axons within the WM pathways of AS model mice are abnormally small in caliber. This defect is associated with slowed nerve conduction, which could contribute to behavioral deficits in AS, including motor dysfunction. PMID:28663201
A taste of dark matter: Flavour constraints on pseudoscalar mediators
Dolan, Matthew J.; Kahlhoefer, Felix; McCabe, Christopher; ...
2015-03-31
Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordialmore » nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation.« less
Axino LSP baryogenesis and dark matter
Monteux, Angelo; Shin, Chang Sub
2015-05-01
We discuss a new mechanism for baryogenesis, in which the baryon asymmetry is generated by the lightest supersymmetric particle (LSP) decay via baryonic R-parity-violating interactions. As a specific example, we use a supersymmetric axion model with an axino LSP. This scenario predicts large R-parity violation for the stop, and an upper limit on the squark masses between 15 and 130 TeV, for different choices of the Peccei-Quinn scale and the soft Xt terms. We discuss the implications for the nature of dark matter in light of the axino baryogenesis mechanism, and find that both the axion and a metastable gravitinomore » can provide the correct dark matter density. In the axion dark matter scenario, the initial misalignment angle is restricted to be Script O(1). On the other hand, the reheating temperature is linked to the PQ scale and should be higher than 104-105 GeV in the gravitino dark matter scenario.« less
Pinning down inelastic dark matter in the Sun and in direct detection
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blennow, Mattias; Clementz, Stefan; Herrero-Garcia, Juan, E-mail: emb@kth.se, E-mail: scl@kth.se, E-mail: juhg@kth.se
2016-04-01
We study the solar capture rate of inelastic dark matter with endothermic and/or exothermic interactions. By assuming that an inelastic dark matter signal will be observed in next generation direct detection experiments we can set a lower bound on the capture rate that is independent of the local dark matter density, the velocity distribution, the galactic escape velocity as well as the scattering cross section. In combination with upper limits from neutrino observatories we can place upper bounds on the annihilation channels leading to neutrinos. We find that, while endothermic scattering limits are weak in the isospin-conserving case, strong boundsmore » may be set for exothermic interactions, in particular in the spin-dependent case. Furthermore, we study the implications of observing two direct detection signals, in which case one can halo-independently obtain the dark matter mass and the mass splitting, and disentangle the endothermic/exothermic nature of the scattering. Finally we discuss isospin violation.« less
Electroweak Kaluza-Klein dark matter
Flacke, Thomas; Kang, Dong Woo; Kong, Kyoungchul; ...
2017-04-07
In models with universal extra dimensions (UED), the lightest Kaluza-Klein excitation of neutral electroweak gauge bosons is a stable, weakly interacting massive particle and thus is a candidate for dark matter thanks to Kaluza-Klein parity. We examine concrete model realizations of such dark matter in the context of non-minimal UED extensions. The boundary localized kinetic terms for the electroweak gauge bosons lead to a non-trivial mixing among the first Kaluza-Klein excitations of themore » $${\\rm SU}(2)_W$$ and $${\\rm U}(1)_Y$$ gauge bosons and the resultant low energy phenomenology is rich. We investigate implications of various experiments including low energy electroweak precision measurements, direct and indirect detection of dark matter particles and direct collider searches at the LHC. Furthermore, we show that the electroweak Kaluza-Klein dark matter can be as heavy as 2.4 TeV, which is significantly higher than $1.3$ TeV as is indicated as an upper bound in the minimal UED model.« less
Tryptophan Metabolism and White Matter Integrity in Schizophrenia
Chiappelli, Joshua; Postolache, Teodor T; Kochunov, Peter; Rowland, Laura M; Wijtenburg, S Andrea; Shukla, Dinesh K; Tagamets, Malle; Du, Xiaoming; Savransky, Anya; Lowry, Christopher A; Can, Adem; Fuchs, Dietmar; Hong, L Elliot
2016-01-01
Schizophrenia is associated with abnormalities in the structure and functioning of white matter, but the underlying neuropathology is unclear. We hypothesized that increased tryptophan degradation in the kynurenine pathway could be associated with white matter microstructure and biochemistry, potentially contributing to white matter abnormalities in schizophrenia. To test this, fasting plasma samples were obtained from 37 schizophrenia patients and 38 healthy controls and levels of total tryptophan and its metabolite kynurenine were assessed. The ratio of kynurenine to tryptophan was used as an index of tryptophan catabolic activity in this pathway. White matter structure and function were assessed by diffusion tensor imaging (DTI) and 1H magnetic resonance spectroscopy (MRS). Tryptophan levels were significantly lower (p<0.001), and kynurenine/tryptophan ratios were correspondingly higher (p=0.018) in patients compared with controls. In patients, lower plasma tryptophan levels corresponded to lower structural integrity (DTI fractional anisotropy) (r=0.347, p=0.038). In both patients and controls, the kynurenine/tryptophan ratio was inversely correlated with frontal white matter glutamate level (r=−0.391 and −0.350 respectively, p=0.024 and 0.036). These results provide initial evidence implicating abnormal tryptophan/kynurenine pathway activity in changes to white matter integrity and white matter glutamate in schizophrenia. PMID:27143602
Icken, W; Looft, C; Schellander, K; Cavero, D; Blanco, A; Schmutz, M; Preisinger, R
2014-01-01
1. The responses to genetic selection on yolk proportion as a technique for increasing egg dry matter content, an important criterion for the egg-product industry, was investigated in a pedigree flock of White Leghorn hens. 2. Parents were preselected on high and low yolk proportion from a base population. The absolute estimated breeding value for yolk proportion of both groups differed by 3%. The realised selection difference in dry matter content of eggs between groups was more than 1% in the analysed offspring population. 3. Heritability estimates were moderate and dry matter had a lower heritability (h(2) = 0.39) than yolk proportion (h(2) = 0.44). 4. The genetic correlation between yolk proportion and dry matter content was highly positive (rg = 0.91). Genetic correlations with egg weight were negative and would have to be compensated for in a breeding programme (rg = -0.76 with yolk proportion and rg = -0.64 with dry matter content). The genetic correlation between the laying performance and yolk proportion was rg = 0.28 and close to zero (rg = -0.05) for dry matter content. 5. Easy recording and lower undesirable correlations make yolk proportion more suitable for commercial selection compared with egg dry matter content in layer breeding.
Indirect detection of neutrino portal dark matter
NASA Astrophysics Data System (ADS)
Batell, Brian; Han, Tao; Shams Es Haghi, Barmak
2018-05-01
We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos generating neutrino masses through the type-I seesaw mechanism and simultaneously mediating interactions with dark matter. Given the small neutrino Yukawa couplings expected in a type-I seesaw, direct detection and accelerator probes of dark matter in this scenario are challenging. However, dark matter can efficiently annihilate to right-handed neutrinos, which then decay via active-sterile mixing through the weak interactions, leading to a variety of indirect astronomical signatures. We derive the existing constraints on this scenario from Planck cosmic microwave background measurements, Fermi dwarf spheroidal galaxy and Galactic center gamma-ray observations, and AMS-02 antiproton observations, and we also discuss the future prospects of Fermi and the Cherenkov Telescope Array. Thermal annihilation rates are already being probed for dark matter lighter than about 50 GeV, and this can be extended to dark matter masses of 100 GeV and beyond in the future. This scenario can also provide a dark matter interpretation of the Fermi Galactic center gamma-ray excess, and we confront this interpretation with other indirect constraints. Finally we discuss some of the exciting implications of extensions of the minimal model with large neutrino Yukawa couplings and Higgs portal couplings.
Multi-Ethnic Genome-Wide Association Study of Cerebral White Matter Hyperintensities on MRI
Verhaaren, Benjamin F.J.; Debette, Stéphanie; Bis, Joshua C.; Smith, Jennifer A.; Ikram, M. Kamran; Adams, Hieab H.; Beecham, Ashley H.; Rajan, Kumar B.; Lopez, Lorna M.; Barral, Sandra; van Buchem, Mark A.; van der Grond, Jeroen; Smith, Albert V.; Hegenscheid, Katrin; Aggarwal, Neelum T.; de Andrade, Mariza; Atkinson, Elizabeth J.; Beekman, Marian; Beiser, Alexa S.; Blanton, Susan H.; Boerwinkle, Eric; Brickman, Adam M.; Bryan, R. Nick; Chauhan, Ganesh; Chen, Christopher P.L.H.; Chouraki, Vincent; de Craen, Anton J.M.; Crivello, Fabrice; Deary, Ian J.; Deelen, Joris; De Jager, Philip L.; Dufouil, Carole; Elkind, Mitchell S.V.; Evans, Denis A.; Freudenberger, Paul; Gottesman, Rebecca F.; Guðnason, Vilmundur; Habes, Mohamad; Heckbert, Susan R.; Heiss, Gerardo; Hilal, Saima; Hofer, Edith; Hofman, Albert; Ibrahim-Verbaas, Carla A.; Knopman, David S.; Lewis, Cora E.; Liao, Jiemin; Liewald, David C.M.; Luciano, Michelle; van der Lugt, Aad; Martinez, Oliver O.; Mayeux, Richard; Mazoyer, Bernard; Nalls, Mike; Nauck, Matthias; Niessen, Wiro J.; Oostra, Ben A.; Psaty, Bruce M.; Rice, Kenneth M.; Rotter, Jerome I.; von Sarnowski, Bettina; Schmidt, Helena; Schreiner, Pamela J.; Schuur, Maaike; Sidney, Stephen S.; Sigurdsson, Sigurdur; Slagboom, P. Eline; Stott, David J.M.; van Swieten, John C.; Teumer, Alexander; Töglhofer, Anna Maria; Traylor, Matthew; Trompet, Stella; Turner, Stephen T.; Tzourio, Christophe; Uh, Hae-Won; Uitterlinden, André G.; Vernooij, Meike W.; Wang, Jing J.; Wong, Tien Y.; Wardlaw, Joanna M.; Windham, B. Gwen; Wittfeld, Katharina; Wolf, Christiane; Wright, Clinton B.; Yang, Qiong; Zhao, Wei; Zijdenbos, Alex; Jukema, J. Wouter; Sacco, Ralph L.; Kardia, Sharon L.R.; Amouyel, Philippe; Mosley, Thomas H.; Longstreth, W. T.; DeCarli, Charles C.; van Duijn, Cornelia M.; Schmidt, Reinhold; Launer, Lenore J.; Grabe, Hans J.; Seshadri, Sudha S.; Ikram, M. Arfan; Fornage, Myriam
2015-01-01
Background The burden of cerebral white matter hyperintensities (WMH) is associated with an increased risk of stroke, dementia, and death. WMH are highly heritable, but their genetic underpinnings are incompletely characterized. To identify novel genetic variants influencing WMH burden, we conducted a meta-analysis of multi-ethnic genome-wide association studies. Methods and Results We included 21,079 middle-aged to elderly individuals from 29 population-based cohorts, who were free of dementia and stroke and were of European (N=17,936), African (N=1,943), Hispanic (N=795), and Asian (N=405) descent. WMH burden was quantified on MRI either by a validated automated segmentation method or a validated visual grading scale. Genotype data in each study were imputed to the 1000 Genomes reference. Within each ethnic group, we investigated the relationship between each SNP and WMH burden using a linear regression model adjusted for age, sex, intracranial volume, and principal components of ancestry. A meta-analysis was conducted for each ethnicity separately and for the combined sample. In the European descent samples, we confirmed a previously known locus on chr17q25 (p=2.7×10−19) and identified novel loci on chr10q24 (p=1.6×10−9) and chr2p21 (p=4.4×10−8). In the multi-ethnic meta-analysis, we identified two additional loci, on chr1q22 (p=2.0×10−8) and chr2p16 (p=1.5×10−8). The novel loci contained genes that have been implicated in Alzheimer’s disease (chr2p21, chr10q24), intracerebral hemorrhage (chr1q22), neuroinflammatory diseases (chr2p21), and glioma (chr10q24, chr2p16). Conclusions We identified four novel genetic loci that implicate inflammatory and glial proliferative pathways in the development of white matter hyperintensities in addition to previously-proposed ischemic mechanisms. PMID:25663218
Perspective: ambient air pollution: inflammatory response and effects on the lung’s vasculature
Esmaeil, Nafiseh; Reibman, Joan
2014-01-01
Abstract Particulates from air pollution are implicated in causing or exacerbating respiratory and systemic cardiovascular diseases and are thought to be among the leading causes of morbidity and mortality. However, the contribution of ambient particulate matter to diseases affecting the pulmonary circulation, the right heart, and especially pulmonary hypertension is much less documented. Our own work and that of other groups has demonstrated that prolonged exposure to antigens via the airways can cause severe pulmonary arterial remodeling. In addition, vascular changes have been well documented in a typical disease of the airways, asthma. These experimental and clinical findings link responses in the airways with responses in the lung’s vasculature. It follows that particulate air pollution could cause, or exacerbate, diseases in the pulmonary circulation and associated pulmonary hypertension. This perspective details the literature for support of this concept. Data regarding the health effects of particulate matter from air pollution on the lung’s vasculature, with emphasis on the lung’s inflammatory responses to particulate matter deposition and pulmonary hypertension, are discussed. A deeper understanding of the health implications of exposure to ambient particulate matter will improve our knowledge of how to improve the management of lung diseases, including diseases of the pulmonary circulation. As man-made ambient particulate air pollution is typically linked to economic growth, a better understanding of the health effects of exposure to particulate air pollution is expected to integrate the global goal of achieving healthy living for all. PMID:25006418
Angiogenic therapy for cardiac repair based on protein delivery systems.
Formiga, F R; Tamayo, E; Simón-Yarza, T; Pelacho, B; Prósper, F; Blanco-Prieto, M J
2012-05-01
Cardiovascular diseases remain the first cause of morbidity and mortality in the developed countries and are a major problem not only in the western nations but also in developing countries. Current standard approaches for treating patients with ischemic heart disease include angioplasty or bypass surgery. However, a large number of patients cannot be treated using these procedures. Novel curative approaches under investigation include gene, cell, and protein therapy. This review focuses on potential growth factors for cardiac repair. The role of these growth factors in the angiogenic process and the therapeutic implications are reviewed. Issues including aspects of growth factor delivery are presented in relation to protein stability, dosage, routes, and safety matters. Finally, different approaches for controlled growth factor delivery are discussed as novel protein delivery platforms for cardiac regeneration.
Volumetric Analysis of Regional Variability in the Cerebellum of Children with Dyslexia
Stuebing, Karla; Juranek, Jenifer; Fletcher, Jack M.
2013-01-01
Cerebellar deficits and subsequent impairment in procedural learning may contribute to both motor difficulties and reading impairment in dyslexia. We used quantitative magnetic resonance imaging to investigate the role of regional variation in cerebellar anatomy in children with single-word decoding impairments (N=23), children with impairment in fluency alone (N=8), and typically developing children (N=16). Children with decoding impairments (dyslexia) demonstrated no statistically significant differences in overall grey and white matter volumes or cerebellar asymmetry; however, reduced volume in the anterior lobe of the cerebellum relative to typically developing children was observed. These results implicate cerebellar involvement in dyslexia and establish an important foundation for future research on the connectivity of the cerebellum and cortical regions typically associated with reading impairment. PMID:23828023
Volumetric analysis of regional variability in the cerebellum of children with dyslexia.
Fernandez, Vindia G; Stuebing, Karla; Juranek, Jenifer; Fletcher, Jack M
2013-12-01
Cerebellar deficits and subsequent impairment in procedural learning may contribute to both motor difficulties and reading impairment in dyslexia. We used quantitative magnetic resonance imaging to investigate the role of regional variation in cerebellar anatomy in children with single-word decoding impairments (N = 23), children with impairment in fluency alone (N = 8), and typically developing children (N = 16). Children with decoding impairments (dyslexia) demonstrated no statistically significant differences in overall grey and white matter volumes or cerebellar asymmetry; however, reduced volume in the anterior lobe of the cerebellum relative to typically developing children was observed. These results implicate cerebellar involvement in dyslexia and establish an important foundation for future research on the connectivity of the cerebellum and cortical regions typically associated with reading impairment.
Organic Biomarker Preservation in Silica-Rich Hydrothermal Systems with Implications to Mars
NASA Astrophysics Data System (ADS)
Jahnke, L. L.; Parenteau, M. N.; Farmer, J. D.
2016-05-01
Microbial community structure and preservation of organic matter in siliceous hydrothermal environments is a critical issue given the discovery of hydrothermal vents and silica on Mars. Here we discuss preservation of cyanobacterial biomarker lipid.
A review of postfeeding larval dispersal in blowflies: implications for forensic entomology
NASA Astrophysics Data System (ADS)
Gomes, Leonardo; Godoy, Wesley Augusto Conde; von Zuben, Claudio José
2006-05-01
Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.
Hot Quark Soup Produced at RHIC
None
2018-01-16
The Relativistic Heavy Ion Collider (RHIC, http://www.bnl.gov/rhic) is a 2.4-mile-circumference particle accelerator/collider that has been operating at Brookhaven Lab since 2000, delivering collisions of heavy ions, protons, and other particles to an international team of physicists investigating the basic structure and fundamental forces of matter. In 2005, RHIC physicists announced that the matter created in RHICs most energetic collisions behaves like a nearly perfect liquid in that it has extraordinarily low viscosity, or resistance to flow. Since then, the scientists have been taking a closer look at this remarkable form of matter, which last existed some 13 billion years ago, a mere fraction of a second after the Big Bang. Scientists have revealed new findings, including the first measurement of temperature very early in the collision events, and their implications for the nature of this early-universe matter.
Searching gamma-ray bursts for gravitational lensing echoes - Implications for compact dark matter
NASA Technical Reports Server (NTRS)
Nemiroff, R. J.; Norris, J. P.; Wickramasinghe, W. A. D. T.; Horack, J. M.; Kouveliotou, C.; Fishman, G. J.; Meegan, C. A.; Wilson, R. B.; Paciesas, W. S.
1993-01-01
The first available 44 gamma-ray bursts (GRBs) detected by the Burst and Transient Source Experiment on board the Compton Gamma-Ray Observatory have been inspected for echo signals following shortly after the main signal. No significant echoes have been found. Echoes would have been expected were the GRBs distant enough and the universe populated with a sufficient density of compact objects composing the dark matter. Constraints on dark matter abundance and GRB redshifts from the present data are presented and discussed. Based on these preliminary results, a universe filled to critical density of compact objects between 10 exp 6.5 and 10 exp 8.1 solar masses are now marginally excluded, or the most likely cosmological distance paradigm for GRBs is not correct. We expect future constraints to be able either to test currently popular cosmological dark matter paradigms or to indicate that GRBs do not lie at cosmological distances.
NASA Astrophysics Data System (ADS)
Bender, Carl M.; Mavromatos, Nick E.; Sarkar, Sarben
2013-03-01
The interplay of dilatonic effects in dilaton cosmology and stochastic quantum space-time defects within the framework of string/brane cosmologies is examined. The Boltzmann equation describes the physics of thermal dark-matter-relic abundances in the presence of rolling dilatons. These dilatons affect the coupling of stringy matter to D-particle defects, which are generic in string theory. This coupling leads to an additional source term in the Boltzmann equation. The techniques of asymptotic matching and boundary-layer theory, which were recently applied by two of the authors (Bender and Sarkar) to a Boltzmann equation, are used here to find the detailed asymptotic relic abundances for all ranges of the expectation value of the dilaton field. The phenomenological implications for the search for supersymmetric dark matter in current colliders, such as the LHC, are discussed.
White matter damage is related to ataxia severity in SCA3.
Kang, J-S; Klein, J C; Baudrexel, S; Deichmann, R; Nolte, D; Hilker, R
2014-02-01
Spinocerebellar ataxia type 3 (SCA3) is the most frequent inherited cerebellar ataxia in Europe, the US and Japan, leading to disability and death through motor complications. Although the affected protein ataxin-3 is found ubiquitously in the brain, grey matter atrophy is predominant in the cerebellum and the brainstem. White matter pathology is generally less severe and thought to occur in the brainstem, spinal cord, and cerebellar white matter. Here, we investigated both grey and white matter pathology in a group of 12 SCA3 patients and matched controls. We used voxel-based morphometry for analysis of tissue loss, and tract-based spatial statistics (TBSS) on diffusion magnetic resonance imaging to investigate microstructural pathology. We analysed correlations between microstructural properties of the brain and ataxia severity, as measured by the Scale for the Assessment and Rating of Ataxia (SARA) score. SCA3 patients exhibited significant loss of both grey and white matter in the cerebellar hemispheres, brainstem including pons and in lateral thalamus. On between-group analysis, TBSS detected widespread microstructural white matter pathology in the cerebellum, brainstem, and bilaterally in thalamus and the cerebral hemispheres. Furthermore, fractional anisotropy in a white matter network comprising frontal, thalamic, brainstem and left cerebellar white matter strongly and negatively correlated with SARA ataxia scores. Tractography identified the thalamic white matter thus implicated as belonging to ventrolateral thalamus. Disruption of white matter integrity in patients suffering from SCA3 is more widespread than previously thought. Moreover, our data provide evidence that microstructural white matter changes in SCA3 are strongly related to the clinical severity of ataxia symptoms.
Soil manganese redox cycling in suboxic zones: Effects on soil carbon stability
Suboxic soil environments contain a disproportionately higher concentration of highly reactive free radicals relative to the surrounding soil matrix, which may have significant implications for soil organic matter cycling and stabilization. This study investigated how Mn-ozidizin...
Leading by Example: The Case for IT Security in Academia
ERIC Educational Resources Information Center
Davidson, Mary Ann
2005-01-01
Leadership in IT security is needed. Security matters: the ethics, the economics, and the social implications. There is much the academic community can do to help ensure cybersecurity. This document discusses steps academia can take to help ensure cybersecurity.
Phenomenology of anomalous chiral transports in heavy-ion collisions
NASA Astrophysics Data System (ADS)
Huang, Xu-Guang
2018-01-01
High-energy Heavy-ion collisions can generate extremely hot quark-gluon matter and also extremely strong magnetic fields and fluid vorticity. Once coupled to chiral anomaly, the magnetic fields and fluid vorticity can induce a variety of novel transport phenomena, including the chiral magnetic effect, chiral vortical effect, etc. Some of them require the environmental violation of parity and thus provide a means to test the possible parity violation in hot strongly interacting matter. We will discuss the underlying mechanism and implications of these anomalous chiral transports in heavy-ion collisions.
NASA Astrophysics Data System (ADS)
Lee, Hyun Min
2018-03-01
We consider the gauged U (1) clockwork theory with a product of multiple gauge groups and discuss the continuum limit of the theory to a massless gauged U (1) with linear dilaton background in five dimensions. The localization of the lightest state of gauge fields on a site in the theory space naturally leads to exponentially small effective couplings of external matter fields localized away from the site. We discuss the implications of our general discussion with some examples, such as mediators of dark matter interactions, flavor-changing B-meson decays as well as D-term SUSY breaking.
The cosmic microwave background
NASA Technical Reports Server (NTRS)
Silk, Joseph
1991-01-01
Recent limits on spectral distortions and angular anisotropies in the cosmic microwave background are reviewed. The various backgrounds are described, and the theoretical implications are assessed. Constraints on inflationary cosmology dominated by cold dark matter (CDM) and on open cosmological models dominated by baryonic dark matter (BDM), with, respectively, primordial random phase scale-invariant curvature fluctuations or non-gaussian isocurvature fluctuations are described. More exotic theories are addressed, and I conclude with the 'bottom line': what theorists expect experimentalists to be measuring within the next two to three years without having to abandon their most cherished theories.
Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin
2012-02-01
In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that have been implicated in EOS and cannabis use disorders (CUD). T1-weighted magnetic resonance images were acquired from adolescents with EOS (n = 35), CUD (n = 16), EOS + CUD (n = 13), and healthy controls (HC) (n = 51). Using FreeSurfer, brain volume was examined within frontal, temporal, parietal and subcortical ROIs by a 2 (EOS versus no EOS) × 2 (CUD versus no CUD) design using multivariate analysis of covariance. In ROIs in which volumetric differences were identified, additional analyses of cortical thickness and surface area were conducted. A significant EOS-by-CUD interaction was observed. In the left superior parietal region, both "pure" EOS and "pure" CUD had smaller gray matter volumes that were associated with lower surface area compared with HC. A similar alteration was observed in the comorbid group compared with HC, but there was no additive volumetric deficit found in the comorbid group compared with the separate groups. In the left thalamus, the comorbid group had smaller gray matter volumes compared with the CUD and HC groups. These preliminary data indicate that the presence of a CUD may moderate the relationship between EOS and cerebral cortical gray matter structure in the left superior parietal lobe. Future research will follow this cohort over adolescence to further examine the impact of cannabis use on neurodevelopment.
NASA Astrophysics Data System (ADS)
Wang, Mei-Yu; Peter, Annika H. G.; Strigari, Louis E.; Zentner, Andrew R.; Arant, Bryan; Garrison-Kimmel, Shea; Rocha, Miguel
2014-11-01
We present a set of N-body simulations of a class of models in which an unstable dark matter particle decays into a stable dark matter particle and a non-interacting light particle with decay lifetime comparable to the Hubble time. We study the effects of the recoil kick velocity (Vk) received by the stable dark matter on the structures of dark matter haloes ranging from galaxy-cluster to Milky Way-mass scales. For Milky Way-mass haloes, we use high-resolution, zoom-in simulations to explore the effects of decays on Galactic substructure. In general, haloes with circular velocities comparable to the magnitude of kick velocity are most strongly affected by decays. We show that models with lifetimes Γ-1 ˜ H_0^{-1} and recoil speeds Vk ˜ 20-40 km s-1 can significantly reduce both the abundance of Galactic subhaloes and their internal densities. We find that decaying dark matter models that do not violate current astrophysical constraints can significantly mitigate both the `missing satellites problem' and the more recent `too big to fail problem'. These decaying models predict significant time evolution of haloes, and this implies that at high redshifts decaying models exhibit the similar sequence of structure formation as cold dark matter. Thus, decaying dark matter models are significantly less constrained by high-redshift phenomena than warm dark matter models. We conclude that models of decaying dark matter make predictions that are relevant for the interpretation of small galaxies observations in the Local Group and can be tested as well as by forthcoming large-scale surveys.
Bringing isolated dark matter out of isolation: Late-time reheating and indirect detection
NASA Astrophysics Data System (ADS)
Erickcek, Adrienne L.; Sinha, Kuver; Watson, Scott
2016-09-01
In standard cosmology, the growth of structure becomes significant following matter-radiation equality. In nonthermal histories, where an effectively matter-dominated phase occurs due to scalar oscillations prior to big bang nucleosynthesis, a new scale at smaller wavelengths appears in the matter power spectrum. Density perturbations that enter the horizon during the early matter-dominated era (EMDE) grow linearly with the scale factor prior to the onset of radiation domination, which leads to enhanced inhomogeneity on small scales if dark matter (DM) thermally and kinetically decouples during the EMDE. The microhalos that form from these enhanced perturbations significantly boost the self-annihilation rate for dark matter. This has important implications for indirect detection experiments: the larger annihilation rate may result in observable signals from dark matter candidates that are usually deemed untestable. As a proof of principle, we consider binos in heavy supersymmetry with an intermediate extended Higgs sector and all other superpartners decoupled. We find that these isolated binos, which lie under the neutrino floor, can account for the dark matter relic density and decouple from the standard model early enough to preserve the enhanced small-scale inhomogeneity generated during the EMDE. If early forming microhalos survive as subhalos within larger microhalos, the resulting boost to the annihilation rate for bino dark matter near the pseudoscalar resonance exceeds the upper limit established by Fermi-LAT's observations of dwarf spheroidal galaxies. These DM candidates motivate the N -body simulations required to eliminate uncertainties in the microhalos' internal structure by exemplifying how an EMDE can enable Fermi-LAT to probe isolated dark matter.
Mechanical properties of gray and white matter brain tissue by indentation
Budday, Silvia; Nay, Richard; de Rooij, Rijk; Steinmann, Paul; Wyrobek, Thomas; Ovaert, Timothy C.; Kuhl, Ellen
2015-01-01
The mammalian brain is composed of an outer layer of gray matter, consisting of cell bodies, dendrites, and unmyelinated axons, and an inner core of white matter, consisting primarily of myelinated axons. Recent evidence suggests that microstructural differences between gray and white matter play an important role during neurodevelopment. While brain tissue as a whole is rheologically well characterized, the individual features of gray and white matter remain poorly understood. Here we quantify the mechanical properties of gray and white matter using a robust, reliable, and repeatable method, flat-punch indentation. To systematically characterize gray and white matter moduli for varying indenter diameters, loading rates, holding times, post-mortem times, and locations we performed a series of n=192 indentation tests. We found that indenting thick, intact coronal slices eliminates the common challenges associated with small specimens: it naturally minimizes boundary effects, dehydration, swelling, and structural degradation. When kept intact and hydrated, brain slices maintained their mechanical characteristics with standard deviations as low as 5% throughout the entire testing period of five days post mortem. White matter, with an average modulus of 1.895kPa±0.592kPa, was on average 39% stiffer than gray matter, p<0.01, with an average modulus of 1.389kPa±0.289kPa, and displayed larger regional variations. It was also more viscous than gray matter and responded less rapidly to mechanical loading. Understanding the rheological differences between gray and white matter may have direct implications on diagnosing and understanding the mechanical environment in neurodevelopment and neurological disorders. PMID:25819199
Cosmological implications of primordial black holes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luis Bernal, José; Bellomo, Nicola; Raccanelli, Alvise
The possibility that a relevant fraction of the dark matter might be comprised of Primordial Black Holes (PBHs) has been seriously reconsidered after LIGO's detection of a ∼ 30 M {sub ⊙} binary black holes merger. Despite the strong interest in the model, there is a lack of studies on possible cosmological implications and effects on cosmological parameters inference. We investigate correlations with the other standard cosmological parameters using cosmic microwave background observations, finding significant degeneracies, especially with the tilt of the primordial power spectrum and the sound horizon at radiation drag. However, these degeneracies can be greatly reduced withmore » the inclusion of small scale polarization data. We also explore if PBHs as dark matter in simple extensions of the standard ΛCDM cosmological model induces extra degeneracies, especially between the additional parameters and the PBH's ones. Finally, we present cosmic microwave background constraints on the fraction of dark matter in PBHs, not only for monochromatic PBH mass distributions but also for popular extended mass distributions. Our results show that extended mass distribution's constraints are tighter, but also that a considerable amount of constraining power comes from the high-ℓ polarization data. Moreover, we constrain the shape of such mass distributions in terms of the correspondent constraints on the PBH mass fraction.« less
Solomon, Christopher T.; Jones, Stuart E.; Weidel, Brian C.; Buffam, Ishi; Fork, Megan L; Karlsson, Jan; Larsen, Soren; Lennon, Jay T.; Read, Jordan S.; Sadro, Steven; Saros, Jasmine E.
2015-01-01
Lake ecosystems and the services that they provide to people are profoundly influenced by dissolved organic matter derived from terrestrial plant tissues. These terrestrial dissolved organic matter (tDOM) inputs to lakes have changed substantially in recent decades, and will likely continue to change. In this paper, we first briefly review the substantial literature describing tDOM effects on lakes and ongoing changes in tDOM inputs. We then identify and provide examples of four major challenges which limit predictions about the implications of tDOM change for lakes, as follows: First, it is currently difficult to forecast future tDOM inputs for particular lakes or lake regions. Second, tDOM influences ecosystems via complex, interacting, physical-chemical-biological effects and our holistic understanding of those effects is still rudimentary. Third, non-linearities and thresholds in relationships between tDOM inputs and ecosystem processes have not been well described. Fourth, much understanding of tDOM effects is built on comparative studies across space that may not capture likely responses through time. We conclude by identifying research approaches that may be important for overcoming those challenges in order to provide policy- and management-relevant predictions about the implications of changing tDOM inputs for lakes.
Peters, Bart D; Voineskos, Aristotle N; Szeszko, Philip R; Lett, Tristram A; DeRosse, Pamela; Guha, Saurav; Karlsgodt, Katherine H; Ikuta, Toshikazu; Felsky, Daniel; John, Majnu; Rotenberg, David J; Kennedy, James L; Lencz, Todd; Malhotra, Anil K
2014-04-30
The genetic and molecular pathways driving human brain white matter (WM) development are only beginning to be discovered. Long chain polyunsaturated fatty acids (LC-PUFAs) have been implicated in myelination in animal models and humans. The biosynthesis of LC-PUFAs is regulated by the fatty acid desaturase (FADS) genes, of which a human-specific haplotype is strongly associated with ω-3 and ω-6 LC-PUFA concentrations in blood. To investigate the relationship between LC-PUFA synthesis and human brain WM development, we examined whether this FADS haplotype is associated with age-related WM differences across the life span in healthy individuals 9-86 years of age (n = 207). Diffusion tensor imaging was performed to measure fractional anisotropy (FA), a putative measure of myelination, of the cerebral WM tracts. FADS haplotype status was determined with a single nucleotide polymorphism (rs174583) that tags this haplotype. Overall, normal age-related WM differences were observed, including higher FA values in early adulthood compared with childhood, followed by lower FA values across older age ranges. However, individuals homozygous for the minor allele (associated with lower LC-PUFA concentrations) did not display these normal age-related WM differences (significant age × genotype interactions, p(corrected) < 0.05). These findings suggest that LC-PUFAs are involved in human brain WM development from childhood into adulthood. This haplotype and LC-PUFAs may play a role in myelin-related disorders of neurodevelopmental origin.
White matter changes and word finding failures with increasing age.
Stamatakis, Emmanuel A; Shafto, Meredith A; Williams, Guy; Tam, Phyllis; Tyler, Lorraine K
2011-01-07
Increasing life expectancy necessitates the better understanding of the neurophysiological underpinnings of age-related cognitive changes. The majority of research examining structural-cognitive relationships in aging focuses on the role of age-related changes to grey matter integrity. In the current study, we examined the relationship between age-related changes in white matter and language production. More specifically, we concentrated on word-finding failures, which increase with age. We used Diffusion tensor MRI (a technique used to image, in vivo, the diffusion of water molecules in brain tissue) to relate white matter integrity to measures of successful and unsuccessful picture naming. Diffusion tensor images were used to calculate Fractional Anisotropy (FA) images. FA is considered to be a measure of white matter organization/integrity. FA images were related to measures of successful picture naming and to word finding failures using voxel-based linear regression analyses. Successful naming rates correlated positively with white matter integrity across a broad range of regions implicated in language production. However, word finding failure rates correlated negatively with a more restricted region in the posterior aspect of superior longitudinal fasciculus. The use of DTI-MRI provides evidence for the relationship between age-related white matter changes in specific language regions and word finding failures in old age.
Wirth, Miranka; Pichet Binette, Alexa; Brunecker, Peter; Köbe, Theresa; Witte, A Veronica; Flöel, Agnes
2017-03-01
Reductions of cerebral blood flow and gray matter structure have been implicated in early pathogenesis of Alzheimer's disease, potentially providing complementary information. The present study evaluated regional patterns of cerebral hypoperfusion and atrophy in patients with mild cognitive impairment and healthy older adults. In each participant, cerebral perfusion and gray matter structure were extracted within selected brain regions vulnerable to Alzheimer's disease using magnetic resonance imaging. Measures were compared between diagnostic groups with/without adjustment for covariates. In mild cognitive impairment patients, cerebral blood flow was significantly reduced in comparison with healthy controls in temporo-parietal regions and the basal ganglia in the absence of local gray matter atrophy. By contrast, gray matter structure was significantly reduced in the hippocampus in the absence of local hypoperfusion. Both, cerebral perfusion and gray matter structure were significantly reduced in the entorhinal and isthmus cingulate cortex in mild cognitive impairment patients compared with healthy older adults. Our results demonstrated partly divergent patterns of temporo-parietal hypoperfusion and medial-temporal atrophy in mild cognitive impairment patients, potentially indicating biomarker sensitivity to dissociable pathological mechanisms. The findings support applicability of cerebral perfusion and gray matter structure as complementary magnetic resonance imaging-based biomarkers in early Alzheimer's disease detection, a hypothesis to be further evaluated in longitudinal studies.
Irizar, A; Rodríguez, M P; Izquierdo, A; Cancio, I; Marigómez, I; Soto, M
2015-01-01
Bioavailability is affected by soil physicochemical characteristics such as pH and organic matter (OM) content. In addition, OM constitutes the energy source of Eisenia fetida, a well established model species for soil toxicity assessment. The present work aimed at assessing the effects of changes in OM content on the toxicity of Cd in E. fetida through the measurement of neutral red uptake (NRU) and mortality, growth, and reproduction (Organisation for Economic Co-operation and Development [OECD] Nos. 207 and 222). Complementarily, metallothionein (MT) and catalase transcription levels were measured. To decrease variability inherent to natural soils, artificial soils (Organization for Economic Cooperation and Development 1984) with different OM content (6, 10, and 14%) and spiked with Cd solutions at increasing concentrations were used. Low OM in soil decreased soil ingestion and Cd bioaccumulation but also increased Cd toxicity causing lower NRU of coelomocytes, 100 % mortality, and stronger reproduction impairment, probably due to the lack of energy to maintain protection mechanisms (production of MT).Cd bioaccumulation did not reflect toxicity, and OM played a pivotal role in Cd toxicity. Thus, OM content should be taken into account when using E. fetida in in vivo exposures for soil health assessment.
Closing in on singlet scalar dark matter: LUX, invisible Higgs decays and gamma-ray lines
Feng, Lei; Profumo, Stefano; Ubaldi, Lorenzo
2015-03-10
Here, we study the implications of the Higgs discovery and of recent results from dark matter searches on real singlet scalar dark matter. The phenomenology of the model is defined by only two parameters, the singlet scalar mass m S and the quartic coupling a 2 between the SU(2) Higgs and the singlet scalar. We concentrate on the window 5 < m S /GeV < 300. The most dramatic impact on the viable parameter space of the model comes from direct dark matter searches with LUX, and, for very low masses in the few GeV range, from constraints from themore » invisible decay width of the Higgs. In the resonant region the best constraints come from gamma-ray line searches. We show that they leave only a small region of viable parameter space, for dark matter masses within a few percent of half the mass of the Higgs. We demonstrate that direct and indirect dark matter searches (especially the search for monochromatic gamma-ray lines) will play a key role in closing the residual parameter space in the near future.« less
Microbiological Insights of the Cycling of Chloroperoxidase-Reacted Organic Matter
NASA Astrophysics Data System (ADS)
Krzmarzick, M. J.; Boothe, M.; Lim, M. L.; Wang, X.; Brooks, M.
2016-12-01
Chloroperoxidase (CPO) enzymes from fungi are one mechanism in which organic matter is halogenated in terrestrial soils. In microcosm experiments, 17 groups of bacteria were found to substantially become enriched upon CPO-reacted organic matter amendment (CPO-OM). Though some enriched groups were organohalide-respiring bacteria, most were not related to any cultured isolates of bacteria and were either loosely linked to organohalide-degrading cultures or not at all. The large diversity of uncultured bacteria that is enriched from this substrate raises new questions regarding the pathways and mechanisms of the turnover of natural organochlorides. Upon changes in organic matter source material, salinity, temperature, and fermentable substrate, large changes in the CPO-OM enrichment culture occurred due to salinity, temperature, and fermentable substrate, though organic matter source material had a minimal effect. Thus, changes in geophysical conditions, not organic matter (pine forest vs oak forest), dominate the selection of bacteria implicated in the turnover of natural organochlorides. In related experiments, the CPO-OM enrichment culture expresses increased activity towards the dechlorination of chlorinated ethenes, indicating a direct connection between natural organochloride turnover and anthropogenic organochloride degradation and bioremediation, and could partly explain the heterogeneity of natural bioremediation potential at contaminated sites.
Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy
Towler, Stephen; Welcome, Suzanne; Halderman, Laura K.; Otto, Ron; Eckert, Mark A.; Chiarello, Christine
2008-01-01
Biological and behavioral differences between the sexes range from obvious to subtle or nonexistent. Neuroanatomical differences are particularly controversial, perhaps due to the implication that they might account for behavioral differences. In this sample of 200 men and women, large effect sizes (Cohen's d > 0.8) were found for sex differences in total cerebral gray and white matter, cerebellum, and gray matter proportion (women had a higher proportion of gray matter). The only one of these sex differences that survived adjustment for the effect of cerebral volume was gray matter proportion. Individual differences in cerebral volume accounted for 21% of the difference in gray matter proportion, while sex accounted for an additional 4%. The relative size of the corpus callosum was 5% larger in women, but this difference was completely explained by a negative relationship between relative callosal size and cerebral volume. In agreement with Jancke et al., individuals with higher cerebral volume tended to have smaller corpora callosa. There were few sex differences in the size of structures in Broca's and Wernicke's area. We conclude that individual differences in brain volume, in both men and women, account for apparent sex differences in relative size. PMID:18440950
Gas Accretion and Angular Momentum
NASA Astrophysics Data System (ADS)
Stewart, Kyle R.
In this chapter, we review the role of gas accretion to the acquisition of angular momentum, both in galaxies and in their gaseous halos. We begin by discussing angular momentum in dark matter halos, with a brief review of tidal torque theory and the importance of mergers, followed by a discussion of the canonical picture of galaxy formation within this framework, where halo gas is presumed to shock-eat to the virial temperature of the halo, following the same spin distribution as the dark matter halo before cooling to the center of the halo to form a galaxy there. In the context of recent observational evidence demonstrating the presence of high angular momentum gas in galaxy halos, we review recent cosmological hydrodynamic simulations that have begun to emphasize the role of "cold flow" accretion—anisotropic gas accretion along cosmic filaments that does not shock-heat before sinking to the central galaxy. We discuss the implications of these simulations, reviewing a number of recent developments in the literature, and suggest a revision to the canonical model as it relates to the expected angular momentum content of gaseous halos around galaxies.
NASA Astrophysics Data System (ADS)
Liu, Yangyang; Shen, Fang; Li, Xiuzhen
2014-11-01
Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary were investigated during the summer of 2013. CDOM absorption showed a substantial portion of the total absorption and clearly dominant among most investigation stations. It generally decreased from the northwest to the southeast, which controlled by physical mixing of fresh water and seawater as was indicated by a conservative behaviour of CDOM. CDOM absorption sharply increased during phytoplankton blooms. Similarly, dissolved organic carbon (DOC) also peaked during blooms period. However, DOC exhibited a more complex behavior relative to a simple conservative mixing, possibly attributed to multiple origins of DOC. CDOM absorption and DOC co-varied to some degree, implying a potential way of DOC estimation from CDOM absorption. However, more detailed information such as CDOM and DOC composition and more validation data were required to obtain a stable CDOM - DOC pattern. Lastly, empirical algorithms with limited data were developed to retrieve CDOM absorption. Further validation of the algorithms were needed when they were to be commonly applied.
Zhao, Jun; Cao, Wenxi; Xu, Zhantang; Ye, Haibin; Yang, Yuezhong; Wang, Guifen; Zhou, Wen; Sun, Zhaohua
2018-04-16
An empirical algorithm is proposed to estimate suspended particulate matter (SPM) ranging from 0.675 to 25.7 mg L -1 in the turbid Pearl River estuary (PRE). Comparisons between model predicted and in situ measured SPM resulted in R 2 s of 0.97 and 0.88 and mean absolute percentage errors (MAPEs) of 23.96% and 29.69% by using the calibration and validation data sets, respectively. The developed algorithm demonstrated the highest accuracy when compared with existing ones for turbid coastal waters. The diurnal dynamics of SPM was revealed by applying the proposed algorithm to reflectance data collected by a moored buoy in the PRE. The established algorithm was implemented to Hyperspectral Imager for the Coastal Ocean (HICO) data and the distribution pattern of SPM in the PRE was elucidated. Validation of HICO-derived reflectance data by using concurrent MODIS/Aqua data as a benchmark indicated their reliability. Factors influencing variability of SPM in the PRE were analyzed, which implicated the combined effects of wind, tide, rainfall, and circulation as the cause.
Beheshti, Iman; Olya, Hossain G T; Demirel, Hasan
2016-04-05
Recently, automatic risk assessment methods have been a target for the detection of Alzheimer's disease (AD) risk. This study aims to develop an automatic computer-aided AD diagnosis technique for risk assessment of AD using information diffusion theory. Information diffusion is a fuzzy mathematics logic of set-value that is used for risk assessment of natural phenomena, which attaches fuzziness (uncertainty) and incompleteness. Data were obtained from voxel-based morphometry analysis of structural magnetic resonance imaging. The information diffusion model results revealed that the risk of AD increases with a reduction of the normalized gray matter ratio (p > 0.5, normalized gray matter ratio <40%). The information diffusion model results were evaluated by calculation of the correlation of two traditional risk assessments of AD, the Mini-Mental State Examination and the Clinical Dementia Rating. The correlation results revealed that the information diffusion model findings were in line with Mini-Mental State Examination and Clinical Dementia Rating results. Application of information diffusion model contributes to the computerization of risk assessment of AD, which has a practical implication for the early detection of AD.
NASA Astrophysics Data System (ADS)
Hasslöf, Helen; Lundegård, Iann; Malmberg, Claes
2016-01-01
In an 'age of measurement' where students' qualification is a hot topic on the political agenda, it is of interest to ask what the function of qualification might implicate in relation to a complex issue as Education for Sustainable Development (ESD) and what function environmental and sustainability issues serve in science education. This paper deals with how secondary and upper secondary teachers in discussions with colleagues articulate qualification in relation to educational aims of ESD. With inspiration from discourse theory, the teachers' articulations of qualification are analysed and put in relation to other functions of education (qualification, socialisation and subjectification). The results of this study show three discourses of qualification: scientific reasoning, awareness of complexity and to be critical. The discourse of 'qualification as to be critical' is articulated as a composite of differing epistemological views. In this discourse, the teachers undulate between rationalistic epistemological views and postmodern views, in a pragmatic way, to articulate a discourse of critical thinking which serves as a reflecting tool to bring about different ways of valuing issues of sustainability, which reformulates 'matter of facts' towards 'matter of concerns'
Ionic transport in high-energy-density matter
Stanton, Liam G.; Murillo, Michael S.
2016-04-08
Ionic transport coefficients for dense plasmas have been numerically computed using an effective Boltzmann approach. Here, we developed a simplified effective potential approach that yields accurate fits for all of the relevant cross sections and collision integrals. These results have been validated with molecular-dynamics simulations for self-diffusion, interdiffusion, viscosity, and thermal conductivity. Molecular dynamics has also been used to examine the underlying assumptions of the Boltzmann approach through a categorization of behaviors of the velocity autocorrelation function in the Yukawa phase diagram. By using a velocity-dependent screening model, we examine the role of dynamical screening in transport. Implications of thesemore » results for Coulomb logarithm approaches are discussed.« less
McDonald, Skye; Dalton, Katie I; Rushby, Jacqueline A; Landin-Romero, Ramon
2018-06-14
Adults with severe traumatic brain injury (TBI) often suffer poor social cognition. Social cognition is complex, requiring verbal, non-verbal, auditory, visual and affective input and integration. While damage to focal temporal and frontal areas has been implicated in disorders of social cognition after TBI, the role of white matter pathology has not been examined. In this study 17 adults with chronic, severe TBI and 17 control participants underwent structural MRI scans and Diffusion Tensor Imaging. The Awareness of Social Inference Test (TASIT) was used to assess their ability to understand emotional states, thoughts, intentions and conversational meaning in everyday exchanges. Track-based spatial statistics were used to perform voxelwise analysis of Fractional Anisotropy (FA) and Mean Diffusivity (MD) of white matter tracts associated with poor social cognitive performance. FA suggested a wide range of tracts were implicated in poor TASIT performance including tracts known to mediate, auditory localisation (planum temporale) communication between nonverbal and verbal processes in general (corpus callosum) and in memory in particular (fornix) as well as tracts and structures associated with semantics and verbal recall (left temporal lobe and hippocampus), multimodal processing and integration (thalamus, external capsule, cerebellum) and with social cognition (orbitofrontal cortex, frontopolar cortex, right temporal lobe). Even when controlling for non-social cognition, the corpus callosum, fornix, bilateral thalamus, right external capsule and right temporal lobe remained significant contributors to social cognitive performance. This study highlights the importance of loss of white matter connectivity in producing complex social information processing deficits after TBI.
Zhao, Yulian; Dong, Faqin; Dai, Qunwei; Li, Gang; Ma, Jie
2017-07-25
This paper aimed to investigate the variation of preserving organic matter bound in the interlayer space of montmorillonite (Mt) induced by a microbe metabolic process. We selected Bacillus pumilus as the common soil native bacteria. The alteration of d 001 value, functional group, and C,N organic matter contents caused by bacteria were analyzed by XRD, FTIR, and elementary analyzer, respectively. XRD results showed that the d 001 value of montmorillonite increased with the concentration decreasing and decreased with the culture time increasing after interacting with bacteria indicating the interlayer space of montmorillonite was connected with the organic matter. The findings of long-term interaction by resetting culture conditions implied that the montmorillonite buffered the organic matter when the nutrition was enough and released again when the nutrition was lacking. The results of the elementary analyzer declared the content of organic matter was according to the d 001 value of montmorillonite and N organic matter which played a major impact. FTIR results confirmed that the Si-O stretching vibrations of Mt were affected by the functional group of organic matter. Our results showed that the montmorillonite under the influence of soil bacteria has a strong buffering capacity for preserving organic matter into the interlayer space in a short-term. It might provide critical implications for understanding the evolution process and the preservation of fertilization which was in the over-fertilization or less-fertilization conditions on farmland.
Asymptotic safety of gravity with matter
NASA Astrophysics Data System (ADS)
Christiansen, Nicolai; Litim, Daniel F.; Pawlowski, Jan M.; Reichert, Manuel
2018-05-01
We study the asymptotic safety conjecture for quantum gravity in the presence of matter fields. A general line of reasoning is put forward explaining why gravitons dominate the high-energy behavior, largely independently of the matter fields as long as these remain sufficiently weakly coupled. Our considerations are put to work for gravity coupled to Yang-Mills theories with the help of the functional renormalization group. In an expansion about flat backgrounds, explicit results for beta functions, fixed points, universal exponents, and scaling solutions are given in systematic approximations exploiting running propagators, vertices, and background couplings. Invariably, we find that the gauge coupling becomes asymptotically free while the gravitational sector becomes asymptotically safe. The dependence on matter field multiplicities is weak. We also explain how the scheme dependence, which is more pronounced, can be handled without changing the physics. Our findings offer a new interpretation of many earlier results, which is explained in detail. The results generalize to theories with minimally coupled scalar and fermionic matter. Some implications for the ultraviolet closure of the Standard Model or its extensions are given.
Empire matters: implications for pastoral care.
LaMothe, Ryan
2007-01-01
In this essay, I argue that the American Empire matters for pastoral care. I begin with a discussion of the meaning of empire and the particular historical roots and characteristics of the American Empire. From this, I contend that the American Empire matters because the United States has had a long history of expansionist aims, which has been couched in idealized secular discourse as well as ensconced in theo-political discourse. These discourses, which have, implicitly or explicitly, supported foreign policies and actions aimed at political, economic, and military dominion, are joined to an empire psyche. This empire psyche and the actions of U.S. governments are matters for pastoral care because of a) the various physical, psychological, and spiritual harms that attend hubris, greed, entitlement, and the quest for hegemony, and b) the theological contradictions inherent in Christian discourse that supports the American Empire. These consequences and contradictions serve as reasons why pastoral theologians and caregivers ought to bring these matters to public reflection and conversation. I conclude with a brief depiction of possible pastoral actions given the reality of the American Empire.
Multiple sclerosis-related white matter microstructural change alters the BOLD hemodynamic response.
Hubbard, Nicholas A; Turner, Monroe; Hutchison, Joanna L; Ouyang, Austin; Strain, Jeremy; Oasay, Larry; Sundaram, Saranya; Davis, Scott; Remington, Gina; Brigante, Ryan; Huang, Hao; Hart, John; Frohman, Teresa; Frohman, Elliot; Biswal, Bharat B; Rypma, Bart
2016-11-01
Multiple sclerosis (MS) results in inflammatory damage to white matter microstructure. Prior research using blood-oxygen-level dependent (BOLD) imaging indicates MS-related alterations to brain function. What is currently unknown is the extent to which white matter microstructural damage influences BOLD signal in MS. Here we assessed changes in parameters of the BOLD hemodynamic response function (HRF) in patients with relapsing-remitting MS compared to healthy controls. We also used diffusion tensor imaging to assess whether MS-related changes to the BOLD-HRF were affected by changes in white matter microstructural integrity. Our results showed MS-related reductions in BOLD-HRF peak amplitude. These MS-related amplitude decreases were influenced by individual differences in white matter microstructural integrity. Other MS-related factors including altered reaction time, limited spatial extent of BOLD activity, elevated lesion burden, or lesion proximity to regions of interest were not mediators of group differences in BOLD-HRF amplitude. Results are discussed in terms of functional hyperemic mechanisms and implications for analysis of BOLD signal differences. © The Author(s) 2015.
Supermassive black holes do not correlate with dark matter haloes of galaxies.
Kormendy, John; Bender, Ralf
2011-01-20
Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black-hole growth and bulge formation regulate each other. That is, black holes and bulges coevolve. Therefore, reports of a similar correlation between black holes and the dark matter haloes in which visible galaxies are embedded have profound implications. Dark matter is likely to be non-baryonic, so these reports suggest that unknown, exotic physics controls black-hole growth. Here we show, in part on the basis of recent measurements of bulgeless galaxies, that there is almost no correlation between dark matter and parameters that measure black holes unless the galaxy also contains a bulge. We conclude that black holes do not correlate directly with dark matter. They do not correlate with galaxy disks, either. Therefore, black holes coevolve only with bulges. This simplifies the puzzle of their coevolution by focusing attention on purely baryonic processes in the galaxy mergers that make bulges.
Seismic Search for Strange Quark Matter
NASA Technical Reports Server (NTRS)
Teplitz, Vigdor
2004-01-01
Two decades ago, Witten suggested that the ground state of matter might be material of nuclear density made from up, down and strange quarks. Since then, much effort has gone into exploring astrophysical and other implications of this possibility. For example, neutron stars would almost certainly be strange quark stars; dark matter might be strange quark matter. Searches for stable strange quark matter have been made in various mass ranges, with negative, but not conclusive results. Recently, we [D. Anderson, E. Herrin, V. Teplitz, and I. Tibuleac, Bull. Seis. Soc. of Am. 93, 2363 (2003)] reported a positive result for passage through the Earth of a multi-ton "nugget" of nuclear density in a search of about a million seismic reports, to the U.S. Geological Survey for the years 1990-93, not associated with known Earthquakes. I will present the evidence (timing of first signals to the 9 stations involved, first signal directions, and unique waveform characteristics) for our conclusion and discuss potential improvements that could be obtained from exploiting the seismologically quieter environments of the moon and Mars.
Family physician perceptions of working with LGBTQ patients: physician training needs.
Beagan, Brenda; Fredericks, Erin; Bryson, Mary
2015-01-01
Medical students and physicians report feeling under-prepared for working with patients who identify as lesbian, gay, bisexual, transgender or queer (LGBTQ). Understanding physician perceptions of this area of practice may aid in developing improved education. In-depth interviews with 24 general practice physicians in Halifax and Vancouver, Canada, were used to explore whether, when and how the gender identity and sexual orientation of LGBTQ women were relevant to good care. Inductive thematic analysis was conducted using ATLAS.ti data analysis software. Three major themes emerged: 1) Some physicians perceived that sexual/gender identity makes little or no difference; treating every patient as an individual while avoiding labels optimises care for everyone. 2) Some physicians perceived sexual/gender identity matters primarily for the provision of holistic care, and in order to address the effects of discrimination. 3) Some physicians perceived that sexual/gender identity both matters and does not matter, as they strove to balance the implications of social group membership with recognition of individual differences. Physicians may be ignoring important aspects of social group memberships that affect health and health care. The authors hold that individual and socio-cultural differences are both important to the provision of quality health care. Distinct from stereotypes, generalisations about social group differences can provide valuable starting points, raising useful lines of inquiry. Emphasizing this distinction in medical education may help change physician approaches to the care of LGBTQ women.
Propulsion Physics Under the Changing Density Field Model
NASA Technical Reports Server (NTRS)
Robertson, Glen A.
2011-01-01
To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model
Structural abnormality of the corticospinal tract in major depressive disorder
2014-01-01
Background Scientists are beginning to document abnormalities in white matter connectivity in major depressive disorder (MDD). Recent developments in diffusion-weighted image analyses, including tractography clustering methods, may yield improved characterization of these white matter abnormalities in MDD. In this study, we acquired diffusion-weighted imaging data from MDD participants and matched healthy controls. We analyzed these data using two tractography clustering methods: automated fiber quantification (AFQ) and the maximum density path (MDP) procedure. We used AFQ to compare fractional anisotropy (FA; an index of water diffusion) in these two groups across major white matter tracts. Subsequently, we used the MDP procedure to compare FA differences in fiber paths related to the abnormalities in major fiber tracts that were identified using AFQ. Results FA was higher in the bilateral corticospinal tracts (CSTs) in MDD (p’s < 0.002). Secondary analyses using the MDP procedure detected primarily increases in FA in the CST-related fiber paths of the bilateral posterior limbs of the internal capsule, right superior corona radiata, and the left external capsule. Conclusions This is the first study to implicate the CST and several related fiber pathways in MDD. These findings suggest important new hypotheses regarding the role of CST abnormalities in MDD, including in relation to explicating CST-related abnormalities to depressive symptoms and RDoC domains and constructs. PMID:25295159
Tuberculosis in the elderly: Why inflammation matters.
Piergallini, Tucker J; Turner, Joanne
2018-05-01
Growing old is associated with an increase in the basal inflammatory state of an individual and susceptibility to many diseases, including infectious diseases. Evidence is growing to support the concept that inflammation and disease susceptibility in the elderly is linked. Our studies focus on the infectious disease tuberculosis (TB), which is caused by Mycobacterium tuberculosis (M.tb), a pathogen that infects approximately one fourth of the world's population. Aging is a major risk factor for developing TB, and inflammation has been strongly implicated. In this review we will discuss the relationship between inflammation in the lung and susceptibility to develop and succumb to TB in old age. Further understanding of the relationship between inflammation, age, and M.tb will lead to informed decisions about TB prevention and treatment strategies that are uniquely designed for the elderly. Copyright © 2017 Elsevier Inc. All rights reserved.
Quantum Theory, Active Information and the Mind-Matter Problem
NASA Astrophysics Data System (ADS)
Pylkkänen, Paavo
Bohm and Hiley suggest that a certain new type of active information plays a key objective role in quantum processes. This chapter discusses the implications of this suggestion to our understanding of the relation between the mental and the physical aspects of reality.
NASA Astrophysics Data System (ADS)
Czaja, A. D.; Osterhout, J. T.; Gangidine, A. J.
2018-04-01
Raman spectroscopy, which will be used by Mars 2020, can identify organic carbon and can assess the level of thermal alteration experienced by organic fossils. This study provides evidence that lithology can also influence apparent thermal alteration.
Neutrino Masses and Mixings and Astrophysics
NASA Astrophysics Data System (ADS)
Fuller, George M.
1998-10-01
Here we discuss the implications of light neutrino masses and neutrino flavor/type mixing for dark matter, big bang nucleosynthesis, and models of heavy element nucleosynthesis in super novae. We will also argue the other way and discuss possible constraints on neutrino physics from these astrophysical considerations.
Creation of X-Ray Transparency of Matter by Stimulated Elastic Forward Scattering.
Stöhr, J; Scherz, A
2015-09-04
X-ray absorption by matter has long been described by the famous Beer-Lambert law. Here, we show how this fundamental law needs to be modified for high-intensity coherent x-ray pulses, now available at x-ray free electron lasers, due to the onset of stimulated elastic forward scattering. We present an analytical expression for the modified polarization-dependent Beer-Lambert law for the case of resonant core-to-valence electronic transitions and incident transform limited x-ray pulses. Upon transmission through a solid, the resonant absorption and dichroic contrasts are found to vanish with increasing x-ray intensity, with the stimulation threshold lowered by orders of magnitude through a resonant superradiantlike effect. Our results have broad implications for the study of matter with x-ray lasers.
Creation of X-Ray Transparency of Matter by Stimulated Elastic Forward Scattering
NASA Astrophysics Data System (ADS)
Stöhr, J.; Scherz, A.
2015-09-01
X-ray absorption by matter has long been described by the famous Beer-Lambert law. Here, we show how this fundamental law needs to be modified for high-intensity coherent x-ray pulses, now available at x-ray free electron lasers, due to the onset of stimulated elastic forward scattering. We present an analytical expression for the modified polarization-dependent Beer-Lambert law for the case of resonant core-to-valence electronic transitions and incident transform limited x-ray pulses. Upon transmission through a solid, the resonant absorption and dichroic contrasts are found to vanish with increasing x-ray intensity, with the stimulation threshold lowered by orders of magnitude through a resonant superradiantlike effect. Our results have broad implications for the study of matter with x-ray lasers.
Murphy, G C; Foreman, P
1993-03-01
Calls for rehabilitation counselors to learn more about the world of work have been recently repeated. The validity of these calls is suggested by a group of studies which indicate that the rehabilitation counseling literature has an established emphasis on matters of counseling and adjustment rather than on matters related to behavior in organizations. A survey of rehabilitation counsellors' beliefs about key topics in organizational behavior indicates that their beliefs are often discrepant with those of practicing managers and supervisors. A summary of dominant models of work motivation adopted by managerial workers is presented and some implications for occupational rehabilitation practice identified. Finally, some contemporary literature relevant to managerial approaches to employee motivation are identified and it is suggested that familiarity with this literature could assist rehabilitation practitioners move from a more narrow occupational rehabilitation role to a broader involvement in organizational life via the expansion of the disability management approach in work organizations.
Collaborative Mother-Toddler Communication and Theory of Mind Development at Age 4
Sung, Jihyun; Hsu, Hui-Chin
2014-01-01
Focusing on social pragmatics, this longitudinal study investigated the contribution of mother-toddler collaborative communication to theory of mind (ToM) development at age 4. At age 2½, 78 toddlers’ (42 boys) and their mothers were observed during pretend play. At age 4, children were tested using 4 false belief understanding tasks. Both mothers and toddlers engaged in more collaborative (inform, guide/request, and support/confirm) than non-collaborative communication acts. Other-focused collaborative acts of support/confirm by mothers and toddlers predicted children’s false belief understanding, even after controlling for 5 covariates. In addition, as active agents in their own ToM development, the contribution of toddlers’ collaborative acts to false belief understanding was independent of their mothers. Finally, the way toddlers and their mothers co-constructing their communication mattered. Only when toddlers engaged in high levels of collaborative acts, the mothers’ high levels of collaborative acts demonstrated a positive effect on children’s ToM development. The applied implications of these findings were discussed. PMID:25132699
Compressing the Inert Doublet Model
Blinov, Nikita; Kozaczuk, Jonathan; Morrissey, David E.; ...
2016-02-16
The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. We found that this stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. In conclusion, we derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.
Braunstein, Samuel L; Pati, Arun K
2007-02-23
Can quantum-information theory shed light on black-hole evaporation? By entangling the in-fallen matter with an external system we show that the black-hole information paradox becomes more severe, even for cosmologically sized black holes. We rule out the possibility that the information about the in-fallen matter might hide in correlations between the Hawking radiation and the internal states of the black hole. As a consequence, either unitarity or Hawking's semiclassical predictions must break down. Any resolution of the black-hole information crisis must elucidate one of these possibilities.
Black hole mining in the RST model
NASA Astrophysics Data System (ADS)
Basavaraju, Rohitvarma; Lowe, David A.
2017-06-01
We consider the possibility of mining black holes in the 1 + 1-dimensional dilaton gravity model of Russo, Susskind and Thorlacius. The model correctly incorporates Hawking radiation and back-reaction in a semiclassical expansion in 1/N, where N is the number of matter species. It is shown that the lifetime of a perturbed black hole is independent of the addition of any extra apparatus when realized by an arbitrary positive energy matter source. We conclude that mining does not occur in the RST model and comment on the implications of this for the black hole information paradox.
In-situ capping of polychlorinated biphenyl (PCB) contaminated sediments with layers of sorbents such as activated carbon has been proposed, but several technical questions remain regarding long-term effectiveness. An activated carbon amended sediment cap was mimicked in laborat...
On the implications of aerosol liquid water and phase separation for organic aerosol mass
Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to org...
Some Principles of Intelligent Tutoring.
ERIC Educational Resources Information Center
Ohlsson, Stellan
1986-01-01
Research on intelligent tutoring systems is discussed from the point of view of providing moment-by-moment adaptation of content and form of instruction to the changing cognitive needs of individual learners. Implications of this goal for cognitive diagnosis, subject matter analysis, teaching tactics, and teaching strategies are analyzed. (Author)
MAMMALIAN CELL CYTOTOXICITY AND GENOTOXICITY OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS
The disinfection of drinking water continues to protect the public health against acute disease. Drinking water disinfection by-products (DBPs) are formed by the reaction of a disinfectant with naturally occurring organic matter. Many DBPs are genotoxic and are implicated as huma...
Formative Assessment Probes: Uncovering Students' Concept of Matter
ERIC Educational Resources Information Center
Keeley, Page
2016-01-01
During early childhood, children interact with objects around them. During these interactions, they develop their own concepts about matter, even before encountering the word matter in school. When they encounter the concept of matter in school, they develop a beginning notion of matter as the "stuff" that makes up the things around…
Krongold, Mark; Cooper, Cassandra; Lebel, Catherine
2015-01-01
Abstract The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior–posterior, left–right, and two clusters with superior–inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development. PMID:26464999
NASA Astrophysics Data System (ADS)
Nesbet, Robert K.
2018-05-01
Velocities in stable circular orbits about galaxies, a measure of centripetal gravitation, exceed the expected Kepler/Newton velocity as orbital radius increases. Standard Λ cold dark matter (ΛCDM) attributes this anomaly to galactic dark matter. McGaugh et al. have recently shown for 153 disc galaxies that observed radial acceleration is an apparently universal function of classical acceleration computed for observed galactic baryonic mass density. This is consistent with the empirical modified Newtonian dynamics (MOND) model, not requiring dark matter. It is shown here that suitably constrained ΛCDM and conformal gravity (CG) also produce such a universal correlation function. ΛCDM requires a very specific dark matter distribution, while the implied CG non-classical acceleration must be independent of galactic mass. All three constrained radial acceleration functions agree with the empirical baryonic v4 Tully-Fisher relation. Accurate rotation data in the nominally flat velocity range could distinguish between MOND, ΛCDM, and CG.
NASA Astrophysics Data System (ADS)
Tahir, Naeem Ahmad; Blanco Sancho, Juan; Schmidt, Ruediger; Shutov, Alaxander; Burkart, Florian; Wollmann, Daniel; Piriz, Antonio Roberto
2013-10-01
Numerical simulations have shown that the range of 7 TeV LHC protons in solid matter will be significantly increased due to hydrodynamic tunneling. For example, in solid copper and solid carbon, these protons and the shower can penetrate up to 35 m and 25 m, respectively. However, their corresponding static range in the two materials is 1 m and 3 m, respectively. This will have important implications on machine protection design. In order to validate these simulation results, experiments have been performed at the CERN HiRadMat facility using the 440 GeV SPS proton beam irradiating solid copper cylindrical target. The phenomenon of hydrodynamic tunneling has been experimentally confirmed and good agreement has been found between the simulations and the experimental results. A very interesting outcome of this work is that the HiRadMat facility can be used to generate High Energy Density matter including Warm Dense Matter and strongly coupled plasmas in the laboratory.
The extreme limit of the generalised Chaplygin gas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piattella, Oliver F., E-mail: oliver.piattella@uninsubria.it
2010-03-01
Unified Dark Matter models describe Dark Matter and Dark Energy as a single entity which is, in the simplest case, embodied in a perfect barotropic fluid. It is a well-established fact that small adiabatic perturbations of Unified Dark Matter have an evolution characterised by oscillations and decay which provide predictions on the Cosmic Background Radiation anisotropies which are in poor agreement with observation. In this paper we investigate the generalised Chaplygin gas and we find that the Integrated Sachs-Wolfe effect excludes the model for 10{sup −3} < α < 350. We discuss the implications on the background evolution of themore » Universe if large values of α are considered. In this case, the Universe expansion mimics a matter-dominated phase abruptly followed by a de Sitter one at the transition redshift z{sub tr}. Thanks to an analysis of the type Ia supernovae Constitution set we are able to place z{sub tr} = 0.22.« less
The effect of lifelong bilingualism on regional grey and white matter volume.
Olsen, Rosanna K; Pangelinan, Melissa M; Bogulski, Cari; Chakravarty, M Mallar; Luk, Gigi; Grady, Cheryl L; Bialystok, Ellen
2015-07-01
Lifelong bilingualism is associated with the delayed diagnosis of dementia, suggesting bilingual experience is relevant to brain health in aging. While the effects of bilingualism on cognitive functions across the lifespan are well documented, less is known about the neural substrates underlying differential behaviour. It is clear that bilingualism affects brain regions that mediate language abilities and that these regions are at least partially overlapping with those that exhibit age-related decline. Moreover, the behavioural advantages observed in bilingualism are generally found in executive function performance, suggesting that the frontal lobes may also be sensitive to bilingualism, which exhibit volume reductions with age. The current study investigated structural differences in the brain of lifelong bilingual older adults (n=14, mean age=70.4) compared with older monolinguals (n=14, mean age=70.6). We employed two analytic approaches: 1) we examined global differences in grey and white matter volumes; and, 2) we examined local differences in volume and cortical thickness of specific regions of interest previously implicated in bilingual/monolingual comparisons (temporal pole) or in aging (entorhinal cortex and hippocampus). We expected bilinguals would exhibit greater volume of the frontal lobe and temporal lobe (grey and white matter), given the importance of these regions in executive and language functions, respectively. We further hypothesized that regions in the medial temporal lobe, which demonstrate early changes in aging and exhibit neural pathology in dementia, would be more preserved in the bilingual group. As predicted, bilinguals exhibit greater frontal lobe white matter compared with monolinguals. Moreover, increasing age was related to decreasing temporal pole cortical thickness in the monolingual group, but no such relationship was observed for bilinguals. Finally, Stroop task performance was positively correlated with frontal lobe white matter, emphasizing the importance of preserved white matter in maintaining executive function in aging. These results underscore previous findings implicating an association between bilingualism and preserved frontal and temporal lobe function in aging. This article is part of a Special Issue entitled SI: Memory Å. Copyright © 2015 Elsevier B.V. All rights reserved.
Cherbuin, Nicolas; Shaw, Marnie E; Walsh, Erin; Sachdev, Perminder; Anstey, Kaarin J
2017-12-14
Strong evidence is available suggesting that effective reduction of exposure to demonstrated modifiable risk factors in mid-life or before could significantly decrease the incidence of Alzheimer's disease (AD) and delay its onset. A key ingredient to achieving this goal is the reliable identification of individuals at risk well before they develop clinical symptoms. The aim of this study was to provide further neuroimaging evidence of the effectiveness of a validated tool, the ANU Alzheimer's Disease Risk Index, for the assessment of future risk of cognitive decline. Participants were 461 (60-64 years, 48% female) community-living individuals free of dementia at baseline. Associations between risk estimates obtained with the ANU-ADRI, total and regional brain volumes including in the default mode network (DMN) measured at the same assessment and diagnosis of MCI/dementia over a 12-year follow-up were tested in a large sample of community-living individuals free of dementia at baseline. Higher risk estimates on the ANU-ADRI were associated with lower cortical gray matter and particularly in the DMN. Importantly, difference in participants with high and low risk scores explained 7-9% of the observed difference in gray matter volume. In this sample, every one additional risk point on the ANU-ADRI was associated with an 8% increased risk of developing MCI/dementia over a 12-year follow-up and this association was partly mediated by a sub-region of the DMN. Risk of cognitive decline assessed with a validated instrument is associated with gray matter volume, particularly in the DMN, a region known to be implicated in the pathological process of the disease.
Wang, Yingying; Mauer, Meaghan V; Raney, Talia; Peysakhovich, Barbara; Becker, Bryce L C; Sliva, Danielle D; Gaab, Nadine
2017-04-01
Developmental dyslexia is a neurodevelopmental disorder with a strong genetic basis. Previous studies observed white matter alterations in the left posterior brain regions in adults and school-age children with dyslexia. However, no study yet has examined the development of tract-specific white matter pathways from the pre-reading to the fluent reading stage in children at familial risk for dyslexia (FHD+) versus controls (FHD-). This study examined white matter integrity at pre-reading, beginning, and fluent reading stages cross-sectionally ( n = 78) and longitudinally (n = 45) using an automated fiber-tract quantification method. Our findings depict white matter alterations and atypical lateralization of the arcuate fasciculus at the pre-reading stage in FHD+ versus FHD- children. Moreover, we demonstrate faster white matter development in subsequent good versus poor readers and a positive association between white matter maturation and reading development using a longitudinal design. Additionally, the combination of white matter maturation, familial risk, and psychometric measures best predicted later reading abilities. Furthermore, within FHD+ children, subsequent good readers exhibited faster white matter development in the right superior longitudinal fasciculus compared with subsequent poor readers, suggesting a compensatory mechanism. Overall, our findings highlight the importance of white matter pathway maturation in the development of typical and atypical reading skills. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.
Robustness of dark matter constraints and interplay with collider searches for New Physics
NASA Astrophysics Data System (ADS)
Arbey, A.; Boudaud, M.; Mahmoudi, F.; Robbins, G.
2017-11-01
We study the implications of dark matter searches, together with collider constraints, on the phenomenological MSSM with neutralino dark matter and focus on the consequences of the related uncertainties in some detail. We consider, inter alia, the latest results from AMS-02, Fermi-LAT and XENON1T. In particular, we examine the impact of the choice of the dark matter halo profile, as well as the propagation model for cosmic rays, for dark matter indirect detection and show that the constraints on the MSSM differ by one to two orders of magnitude depending on the astrophysical hypotheses. On the other hand, our limited knowledge of the local relic density in the vicinity of the Earth and the velocity of Earth in the dark matter halo leads to a factor 3 in the exclusion limits obtained by direct detection experiments. We identified the astrophysical models leading to the most conservative and the most stringent constraints and for each case studied the complementarities with the latest LHC measurements and limits from Higgs, SUSY and monojet searches. We show that combining all data from dark matter searches and colliders, a large fraction of our supersymmetric sample could be probed. Whereas the direct detection constraints are rather robust under the astrophysical assumptions, the uncertainties related to indirect detection can have an important impact on the number of the excluded points.
Financial literacy is associated with white matter integrity in old age.
Han, S Duke; Boyle, Patricia A; Arfanakis, Konstantinos; Fleischman, Debra; Yu, Lei; James, Bryan D; Bennett, David A
2016-04-15
Financial literacy, the ability to understand, access, and utilize information in ways that contribute to optimal financial outcomes, is important for independence and wellbeing in old age. We previously reported that financial literacy is associated with greater functional connectivity between brain regions in old age. Here, we tested the hypothesis that higher financial literacy would be associated with greater white matter integrity in old age. Participants included 346 persons without dementia (mean age=81.36, mean education=15.39, male/female=79/267, mean MMSE=28.52) from the Rush Memory and Aging Project. Financial literacy was assessed using a series of questions imbedded as part of an ongoing decision making study. White matter integrity was assessed with diffusion anisotropy measured with diffusion tensor magnetic resonance imaging (DTI). We tested the hypothesis that higher financial literacy is associated with higher diffusion anisotropy in white matter, adjusting for the effects of age, education, sex, and white matter hyperintense lesions. We then repeated the analysis also adjusting for cognitive function. Analyses revealed regions with significant positive associations between financial literacy and diffusion anisotropy, and many remained significant after accounting for cognitive function. White matter tracts connecting right hemisphere temporal-parietal brain regions were particularly implicated. Greater financial literacy is associated with higher diffusion anisotropy in white matter of nondemented older adults after adjusting for important covariates. These results suggest that financial literacy is positively associated with white matter integrity in old age. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Financial Literacy is Associated with White Matter Integrity in Old Age
Han, S. Duke; Boyle, Patricia A.; Arfanakis, Konstantinos; Fleischman, Debra; Yu, Lei; James, Bryan D.; Bennett, David A.
2016-01-01
Financial literacy, the ability to understand, access, and utilize information in ways that contribute to optimal financial outcomes, is important for independence and wellbeing in old age. We previously reported that financial literacy is associated with greater functional connectivity between brain regions in old age. Here, we tested the hypothesis that higher financial literacy would be associated with greater white matter integrity in old age. Participants included 346 persons without dementia (mean age=81.36, mean education=15.39, male/female=79/267, mean MMSE=28.52) from the Rush Memory and Aging Project. Financial literacy was assessed using a series of questions imbedded as part of an ongoing decision making study. White matter integrity was assessed with diffusion anisotropy measured with diffusion tensor magnetic resonance imaging (DTI). We tested the hypothesis that higher financial literacy is associated with higher diffusion anisotropy in white matter, adjusting for the effects of age, education, sex, and white matter hyperintense lesions. We then repeated the analysis also adjusting for cognitive function. Analyses revealed regions with significant positive associations between financial literacy and diffusion anisotropy, and many remained significant after accounting for cognitive function. White matter tracts connecting right hemisphere temporal-parietal brain regions were particularly implicated. Greater financial literacy is associated with higher diffusion anisotropy in white matter of nondemented older adults after adjusting for important covariates. These results suggest that financial literacy is positively associated with white matter integrity in old age. PMID:26899784
Liu, W; Yan, B; An, D; Niu, R; Tang, Y; Tong, X; Gong, Q; Zhou, D
2017-12-01
This study aimed to assess the evolution of perinodular and contralateral white matter abnormalities in patients with periventricular nodular heterotopia (PNH) and epilepsy. Diffusion tensor imaging (DTI) (64 directions) and 3 T structural magnetic resonance imaging were performed in 29 PNH patients (mean age 27.3 years), and 16 patients underwent a second scan (average time between the two scans 1.1 years). Fractional anisotropy and mean diffusivity were measured within the perilesional and contralateral white matter. Longitudinal analysis showed that white matter located 10 mm from the focal nodule displayed characteristics intermediate to tissue 5 mm away, and normal-appearing white matter (NAWM) also established evolution profiles of perinodular white matter in different cortical lobes. Compared to 29 age- and sex-matched healthy controls, significant decreased fractional anisotropy and elevated mean diffusivity values were observed in regions 5 and 10 mm from nodules (P < 0.01), whilst DTI metrics of the remaining NAWM did not differ significantly from controls. Additionally, normal DTI metrics were shown in the contralateral region in patients with unilateral PNH. Periventricular nodular heterotopia is associated with microstructural abnormalities within the perilesional white matter and the extent decreases with increasing distance from the nodule. In the homologous contralateral region, white matter diffusion metrics were unchanged in unilateral PNH. These findings have clinical implications with respect to the medical and surgical interventions of PNH-related epilepsy. © 2017 EAN.
Molybdenum isotope fractionation during adsorption to organic matter
NASA Astrophysics Data System (ADS)
King, E. K.; Perakis, S. S.; Pett-Ridge, J. C.
2018-02-01
Organic matter is of emerging interest as a control on molybdenum (Mo) biogeochemistry, and information on isotope fractionation during adsorption to organic matter can improve interpretations of Mo isotope variations in natural settings. Molybdenum isotope fractionation was investigated during adsorption onto insolubilized humic acid (IHA), a surrogate for organic matter, as a function of time (2-170 h) and pH (2-7). For the time series experiment performed at pH 4.2, the average Mo isotope fractionation between the solution and the IHA (Δ98Mosolution-IHA) was 1.39‰ (±0.16‰, 2σ, based on 98Mo/95Mo relative to the NIST 3134 standard) at steady state. For the pH series experiment, Mo adsorption decreased as pH increased from 2.0 to 6.9, and the Δ98Mosolution-IHA increased from 0.82‰ to 1.79‰. We also evaluated natural Mo isotope patterns in precipitation, foliage, organic horizon, surface mineral soil, and bedrock from 12 forested sites in the Oregon Coast Range. The average Mo isotope offset observed between precipitation and organic (O) horizon soil was 2.1‰, with light Mo isotopes adsorbing preferentially to organic matter. Fractionation during adsorption to organic matter is similar in magnitude and direction to prior observations of Mo fractionation during adsorption to Fe- and Mn- (oxyhydr)oxides. Our finding that organic matter influences Mo isotope composition has important implications for the role of organic matter as a driver of trace metal retention and isotopic fractionation.
NASA Astrophysics Data System (ADS)
Mann, W. Anthony; Cherdack, Daniel; Musial, Wojciech; Kafka, Tomas
2010-12-01
Neutrinos propagating through matter may participate in forward coherent neutral-current-like scattering arising from nonstandard interactions as well as from the Mikheyev-Smirnov-Wolfenstein matter potential Ve. We show that at fixed long baselines through matter of constant density, the nonstandard interaction potential γμτVe can contribute an additional term to the oscillation phase whose sign differs for ν¯μ versus νμ propagation in matter. Its presence can cause different apparent Δm2 to be erroneously inferred on the basis of oscillations in vacuum, with values lying above (for ν¯μ) or below (for νμ) the actual Δm322 for the case where γμτ is predominantly real-valued and of sign opposite to Δm322. A nonstandard interaction scenario invoking only ℜ(γμτ) is shown to be capable of accounting for a disparity recently reported between oscillation survival for ν¯μ and νμ fluxes measured at 735 km by the MINOS experiment. Implications for mantle traversal by atmospheric neutrinos are examined. The nonstandard interaction matter potential with nonmaximal mixing could evade conventional atmospheric neutrino analyses which do not distinguish νμ from ν¯μ on an event-by-event basis.
Particulate Matter Resuspension in Mississippi Bight Evaluated with CONCORDE's Synthesis Model
NASA Astrophysics Data System (ADS)
O'Brien, S. J.; Quas, L. M.; Miles, T. N.; Pan, C.; Cambazoglu, M. K.; Soto Ramos, I. M.; Greer, A. T.; Church, I.; Wiggert, J. D.
2017-12-01
The CONsortium for oil spill exposure pathways in COastal River-Dominated Ecosystems (CONCORDE) was established to investigate the complex fine-scale biological, chemical and physical interactions in a marine system controlled by pulsed-river plume dynamics. During CONCORDE's spring 2016 field campaign, the In Situ Ichthyoplankton Imaging System (ISIIS) on the R/V Point Sur and the Scanfish on the R/V Pelican comprehensively characterized the physical and biological structure in the region. Increased suspended particulate matter was observed by the ISIIS, with concentrations at depth sufficient to completely occlude the in situ images of planktonic organisms. Data was also collected on the continental shelf during the spring cruise by the RU31 glider in the proximity of the Mississippi River Delta, east of the ISIIS / Scanfish transects. Backscatter and salinity observed by the Scanfish and glider showed elevated suspended particulate matter and increased salinity, suggesting a linkage to shoreward advection from the continental shelf of oceanic waters that are sufficiently energetic to drive sediment resuspension. As part of the CONCORDE research effort, a four-dimensional biogeochemical/lower trophic level synthesis model for Mississippi Sound and Bight has been developed, based on the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System. This study utilizes CONCORDE's synthesis model to investigate the physical forcing mechanisms affecting the increased suspended particulate matter concentration observed in the Mississippi Bight during spring 2016, and advection pathways between estuarine and shelf waters in the northern Gulf of Mexico. The results show that episodic, advection-driven resuspension is a critical aspect controlling suspended sediment distributions in Mississippi Bight, which has implications for observed spatio-temporal patterns of planktonic species.
Clausen, Ashley N.; Billinger, Sandra A.; Sisante, Jason-Flor V.; Suzuki, Hideo; Aupperle, Robin L.
2017-01-01
Background: Combat-exposed veteran populations are at an increased risk for developing cardiovascular disease. The anterior cingulate cortex (ACC) and insula have been implicated in both autonomic arousal to emotional stressors and homeostatic processes, which may contribute to cardiovascular dysfunction in combat veteran populations. The aim of the present study was to explore the intersecting relationships of combat experiences, rostral ACC and posterior insula volume, and cardiovascular health in a sample of combat veterans. Method: Twenty-four male combat veterans completed clinical assessment of combat experiences and posttraumatic stress symptoms. Subjects completed a magnetic resonance imaging scan and autosegmentation using FreeSurfer was used to estimate regional gray matter volume (controlling for total gray matter volume) of the rostral ACC and posterior insula. Flow-mediated dilation (FMD) was conducted to assess cardiovascular health. Theil-sen robust regressions and Welch's analysis of variance were used to examine relationships of combat experiences and PTSD symptomology with (1) FMD and (2) regional gray matter volume. Results: Increased combat experiences, deployment duration, and multiple deployments were related to smaller posterior insula volume. Combat experiences were marginally associated with poorer cardiovascular health. However, cardiovascular health was not related to rostral ACC or posterior insula volume. Conclusion: The present study provides initial evidence for the relationships of combat experiences, deployment duration, and multiple deployments with smaller posterior insula volume. Results may suggest that veterans with increased combat experiences may exhibit more dysfunction regulating the autonomic nervous system, a key function of the posterior insula. However, the relationship between combat and cardiovascular health was not mediated by regional brain volume. Future research is warranted to further clarify the cardiovascular or functional impact of smaller posterior insula volume in combat veterans. PMID:29312038
NASA Astrophysics Data System (ADS)
Datteri, Ryan; Pallavaram, Srivatsan; Konrad, Peter E.; Neimat, Joseph S.; D'Haese, Pierre-François; Dawant, Benoit M.
2011-03-01
A number of groups have reported on the occurrence of intra-operative brain shift during deep brain stimulation (DBS) surgery. This has a number of implications for the procedure including an increased chance of intra-cranial bleeding and complications due to the need for more exploratory electrodes to account for the brain shift. It has been reported that the amount of pneumocephalus or air invasion into the cranial cavity due to the opening of the dura correlates with intraoperative brain shift. Therefore, pre-operatively predicting the amount of pneumocephalus expected during surgery is of interest toward accounting for brain shift. In this study, we used 64 DBS patients who received bilateral electrode implantations and had a post-operative CT scan acquired immediately after surgery (CT-PI). For each patient, the volumes of the pneumocephalus, left ventricle, right ventricle, third ventricle, white matter, grey matter, and cerebral spinal fluid were calculated. The pneumocephalus was calculated from the CT-PI utilizing a region growing technique that was initialized with an atlas-based image registration method. A multi-atlas-based image segmentation method was used to segment out the ventricles of each patient. The Statistical Parametric Mapping (SPM) software package was utilized to calculate the volumes of the cerebral spinal fluid (CSF), white matter and grey matter. The volume of individual structures had a moderate correlation with pneumocephalus. Utilizing a multi-linear regression between the volume of the pneumocephalus and the statistically relevant individual structures a Pearson's coefficient of r = 0.4123 (p = 0.0103) was found. This study shows preliminary results that could be used to develop a method to predict the amount of pneumocephalus ahead of the surgery.
Chemical processing of sea-salt particles in coastal environments significantly impacts concentrations of particle components and gas-phase species and has implications for human exposure to particulate matter and nitrogen deposition to sensitive ecosystems. Emission of sea-sal...
ERIC Educational Resources Information Center
Mercer, Thomas T., Ed.; And Others
Concern over chemical and radioactive particulate matter in industry and over rapidly increasing air pollution has stimulated research both on the properties of airborne particles and methods for assessing them and on their biological effects following inhalation. The Third Rochester International Conference on Environmental Toxicity was,…
Latent Effect of Soil Organic Matter Oxidation on Mercury Cycling within a Southern Boreal Ecosystem
The focus of this study is to investigate processes causing the observed spatial variation of total mercury (THg) in the soil O horizon of watersheds within the Superior National Forest (Minnesota) and to determine if results have implications toward understanding long-term chang...
This NODA requests public comment on two alternative allocation methodologies for existing units, on the unit-level allocations calculated using those alternative methodologies, on the data supporting the calculations, and on any resulting implications.
AMMONIA EMISSIONS AND THEIR IMPLICATIONS ON FINE PARTICULATE MATTER FORMATION IN NORTH CAROLINA
Ammonia (NH3) is an important atmospheric pollutant that plays a key role in several air pollution problems. The accuracy of NH3 emissions can have a large effect on air quality model (AQM) predictions of aerosol sulfate, nitrate, and ammonium concentration...
Epidemiological studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden PM inhibits protein tyrosine phosphatase (PTP) activity in human primary bronchial epithelial cells (HAEC) and leads t...
Value-Added Analysis and Education Policy. Brief 1
ERIC Educational Resources Information Center
Rivkin, Steven G.
2007-01-01
This brief describes estimation and measurement issues relevant to estimating the quality of instruction in the context of a cumulative model of learning. It also discusses implications for the use of value-added estimates in personnel and compensation matters. The discussion highlights the importance of accounting for student differences and the…
Employee Education and Job Performance: Does Education Matter?
ERIC Educational Resources Information Center
Ariss, Sonny S.; Timmins, Sherman A.
1989-01-01
This study examines the relationship between the type of college degree, level of college degree, and superiors' perceptions of managers' attributes and their work performance in some management areas. No significant relationship has been found between managers' college education and their performance at work. Implications of these findings for…
An Investigation of Expertise: Implications for Adult Educators.
ERIC Educational Resources Information Center
Mandernach, Janice B.
To examine the characteristics of expertise, a study at the University of Minnesota cardiac clinic compared differences in diagnostic ability and strategies between novices (fourth year medical students) and experts (specialists in pediatric cardiology). The investigator presented a model for expertise based on knowledge of subject matter content…
Pesticides have been implicated as a major factor in global amphibian declines and may pose great risk to terrestrial phase amphibians moving to and from breeding ponds on agricultural landscapes. Dermal uptake from soil is known to occur in amphibians, but predicting pesticide a...
Does Size Matter? The Impact of Student-Staff Ratios
ERIC Educational Resources Information Center
McDonald, Gael
2013-01-01
Student-staff ratios (SSRs) in higher education have a significant impact on teaching and learning and critical financial implications for organisations. While SSRs are often used as a currency for quality both externally for political reasons and internally within universities for resource allocations, there is a considerable amount of ambiguity…
Why Philosophical Ethics in School: Implications for Education in Technology and in General
ERIC Educational Resources Information Center
Gardelli, Viktor; Alerby, Eva; Persson, Anders
2014-01-01
In this article, we distinguish between three approaches to ethics in school, each giving an interpretation of the expression "ethics in school": the "descriptive facts about ethics approach," roughly consisting of teaching empirical facts about moral matters to students; the "moral fostering approach," consisting of…
The effect of total carbon on microscopic soil properties and implications for crop production
USDA-ARS?s Scientific Manuscript database
Soil structure is a dynamic property affected by physical, chemical, and microbiological processes. Addition of organic matter to soils and the use of different management practices have been reported to impact soil structure and crop production. Moderation in soil temperature and increases in mic...
ERIC Educational Resources Information Center
Arteaga, Brenda
2011-01-01
Creating a healthier school in today's world of budget cuts and seemingly endless to-do lists is not only possible, but it is also imperative. Beyond the health implications, one of the most compelling reasons for creating healthier schools is that wellness serves as a power booster for learning. Numerous studies have documented what educators…
ERIC Educational Resources Information Center
Samsa, Gregory P.
2018-01-01
Collaborative biostatistics is the creative application of statistical tools to biomedical problems. The relatively modest literature about the traits of effective collaborative biostatisticians focuses on four core competencies: (a) technical and analytical; (b) substance-matter knowledge; (c) communication; and (d) problem solving and problem…
Guidelines to Literature Study in the Junior High School.
ERIC Educational Resources Information Center
Dade County Board of Public Instruction, Miami, FL.
GRADES OR AGES: Junior high school (grades 7-9). SUBJECT MATTER: Literature. ORGANIZATION AND PHYSICAL APPEARANCE: The contents of the guide are 1) major objectives, important aspects of the nature of literature, organization of literature study, ways of structuring reading for the individual student, implications of teaching reading skills,…
Psychological Type and the Matching of Cognitive Styles.
ERIC Educational Resources Information Center
Bargar, Robert R.; Hoover, Randy L.
1984-01-01
Carl Jung's theory of psychological type is explored and related to education in this article. A model of the interaction between teacher, student, subject matter, and instructional alternatives is examined and the educational implications are discussed. This theory is used to illustrate how psychological-type influences teaching and learning…
Teacher Supervision, Evaluation and Contract Renewal: Legal and Pastoral Concerns.
ERIC Educational Resources Information Center
Shaughnessy, M. Angela
Except in matters of obvious race and/or sex discrimination, teachers in Catholic and other private schools have fewer Constitutional rights than public school teachers have. Contract law, rather than Constitutional law, governs most teacher employment situations in Catholic schools. An awareness of its implications, together with pastoral (moral…
The Effects of Interdisciplinary Instruction on Simulation Performance.
ERIC Educational Resources Information Center
Clark, Robert A.; Gjerde, Kathy A. Paulson; Skinner, Deborah
2003-01-01
Examines implications of specific subject matter intervention by faculty members in economics and marketing on the choices made by students and the consequences of those choices in an online finance simulation. Findings, although mixed, suggest that interdisciplinary intervention in an online finance simulation has the potential to improve the…
A number of studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to Zn2+ inhibits protein tyrosine phosphatase (PTP) activity and leads to activation of epidermal growth factor receptor (EGFR) signaling in ...
ERIC Educational Resources Information Center
Feuerborn, Laura L.; Tyre, Ashli D.; Beaudoin, Kathleen
2018-01-01
Classified staff are important stakeholders in schools and commonly interact with students across grade levels, subject matter areas, and physical locations--making their involvement in the implementation of schoolwide positive behavior interventions and supports (SWPBIS) essential. However, their voice, including the intentional and systematic…
Job Satisfaction of Academics: Does Gender Matter?
ERIC Educational Resources Information Center
Machado-Taylor, Maria de Lourdes; White, Kate; Gouveia, Odilia
2014-01-01
Academic work in higher education has been influenced by global trends such as accountability, massification and deteriorating financial support. Within this broader context, the performance of academic staff as teachers and researchers has an impact on student learning and implications for the quality of higher education institutions (HEIs).…
Successful Leadership in High Poverty, Urban Schools. Implications from UCEA
ERIC Educational Resources Information Center
Jacobson, Stephen; Terry Orr, M.; Young, Michelle D.
2008-01-01
Research shows that leadership matters in improving student achievement. In fact, among school-related factors over which policy makers have some control, effective leadership practices rank second only to the quality of teaching in influencing student learning (Leithwood, Louis, Anderson & Wahlstrom, 2004). Quality leadership is particularly…
A number of studies have implicated the metallic content of ambient particulate matter (PM) with various indices of pulmonary and cardiovascular morbidity. Among the ambient PM metals, zinc is a ubiquitous contaminant known to cause adverse health effects. To assess its potential...
White Middle Class Identities and Urban Schooling. Identity Studies in the Social Sciences
ERIC Educational Resources Information Center
Reay, Diane; Crozier, Gill; James, David
2011-01-01
This book examines experiences and implications of "against-the-grain" school choices, where white middle class families choose ordinary and "low performing" secondary schools for their children. It offers a unique view of identity formation, taking in matters like family history, locality and whiteness.
Altered White Matter Microstructure in Adolescents with Major Depression: A Preliminary Study
ERIC Educational Resources Information Center
Cullen, Kathryn R.; Klimes-Dougan, Bonnie; Muetzel, Ryan; Mueller, Bryon A.; Camchong, Jazmin; Houri, Alaa; Kurma, Sanjiv; Lim, Kelvin O.
2010-01-01
Objective: Major depressive disorder (MDD) occurs frequently in adolescents, but the neurobiology of depression in youth is poorly understood. Structural neuroimaging studies in both adult and pediatric populations have implicated frontolimbic neural networks in the pathophysiology of MDD. Diffusion tensor imaging (DTI), which measures white…
NASA Astrophysics Data System (ADS)
Das, Gautom K.; Anderson, Donald S.; Wallis, Chris D.; Carratt, Sarah A.; Kennedy, Ian M.; van Winkle, Laura S.
2016-06-01
Ambient ultrafine particulate matter (UPM), less than 100 nm in size, has been linked to the development and exacerbation of pulmonary diseases. Age differences in susceptibility to UPM may be due to a difference in delivered dose as well as age-dependent differences in lung biology and clearance. In this study, we developed and characterized aerosol exposures to novel metal oxide nanoparticles containing lanthanides to study particle deposition in the developing postnatal rat lung. Neonatal, juvenile and adult rats (1, 3 and 12 weeks old) were nose only exposed to 380 μg m-3 of ~30 nm europium doped gadolinium oxide nanoparticles (Gd2O3:Eu3+) for 1 h. The deposited dose in the nose, extrapulmonary airways and lungs was determined using inductively-coupled plasma mass spectroscopy. The dose of deposited particles was significantly greater in the juvenile rats at 2.22 ng per g body weight compared to 1.47 ng per g and 0.097 ng per g for the adult and neonate rats, respectively. Toxicity was investigated in bronchoalveolar lavage fluid (BALF) by quantifying recovered cell types, and measuring lactate dehydrogenase activity and total protein. The toxicity data suggests that the lanthanide particles were not acutely toxic or inflammatory with no increase in neutrophils or lactate dehydrogenase activity at any age. Juvenile and adult rats had the same mass of deposited NPs per gram of lung tissue, while neonatal rats had significantly less NPs deposited per gram of lung tissue. The current study demonstrates the utility of novel lanthanide-based nanoparticles to study inhaled particle deposition in vivo and has important implications for nanoparticles delivery to the developing lung either as therapies or as a portion of particulate matter air pollution.Ambient ultrafine particulate matter (UPM), less than 100 nm in size, has been linked to the development and exacerbation of pulmonary diseases. Age differences in susceptibility to UPM may be due to a difference in delivered dose as well as age-dependent differences in lung biology and clearance. In this study, we developed and characterized aerosol exposures to novel metal oxide nanoparticles containing lanthanides to study particle deposition in the developing postnatal rat lung. Neonatal, juvenile and adult rats (1, 3 and 12 weeks old) were nose only exposed to 380 μg m-3 of ~30 nm europium doped gadolinium oxide nanoparticles (Gd2O3:Eu3+) for 1 h. The deposited dose in the nose, extrapulmonary airways and lungs was determined using inductively-coupled plasma mass spectroscopy. The dose of deposited particles was significantly greater in the juvenile rats at 2.22 ng per g body weight compared to 1.47 ng per g and 0.097 ng per g for the adult and neonate rats, respectively. Toxicity was investigated in bronchoalveolar lavage fluid (BALF) by quantifying recovered cell types, and measuring lactate dehydrogenase activity and total protein. The toxicity data suggests that the lanthanide particles were not acutely toxic or inflammatory with no increase in neutrophils or lactate dehydrogenase activity at any age. Juvenile and adult rats had the same mass of deposited NPs per gram of lung tissue, while neonatal rats had significantly less NPs deposited per gram of lung tissue. The current study demonstrates the utility of novel lanthanide-based nanoparticles to study inhaled particle deposition in vivo and has important implications for nanoparticles delivery to the developing lung either as therapies or as a portion of particulate matter air pollution. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00897f
Hao, F.; Li, S.; Dong, W.; Hu, Z.; Huang, B.
1998-01-01
Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. A number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. Because the reservoir intervals are shallow and very young, they must have filled with gas rapidly. The thick (up to 17 km) Tertiary and Quaternary sedimentary succession is dominated by shales, and is not disrupted by major faulting in the study area, a factor which seems to have had an important effect on both hydrocarbon generation and fluid migration. Organic-matter maturation in the deepest, most overpressured compartment has been significantly retarded as a result of the combined effects of excess pressure, the presence of large volumes of water, and the retention of generated hydrocarbons. This retardation is indicated by both kerogen-related parameters (vitrinite reflectance and Rock-Eval T(max)); and also by parameters based on the analysis of soluble organic matter (such as the C15+ hydrocarbon content, and the concentration of isoprenoid hydrocarbons relative to adjacent normal alkanes). In contrast to this, organic-matter maturation in shallow, normally-pressured strata in the diapiric area has been enhanced by hydrothermal fluid flow, which is clearly not topography-driven in origin. As a result, the hydrocarbon generation 'window' in the basin is considerably wider than could be expected from traditional geochemical modelling. These two unusual and contrasting anomalies in organic-matter maturation, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of the intense overpressuring, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids (both water and hydrocarbons) retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal regime and the enhancement of organic maturation, as well as the accumulation of commercial volumes of gas in a relatively short time interval.Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. To date, a number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. In fact, two unusual and contrasting anomalies in organic-matter maturation have been documented. These two anomalies, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of intense overpowering, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal regime and the enhancement of organic maturation, as well as the accumulation of commercial volumes of gas in a relatively short time interval.
Inheritance of silicate differentiation during lunar origin by giant impact
NASA Technical Reports Server (NTRS)
Warren, Paul H.
1992-01-01
It is pointed out that the implication of the popular giant impact model of lunar origin (e.g., Hartmann and Davis, 1975; Cameron and Ward, 1976; Stevenson, 1987) is that any depth-related silicate differentiation within the impactor (and/or the earth) at the time of the impact must be partly inherited by the preferentially peripheral matter that forms the moon. This paper presents calculations of the magnitude of the net differentiation of the protolunar matter for a variety of elements and scenarios, with different assumptions regarding the geometries of the 'sampled' peripheral zones, the relative proportions of the earth-derived to impactor-derived matter in the final moon, and the degree to which the impactor mantle had crystallized prior to the giant impact. It is shown that these differention effects constrain the overall plausibility of the giant impact hypothesis.
NASA Astrophysics Data System (ADS)
Chiang, Cheng-Wei; Ramsey-Musolf, Michael J.; Senaha, Eibun
2018-01-01
We analyze the theoretical and phenomenological considerations for the electroweak phase transition and dark matter in an extension of the standard model with a complex scalar singlet (cxSM). In contrast with earlier studies, we use a renormalization group improved scalar potential and treat its thermal history in a gauge-invariant manner. We find that the parameter space consistent with a strong first-order electroweak phase transition (SFOEWPT) and present dark matter phenomenological constraints is significantly restricted compared to results of a conventional, gauge-noninvariant analysis. In the simplest variant of the cxSM, recent LUX data and a SFOEWPT require a dark matter mass close to half the mass of the standard model-like Higgs boson. We also comment on various caveats regarding the perturbative treatment of the phase transition dynamics.
Gravitational waves from SU( N) glueball dark matter
Soni, Amarjit; Zhang, Yue
2017-05-30
Here, a hidden sector with pure non-abelian gauge symmetry is an elegant and just about the simplest model of dark matter. In this model the dark matter candidate is the lightest bound state made of the confined gauge fields, the dark glueball. In spite of its simplicity, the model has been shown to have several interesting non-standard implications in cosmology. In this work, we explore the gravitational waves from binary boson stars made of self-gravitating dark glueball fields as a natural and important consequence. We derive the dark SU(N) star mass and radius as functions of the only two fundamentalmore » parameters in the model, the glueball mass m and the number of colors N, and identify the regions that could be probed by the LIGO and future gravitational wave observatories.« less
Van Meter, Robin J; Glinski, Donna A; Henderson, W Matthew; Purucker, S Thomas
2016-11-01
Pesticides have been implicated as a major factor in global amphibian declines and may pose great risk to terrestrial phase amphibians moving to and from breeding ponds on agricultural landscapes. Dermal uptake from soil is known to occur in amphibians, but predicting pesticide availability and bioconcentration across soil types is not well understood. The present study was designed to compare uptake of 5 current-use pesticides (imidacloprid, atrazine, triadimefon, fipronil, and pendimethalin) in American toads (Bufo americanus) from exposure on soils with significant organic matter content differences (14.1% = high organic matter and 3.1% = low organic matter). We placed toads on high- or low-organic matter soil after applying individual current-use pesticides on the soil surface for an 8-h exposure duration. Whole body tissue homogenates and soils were extracted and analyzed using liquid chromatography-mass spectrometry to determine pesticide tissue and soil concentration, as well as bioconcentration factor in toads. Tissue concentrations were greater on the low-organic matter soil than the high-organic matter soil across all pesticides (average ± standard error; 1.23 ± 0.35 ppm and 0.78 ± 0.23 ppm, respectively), and bioconcentration was significantly higher for toads on the low-organic matter soil (analysis of covariance p = 0.002). Soil organic matter is known to play a significant role in the mobility of pesticides and bioavailability to living organisms. Agricultural soils typically have relatively lower organic matter content and serve as a functional habitat for amphibians. The potential for pesticide accumulation in amphibians moving throughout agricultural landscapes may be greater and should be considered in conservation and policy efforts. Environ Toxicol Chem 2016;35:2734-2741. © 2016 SETAC. © 2016 SETAC.
Motives Matter: Motives for Playing Pokémon Go and Implications for Well-Being.
Yang, Chia-Chen; Liu, Dong
2017-01-01
Mobile games such as Pokémon Go have become a major form of entertainment, and yet little is known about why people play the games and how their motives associate with well-being. Although literature on motives for playing video and online games is informative, the findings may not reflect the full spectrum of mobile gaming motives due to some unique affordances of mobile games (e.g., mobility). To catch up with the evolving gaming context, a popular mobile game, Pokémon Go, was taken as an example to explore individuals' mobile gaming motives. A Pokémon Go Motive Scale was developed. Seven motives were identified through factor analyses based on survey data from 262 Pokémon Go players (45 percent women; M age = 30.71, standard deviation = 7.77): Exercise, Fun, Escapism, Nostalgia, Friendship Maintenance, Relationship Initiation, and Achievement. Both Fun and Friendship Maintenance were positive correlates of well-being, whereas Escapism and Nostalgia were negative correlates. Relationship Initiation was associated with both better and poorer well-being. Implications of the findings are discussed.
Gordon, Michael
2013-01-01
The last decade has seen an enormous growth in the interest in the recognition of and intervention in those diagnosed and living with the whole range of cognitive impairment and frank dementia. In the western world, the recognition of the impact on patients, families, health care systems, and societies that dementia poses has led to great efforts to help define the indicators for current and future dementia with the intention to treat those already afflicted even with the primarily symptomatic medications that exist and to recognize those at future risk with the hope of providing counselling to forestall its future development. The idea of "early diagnosis" appears at first glance to be attractive for the purposes of future planning and research studies, but it is not clear what the benefits and risks might be if screening processes define people at risk when beneficial interventions might not yet be determined. The ethical as well as financial implications must be explored and defined before implementation of such screening becomes a normal standard of practice.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1999-06-01
Zeta Phi Beta Sorority National Educational Foundation, in cooperation with Xavier University of New Orleans, and the New Orleans District Office of the United States Equal Employment Opportunity Commission, held the Information and Dialogue Conference on the Human Genome Project for the Minority Communities in the State of Louisiana on April 16-17, 1999. The Conference was held on the campus of Xavier University in New Orleans. Community leaders, government officials, minority professional and social organizations leaders, religious leaders, persons from the educational and academic community, and students were invited. Conference objectives included bringing HGP information and a focus in themore » minority community on the project, in clear and understandable terms, to spread the work in the minority community about the project; to explore the likely positive implications with respect to health care and related matters; to explore possible negative results and strategies to meet them; to discuss the social, legal, and ethical implications; and to facilitate minority input into the HGP as it develops.« less
Newcombe, Virginia F J; Williams, Guy B; Scoffings, Daniel; Cross, Justin; Carpenter, T Adrian; Pickard, John D; Menon, David K
2010-05-01
An improved in vivo understanding of variations in neuropathology in the vegetative state (VS) may aid diagnosis, improve prognostication and help refine the selection of patients for particular treatment regimes. The authors have used diffusion tensor imaging (DTI) to characterise the extent and location of white matter loss in VS secondary to traumatic brain injury (TBI) and ischaemic-hypoxic injury. Twelve patients with VS (seven TBI, five ischaemic/hypoxic injuries) underwent MRI including DTI at a minimum of 3 months postinjury. Mean apparent diffusion coefficient, fractional anisotropy and eigenvalues were obtained for whole-brain grey and white matter, the pons, thalamus, ventral midbrain, dorsal midbrain and the corpus callosum. DTI measures of supratentorial damage were compared with a summed measure from the JFK modified Coma Recovery Scale (CRS-R) and with a three-point scale of functional magnetic resonance imaging (fMRI) response to an auditory paradigm to assess whether residual integrity of supratentorial white matter connectivity correlated with cortical processing. Conventional radiological approaches did not detect lesions in regions where quantitative DTI demonstrated abnormalities. There was evidence of marked, broadly similar, abnormalities in the supratentorial grey- and white-matter compartments from both aetiologies. In contrast, discordant findings were found in the infratentorial compartment, with DTI abnormalities in the brainstem confined to the TBI group. Supratentorial DTI abnormalities correlated with the CRS-R as well as responses to an fMRI paradigm that detected convert cognitive processing. DTI may help to characterise differences in patients in VS. These findings may have implications for response to therapies, and should be taken into account in trials of interventions aimed at arousal in VS.
Travis, Katherine E; Curran, Megan M; Torres, Christina; Leonard, Matthew K; Brown, Timothy T; Dale, Anders M; Elman, Jeffrey L; Halgren, Eric
2014-07-01
Recently, our laboratory has shown that the neural mechanisms for encoding lexico-semantic information in adults operate functionally by 12-18 months of age within left frontotemporal cortices (Travis et al., 2011. Spatiotemporal neural dynamics of word understanding in 12- to 18-month-old-infants. Cereb Cortex. 8:1832-1839). However, there is minimal knowledge of the structural changes that occur within these and other cortical regions important for language development. To identify regional structural changes taking place during this important period in infant development, we examined age-related changes in tissue signal properties of gray matter (GM) and white matter (WM) intensity and contrast. T1-weighted surface-based measures were acquired from 12- to 19-month-old infants and analyzed using a general linear model. Significant age effects were observed for GM and WM intensity and contrast within bilateral inferior lateral and anterovental temporal regions, dorsomedial frontal, and superior parietal cortices. Region of interest (ROI) analyses revealed that GM and WM intensity and contrast significantly increased with age within the same left lateral temporal regions shown to generate lexico-semantic activity in infants and adults. These findings suggest that neurophysiological processes supporting linguistic and cognitive behaviors may develop before cellular and structural maturation is complete within associative cortices. These results have important implications for understanding the neurobiological mechanisms relating structural to functional brain development. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Aldosterone and cardiovascular disease: the heart of the matter
He, B. Julie; Anderson, Mark E.
2012-01-01
Aldosterone contributes to the endocrine basis of heart failure and studies on cardiac aldosterone signaling have reinforced its value as a therapeutic target. Recent focus has shifted to new roles of aldosterone that appear to depend on co-existing pathologic stimuli, cell type, and disease etiology. This review evaluates recent advances in mechanisms underlying aldosterone-induced cardiac disease and highlights the interplay between aldosterone and Ca2+ and calmodulin dependent protein kinase II, whose hyperactivity during heart failure contributes to disease progression. Increasing evidence implicates aldosterone in diastolic dysfunction, and there is need to develop more targeted therapeutics such as aldosterone synthase inhibitors and molecularly specific anti-oxidants. Despite accumulating knowledge, many questions still persist and will likely dictate areas of future research. PMID:23040074
Arguing to learn in science: the role of collaborative, critical discourse.
Osborne, Jonathan
2010-04-23
Argument and debate are common in science, yet they are virtually absent from science education. Recent research shows, however, that opportunities for students to engage in collaborative discourse and argumentation offer a means of enhancing student conceptual understanding and students' skills and capabilities with scientific reasoning. As one of the hallmarks of the scientist is critical, rational skepticism, the lack of opportunities to develop the ability to reason and argue scientifically would appear to be a significant weakness in contemporary educational practice. In short, knowing what is wrong matters as much as knowing what is right. This paper presents a summary of the main features of this body of research and discusses its implications for the teaching and learning of science.
Abid, Mehdi
2017-03-01
The aim of this study is to test the hypothesis of the Environmental Kuznets Curve (EKC) with a sample of 58 MEA (Middle East & African) and 41 EU (European Union) countries for the period 1990 to 2011. The empirical analysis is carried out using the GMM-system method to solve the problem of endogenous variables. We focused on direct and indirect effects of institutional quality (through the efficiency of public expenditure, financial development, trade openness and foreign direct investment) and the income-emission relationship. We found a monotonically increasing relationship between CO 2 emissions and GDP in both MEA and EU regions. The policy implication is clear: in order to have sustainable positive economic performance and to reduce carbon dioxide emission in the country at the same time, policy makers should regulate and enhance the role and efficiency of domestic institutions. Copyright © 2016 Elsevier Ltd. All rights reserved.
Perinatal and Early Childhood Environmental Factors Influencing Allergic Asthma Immunopathogenesis
Gaffin, Jonathan M.; Kanchongkittiphon, Watcharoot; Phipatanakul, Wanda
2014-01-01
Background The prevalence of asthma has increased dramatically over the past several decades. While hereditary factors are highly important, the rapid rise outstrips the pace of genomic variation. Great emphasis has been placed on potential modifiable early life exposures leading to childhood asthma. Methods We reviewed the recent medical literature for important studies discussing the role of the perinatal and early childhood exposures and the inception of childhood asthma. Results and Discussion Early life exposure to allergens (House dust mite (HDM), furred pets, cockroach, rodent and mold)air pollution (nitrogen dioxide (NO2), ozone (O3), volatile organic compounds (VOCs), and particulate matter (PM)) and viral respiratory tract infections (Respiratory syncytial virus (RSV) and human rhinovirus (hRV)) have been implicated in the development of asthma in high risk children. Conversely, exposure to microbial diversity in the perinatal period may diminish the development of atopy and asthma symptoms. PMID:24952205
Planning a mentorship initiative for foster parents: Does gender matter?
Jay Miller, J; Benner, Kalea; Thrasher, Shawndaya; Pope, Natalie; Dumas, Tamikia; Damron, Larry J; Segress, Melissa; Niu, Chunling
2017-10-01
Despite the use of mentoring programs in fields such as business, career training, and youth development, little is known about how mentoring can be used to train and support new foster parents. This paper describes how Concept Mapping was used with current foster parents to develop a conceptual framework suitable to plan a foster parent mentor program. A secondary aim of this study was to explore priority differences in the conceptualization by self-reported gender (foster mothers vs. foster fathers). Participant data was collected via three qualitative brainstorming sessions, and analyzed using non-metric multidimensional scaling and hierarchical cluster analysis. Findings indicate that foster parents participating in this study conceptualized effective mentor programs via a seven cluster solution. Study results also showed no significant differences in cluster ratings by gender. Implications for practice and program planning are identified, as well as areas for future research. Copyright © 2017 Elsevier Ltd. All rights reserved.
Seminar: Developmental Dyslexia
Peterson, Robin L.; Pennington, Bruce F.
2012-01-01
Summary Dyslexia is a neurodevelopmental disorder that is characterized by slow and inaccurate word recognition. Dyslexia has been found in every culture studied, and mounting evidence underscores cross-linguistic similarity in its neurobiological and neurocognitive bases. There has been considerable progress across levels of analysis in the last five years. At a neuropsychological level, the phonological theory remains the most compelling, though it is increasingly clear that phonological problems interact with other cognitive risk factors. At a neurobiological level, recent research confirms that dyslexia is characterized by dysfunction of the normal left hemisphere language network and also implicates abnormal white matter development. Studies accounting for reading experience demonstrate that many observed neural differences reflect causes rather than effects of dyslexia. At an etiologic risk level, six candidate genes have been identified, and there is evidence for gene by environment interaction. This review includes a focus on these and other recent developments. PMID:22513218
Evidence for autophagic gridlock in aging and neurodegeneration.
Bakhoum, Mathieu F; Bakhoum, Christine Y; Ding, Zhixia; Carlton, Susan M; Campbell, Gerald A; Jackson, George R
2014-07-01
Autophagy is essential to neuronal homeostasis, and its impairment is implicated in the development of neurodegenerative pathology. However, the underlying mechanisms and consequences of this phenomenon remain a matter of conjecture. We show that misexpression of human tau in Drosophila induces accumulation of autophagic intermediates with a preponderance of large vacuoles, which we term giant autophagic bodies (GABs), which are reminiscent of dysfunctional autophagic entities. Lowering basal autophagy reduces GABs, whereas increasing autophagy decreases mature autolysosomes. Induction of autophagy is also associated with rescue of the tauopathy phenotype, suggesting that formation of GABs may be a compensatory mechanism rather than a trigger of neurodegeneration. Last, we show that the peculiar Biondi bodies observed in the choroid epithelium of both elderly and Alzheimer's disease human brains express immunoreactive markers similar to those of GABs. Collectively, these data indicate that autophagic gridlock contributes to the development of pathology in aging and neurodegeneration. Published by Mosby, Inc.
The maximal-density mass function for primordial black hole dark matter
NASA Astrophysics Data System (ADS)
Lehmann, Benjamin V.; Profumo, Stefano; Yant, Jackson
2018-04-01
The advent of gravitational wave astronomy has rekindled interest in primordial black holes (PBH) as a dark matter candidate. As there are many different observational probes of the PBH density across different masses, constraints on PBH models are dependent on the functional form of the PBH mass function. This complicates general statements about the mass functions allowed by current data, and, in particular, about the maximum total density of PBH. Numerical studies suggest that some forms of extended mass functions face tighter constraints than monochromatic mass functions, but they do not preclude the existence of a functional form for which constraints are relaxed. We use analytical arguments to show that the mass function which maximizes the fraction of the matter density in PBH subject to all constraints is a finite linear combination of monochromatic mass functions. We explicitly compute the maximum fraction of dark matter in PBH for different combinations of current constraints, allowing for total freedom of the mass function. Our framework elucidates the dependence of the maximum PBH density on the form of observational constraints, and we discuss the implications of current and future constraints for the viability of the PBH dark matter paradigm.
New insights on the matter-gravity coupling paradigm.
Delsate, Térence; Steinhoff, Jan
2012-07-13
The coupling between matter and gravity in general relativity is given by a proportionality relation between the stress tensor and the geometry. This is an oriented assumption driven by the fact that both the stress tensor and the Einstein tensor are divergenceless. However, general relativity is in essence a nonlinear theory, so there is no obvious reason why the coupling to matter should be linear. On another hand, modified theories of gravity usually affect the vacuum dynamics, yet keep the coupling to matter linear. In this Letter, we address the implications of consistent nonlinear gravity-matter coupling. The Eddington-inspired Born-Infeld theory recently introduced by Bañados and Ferreira provides an enlightening realization of such coupling modifications. We find that this theory coupled to a perfect fluid reduces to general relativity coupled to a nonlinearly modified perfect fluid, leading to an ambiguity between modified coupling and modified equation of state. We discuss observational consequences of this degeneracy and argue that such a completion of general relativity is viable from both an experimental and theoretical point of view through energy conditions, consistency, and singularity-avoidance perspectives. We use these results to discuss the impact of changing the coupling paradigm.
Wang, Yueyue; Zhu, Wenfeng; Xiao, Mingyue; Zhang, Qin; Zhao, Yufang; Zhang, Hao; Chen, Xu; Zheng, Yong; Xia, Ling-Xiang
2018-01-01
Angry rumination is a common mental phenomenon which may lead to negative social behaviors such as aggression. Although numerous neuroimaging studies have focused on brain area activation during angry rumination, to our knowledge no study has examined the neuroanatomical and cognitive mechanisms of this process. In this study, we conducted a voxel-based morphometry analysis, using a region of interest analysis to identify the structural and cognitive mechanisms underlying individual differences in trait angry rumination (as measured by the Angry Rumination Scale) in a sample of 82 undergraduate students. We found that angry rumination was positively correlated with gray matter density in the left middle frontal gyrus (left-MFG), which is implicated in inhibition control, working memory, and emotional regulation. The mediation analysis further revealed that hostile attribution bias (as measured by the Social Information Processing–Attribution Bias Questionnaire) acted as a cognitive mechanism underlying the positive association between the left-MFG gray matter density and trait angry rumination. These findings suggest that hostile attribution bias may contribute to trait angry rumination, while the left-MFG may play an important role in the development of hostile attribution bias and trait angry rumination. The study reveals the brain mechanisms of trait angry rumination and plays a role in revealing the cognitive mechanisms of the development of trait angry rumination. PMID:29695990
Long-Term Effects of Acute Stress on the Prefrontal-Limbic System in the Healthy Adult
Wei, Dongtao; Du, Xue; Zhang, Qinglin; Liu, Guangyuan; Qiu, Jiang
2017-01-01
Most people are exposed to at least one traumatic event during the course of their lives, but large numbers of people do not develop posttraumatic stress disorders. Although previous studies have shown that repeated and chronic stress change the brain’s structure and function, few studies have focused on the long-term effects of acute stressful exposure in a nonclinical sample, especially the morphology and functional connectivity changes in brain regions implicated in emotional reactivity and emotion regulation. Forty-one months after the 5/12 Wenchuan earthquake, we investigated the effects of trauma exposure on the structure and functional connectivity of the brains of trauma-exposed healthy individuals compared with healthy controls matched for age, sex, and education. We then used machine-learning algorithms with the brain structural features to distinguish between the two groups at an individual level. In the trauma-exposed healthy individuals, our results showed greater gray matter density in prefrontal-limbic brain systems, including the dorsal anterior cingulate cortex, medial prefrontal cortex, amygdala and hippocampus, than in the controls. Further analysis showed stronger amygdala-hippocampus functional connectivity in the trauma-exposed healthy compared to the controls. Our findings revealed that survival of traumatic experiences, without developing PTSD, was associated with greater gray matter density in the prefrontal-limbic systems related to emotional regulation. PMID:28045980
Sharifi, Mona; Marshall, Gareth; Goldman, Roberta E.; Cunningham, Courtney; Marshall, Richard; Taveras, Elsie M
2015-01-01
Objective To explore outcomes and measures of success that matter most to 'positive outlier' children who improved their body mass index (BMI) despite living in obesogenic neighborhoods. Methods We collected residential address and longitudinal height/weight data from electronic health records of 22,657 children ages 6–12 years in Massachusetts. We defined obesity “hotspots” as zip codes where >15% of children had a BMI ≥95th percentile. Using linear mixed effects models, we generated a BMI z-score slope for each child with a history of obesity. We recruited 10–12 year-olds with negative slopes living in hotspots for focus groups. We analyzed group transcripts and discussed emerging themes in iterative meetings using an immersion/crystallization approach. Results We reached thematic saturation after 4 focus groups with 21 children. Children identified bullying and negative peer comparisons related to physical appearance, clothing size, and athletic ability as motivating them to achieve a healthier weight, and they measured success as improvement in these domains. Positive relationships with friends and family facilitated both behavior change initiation and maintenance. Conclusions The perspectives of positive outlier children can provide insight into children’s motivations leading to successful obesity management. Practice implications: Child/family engagement should guide the development of patient-centered obesity interventions. PMID:26166630
Sokolowska, P; Passemard, S; Mok, A; Schwendimann, L; Gozes, I; Gressens, P
2011-01-26
Activity-dependent neuroprotective protein (ADNP) was shown to be essential for embryogenesis and brain development while NAP, an active motif of ADNP, is neuroprotective in a broad range of neurodegenerative disorders. In the present study, we examined the protective potential of ADNP/NAP in a mouse model of excitotoxic brain lesion mimicking brain damage associated with cerebral palsy. We demonstrated that NAP had a potent neuroprotective effect against ibotenate-induced excitotoxic damage in the cortical plate and the white matter of P5 mice, and moderate against brain lesions of P0 mice. In contrast, endogenous ADNP appears not to be involved in the response to excitotoxic challenge in the studied model. Our findings further show that NAP reduced the number of apoptotic neurons through activation of PI-3K/Akt pathway in the cortical plate or both PI-3K/Akt and MAPK/MEK1 kinases in the white matter. In addition, NAP prevented ibotenate-induced loss of pre-oligodendrocytes without affecting the number of astrocytes or activated microglia around the site of injection. These findings indicate that protective actions of NAP are mediated by triggering transduction pathways that are crucial for neuronal and oligodendroglial survival, thus, NAP might be a promising therapeutic agent for treating developing brain damage. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
Environmental Effects for Gravitational-wave Astrophysics
NASA Astrophysics Data System (ADS)
Barausse, Enrico; Cardoso, Vitor; Pani, Paolo
2015-05-01
The upcoming detection of gravitational waves by terrestrial interferometers will usher in the era of gravitational-wave astronomy. This will be particularly true when space-based detectors will come of age and measure the mass and spin of massive black holes with exquisite precision and up to very high redshifts, thus allowing for better understanding of the symbiotic evolution of black holes with galaxies, and for high-precision tests of General Relativity in strong-field, highly dynamical regimes. Such ambitious goals require that astrophysical environmental pollution of gravitational-wave signals be constrained to negligible levels, so that neither detection nor estimation of the source parameters are significantly affected. Here, we consider the main sources for space-based detectors - the inspiral, merger and ringdown of massive black-hole binaries and extreme mass-ratio inspirals - and account for various effects on their gravitational waveforms, including electromagnetic fields, cosmological evolution, accretion disks, dark matter, “firewalls” and possible deviations from General Relativity. We discover that the black-hole quasinormal modes are sharply different in the presence of matter, but the ringdown signal observed by interferometers is typically unaffected. The effect of accretion disks and dark matter depends critically on their geometry and density profile, but is negligible for most sources, except for few special extreme mass-ratio inspirals. Electromagnetic fields and cosmological effects are always negligible. We finally explore the implications of our findings for proposed tests of General Relativity with gravitational waves, and conclude that environmental effects will not prevent the development of precision gravitational-wave astronomy.
McDonald-Buller, Elena; Kimura, Yosuke; Craig, Michael; McGaughey, Gary; Allen, David; Webster, Mort
2016-02-02
Cap and trade programs have historically been designed to achieve annual or seasonal reductions in emissions of nitrogen oxides and sulfur dioxide from power plants. Emissions reductions may not be temporally coincident with meteorological conditions conducive to the formation of peak ozone and fine particulate matter concentrations. Integrated power system and air quality modeling methods were developed to evaluate time-differentiated emissions price signals on high ozone days in the Mid-Atlantic portion of the Pennsylvania-New Jersey-Maryland (PJM) Interconnection and Electric Reliability Council of Texas (ERCOT) grids. Sufficient flexibility exists in the two grids with marked differences in demand and fuel generation mix to accommodate time-differentiated emissions pricing alone or in combination with a season-wide program. System-wide emissions reductions and production costs from time-differentiated pricing are shown to be competitive with those of a season-wide program on high ozone days and would be more cost-effective if the primary policy goal was to target emissions reductions on these days. Time-differentiated pricing layered as a complement to the Cross-State Air Pollution Rule had particularly pronounced benefits for the Mid-Atlantic PJM system that relies heavily on coal-fired generation. Time-differentiated pricing aimed at reducing ozone concentrations had particulate matter reduction co-benefits, but if particulate matter reductions are the primary objective, other approaches to time-differentiated pricing may lead to greater benefits.
Family physician perceptions of working with LGBTQ patients: physician training needs
Beagan, Brenda; Fredericks, Erin; Bryson, Mary
2015-01-01
Background Medical students and physicians report feeling under-prepared for working with patients who identify as lesbian, gay, bisexual, transgender or queer (LGBTQ). Understanding physician perceptions of this area of practice may aid in developing improved education. Method In-depth interviews with 24 general practice physicians in Halifax and Vancouver, Canada, were used to explore whether, when and how the gender identity and sexual orientation of LGBTQ women were relevant to good care. Inductive thematic analysis was conducted using ATLAS.ti data analysis software. Results Three major themes emerged: 1) Some physicians perceived that sexual/gender identity makes little or no difference; treating every patient as an individual while avoiding labels optimises care for everyone. 2) Some physicians perceived sexual/gender identity matters primarily for the provision of holistic care, and in order to address the effects of discrimination. 3) Some physicians perceived that sexual/gender identity both matters and does not matter, as they strove to balance the implications of social group membership with recognition of individual differences. Conclusions Physicians may be ignoring important aspects of social group memberships that affect health and health care. The authors hold that individual and socio-cultural differences are both important to the provision of quality health care. Distinct from stereotypes, generalisations about social group differences can provide valuable starting points, raising useful lines of inquiry. Emphasizing this distinction in medical education may help change physician approaches to the care of LGBTQ women. PMID:26451226
Ionizing Radiation-Induced Immune and Inflammatory Reactions in the Brain
Lumniczky, Katalin; Szatmári, Tünde; Sáfrány, Géza
2017-01-01
Radiation-induced late brain injury consisting of vascular abnormalities, demyelination, white matter necrosis, and cognitive impairment has been described in patients subjected to cranial radiotherapy for brain tumors. Accumulating evidence suggests that various degrees of cognitive deficit can develop after much lower doses of ionizing radiation, as well. The pathophysiological mechanisms underlying these alterations are not elucidated so far. A permanent deficit in neurogenesis, chronic microvascular alterations, and blood–brain barrier dysfunctionality are considered among the main causative factors. Chronic neuroinflammation and altered immune reactions in the brain, which are inherent complications of brain irradiation, have also been directly implicated in the development of cognitive decline after radiation. This review aims to give a comprehensive overview on radiation-induced immune alterations and inflammatory reactions in the brain and summarizes how these processes can influence cognitive performance. The available data on the risk of low-dose radiation exposure in the development of cognitive impairment and the underlying mechanisms are also discussed. PMID:28529513
NASA Astrophysics Data System (ADS)
Haefner, Leigh Ann; Zembal-Saul, Carla
This study examined prospective elementary teachers' learning about scientific inquiry in the context of an innovative life science course. Research questions included: (1) What do prospective elementary teachers learn about scientific inquiry within the context of the course? and (2) In what ways do their experiences engaging in science investigations and teaching inquiry-oriented science influence prospective elementary teachers' understanding of science and science learning and teaching? Eleven prospective elementary teachers participated in this qualitative, multi-participant case study. Constant comparative analysis strategies attempted to build abstractions and explanations across participants around the constructs of the study. Findings suggest that engaging in scientific inquiry supported the development more appropriate understandings of science and scientific inquiry, and that prospective teachers became more accepting of approaches to teaching science that encourage children's questions about science phenomena. Implications include careful consideration of learning experiences crafted for prospective elementary teachers to support the development of robust subject matter knowledge.
Das, Gautom K; Anderson, Donald S; Wallis, Chris D; Carratt, Sarah A; Kennedy, Ian M; Van Winkle, Laura S
2016-06-02
Ambient ultrafine particulate matter (UPM), less than 100 nm in size, has been linked to the development and exacerbation of pulmonary diseases. Age differences in susceptibility to UPM may be due to a difference in delivered dose as well as age-dependent differences in lung biology and clearance. In this study, we developed and characterized aerosol exposures to novel metal oxide nanoparticles containing lanthanides to study particle deposition in the developing postnatal rat lung. Neonatal, juvenile and adult rats (1, 3 and 12 weeks old) were nose only exposed to 380 μg m(-3) of ∼30 nm europium doped gadolinium oxide nanoparticles (Gd2O3:Eu(3+)) for 1 h. The deposited dose in the nose, extrapulmonary airways and lungs was determined using inductively-coupled plasma mass spectroscopy. The dose of deposited particles was significantly greater in the juvenile rats at 2.22 ng per g body weight compared to 1.47 ng per g and 0.097 ng per g for the adult and neonate rats, respectively. Toxicity was investigated in bronchoalveolar lavage fluid (BALF) by quantifying recovered cell types, and measuring lactate dehydrogenase activity and total protein. The toxicity data suggests that the lanthanide particles were not acutely toxic or inflammatory with no increase in neutrophils or lactate dehydrogenase activity at any age. Juvenile and adult rats had the same mass of deposited NPs per gram of lung tissue, while neonatal rats had significantly less NPs deposited per gram of lung tissue. The current study demonstrates the utility of novel lanthanide-based nanoparticles to study inhaled particle deposition in vivo and has important implications for nanoparticles delivery to the developing lung either as therapies or as a portion of particulate matter air pollution.
From 'implications' to 'dimensions': science, medicine and ethics in society.
Pickersgill, Martyn D
2013-03-01
Much bioethical scholarship is concerned with the social, legal and philosophical implications of new and emerging science and medicine, as well as with the processes of research that under-gird these innovations. Science and technology studies (STS), and the related and interpenetrating disciplines of anthropology and sociology, have also explored what novel technoscience might imply for society, and how the social is constitutive of scientific knowledge and technological artefacts. More recently, social scientists have interrogated the emergence of ethical issues: they have documented how particular matters come to be regarded as in some way to do with 'ethics', and how this in turn enjoins particular types of social action. In this paper, I will discuss some of this and other STS (and STS-inflected) literature and reflect on how it might complement more 'traditional' modes of bioethical enquiry. I argue that STS might (1) cast new light on current bioethical issues, (2) direct the gaze of bioethicists towards matters that may previously have escaped their attention, and (3) indicate the import not only of the ethical implications of biomedical innovation, but also how these innovative and other processes feature ethics as a dimension of everyday laboratory and clinical work. In sum, engagements between STS and bioethics are increasingly important in order to understand and manage the complex dynamics between science, medicine and ethics in society.
Multiple sclerosis pathogenesis: missing pieces of an old puzzle.
Rahmanzadeh, Reza; Brück, Wolfgang; Minagar, Alireza; Sahraian, Mohammad Ali
2018-06-08
Traditionally, multiple sclerosis (MS) was considered to be a CD4 T cell-mediated CNS autoimmunity, compatible with experimental autoimmune encephalitis model, which can be characterized by focal lesions in the white matter. However, studies of recent decades revealed several missing pieces of MS puzzle and showed that MS pathogenesis is more complex than the traditional view and may include the following: a primary degenerative process (e.g. oligodendroglial pathology), generalized abnormality of normal-appearing brain tissue, pronounced gray matter pathology, involvement of innate immunity, and CD8 T cells and B cells. Here, we review these findings and discuss their implications in MS pathogenesis.
Light-matter interaction in doped microcavities
NASA Astrophysics Data System (ADS)
Averkiev, N. S.; Glazov, M. M.
2007-07-01
We discuss theoretically the light-matter coupling in a microcavity containing a quantum well with a two-dimensional electron gas. The high density limit where the bound exciton states are absent is considered. The matrix element of an interband optical absorption demonstrates the Mahan singularity [Phys. Rev. B153, 882 (1967); 163, 612 (1967)] due to strong Coulomb effect between the electrons and a photocreated hole. We extend the nonlocal dielectric response theory to calculate the quantum well reflection and transmission coefficients as well as the microcavity transmission spectra. The new eigenmodes of the system are discussed. Their implications for the steady state and time-resolved spectroscopy experiments are analyzed.
The Nature and Origin of Aromatic Organic Matter in the Tagish Lake Meteorite
NASA Technical Reports Server (NTRS)
Clemett, S. J.; Keller, L. P.; Nakamura, K.; McKay, D. S.
2004-01-01
The Tagish Lake meteorite is an unusual carbonaceous chondrite that does not fit well within existing chondrite taxonomy. Bulk analyses suggest approx. 5 wt.% C of which approx. 1 wt.% is in the form of organic matter and the remainder is present as inorganic carbonate. The exact nature and form of this organic component is, as is the case with the other ordinary and carbonaceous chondrites, still poorly understood. Yet its significance has far reaching implications, from contributing to the abiotic evolution of the early Earth and Mars, to providing geothermal constraints in the evolution of the Solar nebula.
Wang, B; Abdalla, E; Atrio-Barandela, F; Pavón, D
2016-09-01
Models where dark matter and dark energy interact with each other have been proposed to solve the coincidence problem. We review the motivations underlying the need to introduce such interaction, its influence on the background dynamics and how it modifies the evolution of linear perturbations. We test models using the most recent observational data and we find that the interaction is compatible with the current astronomical and cosmological data. Finally, we describe the forthcoming data sets from current and future facilities that are being constructed or designed that will allow a clearer understanding of the physics of the dark sector.
Transport Properties in Nuclear Pasta
NASA Astrophysics Data System (ADS)
Caplan, Matthew; Horowitz, Charles; Berry, Donald; da Silva Schneider, Andre
2016-09-01
At the base of the inner crust of neutron stars, where matter is near the nuclear saturation density, nuclear matter arranges itself into exotic shapes such as cylinders and slabs, called `nuclear pasta.' Lepton scattering from these structures may govern the transport properties of the inner crust; electron scattering from protons in the pasta determines the thermal and electrical conductivity, as well as the shear viscosity of the inner crust. These properties may vary in pasta structures which form at various densities, temperatures, and proton fractions. In this talk, we report on our calculations of lepton transport in nuclear pasta and the implication for neutron star observables.
Defining Nano, Nanotechnology and Nanomedicine: Why Should It Matter?
Satalkar, Priya; Elger, Bernice Simone; Shaw, David M
2016-10-01
Nanotechnology, which involves manipulation of matter on a 'nano' scale, is considered to be a key enabling technology. Medical applications of nanotechnology (commonly known as nanomedicine) are expected to significantly improve disease diagnostic and therapeutic modalities and subsequently reduce health care costs. However, there is no consensus on the definition of nanotechnology or nanomedicine, and this stems from the underlying debate on defining 'nano'. This paper aims to present the diversity in the definition of nanomedicine and its impact on the translation of basic science research in nanotechnology into clinical applications. We present the insights obtained from exploratory qualitative interviews with 46 stakeholders involved in translational nanomedicine from Europe and North America. The definition of nanomedicine has implications for many aspects of translational research including: fund allocation, patents, drug regulatory review processes and approvals, ethical review processes, clinical trials and public acceptance. Given the interdisciplinary nature of the field and common interest in developing effective clinical applications, it is important to have honest and transparent communication about nanomedicine, its benefits and potential harm. A clear and consistent definition of nanomedicine would significantly facilitate trust among various stakeholders including the general public while minimizing the risk of miscommunication and undue fear of nanotechnology and nanomedicine.
Kaulfus, Aaron S; Nair, Udaysankar; Jaffe, Daniel; Christopher, Sundar A; Goodrick, Scott
2017-10-17
We utilize the NOAA Hazard Mapping System smoke product for the period of 2005 to 2016 to develop climatology of smoke occurrence over the Continental United States (CONUS) region and to study the impact of wildland fires on particulate matter air quality at the surface. Our results indicate that smoke is most frequently found over the Great Plains and western states during the summer months. Other hotspots of smoke occurrence are found over state and national parks in the southeast during winter and spring, in the Gulf of Mexico southwards of the Texas and Louisiana coastline during spring season and along the Mississippi River Delta during the fall season. A substantial portion (20%) of the 24 h federal standard for particulate pollution exceedance events in the CONUS region occur when smoke is present. If the U.S. Environmental Protection Agency regulations continue to reduce anthropogenic emissions, wildland fire emissions will become the major contributor to particulate pollution and exceedance events. In this context, we show that HMS smoke product is a valuable tool for analysis of exceptional events caused by wildland fires and our results indicate that these tools can be valuable for policy and decision makers.
Childhood maltreatment moderates the effect of combat exposure on cingulum structural integrity
BANIHASHEMI, LAYLA; WALLACE, MEREDITH L.; SHEU, LEI K.; LEE, MICHAEL C.; GIANAROS, PETER J.; MACKENZIE, ROBERT P.; INSANA, SALVATORE P.; GERMAIN, ANNE; HERRINGA, RYAN J.
2017-01-01
Limbic white matter pathways link emotion, cognition, and behavior and are potentially malleable to the influences of traumatic events throughout development. However, the impact of interactions between childhood and later life trauma on limbic white matter pathways has yet to be examined. Here, we examined whether childhood maltreatment moderated the effect of combat exposure on diffusion tensor imaging measures within a sample of military veterans (N = 28). We examined five limbic tracts of interest: two components of the cingulum (cingulum, cingulate gyrus, and cingulum hippocampus [CGH]), the uncinate fasciculus, the fornix/stria terminalis, and the anterior limb of the internal capsule. Using effect sizes, clinically meaningful moderator effects were found only within the CGH. Greater combat exposure was associated with decreased CGH fractional anisotropy (overall structural integrity) and increased CGH radial diffusivity (perpendicular water diffusivity) among individuals with more severe childhood maltreatment. Our findings provide preliminary evidence of the moderating effect of childhood maltreatment on the relationship between combat exposure and CGH structural integrity. These differences in CGH structural integrity could have maladaptive implications for emotion and memory, as well as provide a potential mechanism by which childhood maltreatment induces vulnerability to later life trauma exposure. PMID:29162178
USDA-ARS?s Scientific Manuscript database
Resolving uncertainty in the carbon cycle is paramount to refining climate predictions. Soil organic carbon (SOC) is a major component of terrestrial C pools, and accuracy of SOC estimates are only as good as the measurements and assumptions used to obtain them. Dryland soils account for a substanti...
Does Major Matter? Considering the Implications of Collecting Vignette Data from Our Students
ERIC Educational Resources Information Center
Collett, Jessica L.; Childs, Ellen
2009-01-01
Social psychologists in both sociology and psychology commonly use vignettes to gauge how people might respond in a given situation. Research subjects in such studies, like those in other experiments, are often undergraduates, surveyed or recruited in classes. While there has been significant attention to the generalizability of students'…
What Is a Controversial Issue? Implications for the Treatment of Religious Beliefs in Education
ERIC Educational Resources Information Center
Cooling, Trevor
2012-01-01
An important debate in the literature on controversial issues concerns how to identify them. This matters for teachers because settled issues should be taught directively and controversial issues should be taught nondirectively. Teachers are professionally accountable for this decision. This article examines the contribution of Michael Hand to the…
We use a 2005–2009 record of isoprene emissions over Africa derived from Ozone Monitoring Instrument (OMI) satellite observations of formaldehyde (HCHO) to better understand the factors controlling isoprene emission in the continent and evaluate the impact on atmospheric co...
Perceptions of Value-Congruence with One's Department Chair: Does Match Matter?
ERIC Educational Resources Information Center
Virick, Meghna; Strage, Amy
2016-01-01
Although studies have examined numerous factors that predict junior faculty success, previous research has paid little attention to the role played by department chairs. Drawing on theory from person-environment fit theory and value congruence, we sought to examine the implication of a match versus mismatch between faculty members and their chairs…
Judging Plagiarism: A Problem of Morality and Convention
ERIC Educational Resources Information Center
East, Julianne
2010-01-01
This paper considers the problem of plagiarism as an issue of morality. Outrage about student plagiarism in universities positions it as dishonesty and a transgression of standards. Despite this, there has been little work analysing the implications of positioning plagiarism as a moral matter in the making of judgments about plagiarism and…
What Neuroscience Has Taught Us about Autism: Implications for Early Intervention
ERIC Educational Resources Information Center
Williams, Diane L.
2008-01-01
Investigation of the brain and brain function in living children and adults with autism has led to new information on the neurobiology of autism. Autism is characterized by early brain overgrowth and alterations in gray and white matter. Functional imaging studies suggest that individuals with autism have reduced synchronization between key brain…
ERIC Educational Resources Information Center
Ahmed, Tutan; Chattopadhyay, Raghabendra
2016-01-01
Purpose: Measurement of returns to vocational education has always remained a matter of controversy (Psacharopoulos, 1994; Bennell and Segerstrom, 1998; Ziderman, 1997). Based upon the return evidence many World Bank projects were scrapped (Middleton and Ziderman, 1997, Bennell and Segerstrom, 1998). However, there is again a growing interest for…
When Leadership Matters: Perspectives from a Teacher Team Implementing Response to Intervention
ERIC Educational Resources Information Center
Meyer, Michele M.; Behar-Horenstein, Linda S.
2015-01-01
Previous research investigating the effectiveness of response to intervention (RTI) has relied on post hoc data analyses and surveys, although few studies have explored interactions among teacher teams. Understanding the synergistic impact of teacher work within the RTI framework may have implications for how school leaders can support teacher…
Taking Charge of Choice: How Charter School Policy Contexts Matter. Research Brief
ERIC Educational Resources Information Center
Smrekar, Claire
2011-01-01
Against the backdrop of urban school politics, in which mayors play increasingly powerful and pivotal roles, the current study examines the origins and implications of mayoral control of charter school authorization and accountability in Indianapolis (see Henig & Rich, 2004; Wong & Shen, 2007). In contrast to analyses of mayoral takeovers…
Bella's Beetle: Approaching Bioscience Practice from Its Silent Kinaesthetic and Affective Side
ERIC Educational Resources Information Center
Hay, David
2017-01-01
This article critically explores the epistemic "practices" of bioscience, using creative writing and analyses of science studies to implicate the non-linguistic side of science where a "feeling for the organism" matters more, perhaps, than theoretical precision. It offers new critique of curricula in science which are so…
Implications of emission inventory choice for modeling fire-related pollution in the U.S.
Fires are a major source of particulate matter (PM), one of the most harmful ambient pollutants for human health globally. Within the U.S., fire emissions can account for more than 30% of total PM emissions annually. In order to represent the influence of fire emissions on atmosp...
OBJECTIVE: Fine particulate matter <2.5 microm (PM2.5) has been implicated in vasoconstriction and potentiation of hypertension in humans. We investigated the effects of short-term exposure to PM2.5 in the angiotensin II (AII) infusion model. METHODS AND RESULTS: Sprague-Dawley r...
New Views of Student Learning: Implications for Educational Measurement.
ERIC Educational Resources Information Center
Masters, Geofferey N.; Mislevy, Robert J.
Recent research in cognitive psychology has drawn attention to the important role that students' personal understandings and representations of subject matter play in the learning process. This paper briefly reviews some of this research and contrasts the kind of learning that results in an individual's changed conception or view of a phenomenon…
The behavior and fate of nanoparticles (NPs) in the marine environment is largely unknown and has the potential to have important environmental and human health implications. The aggregation state and fate of NPs in the marine environment is greatly influenced by their interactio...
Bartholomeusz, Cali F; Cropley, Vanessa L; Wannan, Cassandra; Di Biase, Maria; McGorry, Patrick D; Pantelis, Christos
2017-05-01
This review critically examines the structural neuroimaging evidence in psychotic illness, with a focus on longitudinal imaging across the first-episode psychosis and ultra-high-risk of psychosis illness stages. A thorough search of the literature involving specifically longitudinal neuroimaging in early illness stages of psychosis was conducted. The evidence supporting abnormalities in brain morphology and altered neurodevelopmental trajectories is discussed in the context of a clinical staging model. In general, grey matter (and, to a lesser extent, white matter) declines across multiple frontal, temporal (especially superior regions), insular and parietal regions during the first episode of psychosis, which has a steeper trajectory than that of age-matched healthy counterparts. Although the ultra-high-risk of psychosis literature is considerably mixed, evidence indicates that certain volumetric structural aberrations predate psychotic illness onset (e.g. prefrontal cortex thinning), while other abnormalities present in ultra-high-risk of psychosis populations are potentially non-psychosis-specific (e.g. hippocampal volume reductions). We highlight the advantages of longitudinal designs, discuss the implications such studies have on clinical staging and provide directions for future research.
Molybdenum isotope fractionation during adsorption to organic matter
King, Elizabeth K.; Perakis, Steven; Pett-Ridge, Julie C.
2018-01-01
Organic matter is of emerging interest as a control on molybdenum (Mo) biogeochemistry, and information on isotope fractionation during adsorption to organic matter can improve interpretations of Mo isotope variations in natural settings. Molybdenum isotope fractionation was investigated during adsorption onto insolubilized humic acid (IHA), a surrogate for organic matter, as a function of time (2–170 h) and pH (2–7). For the time series experiment performed at pH 4.2, the average Mo isotope fractionation between the solution and the IHA (Δ98Mosolution-IHA) was 1.39‰ (± 0.16‰, 2σ, based on 98Mo/95Mo relative to the NIST 3134 standard) at steady state. For the pH series experiment, Mo adsorption decreased as pH increased from 2.0 to 6.9, and the Δ98Mosolution-IHA increased from 0.82‰ to 1.79‰. We also evaluated natural Mo isotope patterns in precipitation, foliage, organic horizon, surface mineral soil, and bedrock from 12 forested sites in the Oregon Coast Range. The average Mo isotope offset observed between precipitation and organic (O) horizon soil was 2.1‰, with light Mo isotopes adsorbing preferentially to organic matter. Fractionation during adsorption to organic matter is similar in magnitude and direction to prior observations of Mo fractionation during adsorption to Fe- and Mn- (oxyhydr)oxides. Our finding that organic matter influences Mo isotope composition has important implications for the role of organic matter as a driver of trace metal retention and isotopic fractionation.
Schaeffer, David J; Rodrigue, Amanda L; Burton, Courtney R; Pierce, Jordan E; Murphy, Megan N; Clementz, Brett A; McDowell, Jennifer E
2017-12-01
Recent diffusion tensor imaging (DTI) studies suggest that altered white matter fiber integrity is a pathophysiological feature of schizophrenia. Lower white matter integrity is associated with poor cognitive control, a characteristic of schizophrenia that can be measured using antisaccade tasks. Although the functional neural correlates of poor antisaccade performance have been well documented, fewer studies have investigated the extent to which white matter fibers connecting the functional nodes of this network contribute to antisaccade performance. The aim of the present study was to assess the white matter structural integrity of fibers connecting two functional nodes (putamen and medial frontal eye fields) of the saccadic eye movement network implicated in poor antisaccade performance in schizophrenia. To evaluate white matter integrity, DTI was acquired on subjects with schizophrenia and two comparison groups: (a) behaviorally matched healthy comparison subjects with low levels of cognitive control (LCC group), and (b) healthy subjects with high levels of cognitive control (HCC group). White matter fibers were tracked between functional regions of interest generated from antisaccade fMRI activation maps, and measures of diffusivity were quantified. The results demonstrated lower white matter integrity in the schizophrenia group than in the HCC group, but not the LCC group who showed similarly poor cognitive control performance. Overall, the results suggest that these alterations are not specific to the disease process of schizophrenia, but may rather be a function of uncontrolled cognitive factors that are concomitant with the disease but also observed in some healthy people. © 2017 Society for Psychophysiological Research.
Hunting dark matter gamma-ray lines with the Fermi LAT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vertongen, Gilles; Weniger, Christoph, E-mail: gilles.vertongen@desy.de, E-mail: weniger@mppmu.mpg.de
2011-05-01
Monochromatic photons could be produced in the annihilation or decay of dark matter particles. At high energies, the search for such line features in the cosmic gamma-ray spectrum is essentially background free because plausible astrophysical processes are not expected to produce such a signal. The observation of a gamma-ray line would hence be a 'smoking-gun' signature for dark matter, making the search for such signals particularly attractive. Among the different dark matter models predicting gamma-ray lines, the local supersymmetric extension of the standard model with small R-parity violation and gravitino LSP is of particular interest because it provides a frameworkmore » where primordial nucleosynthesis, gravitino dark matter and thermal leptogenesis are naturally consistent. Using the two-years Fermi LAT data, we present a dedicated search for gamma-ray lines coming from dark matter annihilation or decay in the Galactic halo. Taking into account the full detector response, and using a binned profile likelihood method, we search for significant line features in the energy spectrum of the diffuse flux observed in different regions of the sky. No evidence for a line signal at the 5σ level is found for photon energies between 1 and 300 GeV, and conservative bounds on dark matter decay rates and annihilation cross sections are presented. Implications for gravitino dark matter in presence of small R-parity violation are discussed, as well as the impact of our results on the prospect for seeing long-lived neutralinos or staus at the LHC.« less
Brain grey matter volume alterations in late-life depression
Du, Mingying; Liu, Jia; Chen, Ziqi; Huang, Xiaoqi; Li, Jing; Kuang, Weihong; Yang, Yanchun; Zhang, Wei; Zhou, Dong; Bi, Feng; Kendrick, Keith Maurice; Gong, Qiyong
2014-01-01
Background Voxel-based morphometry (VBM) studies have demonstrated that grey matter abnormalities are involved in the pathophysiology of late-life depression (LLD), but the findings are inconsistent and have not been quantitatively reviewed. The aim of the present study was to conduct a meta-analysis that integrated the reported VBM studies, to determine consistent grey matter alterations in individuals with LLD. Methods A systematic search was conducted to identify VBM studies that compared patients with LLD and healthy controls. We performed a meta-analysis using the effect size signed differential mapping method to quantitatively estimate regional grey matter abnormalities in patients with LLD. Results We included 9 studies with 11 data sets comprising 292 patients with LLD and 278 healthy controls in our meta-analysis. The pooled and subgroup meta-analyses showed robust grey matter reductions in the right lentiform nucleus extending into the parahippocampus, the hippocampus and the amygdala, the bilateral medial frontal gyrus and the right subcallosal gyrus as well as a grey matter increase in the right lingual gyrus. Meta-regression analyses showed that mean age and the percentage of female patients with LLD were not significantly related to grey matter changes. Limitations The analysis techniques, patient characteristics and clinical variables of the studies included were heterogeneous, and most participants were medicated. Conclusion The present meta-analysis is, to our knowledge, the first to overcome previous inconsistencies in the VBM studies of LLD and provide robust evidence for grey matter alterations within fronto–striatal–limbic networks, thereby implicating them in the pathophysiology of LLD. The mean age and the percentage of female patients with LLD did not appear to have a measurable impact on grey matter changes, although we cannot rule out the contributory effects of medication. PMID:24949867
Brain grey matter volume alterations in late-life depression.
Du, Mingying; Liu, Jia; Chen, Ziqi; Huang, Xiaoqi; Li, Jing; Kuang, Weihong; Yang, Yanchun; Zhang, Wei; Zhou, Dong; Bi, Feng; Kendrick, Keith M; Gong, Qiyong
2014-11-01
Voxel-based morphometry (VBM) studies have demonstrated that grey matter abnormalities are involved in the pathophysiology of late-life depression (LLD), but the findings are inconsistent and have not been quantitatively reviewed. The aim of the present study was to conduct a meta-analysis that integrated the reported VBM studies, to determine consistent grey matter alterations in individuals with LLD. A systematic search was conducted to identify VBM studies that compared patients with LLD and healthy controls. We performed a meta-analysis using the effect size signed differential mapping method to quantitatively estimate regional grey matter abnormalities in patients with LLD. We included 9 studies with 11 data sets comprising 292 patients with LLD and 278 healthy controls in our meta-analysis. The pooled and subgroup meta-analyses showed robust grey matter reductions in the right lentiform nucleus extending into the parahippocampus, the hippocampus and the amygdala, the bilateral medial frontal gyrus and the right subcallosal gyrus as well as a grey matter increase in the right lingual gyrus. Meta-regression analyses showed that mean age and the percentage of female patients with LLD were not significantly related to grey matter changes. The analysis techniques, patient characteristics and clinical variables of the studies included were heterogeneous, and most participants were medicated. The present meta-analysis is, to our knowledge, the first to overcome previous inconsistencies in the VBM studies of LLD and provide robust evidence for grey matter alterations within fronto-striatal-limbic networks, thereby implicating them in the pathophysiology of LLD. The mean age and the percentage of female patients with LLD did not appear to have a measurable impact on grey matter changes, although we cannot rule out the contributory effects of medication.
TLR4 Methylation Moderates the Relationship Between Alcohol Use Severity and Gray Matter Loss.
Karoly, Hollis C; Thayer, Rachel E; Hagerty, Sarah L; Hutchison, Kent E
2017-09-01
Alcohol use disorders (AUDs) are associated with decreased gray matter, and neuroinflammation is one mechanism through which alcohol may confer such damage, given that heavy alcohol use may promote neural damage via activation of toll-like receptor 4 (TLR4)-mediated inflammatory signaling cascades. We previously demonstrated that TLR4 is differentially methylated in AUD compared with control subjects, and the present study aims to extend this work by examining whether TLR4 methylation moderates the relationship between alcohol use and gray matter. We examined TLR4 methylation and gray matter thickness in a large sample (N = 707; 441 males) of adults (ages 18-56) reporting a range of AUD severity (mean Alcohol Use Disorders Identification Test score = 13.18; SD = 8.02). We used a series of ordinary least squares multiple regression equations to regress gray matter in four bilateral brain regions (precuneus, lateral orbitofrontal, inferior parietal, and superior temporal) on alcohol use, TLR4 methylation, and their interaction, controlling for demographic, psychological, and other substance use variables. After we corrected for multiple tests, a significant Alcohol × TLR4 Methylation interaction emerged in the equations modeling left precuneus and right inferior parietal gray matter. Follow-up analyses examining the nature of these interactions demonstrated a significant negative association between alcohol and precuneus and inferior parietal gray matter in individuals with low TLR4 methylation, but no relationship between alcohol and gray matter in the high methylation group. These findings suggest that TLR4 methylation may be protective against the damage conferred by alcohol on precuneus and inferior parietal gray matter, thereby implicating TLR4 for further investigation as a possible AUD treatment target.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Walsh, L.E.
1993-08-04
In October and November 1986, two secret U.S. Government operations were publicly exposed, potentially implicating Reagan Administration officials in illegal activities. These operations were the provision of assistance to the military activities of the Nicaraguan contra rebels during an October 1984 to October 1986 prohibition on such aid, and the sale of U.S. arms to Iran in contravention of stated U.S. policy and in possible violation of arms-export controls. In late November 1986, Reagan Administration officials announced that some of the proceeds from the sale of U.S. arms to Iran had been diverted to the contras. As a result, Attorneymore » General Edwin Meese III sought the appointment of an independent counsel to investigate and prosecute possible crimes. Volume II contains indictments, plea agreements, interim reports to Congress and administrative matters from that investigation.« less
Tachyon cosmology with non-vanishing minimum potential: a unified model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Huiquan, E-mail: hqli@ustc.edu.cn
2012-07-01
We investigate the tachyon condensation process in the effective theory with non-vanishing minimum potential and its implications to cosmology. It is shown that the tachyon condensation on an unstable three-brane described by this modified tachyon field theory leads to lower-dimensional branes (defects) forming within a stable three-brane. Thus, in the cosmological background, we can get well-behaved tachyon matter after tachyon inflation, (partially) avoiding difficulties encountered in the original tachyon cosmological models. This feature also implies that the tachyon inflated and reheated universe is followed by a Chaplygin gas dark matter and dark energy universe. Hence, such an unstable three-brane behavesmore » quite like our universe, reproducing the key features of the whole evolutionary history of the universe and providing a unified description of inflaton, dark matter and dark energy in a very simple single-scalar field model.« less
Steketee, Rebecca M E; Meijboom, Rozanna; de Groot, Marius; Bron, Esther E; Niessen, Wiro J; van der Lugt, Aad; van Swieten, John C; Smits, Marion
2016-07-01
This study investigates regional coherence between white matter (WM) microstructure and gray matter (GM) volume and perfusion measures in Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) using a correlational approach. WM-GM coherence, compared with controls, was stronger between cingulum WM and frontotemporal GM in AD, and temporoparietal GM in bvFTD. In addition, in AD compared with controls, coherence was stronger between inferior fronto-occipital fasciculus WM microstructure and occipital GM perfusion. In this first study assessing regional WM-GM coherence in AD and bvFTD, we show that WM microstructure and GM volume and perfusion measures are coherent, particularly in regions implicated in AD and bvFTD pathology. This indicates concurrent degeneration in disease-specific networks. Our methodology allows for the detection of incipient abnormalities that go undetected in conventional between-group analyses. Copyright © 2016 Elsevier Inc. All rights reserved.
Facebook usage on smartphones and gray matter volume of the nucleus accumbens.
Montag, Christian; Markowetz, Alexander; Blaszkiewicz, Konrad; Andone, Ionut; Lachmann, Bernd; Sariyska, Rayna; Trendafilov, Boris; Eibes, Mark; Kolb, Julia; Reuter, Martin; Weber, Bernd; Markett, Sebastian
2017-06-30
A recent study has implicated the nucleus accumbens of the ventral striatum in explaining why online-users spend time on the social network platform Facebook. Here, higher activity of the nucleus accumbens was associated with gaining reputation on social media. In the present study, we touched a related research field. We recorded the actual Facebook usage of N=62 participants on their smartphones over the course of five weeks and correlated summary measures of Facebook use with gray matter volume of the nucleus accumbens. It appeared, that in particular higher daily frequency of checking Facebook on the smartphone was robustly linked with smaller gray matter volumes of the nucleus accumbens. The present study gives additional support for the rewarding aspects of Facebook usage. Moreover, it shows the feasibility to include real life behavior variables in human neuroscientific research. Copyright © 2017 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stöhr, J.; Scherz, A.
X-ray absorption by matter has long been described by the famous Beer-Lambert law. Here we show how this fundamental law needs to be modified for high-intensity coherent x-ray pulses, now available at x-ray free electron lasers, due to the onset of stimulated elastic forward scattering. We present an analytical expression for the modified polarization-dependent Beer-Lambert law for the case of resonant core-to-valence electronic transitions and incident transform limited x-ray pulses. Upon transmission through a solid, the absorption and dichroic contrasts are found to vanish with increasing x-ray intensity, with the stimulation threshold lowered by orders of magnitude through a super-radiativemore » coherent effect. Our results have broad implications for the study of matter with x-ray lasers.« less
Particle tagging and its implications for stellar population dynamics
NASA Astrophysics Data System (ADS)
Le Bret, Theo; Pontzen, Andrew; Cooper, Andrew P.; Frenk, Carlos; Zolotov, Adi; Brooks, Alyson M.; Governato, Fabio; Parry, Owen H.
2017-07-01
We establish a controlled comparison between the properties of galactic stellar haloes obtained with hydrodynamical simulations and with 'particle tagging'. Tagging is a fast way to obtain stellar population dynamics: instead of tracking gas and star formation, it 'paints' stars directly on to a suitably defined subset of dark matter particles in a collisionless, dark-matter-only simulation. Our study shows that 'live' particle tagging schemes, where stellar masses are painted on to the dark matter particles dynamically throughout the simulation, can generate good fits to the hydrodynamical stellar density profiles of a central Milky Way-like galaxy and its most prominent substructure. Energy diffusion processes are crucial to reshaping the distribution of stars in infalling spheroidal systems and hence the final stellar halo. We conclude that the success of any particular tagging scheme hinges on this diffusion being taken into account, and discuss the role of different subgrid feedback prescriptions in driving this diffusion.
Electromagnetic toroidal excitations in matter and free space.
Papasimakis, N; Fedotov, V A; Savinov, V; Raybould, T A; Zheludev, N I
2016-03-01
The toroidal dipole is a localized electromagnetic excitation, distinct from the magnetic and electric dipoles. While the electric dipole can be understood as a pair of opposite charges and the magnetic dipole as a current loop, the toroidal dipole corresponds to currents flowing on the surface of a torus. Toroidal dipoles provide physically significant contributions to the basic characteristics of matter including absorption, dispersion and optical activity. Toroidal excitations also exist in free space as spatially and temporally localized electromagnetic pulses propagating at the speed of light and interacting with matter. We review recent experimental observations of resonant toroidal dipole excitations in metamaterials and the discovery of anapoles, non-radiating charge-current configurations involving toroidal dipoles. While certain fundamental and practical aspects of toroidal electrodynamics remain open for the moment, we envision that exploitation of toroidal excitations can have important implications for the fields of photonics, sensing, energy and information.
Non-minimal derivative couplings of the composite metric
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heisenberg, Lavinia, E-mail: laviniah@kth.se
2015-11-01
In the context of massive gravity, bi-gravity and multi-gravity non-minimal matter couplings via a specific composite effective metric were investigated recently. Even if these couplings generically reintroduce the Boulware-Deser ghost, this composite metric is unique in the sense that the ghost reemerges only beyond the decoupling limit and the matter quantum loop corrections do not detune the potential interactions. We consider non-minimal derivative couplings of the composite metric to matter fields for a specific subclass of Horndeski scalar-tensor interactions. We first explore these couplings in the mini-superspace and investigate in which scenario the ghost remains absent. We further study thesemore » non-minimal derivative couplings in the decoupling-limit of the theory and show that the equation of motion for the helicity-0 mode remains second order in derivatives. Finally, we discuss preliminary implications for cosmology.« less
Non-minimal derivative couplings of the composite metric
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heisenberg, Lavinia; Department of Physics & The Oskar Klein Centre,AlbaNova University Centre, 10691 Stockholm
2015-11-04
In the context of massive gravity, bi-gravity and multi-gravity non-minimal matter couplings via a specific composite effective metric were investigated recently. Even if these couplings generically reintroduce the Boulware-Deser ghost, this composite metric is unique in the sense that the ghost reemerges only beyond the decoupling limit and the matter quantum loop corrections do not detune the potential interactions. We consider non-minimal derivative couplings of the composite metric to matter fields for a specific subclass of Horndeski scalar-tensor interactions. We first explore these couplings in the mini-superspace and investigate in which scenario the ghost remains absent. We further study thesemore » non-minimal derivative couplings in the decoupling-limit of the theory and show that the equation of motion for the helicity-0 mode remains second order in derivatives. Finally, we discuss preliminary implications for cosmology.« less
Cosmological moduli and the post-inflationary universe: A critical review
NASA Astrophysics Data System (ADS)
Kane, Gordon; Sinha, Kuver; Watson, Scott
2015-06-01
We critically review the role of cosmological moduli in determining the post-inflationary history of the universe. Moduli are ubiquitous in string and M-theory constructions of beyond the Standard Model physics, where they parametrize the geometry of the compactification manifold. For those with masses determined by supersymmetry (SUSY) breaking this leads to their eventual decay slightly before Big Bang nucleosynthesis (BBN) (without spoiling its predictions). This results in a matter dominated phase shortly after inflation ends, which can influence baryon and dark matter genesis, as well as observations of the cosmic microwave background (CMB) and the growth of large-scale structure. Given progress within fundamental theory, and guidance from dark matter and collider experiments, nonthermal histories have emerged as a robust and theoretically well-motivated alternative to a strictly thermal one. We review this approach to the early universe and discuss both the theoretical challenges and the observational implications.
Neutron Star Spin Measurements and Dense Matter with LOFT
NASA Technical Reports Server (NTRS)
Strohmayer, Tod
2011-01-01
Observations over the last decade with RXTE have begun to reveal the X-ray binary progenitors of the fastest spinning neutron stars presently known. Detection and study of the spin rates of binary neutron stars has important implications for constraining the nature of dense matter present in neutron star interiors, as both the maximum spin rate and mass for neutron stars is set by the equation of state. Precision pulse timing of accreting neutron star binaries can enable mass constraints. Particularly promIsing is the combination of the pulse and eclipse timing, as for example, in systems like Swift 11749.4-2807. With its greater sensitivity, LOFT will enable deeper searches for the spin periods of the neutron stars, both during persistent outburst intervals and thermonuclear X-ray bursts, and enable more precise modeling of detected pulsations. I will explore the anticipated impact of LOFT on spin measurements and its potential for constraining dense matter in neutron stars
Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold
NASA Astrophysics Data System (ADS)
Xu, Jingke; Shields, Emily; Calaprice, Frank; Westerdale, Shawn; Froborg, Francis; Suerfu, Burkhant; Alexander, Thomas; Aprahamian, Ani; Back, Henning O.; Casarella, Clark; Fang, Xiao; Gupta, Yogesh K.; Ianni, Aldo; Lamere, Edward; Lippincott, W. Hugh; Liu, Qian; Lyons, Stephanie; Siegl, Kevin; Smith, Mallory; Tan, Wanpeng; Kolk, Bryant Vande
2015-07-01
The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3 to 52 keVnr, covering the whole DAMA/LIBRA energy region for dark matter-Na scattering interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies but fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal.
Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Jingke; Shields, Emily; Calaprice, Frank
2015-07-01
The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3 to 52 keVnr, covering the whole DAMA/LIBRA energy region for dark matter-Na scattering interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies butmore » fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal.« less
Fibromyalgia interacts with age to change the brain☆☆☆
Ceko, Marta; Bushnell, M. Catherine; Fitzcharles, Mary-Ann; Schweinhardt, Petra
2013-01-01
Although brain plasticity in the form of gray matter increases and decreases has been observed in chronic pain, factors determining the patterns of directionality are largely unknown. Here we tested the hypothesis that fibromyalgia interacts with age to produce distinct patterns of gray matter differences, specifically increases in younger and decreases in older patients, when compared to age-matched healthy controls. The relative contribution of pain duration was also investigated. Regional gray matter was measured in younger (n = 14, mean age 43, range 29–49) and older (n = 14; mean age 55, range 51–60) female fibromyalgia patients and matched controls using voxel-based morphometry and cortical thickness analysis of T1-weighted magnetic resonance images. To examine their functional significance, gray matter differences were compared with experimental pain sensitivity. Diffusion-tensor imaging was used to assess whether white matter changed in parallel with gray matter, and resting-state fMRI was acquired to examine whether pain-related gray matter changes are associated with altered functional connectivity. Older patients showed exclusively decreased gray matter, accompanied by compromised white matter integrity. In contrast, younger patients showed exclusively gray matter increases, namely in the basal ganglia and insula, which were independent of pain duration. Associated white matter changes in younger patients were compatible with gray matter hypertrophy. In both age groups, structural brain alterations were associated with experimental pain sensitivity, which was increased in older patients but normal in younger patients. Whereas more pronounced gray matter decreases in the posterior cingulate cortex were related to increased experimental pain sensitivity in older patients, insular gray matter increases in younger patients correlated with lower pain sensitivity, possibly indicating the recruitment of endogenous pain modulatory mechanisms. This is supported by the finding that the insula in younger patients showed functional decoupling from an important pain-processing region, the dorsal anterior cingulate cortex. These results suggest that brain structure and function shift from being adaptive in younger to being maladaptive in older patients, which might have important treatment implications. PMID:24273710
Boosted dark matter and its implications for the features in IceCube HESE data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bhattacharya, Atri; Gandhi, Raj; Gupta, Aritra
2017-05-01
We study the implications of the premise that any new, relativistic, highly energetic neutral particle that interacts with quarks and gluons would create cascade-like events in the IceCube (IC) detector. Such events would be observationally indistinguishable from neutral current deep-inelastic (DIS) scattering events due to neutrinos. Consequently, one reason for deviations, breaks or excesses in the expected astrophysical power-law neutrino spectrum could be the flux of such a particle. Motivated by features in the recent 1347-day IceCube high energy starting event (HESE) data, we focus on particular boosted dark matter (χ) related realizations of this premise. Here, χ is assumedmore » to be much lighter than, and the result of, the slow decay of a massive scalar (φ ) which constitutes a major fraction of the Universe's dark matter (DM) . We show that this hypothesis, coupled with a standard power-law astrophysical neutrino flux is capable of providing very good fits to the present data, along with a possible explanation of other features in the HESE sample. These features include a) the paucity of events beyond ∼ 2 PeV b) a spectral feature resembling a dip or a spectral change in the 400 TeV–1 PeV region and c) an excess in the 50−100 TeV region. We consider two different boosted DM scenarios, and determine the allowed mass ranges and couplings for four different types of mediators (scalar, pseudoscalar, vector and axial-vector) which could connect the standard and dark sectors.We consider constraints from gamma-ray observations and collider searches. We find that the gamma-ray observations provide the most restrictive constraints, disfavouring the 1σ allowed parameter space from IC fits, while still being consistent with the 3σ allowed region. We also test our proposal and its implications against the (statistically independent) sample of six year through-going muon track data recently released by IceCube.« less
The Self-Liking Brain: A VBM Study on the Structural Substrate of Self-Esteem
Agroskin, Dmitrij; Klackl, Johannes; Jonas, Eva
2014-01-01
Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL), positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC), right lateral prefrontal cortex (LPFC), right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ), which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource. PMID:24489727
Searching for Dark Matter with Cosmic Rays
NASA Astrophysics Data System (ADS)
Seo, Eun-Suk
2015-04-01
One of the most exciting possibilities in cosmic ray research is the potential to discover new phenomena. A number of elementary particles were discovered in cosmic rays before modern-day accelerators became available to study their detailed properties. Since the discovery of cosmic ray antiprotons in 1979 using a balloon-borne magnet spectrometer, a series of magnet spectrometers have been flown to search for the signature of dark matter annihilation in antiprotons and positrons. Being the same as particles except for their opposite charge sign, antiparticles are readily distinguished as they bend in opposite directions in the magnetic field. As long-duration balloon flights over Antarctica became available, not only antiproton to proton ratios but also measurements of antiproton energy spectra became possible. More recently, space missions are also providing precision measurements of electron and position energy spectra. With other measurements to constrain cosmic ray propagation models, these new measurements play key roles in constraining dark-matter models for understanding the nature of dark matter. Recent results, their implications, and outlook for the field will be presented.
The self-liking brain: a VBM study on the structural substrate of self-esteem.
Agroskin, Dmitrij; Klackl, Johannes; Jonas, Eva
2014-01-01
Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL), positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC), right lateral prefrontal cortex (LPFC), right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ), which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource.
Latzman, Robert D.; Taglialatela, Jared P.; Hopkins, William D.
2015-01-01
Individual variability in delay of gratification (DG) is associated with a number of important outcomes in both non-human and human primates. Using diffusion tensor imaging (DTI), this study describes the relationship between probabilistic estimates of white matter tracts projecting from the caudate to the prefrontal cortex (PFC) and DG abilities in a sample of 49 captive chimpanzees (Pan troglodytes). After accounting for time between collection of DTI scans and DG measurement, age and sex, higher white matter connectivity between the caudate and right dorsal PFC was found to be significantly associated with the acquisition (i.e. training phase) but not the maintenance of DG abilities. No other associations were found to be significant. The integrity of white matter connectivity between regions of the striatum and the PFC appear to be associated with inhibitory control in chimpanzees, with perturbations on this circuit potentially leading to a variety of maladaptive outcomes. Additionally, results have potential translational implications for understanding the pathophysiology of a number of psychiatric and clinical outcomes in humans. PMID:26041344
Mastalerz, Maria; Hower, J.C.; Carmo, A.
1998-01-01
Protosalvinia from Devonian rocks in Kentucky has been analyzed using petrographic and in situ FTIR and flash pyrolysis/GC-MS techniques in order to discuss its origin and placement in organic matter classification. In reflected light, Protosalvinia resembles cutinite in shape, color and reflectance, whereas in fluorescent mode it reveals yellow-green fluorescence, reminiscent of alginite. Alkylbenzenes, alkylnaphthalenes, and n-alkanes are the principal compounds in the pyrolyzates, whereas alkylphenols and n-alk-l-enes are present in minor concentrations. FTIR results show that aliphatic bands (both in stretching and bending modes) are prominent. Protosalvinia also reveals well developed aromatic bands in the out-of-plane region. Such a mixture of aliphatic and aromatic components is not known in documented organic matter types of either marine or terrestrial origin. It is suggested that Protosalvinia might belong to rare marine organisms that yield aromatic pyrolyzates. Based on morphological features and optical properties Protosalvinia should be classified as a maceral of the liptinite group. It does not, however, fit precisely within any of the established categories of the liptinite macerals.Protosalvinia from Devonian rocks in Kentucky has been analyzed using petrographic and in situ FTIR and flash pyrolysis/GC-MS techniques in order to discuss its origin and placement in organic matter classification. In reflected light, Protosalvinia resembles cutinite in shape, color and reflectance, whereas in fluorescent mode it reveals yellow-green fluorescence, reminiscent of alginite. Alkylbenzenes, alkylnaphthalenes, and n-alkanes are the principal compounds in the pyrolyzates, whereas alkylphenols and n-alk-l-enes are present in minor concentrations. FTIR results show that aliphatic bands (both in stretching and bending modes) are prominent. Protosalvinia also reveals well developed aromatic bands in the out-of-plane region. Such a mixture of aliphatic and aromatic components is not known in documented organic matter types of either marine or terrestrial origin. It is suggested that Protosalvinia might belong to rare marine organisms that yield aromatic pyrolyzates. Based on morphological features and optical properties Protosalvinia should be classified as a maceral of the liptinite group. It does not, however, fit precisely within any of the established categories of the liptinite macerals.
Peters, Bart D; de Haan, Lieuwe; Vlieger, Erik-Jan; Majoie, Charles B; den Heeten, Gerard J; Linszen, Don H
2009-01-01
There is growing evidence that brain white matter abnormalities are implicated in the pathophysiology of schizophrenia. Cannabis use is an independent risk factor for schizophrenia.We tested the hypothesis that cannabis use during early adolescence is associated with white matter abnormalities in schizophrenia patients. Thirtyfive male recent-onset schizophrenia patients, with and without a history of cannabis use before age 17, and twenty-one matched healthy comparison men without illicit drug use were assessed with diffusion tensor imaging (DTI).White matter regions of interest were examined in co-registered DTI images. Compared to controls, patients with cannabis use before age 17 showed increased directional coherence in the bilateral uncinate fasciculus, anterior internal capsule and frontal white matter. These abnormalities were absent in patients without cannabis use before age 17. The abnormalities were not related to lifetime doses of cannabis or other illicit drugs.We could not exclude confounding effects of other illicit drugs. Recent-onset schizophrenia patients with start of cannabis use during early adolescence use may represent a subgroup of schizophrenia patients with increased white matter directional coherence, which may reflect structural hyperconnectivity. This is in contrast with most DTI studies in schizophrenia, which have produced evidence for hypoconnectivity. Further studies are necessary to assess the effect of adolescent cannabis and other illicit drug use on brain white matter in schizophrenia.
White Matter Development during Adolescence as Shown by Diffusion MRI
ERIC Educational Resources Information Center
Schmithorst, Vincent J.; Yuan, Weihong
2010-01-01
Previous volumetric developmental MRI studies of the brain have shown white matter development continuing through adolescence and into adulthood. This review presents current findings regarding white matter development and organization from diffusion MRI studies. The general trend during adolescence (age 12-18 years) is towards increasing…
Creed, Irena F; Bergström, Ann-Kristin; Trick, Charles G; Grimm, Nancy B; Hessen, Dag O; Karlsson, Jan; Kidd, Karen A; Kritzberg, Emma; McKnight, Diane M; Freeman, Erika C; Senar, Oscar E; Andersson, Agneta; Ask, Jenny; Berggren, Martin; Cherif, Mehdi; Giesler, Reiner; Hotchkiss, Erin R; Kortelainen, Pirkko; Palta, Monica M; Vrede, Tobias; Weyhenmeyer, Gesa A
2018-03-15
Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans. © 2018 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Watters, James J.; Ginns, Ian S.
1997-03-01
The implementation of effective science programmes in primary schools is of continuing interest and concern for professional developers. As part of the Australian Academy of science's approach to creating an awareness of Primary Investigations, a project team trialed a series of satellite television broadcasts of lessons related to two units of the curriculum for Year 3 and 4 children in 48 participating schools. The professional development project entitled Simply Science, included a focused component for the respective classroom teachers, which was also conducted by satellite. This paper reports the involvement of a Year 4 teacher in the project and describes her professional growth. Already an experienced and confident teacher, no quantitative changes in science teaching self efficacy were detected. However, her pedagogical content knowledge and confidence to teach science in the concept areas of matter and energy were enhanced. Changes in the teacher's views about the co-operative learning strategies espoused by Primary Investigations were also evident. Implications for the design of professional development programmes for primary science teachers are discussed.
Under Project No. WP-1538 of the Strategic Environmental Research and Development Program, the U. S. Air Force's Arnold Engineering Development Center (AEDC) is developing an interim test method for non-volatile particulate matter (PM) specifically for the Joint Strike Fighter (J...
Gestational age at birth and brain white matter development in term-born infants and children
USDA-ARS?s Scientific Manuscript database
Studies on infants and children born preterm have shown that adequate gestational length is critical for brain white matter development. Less is known regarding how variations in gestational age at birth in term infants and children affect white matter development, which was evaluated in this study....
Designing and Developing Technical Curriculum: Finding the Right Subject Matter Expert
ERIC Educational Resources Information Center
Mattoon, Joseph Sterling
2005-01-01
Subject matter experts play an essential role in technical curriculum development by providing accurate and up-to-date information that matches education, training, and workforce needs. The Subject Matter Expert (SME) COMlist is proposed as a tool that enables instructional developers to evaluate an SME's capability and suitability to support…
Kochunov, Peter; Ganjgahi, Habib; Winkler, Anderson; Kelly, Sinead; Shukla, Dinesh K; Du, Xiaoming; Jahanshad, Neda; Rowland, Laura; Sampath, Hemalatha; Patel, Binish; O'Donnell, Patricio; Xie, Zhiyong; Paciga, Sara A; Schubert, Christian R; Chen, Jian; Zhang, Guohao; Thompson, Paul M; Nichols, Thomas E; Hong, L Elliot
2016-12-01
Altered brain connectivity is implicated in the development and clinical burden of schizophrenia. Relative to matched controls, schizophrenia patients show (1) a global and regional reduction in the integrity of the brain's white matter (WM), assessed using diffusion tensor imaging (DTI) fractional anisotropy (FA), and (2) accelerated age-related decline in FA values. In the largest mega-analysis to date, we tested if differences in the trajectories of WM tract development influenced patient-control differences in FA. We also assessed if specific tracts showed exacerbated decline with aging. Three cohorts of schizophrenia patients (total n = 177) and controls (total n = 249; age = 18-61 years) were ascertained with three 3T Siemens MRI scanners. Whole-brain and regional FA values were extracted using ENIGMA-DTI protocols. Statistics were evaluated using mega- and meta-analyses to detect effects of diagnosis and age-by-diagnosis interactions. In mega-analysis of whole-brain averaged FA, schizophrenia patients had lower FA (P = 10 -11 ) and faster age-related decline in FA (P = 0.02) compared with controls. Tract-specific heterochronicity measures, that is, abnormal rates of adolescent maturation and aging explained approximately 50% of the regional variance effects of diagnosis and age-by-diagnosis interaction in patients. Interactive, three-dimensional visualization of the results is available at www.enigma-viewer.org. WM tracts that mature later in life appeared more sensitive to the pathophysiology of schizophrenia and were more susceptible to faster age-related decline in FA values. Hum Brain Mapp 37:4673-4688, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Naltrexone treatment reverses astrocyte atrophy and immune dysfunction in self-harming macaques
Lee, Kim M.; Chiu, Kevin B.; Didier, Peter J.; Baker, Kate C.; MacLean, Andrew G.
2015-01-01
The role of glia in the development and treatment of behavioral abnormalities is understudied. Recent reports have observed glial activation in several disorders, including depression, autism spectrum disorders and self-injurious behaviors (SIB). In the current study, we examined SIB in the physiologically and anatomically relevant nonhuman primate (NHP) model. At the Tulane National Primate Research Center (TNPRC), approximately 5% of singly housed macaques develop symptoms of SIB. We have previously demonstrated that naltrexone hydrochloride can be effective in reducing SIB. We have also demonstrated that the astrocytes of animals with SIB are distinctly atrophic and display heightened innate immune activation compared with control animals. We have added a third group of animals (five macaques identified with SIB and treated with oral naltrexone at a dose of 3.2 mg/kg) to the previous cohort (six macaques with a history of SIB but not treated, and nine animals with no history of SIB) for this study. Gray and white matter astrocytes from frontal cortical tissue were examined following necropsy. Innate immune activation of astrocytes, which was increased in SIB animals, was markedly decreased in animals receiving naltrexone, as was atrophy of both grey and white matter astrocytes. This was concomitant with improved behavioral correlates. Preventing astrocyte activation in select areas of the brain to reduce injurious behavior is an innovative concept with implications for mental health studies. Differences in multiple areas of primate brain would help determine how self-injurious behavior develops. These studies suggest a stronger role for astrocytes in the cellular events associated with self-injurious behaviors. PMID:26191654
Naltrexone treatment reverses astrocyte atrophy and immune dysfunction in self-harming macaques.
Lee, Kim M; Chiu, Kevin B; Didier, Peter J; Baker, Kate C; MacLean, Andrew G
2015-11-01
The role of glia in the development and treatment of behavioral abnormalities is understudied. Recent reports have observed glial activation in several disorders, including depression, autism spectrum disorders and self-injurious behaviors (SIB). In the current study, we examined SIB in the physiologically and anatomically relevant nonhuman primate (NHP) model. At the Tulane National Primate Research Center (TNPRC), approximately 5% of singly housed macaques develop symptoms of SIB. We have previously demonstrated that naltrexone hydrochloride can be effective in reducing SIB. We have also demonstrated that the astrocytes of animals with SIB are distinctly atrophic and display heightened innate immune activation compared with control animals. We have added a third group of animals (five macaques identified with SIB and treated with oral naltrexone at a dose of 3.2mg/kg) to the previous cohort (six macaques with a history of SIB but not treated, and nine animals with no history of SIB) for this study. Gray and white matter astrocytes from frontal cortical tissue were examined following necropsy. Innate immune activation of astrocytes, which was increased in SIB animals, was markedly decreased in animals receiving naltrexone, as was atrophy of both grey and white matter astrocytes. This was concomitant with improved behavioral correlates. Preventing astrocyte activation in select areas of the brain to reduce injurious behavior is an innovative concept with implications for mental health studies. Differences in multiple areas of primate brain would help determine how self-injurious behavior develops. These studies suggest a stronger role for astrocytes in the cellular events associated with self-injurious behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.
From Vision to the Implementation of the U.S. National Nanotechnology Initiative
NASA Astrophysics Data System (ADS)
Roco, M. C.
2001-02-01
All natural and living systems are governed by atomic and molecular behavior at the nanoscale. Research is now seeking systematic approaches to create revolutionary new products and technologies by control of matter at the same scale. Fundamental discoveries and potential implications of nanotechnology to wealth, health and peace have captured the imagination of scientists, industry and government experts. The National Nanotechnology Initiative (NNI) has become a top national priority in science and technology in U.S. for fiscal year 2001, with a Federal nanotechnology investment portfolio of 422 million. Nanotechnology is expected to have a profound impact on our economy and society in the earlier 21st century. The vision, research and development strategy, and timeline of NNI are presented by using several recent scientific discoveries and results from industry.
Investigating the Equatorial Gaps in Snowball Earth Sea Glaciers
NASA Astrophysics Data System (ADS)
Spaulding-Astudillo, F.; Ashkenazy, Y.; Tziperman, E.; Abbot, D. S.
2017-12-01
The way photosynthetic life survived the Neoproterozoic Snowball Earth events is still a matter of debate that has deep implications for planetary habitability. One option is that gaps in thick, semi-global ice coverage (sea glaciers) could be maintained at the equator by ocean-ice-atmosphere dynamics. We investigate this idea by modifying a global ocean-thick-marine-ice model developed for modeling Neoproterozoic Snowball Events to account for gaps in thick ice and interactions with atmospheric dynamics. Our hypothesis is that in the parameter regime that allows for sea glacier flow, ice flow will make gaps in the thick ice, and therefore an open ocean solution, less likely. This would suggest that oases in thick ice are a more viable survival mechanism for photosynthetic life during a Snowball Earth event.
Occupational health and safety of merchant seafarers from Kiribati and Tuvalu.
Borovnik, Maria
2011-01-01
Intensifying international competition in the shipping industry in response to global pressures makes seafarers' jobs increasingly difficult. Challenging conditions in ship employment are problematic, particularly in a development context where home communities' dependence on seafarers' income is high and social protection is low. Qualitative fieldwork revealed that seafarers from Kiribati and Tuvalu endure exceptionally lengthy work periods at sea to remain competitive. Absence from home while working in constrained and mobile spaces with multinational crews, frequent security controls and speedy turnarounds impacting on sleep deprivation and decreased shore time have implications for physical and emotional health and can become safety matters. Hence, there is a growing need to address mechanisms to protect seafarers from the physical and emotional effects of global demands in the shipping industry.
NASA Technical Reports Server (NTRS)
Sekanina, Z.
1976-01-01
The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of evolution. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tail is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.
NASA Technical Reports Server (NTRS)
Sekanina, Z.
1977-01-01
The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of the evolution of cometary dust. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tails is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.
Li, Han; Wan, Yanjian; Chen, Xiao; Cheng, Lu; Yang, Xueyu; Xia, Wei; Xu, Shunqing; Zhang, Hongling
2018-05-01
Nickel is a widespread environmental contaminant, and it is toxic to humans in certain forms at high doses. Despite this, nationwide data on nickel in outdoor air particulate matter and human exposure to nickel through inhalation in China are limited. In the present study, 662 outdoor air samples from seven representative provinces such as Shanghai, Hubei, Hunan, Hebei, Guangdong, Yunnan, and Shanxi were collected between March 2013 and February 2014 and analyzed by inductively coupled plasma mass spectrometry. The concentrations of nickel in the air were in the range of 2.1-80.9 ng/m 3 (geometric mean: 14.4 ng/m 3 ). In most areas, the concentrations of nickel were higher in winter and spring than those measured in summer and autumn. The daily intake (median) of nickel through inhalation of air particulate matter was estimated. Although the nickel concentrations in some air samples were high, inhalation of the air particulate matter accounted for a minor part of the total nickel intake; however, the adverse effects of human exposure to nickel through inhalation and its potential sources require more attention, particularly in Shanghai. This is a multiregional survey of nickel in outdoor air particulate matter in China. Copyright © 2018 Elsevier Ltd. All rights reserved.
Harrison, Daniel M; Oh, Jiwon; Roy, Snehashis; Wood, Emily T; Whetstone, Anna; Seigo, Michaela A; Jones, Craig K; Pham, Dzung; van Zijl, Peter; Reich, Daniel S; Calabresi, Peter A
2015-08-01
Pathology in both cortex and deep gray matter contribute to disability in multiple sclerosis (MS). We used the increased signal-to-noise ratio of 7-tesla (7T) MRI to visualize small lesions within the thalamus and to relate this to clinical information and cortical lesions. We obtained 7T MRI scans on 34 MS cases and 15 healthy volunteers. Thalamic lesion number and volume were related to demographic data, clinical disability measures, and lesions in cortical gray matter. Thalamic lesions were found in 24/34 of MS cases. Two lesion subtypes were noted: discrete, ovoid lesions, and more diffuse lesional areas lining the periventricular surface. The number of thalamic lesions was greater in progressive MS compared to relapsing-remitting (mean ±SD, 10.7 ±0.7 vs. 3.0 ±0.7, respectively, p < 0.001). Thalamic lesion burden (count and volume) correlated with EDSS score and measures of cortical lesion burden, but not with white matter lesion burden or white matter volume. Using 7T MRI allows identification of thalamic lesions in MS, which are associated with disability, progressive disease, and cortical lesions. Thalamic lesion analysis may be a simpler, more rapid estimate of overall gray matter lesion burden in MS. © The Author(s), 2015.
Semiclassical black holes expose forbidden charges and censor divergent densities
NASA Astrophysics Data System (ADS)
Brustein, Ram; Medved, A. J. M.
2013-09-01
Classically, the horizon of a Schwarzschild black hole (BH) is a rigid surface of infinite redshift; whereas the uncertainty principle dictates that the semiclassical (would-be) horizon cannot be fixed in space nor can it exhibit any divergences. We propose that this distinction underlies the BH information-loss paradox, the apparent absence of BH hair, the so-called trans-Planckian problem and the recent "firewall" controversy. We argue that the correct prescription is to first integrate out the fluctuations of the background geometry and only then evaluate matter observables. The basic idea is illustrated using a system of two strongly coupled harmonic oscillators, with the heavier oscillator representing the background. We then apply our proposal to matter fields near a BH horizon, initially treating the matter fields as classical and the background as semiclassical. In this case, the average value of the associated current does not vanish; so that it is possible, in pr inciple, to measure the global charge of the BH. Then the matter is, in addition to the background, treated quantum mechanically. We show that the average energy density of matter as seen by an asymptotic observer is finite and proportional to the BH entropy, rather than divergent. We discuss the implications of our results for the various controversial issues concerning BH physics.
NASA Astrophysics Data System (ADS)
Lin, Yangting; El Goresy, Ahmed; Hu, Sen; Zhang, Jianchao; Gillet, Philippe; Xu, Yuchen; Hao, Jialong; Miyahara, Masaaki; Ouyang, Ziyuan; Ohtani, Eiji; Xu, Lin; Yang, Wei; Feng, Lu; Zhao, Xuchao; Yang, Jing; Ozawa, Shin
2014-12-01
Two petrographic settings of carbonaceous components, mainly filling open fractures and occasionally enclosed in shock-melt veins, were found in the recently fallen Tissint Martian meteorite. The presence in shock-melt veins and the deuterium enrichments (δD up to +1183‰) of these components clearly indicate a pristine Martian origin. The carbonaceous components are kerogen-like, based on micro-Raman spectra and multielemental ratios, and were probably deposited from fluids in shock-induced fractures in the parent rock of Tissint. After precipitation of the organic matter, the rock experienced another severe shock event, producing the melt veins that encapsulated a part of the organic matter. The C isotopic compositions of the organic matter (δ13C = -12.8 to -33.1‰) are significantly lighter than Martian atmospheric CO2 and carbonate, providing a tantalizing hint for a possible biotic process. Alternatively, the organic matter could be derived from carbonaceous chondrites, as insoluble organic matter from the latter has similar chemical and isotopic compositions. The presence of organic-rich fluids that infiltrated rocks near the surface of Mars has significant implications for the study of Martian paleoenvironment and perhaps to search for possible ancient biological activities on Mars.
NASA Astrophysics Data System (ADS)
Tucker, Wallace H.
2017-03-01
On July 23, 1999, the Chandra X-Ray Observatory, the most powerful X-ray telescope ever built, was launched aboard the space shuttle Columbia. Since then, Chandra has given us a view of the universe that is largely hidden from telescopes sensitive only to visible light. In Chandra's Cosmos, the Smithsonian Astrophysical Observatory's Chandra science spokesperson Wallace H. Tucker uses a series of short, connected stories to describe the telescope's exploration of the hot, high-energy face of the universe. The book is organized in three parts: "The Big," covering the cosmic web, dark energy, dark matter, and massive clusters of galaxies; "The Bad," exploring neutron stars, stellar black holes, and supermassive black holes; and "The Beautiful," discussing stars, exoplanets, and life. Chandra has imaged the spectacular, glowing remains of exploded stars and taken spectra showing the dispersal of their elements. Chandra has observed the region around the supermassive black hole in the center of our Milky Way and traced the separation of dark matter from normal matter in the collision of galaxies, contributing to both dark matter and dark energy studies. Tucker explores the implications of these observations in an entertaining, informative narrative aimed at space buffs and general readers alike.
NASA Astrophysics Data System (ADS)
Nico, P. S.
2015-12-01
Interactions between naturally occurring organic matter and minerals surfaces play a determining role on the transport, chemical composition, and bio-availability of reduced carbon. These processes are controlled on the molecular scale by mineral dissolution and precipitation dynamics which are in turn controlled by both changing solution chemistry and redox regime. The presentation will highlight recent work by our group and others on elucidating some of these mechanisms with particular emphasis on the impacts of redox cycling and Fe mineral transformation. We are particular interested in how the form of organic matter impacts the formation and transformation of iron minerals and vis-a-versa under fluctuating redox conditions, and how that in turn impacts the transport of other elements controlled by Fe surfaces, e.g. uranium. In two different field conditions, in a ground water well and at a ground water-surface water interface, Fe(II) was oxidized in an organic rich environment leading to different types of Fe-organic matter co-precipitates. We followed the evolution of those participates under a return to reduced conditions in order to understand the transformations, or lack thereof, of the Fe minerals and the fate of the associated organic matter.
ERIC Educational Resources Information Center
Nokia, Miriam S.; Waselius, Tomi; Mikkonen, Jarno E.; Wikgren, Jan; Penttonen, Markku
2015-01-01
Hippocampal ? (3-12 Hz) oscillations are implicated in learning and memory, but their functional role remains unclear. We studied the effect of the phase of local ? oscillation on hippocampal responses to a neutral conditioned stimulus (CS) and subsequent learning of classical trace eyeblink conditioning in adult rabbits. High-amplitude, regular…
Masked Phonological Priming Effects in English: Are They Real? Do They Matter?
ERIC Educational Resources Information Center
Rastle, Kathleen; Brysbaert, Marc
2006-01-01
For over 15 years, masked phonological priming effects have been offered as evidence that phonology plays a leading role in visual word recognition. The existence of these effects--along with their theoretical implications--has, however, been disputed. The authors present three sources of evidence relevant to an assessment of the existence and…
Immigrant Students in the Trump Era: What We Know and Do Not Know
ERIC Educational Resources Information Center
Nguyen, Chi; Kebede, Maraki
2017-01-01
The 2016 U.S. presidential election marked a time of deep political divide for the nation and resulted in an administrative transition that represented a drastic shift in values and opinions on several matters, including immigration. This article explores the implications of this political transition for immigrants' K-16 educational experiences…
ERIC Educational Resources Information Center
Kolano, Lan Quach; Dávila, Liv Thorstensson; Lachance, Joan; Coffey, Heather
2014-01-01
Numerous studies show that mainstream classroom teachers still remain inadequately prepared to teach diverse students and lack the knowledge base and skills to teach English language learners (ELLs). This has profound implications, particularly in the Southeast, where the rate of school-aged Latino immigrants has grown significantly. Thus, this…
ERIC Educational Resources Information Center
Buchsbaum, Bradley R.; Baldo, Juliana; Okada, Kayoko; Berman, Karen F.; Dronkers, Nina; D'Esposito, Mark; Hickok, Gregory
2011-01-01
Conduction aphasia is a language disorder characterized by frequent speech errors, impaired verbatim repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of otherwise fluent and grammatical speech output. While traditional models of conduction aphasia have typically implicated white matter pathways,…
ERIC Educational Resources Information Center
Oliveira, Cecilia Helena Lorenzini de Salles
1998-01-01
Brings a different reading of 1824's Brazilian Imperial Political Constitution. Discusses some historical and political circumstances of the document's construction. Investigates practices, conceptions, and supports that could have clarified some principles stressed by the document, especially those related to citizenship matters. (PA)
The Impact of "Hazelwood" on the Student Press in Public Higher Education.
ERIC Educational Resources Information Center
Janosik, Steven M.; Sina, Julie A.
1991-01-01
Examines the findings in Hazelwood School District v. Kuhlmeir and discusses their implications for the future of the student press in public higher education. Recommends that the relationship between the institution and the newspaper should be a matter of policy and that the policy and its accompanying procedures or standards should be clarified…
Peer Effects and Human Capital Accumulation: the Externalities of ADD. NBER Working Paper No. 14354
ERIC Educational Resources Information Center
Aizer, Anna
2008-01-01
Although recent work has shown that peers affect human capital accumulation, the mechanisms are not well understood. Knowing why high achieving peers matter, because of their innate ability, disciplined behavior or some other factor, has important implications for our understanding of the education production function and for how we organize…
Not Just Any Path: Implications of Identity-Based Motivation for Disparities in School Outcomes
ERIC Educational Resources Information Center
Oyserman, Daphna
2013-01-01
Low-income and minority children aspire to school success and expect to attend college. These aspirations and expectations matter--predicting college attendance and graduation when present and failure to attend college otherwise. But aspiring to college does not necessarily result in relevant behavior; many children with high aspirations do not…
ERIC Educational Resources Information Center
Ram, Rajesh; France, Bev; Birdsall, Sally
2016-01-01
Background: Research on biosecurity is important as New Zealand's agricultural export-driven economy is susceptible to biosecurity threats. Because New Zealand is reliant on the primary industries to drive its economy, bovine diseases such as foot and mouth could have a devastating effect on the economy. Purpose: Making sure that the general…
Does Time-on-Task Estimation Matter? Implications for the Validity of Learning Analytics Findings
ERIC Educational Resources Information Center
Kovanovic, Vitomir; Gaševic, Dragan; Dawson, Shane; Joksimovic, Srecko; Baker, Ryan S.; Hatala, Marek
2015-01-01
With\twidespread adoption of Learning Management Systems (LMS) and other learning technology, large amounts of data--commonly known as trace data--are readily accessible to researchers. Trace data has been extensively used to calculate time that students spend on different learning activities--typically referred to as time-on-task. These measures…
Teaching Chemistry in Primary Science: What Does the Research Suggest?
ERIC Educational Resources Information Center
Skamp, Keith
2011-01-01
The new Australian national science curriculum includes chemistry content at the primary level. Chemistry for young students is learning about changes in material stuff (matter) and, by implication, of what stuff is made. Pedagogy in this area needs to be guided by research if stepping stones to later learning of chemical ideas are to facilitate…
USDA-ARS?s Scientific Manuscript database
Long-term soil conservation management decreases soil bulk density, increases water infiltration and water holding capacity. In the Virginia Coastal Plain, growers have been practicing rotational no-tillage and continuous no-tillage with and without biosolid application over 20 years to improve soi...
Fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., fire emissions can account for more than 30% of total PM2.5 emissions annually. In order to represent the influence of fire emission...
Language Ability of Young English Language Learners: Definition, Configuration, and Implications
ERIC Educational Resources Information Center
Gu, Lin
2015-01-01
In this study I examined the dimensionality of the latent ability underlying language use that is needed to fulfill the demands young learners face in English-medium instructional environments, where English is used as the means of instruction for teaching subject matters. Previous research on English language use by school-age children provided…
What Do Studies of the Brain Tell Us about Learning?
ERIC Educational Resources Information Center
Harlen, Wynne
2010-01-01
Until the 1990s, the inside of the brain was a matter of mystery to all except the few, the brain surgeons, revered for their specialist knowledge. Early work was focused on explaining and attempting to treat unusual behaviours and conditions, but interest now extends to the implications of neuroscience for regular education. Non-intrusive imaging…
USDA-ARS?s Scientific Manuscript database
Extreme weather events such as severe droughts and heat waves may have permanent consequences on soil quality and functioning in agroecosystems. The Southern High Plains (SHP) region of Texas, U.S., a large cotton producing area, experienced a historically extreme drought and heat wave during 2011,...
The African Ethic of "Ubuntu/Botho": Implications for Research on Morality
ERIC Educational Resources Information Center
Metz, Thaddeus; Gaie, Joseph B. R.
2010-01-01
In this article we provide a theoretical reconstruction of sub-Saharan ethics that we argue is a strong competitor to typical Western approaches to morality. According to our African moral theory, actions are right roughly insofar as they are a matter of living harmoniously with others or honouring communal relationships. After spelling out this…
Does Knowledge Matter? Disciplinary Identities and Students' Readiness for University
ERIC Educational Resources Information Center
McPhail, Graham J.
2017-01-01
There is no doubt cultural and technological changes in the late 20th century and beyond have had profound effects on what counts as knowledge and what knowledge counts both at school and at university. This paper considers some implications of a disjuncture identified by Gould ("The New Zealand Herald," 2010) between the curricula and…
Non-absorbable mesoporous silica for the development of protein sequestration therapies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garcia-Bennett, Alfonso E., E-mail: alf.garcia@mq.edu.au; Ballell, Lluis, E-mail: lluis.p.ballell@gsk.com
While our understanding of the molecular events leading to disease onset and progression have increased exponentially, our capacity to therapeutically intervene in these events with new chemical diversity has clearly fallen short of that pace. In the quest to readdress this situation, the drug discovery sector is slowly but increasingly exploring sources of alternative chemical matter, such as the ones provided by material science and nanotechnology. While new functional nano-sized materials hold great promise for the future, our lack of understanding of the long term safety implications associated with systemic exposure as well as the unclear regulatory path ahead hampermore » their present impact in drug development. Paradoxically, the exploitation of novel, functionally active micron-sized, synthetic, non-absorbable chemical matter, for the treatment or prevention of a number of epidemiologically significant conditions remains clearly underexplored. A combination of pre-existing evidence and future potential indicates that micron-sized mesoporous silica materials could be an untapped source of new drug candidates. These are free from both the dreaded high attrition associated with small molecule drug discovery and the uncertainties of nano-size technologies. This, together with the coming of age of synthetic methodologies to control particle size and shape; pore size and geometry; surface chemistry, bioconjugation and formulation, open up exciting possibilities to exploit this novel chemistry-biology therapeutic interface. - Highlights: • The development of functionally active micron-sized particles in medicine is underexplored. • Mesoporous materials offer the advantage of nanostructured particles in the micron size. • Non-absorbable drugs based on such particles for enzyme inhibition are being developed. • Several conditions can be targeted such as obesity, sepsis or celiac disease.« less
van Ewijk, Hanneke; Groenman, Annabeth P; Zwiers, Marcel P; Heslenfeld, Dirk J; Faraone, Stephen V; Hartman, Catharina A; Luman, Marjolein; Greven, Corina U; Hoekstra, Pieter J; Franke, Barbara; Buitelaar, Jan; Oosterlaan, Jaap
2015-03-01
Brain white matter (WM) tracts, playing a vital role in the communication between brain regions, undergo important maturational changes during adolescence and young adulthood, a critical period for the development of nicotine dependence. Attention-deficit/hyperactivity disorder (ADHD) is associated with increased smoking and widespread WM abnormalities, suggesting that the developing ADHD brain might be especially vulnerable to effects of smoking. This study aims to investigate the effect of smoking on (WM) microstructure in adolescents and young adults with and without ADHD. Diffusion tensor imaging was performed in an extensively phenotyped sample of nonsmokers (n = 95, 50.5% ADHD), irregular smokers (n = 41, 58.5% ADHD), and regular smokers (n = 50, 82.5% ADHD), aged 14-24 years. A whole-brain voxelwise approach investigated associations of smoking, ADHD and their interaction, with WM microstructure as measured by fractional anisotropy (FA) and mean diffusivity (MD). Widespread alterations in FA and MD were found for regular smokers compared to irregular and nonsmokers, mainly located in the corpus callosum and WM tracts surrounding the basal ganglia. Several regions overlapped with regions of altered FA for ADHD versus controls, albeit in different directions. Irregular and nonsmokers did not differ, and ADHD and smoking did not interact. Results implicate that smoking and ADHD have independent effects on WM microstructure, and possibly do not share underlying mechanisms. Two mechanisms may play a role in the current results. First, smoking may cause alterations in WM microstructure in the maturing brain. Second, pre-existing WM microstructure differences possibly reflect a risk factor for development of a smoking addiction. © 2014 Wiley Periodicals, Inc.
Mapping White Matter Microstructure in the One Month Human Brain.
Dean, D C; Planalp, E M; Wooten, W; Adluru, N; Kecskemeti, S R; Frye, C; Schmidt, C K; Schmidt, N L; Styner, M A; Goldsmith, H H; Davidson, R J; Alexander, A L
2017-08-29
White matter microstructure, essential for efficient and coordinated transmission of neural communications, undergoes pronounced development during the first years of life, while deviations to this neurodevelopmental trajectory likely result in alterations of brain connectivity relevant to behavior. Hence, systematic evaluation of white matter microstructure in the normative brain is critical for a neuroscientific approach to both typical and atypical early behavioral development. However, few studies have examined the infant brain in detail, particularly in infants under 3 months of age. Here, we utilize quantitative techniques of diffusion tensor imaging and neurite orientation dispersion and density imaging to investigate neonatal white matter microstructure in 104 infants. An optimized multiple b-value diffusion protocol was developed to allow for successful acquisition during non-sedated sleep. Associations between white matter microstructure measures and gestation corrected age, regional asymmetries, infant sex, as well as newborn growth measures were assessed. Results highlight changes of white matter microstructure during the earliest periods of development and demonstrate differential timing of developing regions and regional asymmetries. Our results contribute to a growing body of research investigating the neurobiological changes associated with neurodevelopment and suggest that characteristics of white matter microstructure are already underway in the weeks immediately following birth.
Cosmological implications of Dark Matter bound states
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mitridate, Andrea; Redi, Michele; Smirnov, Juri
2017-05-01
We present generic formulæ for computing how Sommerfeld corrections together with bound-state formation affects the thermal abundance of Dark Matter with non-abelian gauge interactions. We consider DM as a fermion 3plet (wino) or 5plet under SU(2) {sub L} . In the latter case bound states raise to 11.5 TeV the DM mass required to reproduce the cosmological DM abundance and give indirect detection signals such as (for this mass) a dominant γ-line around 70 GeV. Furthermore, we consider DM co-annihilating with a colored particle, such as a squark or a gluino, finding that bound state effects are especially relevant inmore » the latter case.« less
Mazerolle, Erin L; D'Arcy, Ryan CN; Beyea, Steven D
2008-01-01
Background It is generally believed that activation in functional magnetic resonance imaging (fMRI) is restricted to gray matter. Despite this, a number of studies have reported white matter activation, particularly when the corpus callosum is targeted using interhemispheric transfer tasks. These findings suggest that fMRI signals may not be neatly confined to gray matter tissue. In the current experiment, 4 T fMRI was employed to evaluate whether it is possible to detect white matter activation. We used an interhemispheric transfer task modelled after neurological studies of callosal disconnection. It was hypothesized that white matter activation could be detected using fMRI. Results Both group and individual data were considered. At liberal statistical thresholds (p < 0.005, uncorrected), group level activation was detected in the isthmus of the corpus callosum. This region connects the superior parietal cortices, which have been implicated previously in interhemispheric transfer. At the individual level, five of the 24 subjects (21%) had activation clusters that were located primarily within the corpus callosum. Consistent with the group results, the clusters of all five subjects were located in posterior callosal regions. The signal time courses for these clusters were comparable to those observed for task related gray matter activation. Conclusion The findings support the idea that, despite the inherent challenges, fMRI activation can be detected in the corpus callosum at the individual level. Future work is needed to determine whether the detection of this activation can be improved by utilizing higher spatial resolution, optimizing acquisition parameters, and analyzing the data with tissue specific models of the hemodynamic response. The ability to detect white matter fMRI activation expands the scope of basic and clinical brain mapping research, and provides a new approach for understanding brain connectivity. PMID:18789154
NASA Astrophysics Data System (ADS)
Hossain, H. M. Z.; Sampei, Y.; Kawahata, H.
2016-12-01
The distribution, source, and redox variation of sedimentary organic matter in the Andaman Sea is significant for understanding its biogeochemical cycle, which we determined the total organic carbon (TOC), total nitrogen (TN), and n-alkanes contents. TOC and TN concentrations varied from 0.61 to 1.18 wt.% (average 0.87 wt.%) and 0.07 to 0.17 wt.% (average 0.13 wt.%), respectively with high TOC in the clay-rich sediments indicate hydrodynamic sorting readily controlled TOC abundances. Bulk C/N ratio (5.51 to 11.92, average 7.89) is attributed to the high inputs of organic matter from planktonic sources and an appreciable amounts of terrestrial derived organic matter. n-Alkane distributions from the Andaman Sea sediment cores are characterized mainly by C17 to C35, with odd-over-even predominance suggest a diverse origin of organic matter. High relative abundances of mid-chain n-alkanes of C23 and C25 recorded in the samples that are characteristically derived from submerges/floating aquatic macrophytes. However, odd long-chain n-alkanes from C27 to C33 with high peaks at C29 and C31 were detected in the samples reflecting a terrigenous origin of organic matter. The average chain length (ACL), carbon preference index (CPI), Paq and Pwax ratio values further suggested that major influence of organic matter from non-emergent aquatic macrophytes together significant proportions of grasses and herbs. Low Pr/Ph and Tm/Ts ratios in most section implying a more reducing to suboxic conditions prevailed during organic matter preservation in the oceanic event. However, high ACL values and low Paq values in the down-core variation could suggest initially cold and dry climates and gradually shifted to warm and humid conditions.
Beyond minimal lepton-flavored Dark Matter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Mu-Chun; Huang, Jinrui; Takhistov, Volodymyr
In this paper ,we consider a class of flavored dark matter (DM) theories where dark matter interacts with the Standard Model lepton fields at the renormalizable level. We allow for a general coupling matrix between the dark matter and leptons whose structure is beyond the one permitted by the minimal flavor violation (MFV) assumption. It is assumed that this is the only new source of flavor violation in addition to the Standard Model (SM) Yukawa interactions. The setup can be described by augmenting the SM flavor symmetry by an additional SU(3) χ, under which the dark matter χ transforms. Thismore » framework is especially phenomenologically rich, due to possible novel flavor-changing interactions which are not present within the more restrictive MFV framework. As a representative case study of this setting, which we call “beyond MFV” (BMFV), we consider Dirac fermion dark matter which transforms as a singlet under the SM gauge group and a triplet under SU(3) χ. The DM fermion couples to the SM lepton sector through a scalar mediator Φ. Unlike the case of quark-flavored DM, we show that there is no Z 3 symmetry within either the MFV or BMFV settings which automatically stabilizes the lepton-flavored DM. We discuss constraints on this setup from flavor-changing processes, DM relic abundance as well as direct and indirect detections. We find that relatively large flavor-changing couplings are possible, while the dark matter mass is still within the phenomenologically interesting region below the TeV scale. Collider signatures which can be potentially searched for at the lepton and hadron colliders are discussed. Finally, we discuss the implications for decaying dark matter, which can appear if an additional stabilizing symmetry is not imposed.« less
Beyond minimal lepton-flavored Dark Matter
Chen, Mu-Chun; Huang, Jinrui; Takhistov, Volodymyr
2016-02-09
In this paper ,we consider a class of flavored dark matter (DM) theories where dark matter interacts with the Standard Model lepton fields at the renormalizable level. We allow for a general coupling matrix between the dark matter and leptons whose structure is beyond the one permitted by the minimal flavor violation (MFV) assumption. It is assumed that this is the only new source of flavor violation in addition to the Standard Model (SM) Yukawa interactions. The setup can be described by augmenting the SM flavor symmetry by an additional SU(3) χ, under which the dark matter χ transforms. Thismore » framework is especially phenomenologically rich, due to possible novel flavor-changing interactions which are not present within the more restrictive MFV framework. As a representative case study of this setting, which we call “beyond MFV” (BMFV), we consider Dirac fermion dark matter which transforms as a singlet under the SM gauge group and a triplet under SU(3) χ. The DM fermion couples to the SM lepton sector through a scalar mediator Φ. Unlike the case of quark-flavored DM, we show that there is no Z 3 symmetry within either the MFV or BMFV settings which automatically stabilizes the lepton-flavored DM. We discuss constraints on this setup from flavor-changing processes, DM relic abundance as well as direct and indirect detections. We find that relatively large flavor-changing couplings are possible, while the dark matter mass is still within the phenomenologically interesting region below the TeV scale. Collider signatures which can be potentially searched for at the lepton and hadron colliders are discussed. Finally, we discuss the implications for decaying dark matter, which can appear if an additional stabilizing symmetry is not imposed.« less
Grey matter correlates of susceptibility to scams in community-dwelling older adults.
Duke Han, S; Boyle, Patricia A; Yu, Lei; Arfanakis, Konstantinos; James, Bryan D; Fleischman, Debra A; Bennett, David A
2016-06-01
Susceptibility to scams is a significant issue among older adults, even among those with intact cognition. Age-related changes in brain macrostructure may be associated with susceptibility to scams; however, this has yet to be explored. Based on previous work implicating frontal and temporal lobe functioning as important in decision making, we tested the hypothesis that susceptibility to scams is associated with smaller grey matter volume in frontal and temporal lobe regions in a large community-dwelling cohort of non-demented older adults. Participants (N = 327, mean age = 81.55, mean education = 15.30, 78.9 % female) completed a self-report measure used to assess susceptibility to scams and an MRI brain scan. Results indicated an inverse association between overall grey matter and susceptibility to scams in models adjusted for age, education, and sex; and in models further adjusted for cognitive function. No significant associations were observed for white matter, cerebrospinal fluid, or total brain volume. Models adjusted for age, education, and sex revealed seven clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, left middle temporal, left orbitofrontal, right ventromedial prefrontal, right middle temporal, right precuneus, and right dorsolateral prefrontal regions. In models further adjusted for cognitive function, results revealed three significant clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, right hippocampal, and right middle temporal regions. Lower grey matter concentration in specific brain regions may be associated with susceptibility to scams, even after adjusting for cognitive ability. Future research is needed to determine whether grey matter reductions in these regions may be a biomarker for susceptibility to scams in old age.
Yu, Bingsong; Dong, Hailiang; Jiang, Hongchen; Lv, Guo; Eberl, Dennis D.; Li, Shanying; Kim, Jinwook
2009-01-01
The role of saline lake sediments in preserving organic matter has long been recognized. In order to further understand the preservation mechanisms, the role of clay minerals was studied. Three sediment cores, 25, 57, and 500 cm long, were collected from Qinghai Lake, NW China, and dissected into multiple subsamples. Multiple techniques were employed, including density fractionation, X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM), total organic carbon (TOC) and carbon compound analyses, and surface area determination. The sediments were oxic near the water-sediment interface, but became anoxic at depth. The clay mineral content was as much as 36.8%, consisting mostly of illite, chlorite, and halloysite. The TEM observations revealed that organic matter occurred primarily as organic matter-clay mineral aggregates. The TOC and clay mineral abundances are greatest in the mid-density fraction, with a positive correlation between the TOC and mineral surface area. The TOC of the bulk sediments ranges from 1 to 3% with the non-hydrocarbon fraction being predominant, followed by bitumen, saturated hydrocarbon, aromatic hydrocarbons, and chloroform-soluble bitumen. The bimodal distribution of carbon compounds of the saturated hydrocarbon fraction suggests that organic matter in the sediments was derived from two sources: terrestrial plants and microorganisms/algae. Depthrelated systematic changes in the distribution patterns of the carbon compounds suggest that the oxidizing conditions and microbial abundance near the water-sediment interface promote degradation of labile organic matter, probably in adsorbed form. The reducing conditions and small microbial biomass deeper in the sediments favor preservation of organic matter, because of the less labile nature of organic matter, probably occurring within clay mineral-organic matter aggregates that are inaccessible to microorganisms. These results have important implications for our understanding of mechanisms of organic matter preservation in saline lake sediments.
Chronic Kidney Disease Is Associated With White Matter Hyperintensity Volume
Khatri, Minesh; Wright, Clinton B.; Nickolas, Thomas L.; Yoshita, Mitsuhiro; Paik, Myunghee C.; Kranwinkel, Grace; Sacco, Ralph L.; DeCarli, Charles
2010-01-01
Background and Purpose White matter hyperintensities have been associated with increased risk of stroke, cognitive decline, and dementia. Chronic kidney disease is a risk factor for vascular disease and has been associated with inflammation and endothelial dysfunction, which have been implicated in the pathogenesis of white matter hyperintensities. Few studies have explored the relationship between chronic kidney disease and white matter hyperintensities. Methods The Northern Manhattan Study is a prospective, community-based cohort of which a subset of stroke-free participants underwent MRIs. MRIs were analyzed quantitatively for white matter hyperintensities volume, which was log-transformed to yield a normal distribution (log-white matter hyperintensity volume). Kidney function was modeled using serum creatinine, the Cockcroft-Gault formula for creatinine clearance, and the Modification of Diet in Renal Disease formula for estimated glomerular filtration rate. Creatinine clearance and estimated glomerular filtration rate were trichotomized to 15 to 60 mL/min, 60 to 90 mL/min, and >90 mL/min (reference). Linear regression was used to measure the association between kidney function and log-white matter hyperintensity volume adjusting for age, gender, race–ethnicity, education, cardiac disease, diabetes, homocysteine, and hypertension. Results Baseline data were available on 615 subjects (mean age 70 years, 60% women, 18% whites, 21% blacks, 62% Hispanics). In multivariate analysis, creatinine clearance 15 to 60 mL/min was associated with increased log-white matter hyperintensity volume (β 0.322; 95% CI, 0.095 to 0.550) as was estimated glomerular filtration rate 15 to 60 mL/min (β 0.322; 95% CI, 0.080 to 0.564). Serum creatinine, per 1-mg/dL increase, was also positively associated with log-white matter hyperintensity volume (β 1.479; 95% CI, 1.067 to 2.050). Conclusions The association between moderate–severe chronic kidney disease and white matter hyperintensity volume highlights the growing importance of kidney disease as a possible determinant of cerebrovascular disease and/or as a marker of microangiopathy. PMID:17962588
Maternal Dietary Choline Status Influences Brain Gray and White Matter Development in Young Pigs
Mudd, Austin T; Getty, Caitlyn M; Dilger, Ryan N
2018-01-01
Abstract Background Choline is an essential nutrient that is pivotal to proper brain development. Research in animal models suggests that perinatal choline deficiency influences neuron development in the hippocampus and cortex, yet these observations require invasive techniques. Objective This study aimed to characterize the effects of perinatal choline deficiency on gray and white matter development with the use of noninvasive neuroimaging techniques in young pigs. Methods During the last 64 d of the 114-d gestation period Yorkshire sows were provided with a choline-sufficient (CS) or choline-deficient (CD) diet, analyzed to contain 1214 mg or 483 mg total choline/kg diet, respectively. Upon farrowing, pigs (Sus scrofa domesticus) were allowed colostrum consumption for ≤48 h, were further stratified into postnatal treatment groups, and were provided either CS or CD milk replacers, analyzed to contain 1591 or 518 mg total choline/kg diet, respectively, for 28 d. At 30 d of age, pigs were subjected to MRI procedures to assess brain development. Gray and white matter development was assessed through voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) to assess the effects of prenatal and postnatal dietary choline status. Results VBM analysis indicated that prenatally CS pigs exhibited increased (P < 0.01) gray matter in the left and right cortex compared with prenatally CD pigs. Analysis of white matter indicated that prenatally CS pigs exhibited increased (P < 0.01) white matter in the internal capsule, putamen–globus pallidus, and right cortex compared with prenatally CD pigs. No postnatal effects (P > 0.05) of choline status were noted for VBM analyses of gray and white matter. TBSS also showed no significant effects (P > 0.05) of prenatal or postnatal choline status for diffusion values along white matter tracts. Conclusions Observations from this study suggest that prenatal choline deficiency results in altered cortical gray matter and reduced white matter in the internal capsule and putamen of young pigs. With the use of noninvasive neuroimaging techniques, results from our study indicate that prenatal choline deficiency greatly alters gray and white matter development in pigs, thereby providing a translational assessment that may be used in clinical populations.
[The legal risk in obstetrics in XVIIth and XVIIIth centuries].
Seguy, B
2008-12-01
The implication of obstetricians in case of an unfavourable parturition ending is not a particularism nor an innovation of our present times, as modern practitioners may believe. In fact, implications in court cases and public contests are as old as the practice of midwifery itself. So it sounds interesting to present to modern obstetricians the atmosphere around contentious matters in midwifery practice along the xviith and xviiith centuries, in France, which was at thoses times the preeminent country in Europe in medecine and midwifery domains. This historic review will allow, by the way, a quick reminding of the knowledge of those times.
The "AIDS and MDGs" approach: what is it, why does it matter, and how do we take it forward?
Kim, Julia; Lutz, Brian; Dhaliwal, Mandeep; O'Malley, Jeffrey
2011-01-01
Progress towards the Millennium Development Goals (MDGs) has been mixed, and many observers have noted the tendency for development actors to address individual MDGs largely in isolation from one another. This in turn has resulted in missed opportunities to catalyse greater interdisciplinary collaboration and innovation towards MDG achievement. The term 'AIDS and MDGs' is gaining currency as an approach that aims to explore, strengthen and leverage the links between AIDS and other health and development issues. Drawing from academic literature and from MDG country reports, this article sets out three important pillars to an AIDS and MDGs approach: 1) understanding how AIDS and the other MDGs affect one another; 2) documenting and exchanging lessons learned across MDGs; and 3) creating cross- MDG synergy. We propose broader policy level implications for this approach and how UNDP and other partners can take this agenda forward. Because the MDGs explicitly locate HIV within a broader international commitment to human development targets, they provide a critical platform for development partners to galvanise resources, political will and momentum behind a broader, systematic and structural approach to HIV, health and development.
Commercialisation and entrepreneurialism in maternity.
Mander, Rosemary
2011-08-01
against an international background, to examine the implications of private sector activity for maternity care in the United Kingdom National Health Service (UK NHS). the private sector and commercial or entrepreneurial activity in maternity services have attracted limited attention in the UK compared with, for e.g., Greece and the Irish Republic. discursive paper. despite rhetoric to the contrary, financial costs have always featured in the UK NHS. Financial payments in maternity have increased gradually. Commercial and entrepreneurial activity in maternity now includes 'entertainment ultrasound', reflecting a greater hegemonic imbalance. The commercialisation of maternity raises organisational, professional, quality-related and systematic issues, which all carry implications for the childbearing woman. the childbearing woman shoulders financial costs, whose origins and implications matter to both midwife and woman. The mixed benefits of medical investigations deserve closer attention. Copyright © 2011 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Tzanavaris, Panayiotis
Fluorescent Fe K emission from neutral matter in AGN spectracan arise in the accretion disk around the centralsupermassive black hole [SMBH] ("broad" line) and/or in distant matter ("narrow"line). If it is broad, it provides a unique windowto the strong gravity SMBH regime, including information on SMBH spin;if it is narrow, it probesthe distant reprocessor, likely a clumpy torus. We will use broadband X-ray data from four NASA X-ray missionsfor 45 nearby AGNs, and 1. Assess whether any known "broad" relativistic lines can be modeledas "narrow"instead, by means of self-consistent modeling of fluorescence,direct, and scattered continua; 2. Measure absorbing column densities both in and out of the line of sight; 3. Bootstrap measures of intrinsic bolometric AGN luminosity, with X-ray and optical data. This work will provide updated results on a) black hole spin, with implications on AGN jet power and accretion history; b) the census of highly-obscured (Compton thick) vs. Compton thin AGNs, with implications on models of the Cosmic X-ray Background; c) calibrations of Fe K line, X-ray intrinsic continuum, [OIII] and [OIV] luminosities as measures of intrinsc bolometric AGN luminosity, with implications on AGN feedback and galaxy evolution. Key in our approach is a physically based, self-consistent modeling of the narrow line, with finite column density in and out of the line of sight, and the latest relativistic modeling of the broad line.
Organizational Conspiracy Beliefs: Implications for Leadership Styles and Employee Outcomes.
van Prooijen, Jan-Willem; de Vries, Reinout E
2016-01-01
Belief in conspiracy theories about societal events is widespread among citizens. The extent to which conspiracy beliefs about managers and supervisors matter in the micro-level setting of organizations has not yet been examined, however. We investigated if leadership styles predict conspiracy beliefs among employees in the context of organizations. Furthermore, we examined if such organizational conspiracy beliefs have implications for organizational commitment and turnover intentions. We conducted a survey among a random sample of the US working population ( N = 193). Despotic, laissez-faire, and participative leadership styles predicted organizational conspiracy beliefs, and the relations of despotic and laissez-faire leadership with conspiracy beliefs were mediated by feelings of job insecurity. Furthermore, organizational conspiracy beliefs predicted, via decreased organizational commitment, increased turnover intentions. Organizational conspiracy beliefs matter for how employees perceive their leaders, how they feel about their organization, and whether or not they plan to quit their jobs. A practical implication, therefore, is that it would be a mistake for managers to dismiss organizational conspiracy beliefs as innocent rumors that are harmless to the organization. Three novel conclusions emerge from this study. First, organizational conspiracy beliefs occur frequently among employees. Second, participative leadership predicts decreased organizational conspiracy beliefs; despotic and laissez-faire leadership predict increased organizational conspiracy beliefs due to the contribution of these destructive leadership styles to an insecure work environment. Third, organizational conspiracy beliefs harm organizations by influencing employee commitment and, indirectly, turnover intentions.
Dance and the brain: a review.
Karpati, Falisha J; Giacosa, Chiara; Foster, Nicholas E V; Penhune, Virginia B; Hyde, Krista L
2015-03-01
Dance is a universal form of human expression that offers a rich source for scientific study. Dance provides a unique opportunity to investigate brain plasticity and its interaction with behavior. Several studies have investigated the behavioral correlates of dance, but less is known about the brain basis of dance. Studies on dance observation suggest that long- and short-term dance training affect brain activity in the action observation and simulation networks. Despite methodological challenges, the feasibility of conducting neuroimaging while dancing has been demonstrated, and several brain regions have been implicated in dance execution. Preliminary work from our laboratory suggests that long-term dance training changes both gray and white matter structure. This article provides a critical summary of work investigating the neural correlates of dance. It covers functional neuroimaging studies of dance observation and performance as well as structural neuroimaging studies of expert dancers. To stimulate ongoing dialogue between dance and science, future directions in dance and brain research as well as implications are discussed. Research on the neuroscience of dance will lead to a better understanding of brain-behavior relationships and brain plasticity in experts and nonexperts and can be applied to the development of dance-based therapy programs. © 2014 New York Academy of Sciences.
Dust emission and soil loss due to anthropogenic activities by wind erosion simulations
NASA Astrophysics Data System (ADS)
Katra, Itzhak; Swet, Nitzan; Tanner, Smadar
2017-04-01
Wind erosion is major process of soil loss and air pollution by dust emission of clays, nutrients, and microorganisms. Many soils throughout the world are currently or potentially associated with dust emissions, especially in dryland zones. The research focuses on wind erosion in semi-arid soils (Northern Negev, Israel) that are subjected to increased human activities of urban development and agriculture. A boundary-layer wind tunnel has been used to study dust emission and soil loss by simulation and quantification of high-resolution wind processes. Field experiments were conducted in various surface types of dry loess soils. The experimental plots represent soils with long-term and short term influences of land uses such as agriculture (conventional and organic practices), grazing, and natural preserves. The wind tunnel was operated under various wind velocities that are above the threshold velocity of aeolian erosion. Total soil sediment and particulate matter (PM) fluxes were calculated. Topsoil samples from the experimental plots were analysed in the laboratory for physical and chemical characteristics including aggregation, organic matter, and high-resolution particle size distribution. The results showed variations in dust emission in response to surface types and winds to provide quantitative estimates of soil loss over time. Substantial loss of particulate matter that is < 10 micrometer in diameter, including clays and nutrients, was recorded in most experimental conditions. Integrative analyses of the topsoil properties and dust experiment highlight the significant implications for soil nutrient resources and management strategies as well as for PM loading to the atmosphere and air pollution.
Hardy, Chris J D; Agustus, Jennifer L; Marshall, Charles R; Clark, Camilla N; Russell, Lucy L; Bond, Rebecca L; Brotherhood, Emilie V; Thomas, David L; Crutch, Sebastian J; Rohrer, Jonathan D; Warren, Jason D
2017-07-27
Non-verbal auditory impairment is increasingly recognised in the primary progressive aphasias (PPAs) but its relationship to speech processing and brain substrates has not been defined. Here we addressed these issues in patients representing the non-fluent variant (nfvPPA) and semantic variant (svPPA) syndromes of PPA. We studied 19 patients with PPA in relation to 19 healthy older individuals. We manipulated three key auditory parameters-temporal regularity, phonemic spectral structure and prosodic predictability (an index of fundamental information content, or entropy)-in sequences of spoken syllables. The ability of participants to process these parameters was assessed using two-alternative, forced-choice tasks and neuroanatomical associations of task performance were assessed using voxel-based morphometry of patients' brain magnetic resonance images. Relative to healthy controls, both the nfvPPA and svPPA groups had impaired processing of phonemic spectral structure and signal predictability while the nfvPPA group additionally had impaired processing of temporal regularity in speech signals. Task performance correlated with standard disease severity and neurolinguistic measures. Across the patient cohort, performance on the temporal regularity task was associated with grey matter in the left supplementary motor area and right caudate, performance on the phoneme processing task was associated with grey matter in the left supramarginal gyrus, and performance on the prosodic predictability task was associated with grey matter in the right putamen. Our findings suggest that PPA syndromes may be underpinned by more generic deficits of auditory signal analysis, with a distributed cortico-subcortical neuraoanatomical substrate extending beyond the canonical language network. This has implications for syndrome classification and biomarker development.
Lenhart, Christian F; Brooks, Kenneth N; Heneley, Daniel; Magner, Joseph A
2010-06-01
The Minnesota River Basin (MRB), situated in the prairie pothole region of the Upper Midwest, contributes excessive sediment and nutrient loads to the Upper Mississippi River. Over 330 stream channels in the MRB are listed as impaired by the Minnesota Pollution Control Agency, with turbidity levels exceeding water quality standards in much of the basin. Addressing turbidity impairment requires an understanding of pollutant sources that drive turbidity, which was the focus of this study. Suspended volatile solids (SVS), total suspended solids (TSS), and turbidity were measured over two sampling seasons at ten monitoring stations in Elm Creek, a turbidity impaired tributary in the MRB. Turbidity levels exceeded the Minnesota standard of 25 nephelometric units in 73% of Elm Creek samples. Turbidity and TSS were correlated (r (2) = 0.76), yet they varied with discharge and season. High levels of turbidity occurred during periods of high stream flow (May-June) because of excessive suspended inorganic sediment from watershed runoff, stream bank, and channel contributions. Both turbidity and TSS increased exponentially downstream with increasing stream power, bank height, and bluff erosion. However, organic matter discharged from wetlands and eutrophic lakes elevated SVS levels and stream turbidity in late summer when flows were low. SVS concentrations reached maxima at lake outlets (50 mg/l) in August. Relying on turbidity measurements alone fails to identify the cause of water quality impairment whether from suspended inorganic sediment or organic matter. Therefore, developing mitigation measures requires monitoring of both TSS and SVS from upstream to downstream reaches.
Hazlett, Heather Cody; Poe, Michele D.; Lightbody, Amy A.; Styner, Martin; MacFall, James R.; Reiss, Allan L.; Piven, Joseph
2012-01-01
Objective To examine patterns of early brain growth in young children with fragile X syndrome (FXS) compared to a comparison group (controls) and a group with idiopathic autism. Method The study included 53 boys between 18–42 months of age with FXS, 68 boys with idiopathic autism (ASD), and a comparison group of 50 typically-developing and developmentally-delayed controls. We examined structural brain volumes using magnetic resonance imaging (MRI) across two timepoints between ages 2–3 and 4–5 years and examined total brain volumes and regional (lobar) tissue volumes. Additionally, we studied a selected group of subcortical structures implicated in the behavioral features of FXS (e.g., basal ganglia, hippocampus, amygdala). Results Children with FXS had greater global brain volumes compared to controls, but were not different than children with idiopathic autism, and the rate of brain growth between ages 2 and 5 paralleled that seen in controls. In contrast to the children with idiopathic autism who had generalized cortical lobe enlargement, the children with FXS showed a specific enlargement in temporal lobe white matter, cerebellar gray matter, and caudate nucleus, but significantly smaller amygdala. Conclusions This structural longitudinal MRI study of preschoolers with FXS observed generalized brain overgrowth in FXS compared to controls, evident at age 2 and maintained across ages 4–5. We also find different patterns of brain growth that distinguishes boys with FXS from children with idiopathic autism. PMID:22917205
Stabilization of polar soils organic matter: insights from 13-C NMR and ESR spectroscopy
NASA Astrophysics Data System (ADS)
Abakumov, Evgeny
2017-04-01
Polar soils play a key role in the global carbon balance, as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Low temperature and severe conditions provides the accumulation of large amounts of organic matter in permafrost soils over thousands of years. The quality and composition of organic matter of polar soils is underestimated. In order to better understand the implication of permafrost SOM to greenhouse gas emissions, an accurate knowledge of its spatial distribution, both in terms of quantity and quality (i.e. biodegradability, chemical composition and humification degree) is needed. The chemical composition of SOM determines its decomposability and, therefore, it determines the rate at which carbon may be transferred from soils to the atmosphere under warming conditions. Biodegradability of SOM has been related to humification degree, as more advanced stages in the humification process imply a depletion of the labile molecules, as well as an increase in the bulk aromaticity, which provides a higher stability of the SOM. Soils from Antarctic and different sectors of Arctic biome were investigated by 13-C NMR and electron spin resonance spectroscopy. It was shown, that the characteristic feature of polar soils humic acids is the dominance of aliphatic compounds on the aromatic one. This is related to the humification precursors component composition, namely to dominance of the remnants of lower plants, especially in Antarctic and low period of biological activity, which regulates the humification rate. Humic acids of Antarctic and various Arctic soils show the portion of aromatic components not more than 30 %. ESR spectroscopy shown that the concentration of free radicals is proportional to the humic acids stabilization degree. Less humified organic materials show the highest portion of free radical content, while the most developed soils and buried organic layers show decreased contents of free radicals. The database on soil organic matter composition of polar soil should be created with aim to evaluate current state of the humosphere and to provide the prognostic scenarios of possible mineralisation of humus.
Tissue-Selective Salvage of the White Matter by Successful Endovascular Stroke Therapy.
Kleine, Justus F; Kaesmacher, Mirjam; Wiestler, Benedikt; Kaesmacher, Johannes
2017-10-01
White matter (WM) is less vulnerable to ischemia than gray matter. In ischemic stroke caused by acute large-vessel occlusion, successful recanalization might therefore sometimes selectively salvage the WM, leading to infarct patterns confined to gray matter. This study examines occurrence, determinants, and clinical significance of such effects. Three hundred twenty-two patients with acute middle cerebral artery occlusion subjected to mechanical thrombectomy were included. Infarct patterns were categorized into WM - (sparing the WM) and WM + (involving WM). National Institutes of Health Stroke Scale-based measures of neurological outcome, including National Institutes of Health Stroke Scale improvement or National Institutes of Health Stroke Scale worsening, good functional midterm outcome (day 90-modified Rankin Scale score of ≤2), the occurrence of malignant swelling, and in-hospital mortality were predefined outcome measures. WM - infarcts occurred in 118 of 322 patients and were associated with successful recanalization and better collateral grades ( P <0.05). Shorter symptom-onset to recanalization times were also associated with WM - infarcts in univariate analysis, but not when adjusted for collateral grades. WM - infarcts were independently associated with good neurological outcome (adjusted odds ratio, 3.003; 95% confidence interval, 1.186-7.607; P =0.020) and good functional midterm outcome (adjusted odds ratio, 8.618; 95% confidence interval, 2.409-30.828; P =0.001) after correcting for potential confounders, including final infarct volume. Only 2.6% of WM - patients, but 20.5% of WM + patients exhibited neurological worsening, and none versus 12.8% developed malignant swelling ( P <0.001), contributing to lower mortality in this group (2.5% versus 10.3%; P =0.014). WM infarction commonly commences later than gray matter infarction after acute middle cerebral artery occlusion. Successful recanalization can therefore salvage completely the WM at risk in many patients even several hours after symptom onset. Preservation of the WM is associated with better neurological recovery, prevention of malignant swelling, and reduced mortality. This has important implications for neuroprotective strategies, and perfusion imaging-based patient selection, and provides a rationale for treating selected patients in extended time windows. © 2017 American Heart Association, Inc.
Learning for Well-Being: Personal, Social and Health Education and a Changing Curriculum
ERIC Educational Resources Information Center
Crow, Fergus
2008-01-01
This article explores the current context for personal, social and health education (PSHE) in English schools, and examines what the implications of the "Every Child Matters" (ECM) agenda are for schools in the future and how these changes may affect the profile and provision of PSHE in the curriculum. The author begins by revisiting the…
ERIC Educational Resources Information Center
Cordiner, Moira; Thomas, Sharon; Green, Wendy
2018-01-01
Organisational change literature is littered with labels for those who instigate, support, resist, or implement change. Absent is research into the perspectives of those who are given these labels. This paper reports findings from a literature search, journal scan and a case study of an Australian university where change agents were labelled…
Kassidy N. Yatso; Erik A. Lilleskov
2016-01-01
Invasive earthworm communities are expanding into previously earthworm-free forests of North America, producing profound ecosystem changes. Lumbricus terrestris is an invasive anecic earthworm that consumes a large portion of the detritus on the soil surface, eliminating forest floor organic horizons and reducing soil organic matter. Two mesocosm...
ERIC Educational Resources Information Center
Gika, Artemis D.; Siddiqui, Ata; Hulse, Anthony J.; Edward, Selvakumari; Fallon, Penny; McEntagart, Meriel E.; Jan, Wajanat; Josifova, Dragana; Lerman-Sagie, Tally; Drummond, James; Thompson, Edward; Refetoff, Samuel; Bonnemann, Carsten G.; Jungbluth, Heinz
2010-01-01
Aim: Mutations in the "SLC16A2" gene have been implicated in Allan-Herndon-Dudley syndrome (AHDS), an X-linked learning disability syndrome associated with thyroid function test (TFT) abnormalities. Delayed myelination is a non-specific finding in individuals with learning disability whose genetic basis is often uncertain. The aim of this study…
After Eric Garner: Invoking the Black Radical Tradition in Practice and in Theory #BlackLivesMatter
ERIC Educational Resources Information Center
Shieh, Eric
2016-01-01
In this article, I document a series of pedagogical responses in my high school instrumental music classroom following the events of Eric Garner's murder in New York City. Foregrounding traditions of black radical politics and aesthetics originating with the Black Power Movement in the 1960s, I explore their implications for classroom practice in…
ERIC Educational Resources Information Center
Ahmadi, Alireza; Sahragard, Rahman; Babaie Shalmani, Hamed
2017-01-01
The present study aimed to examine whether agent-based instruction would privilege English as a Foreign Language (EFL) learners any better than mainstream approaches (e.g. analogical reasoning, guessing from context, image formation, semantic analysis, etc.) when it comes to the teaching of English idioms. It also sought to explore whether…
ERIC Educational Resources Information Center
McCarthy, Matthew T.
2017-01-01
Artificial intelligence (AI) that is based upon semantic search has become one of the dominant means for accessing information in recent years. This is particularly the case in mobile contexts, as search-based AI are embedded in each of the major mobile operating systems. The implications are such that information is becoming less a matter of…
A New Way to Look at Literature: A Visual Model for Analyzing Fiction and Nonfiction Texts
ERIC Educational Resources Information Center
Colman, Penny
2007-01-01
The relative absence of nonfiction in literature for young readers may have serious implications because nonfiction literacy matters. Nonfiction material is the crucible within which readers can gain the knowledge and skills that enable them to reach sound decisions in all arenas of life, avoid gullibility born of ignorance, and participate in an…
Lunar and Planetary Science XXXV: Astrobiology
NASA Technical Reports Server (NTRS)
2004-01-01
The session "Astrobiology" included the following reports:The Role of Cometary and Meteoritic Delivery in the Origin and Evolution of Life: Biogeological Evidences Revisited; Hopane Biomarkers Traced from Bedrock to Recent Sediments and Ice at the Haughton Impact Structure, Devon Island: Implications for the Search for Biomarkers on Mars; and Survival of Organic Matter After High Temperature Events (Meteorite Impacts, Igneous Intrusions).
Wildland fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., wildland fires can account for more than 30% of total annual PM2.5 emissions. In order to represent the influence of fire e...
Wildland fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., wildland fires can account for more than 30% of total annual PM2.5 emissions. In order to represent the influence of fire e...
ERIC Educational Resources Information Center
Becker, Sarah; Paul, Crystal
2015-01-01
Prior research measuring service-learning program successes reveals the approach can positively affect students' attitudes toward community service, can increase students' motivation to learn and ability to internalize class material, and can change their view of social issues. Studies also suggest that college students sometimes enter and leave a…
B.M. Cheever; J. R. Webster; E. E. Bilger; S. A. Thomas
2013-01-01
Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with
Style in English. The Bobbs-Merrill Series in Composition and Rhetoric.
ERIC Educational Resources Information Center
Nist, John, Ed.
The thesis that style through the manner of expression provides the writer or speaker with the matter of his discourse is the subject of these eight essays. Articles are by (1) Louis T. Milic, who explores the implication of stylistic theory for the teaching of composition, (2) Martin Joos, who relates style theories to the national enthusiasm for…
Latent effect of soil organic matter oxidation on mercury cycling within a southern boreal ecosystem
Mark Gabriel; Randy Kolka; Trent Wickman; Laurel Woodruff; Ed. Nater
2012-01-01
The focus of this study is to investigate processes causing the observed spatial variation of total mercury (THg) in the soil O horizon of watersheds within the Superior National Forest (Minnesota) and to determine if results have implications toward understanding long-term changes in THg concentrations for resident fish. Principal component analysis was used to...
ERIC Educational Resources Information Center
Hyldgaard, Kirsten
2009-01-01
In much of educational philosophy and sciences the fundamental concepts are the subject conceived of as conscious and constituting and the learning process conceived of as a matter of cognition. This article asks what the effect would be on educational research method and educational theory in general if the fundamental concept were the subject in…
Effects of fire behavior on prescribed fire smoke characteristics: A case study [Chapter 50
Wayne Einfeld; Darold E. Ward; Colin Hardy
1991-01-01
Biomass burning on a global scale injects a substantial quantity of gaseous and particulate matter emissions into the troposphere. Some of these combustion products are known to accumulate in the atmosphere and are implicated in observed changes in tropospheric composition and chemistry. The practice of open burning of biomass has come under close examination as a...
Findings and Implications from the Mathematics Support Center at Cornell University.
ERIC Educational Resources Information Center
Rosamond, Frances
The nature and use of the Cornell Mathematics Support Center (MSC) is discussed. It is viewed as significantly different from other existing support programs in that it is part of the Department of Mathematics and offers encouragement and support to any interested student, no matter what that pupil's mathematics level is. The MSC is based on the…
Aberrant Upregulation of Astroglial Ceramide Potentiates Oligodendrocyte Injury
Kim, SunJa; Steelman, Andrew J.; Zhang, Yumin; Kinney, Hannah C.; Li, Jianrong
2015-01-01
Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis and periventricular leukomalacia. Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of multiple sclerosis and periventricular leukomalacia, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination and revealed a concomitant increase of sphingosine as well as a suppression of sphingosine-1-phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders. PMID:21615590
On-Site Pedagogical Content Knowledge Development
NASA Astrophysics Data System (ADS)
Chan, Kennedy Kam Ho; Yung, Benny Hin Wai
2015-05-01
Experiences and reflection have long been regarded as a foundation for pedagogical content knowledge (PCK) development. However, little is known about how experienced teachers develop their PCK via reflection-in-action during their moment-to-moment classroom instruction. Drawing upon data sources including classroom observations, semi-structured interviews and stimulated recall interviews based on lesson videos, this study examined instances when four experienced teachers were found to invent new instructional strategies/representations on the spot during the lesson (referred to as on-site PCK development) in their first attempts at teaching a new topic. The study documented the moment-to-moment experiences of the teachers, including their reconstructed thought processes associated with these instances of on-site PCK development. An explanatory model of a three-step process comprising a stimulus, an integration process and a response was advanced to account for the on-site PCK development observed among the teachers. Three categories of stimulus that triggered on-site PCK development were identified. Factors influencing the integration process and, hence, the resulting response, included teachers' subject matter knowledge of the new topic, their general pedagogical knowledge and their knowledge of student learning difficulties/prior knowledge related to the new topic. Implications for teacher professional development in terms of how to enhance teachers' on-site PCK development are discussed.
Structural covariance mapping delineates medial and medio-lateral temporal networks in déjà vu.
Shaw, Daniel Joel; Mareček, Radek; Brázdil, Milan
2016-12-01
Déjà vu (DV) is an eerie phenomenon experienced frequently as an aura of temporal lobe epilepsy, but also reported commonly by healthy individuals. The former pathological manifestation appears to result from aberrant neural activity among brain structures within the medial temporal lobes. Recent studies also implicate medial temporal brain structures in the non-pathological experience of DV, but as one element of a diffuse neuroanatomical correlate; it remains to be seen if neural activity among the medial temporal lobes also underlies this benign manifestation. The present study set out to investigate this. Due to its unpredictable and infrequent occurrence, however, non-pathological DV does not lend itself easily to functional neuroimaging. Instead, we draw on research showing that brain structure covaries among regions that interact frequently as nodes of functional networks. Specifically, we assessed whether grey-matter covariance among structures implicated in non-pathological DV differs according to the frequency with which the phenomenon is experienced. This revealed two diverging patterns of structural covariation: Among the first, comprised primarily of medial temporal structures and the caudate, grey-matter volume becomes more positively correlated with higher frequency of DV experience. The second pattern encompasses medial and lateral temporal structures, among which greater DV frequency is associated with more negatively correlated grey matter. Using a meta-analytic method of co-activation mapping, we demonstrate a higher probability of functional interactions among brain structures constituting the former pattern, particularly during memory-related processes. Our findings suggest that altered neural signalling within memory-related medial temporal brain structures underlies both pathological and non-pathological DV.
Bisecco, Alvino; Rocca, Maria A; Pagani, Elisabetta; Mancini, Laura; Enzinger, Christian; Gallo, Antonio; Vrenken, Hugo; Stromillo, Maria Laura; Copetti, Massimiliano; Thomas, David L; Fazekas, Franz; Tedeschi, Gioacchino; Barkhof, Frederik; Stefano, Nicola De; Filippi, Massimo
2015-07-01
In this multicenter study, we performed a tractography-based parcellation of the thalamus and its white matter connections to investigate the relationship between thalamic connectivity abnormalities and cognitive impairment in multiple sclerosis (MS). Dual-echo, morphological and diffusion tensor (DT) magnetic resonance imaging (MRI) scans were collected from 52 relapsing-remitting MS patients and 57 healthy controls from six European centers. Patients underwent an extensive neuropsychological assessment. Thalamic connectivity defined regions (CDRs) were segmented based on their cortical connectivity using diffusion tractography-based parcellation. Between-group differences of CDRs and cortico-thalamic tracts DT MRI indices were assessed. A vertex analysis of thalamic shape was also performed. A random forest analysis was run to identify the best imaging predictor of global cognitive impairment and deficits of specific cognitive domains. Twenty-two (43%) MS patients were cognitively impaired (CI). Compared to cognitively preserved, CI MS patients had increased fractional anisotropy of frontal, motor, postcentral and occipital connected CDRs (0.002