Juan Du; Eriko Miura; Marcel Robischon; Ciera Martinez; Andrew Groover
2011-01-01
The developmental mechanisms regulating cell differentiation and patterning during the secondary growth of woody tissues are poorly understood. Class III HD ZIP transcription factors are evolutionarily ancient and play fundamental roles in various aspects of plant development. Here we investigate the role of a Class III HD ZIP transcription factor, ...
ERIC Educational Resources Information Center
Annesi, James J.; Whitaker, Ann C.
2010-01-01
The behavioral processes of weight reduction are poorly understood, and responses to treatments based primarily on caloric restriction have been unfavorable. A theory-based path derived from proposed relations of physical activity, changes in psychological factors, and weight loss was separately tested with women with Class I and Class II obesity…
Long-term trends and a sustainability transition
Kates, Robert W.; Parris, Thomas M.
2003-01-01
How do long-term global trends affect a transition to sustainability? We emphasize the “multitrend” nature of 10 classes of trends, which makes them complex, contradictory, and often poorly understood. Each class includes trends that make a sustainability transition more feasible as well as trends that make it more difficult. Taken in their entirety, they serve as a checklist for the consideration of global trends that impact place-based sustainability studies. PMID:12829798
METABOLISM OF PBDES IN FATHEAD MINNOWS (PIMEPHALES PROMELAS) AND EFFECTS ON THYROID REGULATION
PBDE effects on fish and other wildlife continue to be poorly understood, and this research will contribute to filling this data gap. It will increase our understanding of PBDE metabolic pathways and mechanisms of thyroid dysfunction in fish exposed to this important class of ...
The consensus among environmental scientists and risk assessors is that the fate and effects of pharmaceutical and personal care products (PPCPS) in the environment are poorly understood. Many classes of PPCPs have yet to be investigated. Acquisition of trends data for a suite of...
The Populus homeobox gene ARBORKNOX2 regulates cell differentiation during secondary growth
Juan Du; Shawn D. Mansfield; Andrew T. Groover
2009-01-01
The stem cells of the vascular cambium divide to produce daughter cells, which in turn divide before undergoing differentiation during the radial growth of woody stems. The genetic regulation of these developmental events is poorly understood, however. We report here the cloning and functional characterization of a Populus class-I KNOX...
The mystery of a supposed massive star exploding in a brightest cluster galaxy
NASA Astrophysics Data System (ADS)
Hosseinzadeh, Griffin
2017-08-01
Most of the diversity of core-collapse supernovae results from late-stage mass loss by their progenitor stars. Supernovae that interact with circumstellar material (CSM) are a particularly good probe of these last stages of stellar evolution. Type Ibn supernovae are a rare and poorly understood class of hydrogen-poor explosions that show signs of interaction with helium-rich CSM. The leading hypothesis is that they are explosions of very massive Wolf-Rayet stars in which the supernova ejecta excites material previously lost by stellar winds. These massive stars have very short lifetimes, and therefore should only found in actively star-forming galaxies. However, PS1-12sk is a Type Ibn supernova found on the outskirts of a giant elliptical galaxy. As this is extraordinary unlikely, we propose to obtain deep UV images of the host environment of PS1-12sk in order to map nearby star formation and/or find a potential unseen star-forming host. If star formation is detected, its amount and location will provide deep insights into the progenitor picture for the poorly-understood Type Ibn class. If star formation is still not detected, these observations would challenge the well-accepted hypothesis that these are core-collapse supernovae at all.
Horton, Sarah B
2013-01-01
Because studies of migrants' 'medical returns' have been largely confined to the field of public health, such forms of return migration are rarely contextualized within the rich social scientific literature on transnational migration. Drawing on ethnographic interviews with Mexican migrants in an immigrant enclave in central California, I show that migrants' reasons for returning to their hometowns for care must be understood within the class disjunctures facilitated by migration. While migrants' Medicaid insurance confined them to public clinics and hospitals in the United States, their migrant dollars enabled them to visit private doctors and clinics in Mexico. Yet medical returns were not mere medical arbitrage, but also allowed migrants to access care that had previously been foreclosed to them as poor peasants in Mexico. Thus crossing the border enabled a dual class transformation, as Mexican migrants transitioned from Medicaid recipients to cash-paying patients, and from poor rural peasants to 'returning royalty.'
USDA-ARS?s Scientific Manuscript database
Eukaryotic cells compartmentalize neutral lipids into organelles called lipid droplets (LDs), and while much is known about the role of LDs in storing triacylglycerols (TAGs) in seeds, their biogenesis and function in non-seed tissues is poorly understood. Recently, we identified a class of plant-sp...
Blogging in the Political Science Classroom
ERIC Educational Resources Information Center
Lawrence, Christopher N.; Dion, Michelle L.
2010-01-01
Weblogs (or blogs), as a form of communication on the Internet, have recently risen in prominence but may be poorly understood by both faculty and students. This article explains how blogs differ from other online communication tools and how political science faculty can make use of blogs in their classes. The focus is on using blogs as part of…
NASA Astrophysics Data System (ADS)
Ludwig, Bethany Ann; Cunningham, Nichol
2017-01-01
We present results from an investigation of class II 6.7GHz methanol masers towards four Massive Young Stellar Objects (MYSOs). The sources, selected from the Red MSX Source (RMS) Survey (Lumsden et al. 2013), were previously understood to be non-detections for class II methanol maser emission in the methanol multi-beam (MMB) Survey (Caswell et al. 2010.) Class II methanol masers are a well-known sign post of massive star forming regions and may be utilized to probe their relatively poorly understood formation. It is possible that these non-detections are simply weak masers that are potentially associated with a younger evolutionary phase of MYSOs as hypothesized by Olmi et al. (2014). The sources were chosen to sample various stages of evolution, having similar 21 to 8 micron flux ratios and bolometric luminosities as other MYSOs with previous class II methanol maser detections. We observed all 4 MYSOs with ATCA (~2" resolution) at 10 times deeper sensitivity than previously obtained with the MMB survey and have a spectral resolution of 0.087kms^-1 . The raw data is reduced using the program Miriad (Sault, R. J., et al., 1995) and deconvolutioned using the program CASA (McMullin, J. P., et al. 2007.) We determine one of the four observed MYSOs is harboring a weak class II methanol maser. We discuss the possibility of sensitivity limitations on the remaining sources as well as environmental and evolutionary differences between the sources.
TBK1 controls IgA class switching by negatively regulating noncanonical NF-κB signaling
Jin, Jin; Xiao, Yichuan; Chang, Jae-Hoon; Yu, Jiayi; Hu, Hongbo; Starr, Robyn; Brittain, George C.; Chang, Mikyoung; Cheng, Xuhong; Sun, Shao-Cong
2012-01-01
Immunoglobulin (Ig) class switching is crucial for generating antibody diversity in humoral immunity and, if deregulated, also has severe pathological consequences. How the magnitude of Ig isotype switching is controlled is still poorly understood. Here we identify TANK-binding kinase 1 (TBK1) as a pivotal negative regulator of IgA class switching. B cell-specific TBK1 ablation in mice resulted in uncontrolled production of IgA and development of nephropathy-like disease symptoms. TBK1 negatively regulated IgA class switching by attenuating noncanonical NF-κB signaling, an action that involved TBK1-mediated phosphorylation and subsequent degradation of the NF-κB-inducing kinase. These findings establish TBK1 as a pivotal negative regulator of the noncanonical NF-κB pathway and highlight a unique mechanism that controls IgA production. PMID:23023393
Grass competition suppresses savanna tree growth across multiple demographic stages.
Riginos, Corinna
2009-02-01
Savanna ecosystems, defined by the codominance of trees and grasses, cover one-fifth of the world's land surface and are of great socioeconomic and biological importance. Yet, the fundamental question of how trees and grasses coexist to maintain the savanna state remains poorly understood. Many models have been put forward to explain tree-grass coexistence, but nearly all have assumed that grasses do not limit tree growth and demography beyond the sapling stage. This assumption, however, has rarely been tested. Here I show that grass can strongly suppress the growth of trees. I removed grass around trees of three size classes in an Acacia drepanolobium savanna in Laikipia, Kenya. For even the largest trees, grass removal led to a doubling in growth and a doubling in the probability of transitioning to the next size class over two years. These results suggest that grass competition in productive (nutrient-rich) savannas may limit tree growth as much as herbivory and fire (the main factors thought to determine tree demography within a rainfall region) and should be incorporated into savanna models if tree-grass coexistence and savanna dynamics are to be understood.
Hunter, Karen E; Quick, Marsha L; Sadanandam, Anguraj; Hanahan, Douglas; Joyce, Johanna A
2013-01-01
Pancreatic neuroendocrine tumors (PanNETs) are a relatively rare but clinically challenging tumor type. In particular, high grade, poorly-differentiated PanNETs have the worst patient prognosis, and the underlying mechanisms of disease are poorly understood. In this study we have identified and characterized a previously undescribed class of poorly differentiated PanNETs in the RIP1-Tag2 mouse model. We found that while the majority of tumors in the RIP1-Tag2 model are well-differentiated insulinomas, a subset of tumors had lost multiple markers of beta-cell differentiation and were highly invasive, leading us to term them poorly differentiated invasive carcinomas (PDICs). In addition, we found that these tumors exhibited a high mitotic index, resembling poorly differentiated (PD)-PanNETs in human patients. Interestingly, we identified expression of Id1, an inhibitor of DNA binding gene, and a regulator of differentiation, specifically in PDIC tumor cells by histological analysis. The identification of PDICs in this mouse model provides a unique opportunity to study the pathology and molecular characteristics of PD-PanNETs.
Lee, Sungwook; Park, Boyoun; Kang, Kwonyoon
2009-01-01
In contrast to the fairly well-characterized mechanism of assembly of MHC class I-peptide complexes, the disassembly mechanism by which peptide-loaded MHC class I molecules are released from the peptide-loading complex and exit the endoplasmic reticulum (ER) is poorly understood. Optimal peptide binding by MHC class I molecules is assumed to be sufficient for triggering exit of peptide-filled MHC class I molecules from the ER. We now show that protein disulfide isomerase (PDI) controls MHC class I disassembly by regulating dissociation of the tapasin-ERp57 disulfide conjugate. PDI acts as a peptide-dependent molecular switch; in the peptide-bound state, it binds to tapasin and ERp57 and induces dissociation of the tapasin-ERp57 conjugate. In the peptide-free state, PDI is incompetent to bind to tapasin or ERp57 and fails to dissociate the tapasin-ERp57 conjugates, resulting in ER retention of MHC class I molecules. Thus, our results indicate that even after optimal peptide loading, MHC class I disassembly does not occur by default but, rather, is a regulated process involving PDI-mediated interactions within the peptide-loading complex. PMID:19477919
Thoma, Vladimiros; Knapek, Stephan; Arai, Shogo; Hartl, Marion; Kohsaka, Hiroshi; Sirigrivatanawong, Pudith; Abe, Ayako; Hashimoto, Koichi; Tanimoto, Hiromu
2016-01-01
Finding food sources is essential for survival. Insects detect nutrients with external taste receptor neurons. Drosophila possesses multiple taste organs that are distributed throughout its body. However, the role of different taste organs in feeding remains poorly understood. By blocking subsets of sweet taste receptor neurons, we show that receptor neurons in the legs are required for immediate sugar choice. Furthermore, we identify two anatomically distinct classes of sweet taste receptor neurons in the leg. The axonal projections of one class terminate in the thoracic ganglia, whereas the other projects directly to the brain. These two classes are functionally distinct: the brain-projecting neurons are involved in feeding initiation, whereas the thoracic ganglia-projecting neurons play a role in sugar-dependent suppression of locomotion. Distinct receptor neurons for the same taste quality may coordinate early appetitive responses, taking advantage of the legs as the first appendages to contact food. PMID:26893070
Regulating infidelity: RNA-mediated recruitment of AID to DNA during class switch recombination.
DiMenna, Lauren J; Chaudhuri, Jayanta
2016-03-01
The mechanism by which the DNA deaminase activation-induced cytidine deaminase (AID) is specifically recruited to repetitive switch region DNA during class switch recombination is still poorly understood. Work over the past decade has revealed a strong link between transcription and RNA polymerase-associated factors in AID recruitment, yet none of these processes satisfactorily explain how AID specificity is affected. Here, we review a recent finding wherein AID is guided to switch regions not by a protein factor but by an RNA moiety, and especially one associated with a noncoding RNA that has been long thought of as being inert. This work explains the long-standing requirement of splicing of noncoding transcripts during class switching, and has implications in both B cell-mediated immunity as well as the underlying pathological syndromes associated with the recombination reaction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Pietiläinen, Olli; Ferrie, Jane; Kivimäki, Mika; Lahti, Jouni; Marmot, Michael; Rahkonen, Ossi; Sekine, Michikazu; Shipley, Martin; Tatsuse, Takashi; Lallukka, Tea
2016-01-01
Introduction: Socioeconomic differences in smoking over time and across national contexts are poorly understood. We assessed the magnitude of relative and absolute social class differences in smoking in cohorts from Britain, Finland, and Japan over 5–7 years. Methods: The British Whitehall II study (n = 4350), Finnish Helsinki Health Study (n = 6328), and Japanese Civil Servants Study (n = 1993) all included employed men and women aged 35–68 at baseline in 1997–2002. Follow-up was in 2003–2007 (mean follow-up 5.1, 6.5, and 3.6 years, respectively). Occupational social class (managers, professionals and clerical employees) was measured at baseline. Current smoking and covariates (age, marital status, body mass index, and self-rated health) were measured at baseline and follow-up. We assessed relative social class differences using the Relative Index of Inequality and absolute differences using the Slope Index of Inequality. Results: Social class differences in smoking were found in Britain and Finland, but not in Japan. Age-adjusted relative differences at baseline ranged from Relative Index of Inequality 3.08 (95% confidence interval 1.99–4.78) among Finnish men to 2.32 (1.24–4.32) among British women, with differences at follow-up greater by 8%–58%. Absolute differences remained stable and varied from Slope Index of Inequality 0.27 (0.15–0.40) among Finnish men to 0.10 (0.03–0.16) among British women. Further adjustment for covariates had modest effects on inequality indices. Conclusions: Large social class differences in smoking persisted among British and Finnish men and women, with widening tendencies in relative differences over time. No differences could be confirmed among Japanese men or women. Implications: Changes over time in social class differences in smoking are poorly understood across countries. Our study focused on employees from Britain, Finland and Japan, and found relative and absolute and class differences among British and Finnish men and women. Key covariates had modest effects on the differences. Relative differences tended to widen over the 4- to 7-year follow-up, whereas absolute differences remained stable. In contrast, class differences in smoking among Japanese men or women were not found. Britain and Finland are at the late stage of the smoking epidemic model, whereas Japan may not follow the same model. PMID:26764256
Protein disulphide isomerase is required for signal peptide peptidase-mediated protein degradation
Lee, Seong-Ok; Cho, Kwangmin; Cho, Sunglim; Kim, Ilkwon; Oh, Changhoon; Ahn, Kwangseog
2010-01-01
The human cytomegalovirus glycoprotein US2 induces dislocation of MHC class I heavy chains from the endoplasmic reticulum (ER) into the cytosol and targets them for proteasomal degradation. Signal peptide peptidase (SPP) has been shown to be integral for US2-induced dislocation of MHC class I heavy chains although its mechanism of action remains poorly understood. Here, we show that knockdown of protein disulphide isomerase (PDI) by RNA-mediated interference inhibited the degradation of MHC class I molecules catalysed by US2 but not by its functional homolog US11. Overexpression of the substrate-binding mutant of PDI, but not the catalytically inactive mutant, dominant-negatively inhibited US2-mediated dislocation of MHC class I molecules by preventing their release from US2. Furthermore, PDI associated with SPP independently of US2 and knockdown of PDI inhibited SPP-mediated degradation of CD3δ but not Derlin-1-dependent degradation of CFTR DeltaF508. Together, our data suggest that PDI is a component of the SPP-mediated ER-associated degradation machinery. PMID:19942855
Protein disulphide isomerase is required for signal peptide peptidase-mediated protein degradation.
Lee, Seong-Ok; Cho, Kwangmin; Cho, Sunglim; Kim, Ilkwon; Oh, Changhoon; Ahn, Kwangseog
2010-01-20
The human cytomegalovirus glycoprotein US2 induces dislocation of MHC class I heavy chains from the endoplasmic reticulum (ER) into the cytosol and targets them for proteasomal degradation. Signal peptide peptidase (SPP) has been shown to be integral for US2-induced dislocation of MHC class I heavy chains although its mechanism of action remains poorly understood. Here, we show that knockdown of protein disulphide isomerase (PDI) by RNA-mediated interference inhibited the degradation of MHC class I molecules catalysed by US2 but not by its functional homolog US11. Overexpression of the substrate-binding mutant of PDI, but not the catalytically inactive mutant, dominant-negatively inhibited US2-mediated dislocation of MHC class I molecules by preventing their release from US2. Furthermore, PDI associated with SPP independently of US2 and knockdown of PDI inhibited SPP-mediated degradation of CD3delta but not Derlin-1-dependent degradation of CFTR DeltaF508. Together, our data suggest that PDI is a component of the SPP-mediated ER-associated degradation machinery.
Bergen, Gwen; West, Bethany A; Luo, Feijun; Bird, Donna C; Freund, Katherine; Fortinsky, Richard H; Staplin, Loren
2017-06-01
Motor-vehicle crashes were the second leading cause of injury death for adults aged 65-84years in 2014. Some older drivers choose to self-regulate their driving to maintain mobility while reducing driving risk, yet the process remains poorly understood. Data from 729 older adults (aged ≥60years) who joined an older adult ride service program between April 1, 2010 and November 8, 2013 were analyzed to define and describe classes of driving self-regulation. Latent class analysis was employed to characterize older adult driving self-regulation classes using driving frequency and avoidance of seven driving situations. Logistic regression was used to explore associations between characteristics affecting mobility and self-regulation class. Three classes were identified (low, medium, and high self-regulation). High self-regulating participants reported the highest proportion of always avoiding seven risky driving situations and the lowest driving frequency followed by medium and low self-regulators. Those who were female, aged 80years or older, visually impaired, assistive device users, and those with special health needs were more likely to be high self-regulating compared with low self-regulating. Avoidance of certain driving situations and weekly driving frequency are valid indicators for describing driving self-regulation classes in older adults. Understanding the unique characteristics and mobility limitations of each class can guide optimal transportation strategies for older adults. Published by Elsevier Ltd.
Electronic and Chemical Properties of a Surface-Terminated Screw Dislocation in MgO
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mckenna, Keith P.
2013-12-18
Dislocations represent an important and ubiquitous class of topological defect found at the surfaces of metal oxide materials. They are thought to influence processes as diverse as crystal growth, corrosion, charge trapping, luminescence, molecular adsorption and catalytic activity, however, their electronic and chemical properties remain poorly understood. Here, through a detailed first principles investigation into the properties of a surface terminated screw dislocation in MgO we provide atomistic insight into these issues. We show that surface dislocations can exhibit intriguing electron trapping properties which are important for understanding the chemical and electronic characteristics of oxide surfaces. The results presented inmore » this article taken together with recent experimental reports show that surface dislocations can be equally as important as more commonly considered surface defects, such as steps, kinks and vacanies, but are now just beginning to be understood.« less
Electronic and Chemical Properties of a Surface-Terminated Screw Dislocation in MgO
2013-01-01
Dislocations represent an important and ubiquitous class of topological defect found at the surfaces of metal oxide materials. They are thought to influence processes as diverse as crystal growth, corrosion, charge trapping, luminescence, molecular adsorption, and catalytic activity; however, their electronic and chemical properties remain poorly understood. Here, through a detailed first-principles investigation into the properties of a surface-terminated screw dislocation in MgO we provide atomistic insight into these issues. We show that surface dislocations can exhibit intriguing electron trapping properties which are important for understanding the chemical and electronic characteristics of oxide surfaces. The results presented in this article taken together with recent experimental reports show that surface dislocations can be equally as important as more commonly considered surface defects, such as steps, kinks, and vacancies, but are now just beginning to be understood. PMID:24279391
Siria, A; Barois, T; Vilella, K; Perisanu, S; Ayari, A; Guillot, D; Purcell, S T; Poncharal, P
2012-07-11
This article presents a study of the poorly understood "shear-force" used in an important class of near-field instruments that use mechanical resonance feedback detection. In the case of a metallic probe near a metallic surface in vacuum, we show that in the 10-60 nm range there is no such a thing as a shear-force in the sense of the nonconservative friction force. Fluctuations of the oscillator resonance frequency, likely induced by local charge variations, could account for the reported effects in the literature without introducing a dissipative force.
Fernandes, Noemi M; Vizzoni, Vinicius F; Borges, Bárbara do N; A G Soares, Carlos; Silva-Neto, Inácio D da; S Paiva, Thiago da
2018-04-18
The odontostomatids are among the least studied ciliates, possibly due to their small sizes, restriction to anaerobic environments and difficulty in culturing. Consequently, their phylogenetic affinities to other ciliate taxa are still poorly understood. In the present study, we analyzed newly obtained ribosomal gene sequences of the odontostomatids Discomorphella pedroeneasi and Saprodinium dentatum, together with sequences from the literature, including Epalxella antiquorum and a large assemblage of ciliate sequences representing the major recognized classes. The results show that D. pedroeneasi and S. dentatum form a deep-diverging branch related to metopid and clevelandellid armophoreans, corroborating the old literature. However E. antiquorum clustered with the morphologically discrepant plagiopylids, indicating that either the complex odontostomatid body architecture evolved convergently, or the positioning of E. antiquorum as a plagiopylid is artifactual. A new ciliate class, Odontostomatea n. cl., is proposed based on molecular analyses and comparative morphology of odontostomatids with related taxa. Copyright © 2018. Published by Elsevier Inc.
Ferguson, Bradley S; Harrison, Brooke C; Jeong, Mark Y; Reid, Brian G; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; McKinsey, Timothy A
2013-06-11
Cardiac hypertrophy is a strong predictor of morbidity and mortality in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors have been shown to suppress cardiac hypertrophy through mechanisms that remain poorly understood. We report that class I HDACs function as signal-dependent repressors of cardiac hypertrophy via inhibition of the gene encoding dual-specificity phosphatase 5 (DUSP5) DUSP5, a nuclear phosphatase that negatively regulates prohypertrophic signaling by ERK1/2. Inhibition of DUSP5 by class I HDACs requires activity of the ERK kinase, mitogen-activated protein kinase kinase (MEK), revealing a self-reinforcing mechanism for promotion of cardiac ERK signaling. In cardiac myocytes treated with highly selective class I HDAC inhibitors, nuclear ERK1/2 signaling is suppressed in a manner that is absolutely dependent on DUSP5. In contrast, cytosolic ERK1/2 activation is maintained under these same conditions. Ectopic expression of DUSP5 in cardiomyocytes results in potent inhibition of agonist-dependent hypertrophy through a mechanism involving suppression of the gene program for hypertrophic growth. These findings define unique roles for class I HDACs and DUSP5 as integral components of a regulatory signaling circuit that controls cardiac hypertrophy.
Th-1 polarization is regulated by dendritic-cell comparison of MHC class I and class II antigens
Xing, Dongxia; Li, Sufang; Robinson, Simon N.; Yang, Hong; Steiner, David; Komanduri, Krishna V.; Shpall, Elizabeth J.
2009-01-01
In the control of T-helper type I (Th-1) polarization, dendritic cells (DCs) must interpret a complex array of stimuli, many of which are poorly understood. Here we demonstrate that Th-1 polarization is heavily influenced by DC-autonomous phenomena triggered by the loading of DCs with antigenically matched major histocompatibility complex (MHC) class I and class II determinants, that is, class I and II peptide epitopes exhibiting significant amino acid sequence overlap (such as would be physiologically present during infectious processes requiring Th-1 immunity for clearance). Data were derived from 13 independent antigenic models including whole-cell systems, single-protein systems, and 3 different pairs of overlapping class I and II binding epitopes. Once loaded with matched class I and II antigens, these “Th-1 DCs” exhibited differential cytokine secretion and surface marker expression, a distinct transcriptional signature, and acquired the ability to enhance generation of CD8+ T lymphocytes. Mechanistically, tRNA-synthetases were implicated as components of a putative sensor complex involved in the comparison of class I and II epitopes. These data provide rigorous conceptual explanations for the process of Th-1 polarization and the antigenic specificity of cognate T-cell help, enhance the understanding of Th-1 responses, and should contribute to the formulation of more effective vaccination strategies. PMID:19171878
Green, Michael J; Espie, Colin A; Hunt, Kate; Benzeval, Michaela
2012-06-01
The natural history of insomnia symptomatology is poorly understood. Cross-sectional associations have been demonstrated among socioeconomic disadvantage, female sex, and poor sleep but it is unclear how these social factors predict patterns of insomnia symptoms over time. The aim of this article is to describe longitudinal patterns of insomnia symptoms as people age and investigate how they vary by sex and occupational class. A prospective cohort study with 20 yr of follow-up from 1987 to 1988. West of Scotland. One cohort approximately 36 yr of age at baseline aging to 57 yr (n = 1,444), and another aging from approximately 56 to 76 yr (n = 1,551). N/A. At approximately 5-yr intervals, respondents self-reported trouble initiating and maintaining sleep. Latent class analysis identified 4 main sleep patterns: a healthy pattern with little sleeping trouble across the 20 yr; an episodic pattern, characterized by trouble maintaining sleep; a chronic pattern with trouble maintaining and initiating sleep throughout the study; and a pattern where symptoms developed during the 20-yr follow-up. Chronic patterns were more likely in the older cohort than the younger one, for women than men in the older cohort, and for those from a manual rather than a nonmanual occupational class in both cohorts. In the middle-aged cohort a developing pattern was more likely for women than men. Chronic symptoms, characterized by both trouble maintaining and initiating sleep, are patterned by social factors.
Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation
Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong
2013-01-01
As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media. PMID:23938301
Patterson, Larissa B.; Bain, Emily J.; Parichy, David M.
2014-01-01
Fishes have diverse pigment patterns, yet mechanisms of pattern evolution remain poorly understood. In zebrafish, Danio rerio, pigment-cell autonomous interactions generate dark stripes of melanophores that alternate with light interstripes of xanthophores and iridophores. Here, we identify mechanisms underlying the evolution of a uniform pattern in D. albolineatus in which all three pigment cell classes are intermingled. We show that in this species xanthophores differentiate precociously over a wider area, and that cis regulatory evolution has increased expression of xanthogenic Colony Stimulating Factor-1 (Csf1). Expressing Csf1 similarly in D. rerio has cascading effects, driving the intermingling of all three pigment cell classes and resulting in the loss of stripes, as in D. albolineatus. Our results identify novel mechanisms of pattern development and illustrate how pattern diversity can be generated when a core network of pigment-cell autonomous interactions is coupled with changes in pigment cell differentiation. PMID:25374113
Confinement Stabilizes a Bacterial Suspension into a Spiral Vortex
NASA Astrophysics Data System (ADS)
Wioland, Hugo; Woodhouse, Francis G.; Dunkel, Jörn; Kessler, John O.; Goldstein, Raymond E.
2013-06-01
Confining surfaces play crucial roles in dynamics, transport, and order in many physical systems, but their effects on active matter, a broad class of dynamically self-organizing systems, are poorly understood. We investigate here the influence of global confinement and surface curvature on collective motion by studying the flow and orientational order within small droplets of a dense bacterial suspension. The competition between radial confinement, self-propulsion, steric interactions, and hydrodynamics robustly induces an intriguing steady single-vortex state, in which cells align in inward spiraling patterns accompanied by a thin counterrotating boundary layer. A minimal continuum model is shown to be in good agreement with these observations.
Proteomics show antigen presentation processes in human immune cells after AS03-H5N1 vaccination.
Galassie, Allison C; Goll, Johannes B; Samir, Parimal; Jensen, Travis L; Hoek, Kristen L; Howard, Leigh M; Allos, Tara M; Niu, Xinnan; Gordy, Laura E; Creech, C Buddy; Hill, Heather; Joyce, Sebastian; Edwards, Kathryn M; Link, Andrew J
2017-06-01
Adjuvants enhance immunity elicited by vaccines through mechanisms that are poorly understood. Using a systems biology approach, we investigated temporal protein expression changes in five primary human immune cell populations: neutrophils, monocytes, natural killer cells, T cells, and B cells after administration of either an Adjuvant System 03 adjuvanted or unadjuvanted split-virus H5N1 influenza vaccine. Monocytes demonstrated the strongest differential signal between vaccine groups. On day 3 post-vaccination, several antigen presentation-related pathways, including MHC class I-mediated antigen processing and presentation, were enriched in monocytes and neutrophils and expression of HLA class I proteins was increased in the Adjuvant System 03 group. We identified several protein families whose proteomic responses predicted seroprotective antibody responses (>1:40 hemagglutination inhibition titer), including inflammation and oxidative stress proteins at day 1 as well as immunoproteasome subunit (PSME1 and PSME2) and HLA class I proteins at day 3 in monocytes. While comparison between temporal proteomic and transcriptomic results showed little overlap overall, enrichment of the MHC class I antigen processing and presentation pathway in monocytes and neutrophils was confirmed by both approaches. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Magnetic Field of the Class I Protostar WL 17
NASA Astrophysics Data System (ADS)
Johns-Krull, Christopher M.; Greene, T. P.; Doppmann, G.; Covey, K. R.
2007-12-01
Strong stellar magnetic fields are believed to truncate the inner accretion disks around young stars, redirecting the accreting material to the high latitude regions of the stellar surface. In the past few years, observations of strong stellar fields on Classical T Tauri stars [class II young stellar objects (YSOs)] with field strengths in general agreement with the predictions of magnetopsheric accretion theory have bolstered this picture. Currently, nothing is known about the magnetic field properties of younger, more embedded class I YSOs. It is during this protostellar evolutionary phase that stars accrete most of their final mass, but the physics governing this process remains poorly understood. Here, we use high resolution near infrared spectra obtained with NIRSPEC on Keck and with PHOENIX on Gemini South to measure the magnetic field properties of the class I protostar WL 17. We find clear signatures of a strong stellar magnetic field. Initial analysis of this data suggests a surface average field strength of 3.6 kG on the surface of WL 17. This is the highest mean surface field detected to date on any YSO. We present our field measurements and discuss how they fit with the general model of magnetospheric accretion in young stars.
Ferguson, Bradley S.; Harrison, Brooke C.; Jeong, Mark Y.; Reid, Brian G.; Wempe, Michael F.; Wagner, Florence F.; Holson, Edward B.; McKinsey, Timothy A.
2013-01-01
Cardiac hypertrophy is a strong predictor of morbidity and mortality in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors have been shown to suppress cardiac hypertrophy through mechanisms that remain poorly understood. We report that class I HDACs function as signal-dependent repressors of cardiac hypertrophy via inhibition of the gene encoding dual-specificity phosphatase 5 (DUSP5) DUSP5, a nuclear phosphatase that negatively regulates prohypertrophic signaling by ERK1/2. Inhibition of DUSP5 by class I HDACs requires activity of the ERK kinase, mitogen-activated protein kinase kinase (MEK), revealing a self-reinforcing mechanism for promotion of cardiac ERK signaling. In cardiac myocytes treated with highly selective class I HDAC inhibitors, nuclear ERK1/2 signaling is suppressed in a manner that is absolutely dependent on DUSP5. In contrast, cytosolic ERK1/2 activation is maintained under these same conditions. Ectopic expression of DUSP5 in cardiomyocytes results in potent inhibition of agonist-dependent hypertrophy through a mechanism involving suppression of the gene program for hypertrophic growth. These findings define unique roles for class I HDACs and DUSP5 as integral components of a regulatory signaling circuit that controls cardiac hypertrophy. PMID:23720316
Class I HDACs control a JIP1-dependent pathway for kinesin-microtubule binding in cardiomyocytes
Blakeslee, Weston W.; Lin, Ying-Hsi; Stratton, Matthew S.; Tatman, Philip D.; Hu, Tianjing; Ferguson, Bradley S.; McKinsey, Timothy A.
2018-01-01
Class I histone deacetylase (HDAC) inhibitors block hypertrophy and fibrosis of the heart by suppressing pathological signaling and gene expression programs in cardiac myocytes and fibroblasts. The impact of HDAC inhibition in unstressed cardiac cells remains poorly understood. Here, we demonstrate that treatment of cultured cardiomyocytes with small molecule HDAC inhibitors leads to dramatic induction of c-Jun amino-terminal kinase (JNK)-interacting protein-1 (JIP1) mRNA and protein expression. In contrast to prior findings, elevated levels of endogenous JIP1 in cardiomyocytes failed to significantly alter JNK signaling or cardiomyocyte hypertrophy. Instead, HDAC inhibitor-mediated induction of JIP1 was required to stimulate expression of the kinesin heavy chain family member, KIF5A. We provide evidence for an HDAC-dependent regulatory circuit that promotes formation of JIP1:KIF5A:microtubule complexes that regulate intracellular transport of cargo such as autophagosomes. These findings define a novel role for class I HDACs in the control of the JIP1/kinesin axis in cardiomyocytes, and suggest that HDAC inhibitors could be used to alter microtubule transport in the heart. PMID:28886967
Dankner, Matthew; Lajoie, Mathieu; Moldoveanu, Dan; Nguyen, Tan-Trieu; Savage, Paul; Rajkumar, Shivshankari; Huang, Xiu; Lvova, Maria; Protopopov, Alexei; Vuzman, Dana; Hogg, David; Park, Morag; Guiot, Marie-Christine; Petrecca, Kevin; Mihalcioiu, Catalin; Watson, Ian R; Siegel, Peter M; Rose, April A N
2018-06-14
Dual MAPK pathway inhibition (dMAPKi) with BRAF and MEK inhibitors improves survival in BRAF V600E/K mutant melanoma, but the efficacy of dMAPKi in non-V600 BRAF mutant tumors is poorly understood. We sought to characterize the responsiveness of class II (enhanced kinase activity, dimerization dependent) BRAF mutant melanoma to dMAPKi. Tumors from patients with BRAF WT, V600E (class I) and L597S (class II) metastatic melanoma were used to generate patient-derived-xenografts (PDX). We assembled a panel of melanoma cell lines with class IIa (activation segment) or IIb (p-loop) mutations and compared these to wild-type or V600E/K BRAF mutant cells. Cell lines and PDXs were treated with BRAFi (vemurafenib, dabrafenib, encorafenib, LY3009120), MEKi (cobimetinib, trametinib, binimetinib) or the combination. We identified two patients with BRAF L597S metastatic melanoma who were treated with dMAPKi. BRAFi impaired MAPK signalling and cell growth in class I and II BRAF mutant cells. dMAPKi was more effective than either single MAPKi at inhibiting cell growth in all class II BRAF mutant cells tested. dMAPKi caused tumor regression in two melanoma PDXs with class II BRAF mutations, and prolonged survival of mice with class II BRAF mutant melanoma brain metastases. Two patients with BRAF L597S mutant melanoma clinically responded to dMAPKi. Class II BRAF mutant melanoma are growth inhibited by dMAPKi. Responses to dMAPKi have been observed in two patients with class II BRAF mutant melanoma. This data provides rationale for clinical investigation of dMAPKi in patients with class II BRAF mutant metastatic melanoma. Copyright ©2018, American Association for Cancer Research.
How to train your microbe: methods for dynamically characterizing gene networks
Castillo-Hair, Sebastian M.; Igoshin, Oleg A.; Tabor, Jeffrey J.
2015-01-01
Gene networks regulate biological processes dynamically. However, researchers have largely relied upon static perturbations, such as growth media variations and gene knockouts, to elucidate gene network structure and function. Thus, much of the regulation on the path from DNA to phenotype remains poorly understood. Recent studies have utilized improved genetic tools, hardware, and computational control strategies to generate precise temporal perturbations outside and inside of live cells. These experiments have, in turn, provided new insights into the organizing principles of biology. Here, we introduce the major classes of dynamical perturbations that can be used to study gene networks, and discuss technologies available for creating them in a wide range of microbial pathways. PMID:25677419
Cañavate, José Pedro; Armada, Isabel; Hachero-Cruzado, Ismael
2017-01-01
The response of marine microalgal lipids to phosphorus is of central importance in phytoplankton ecology but remains poorly understood. We determined how taxonomically diverse microalgal species remodelled their lipid class profile in response to phosphorus availability and whether these changes coincided with those already known to occur in land plants and in the limited number of phytoplankton species for which data are available. The complete lipid class profile and specific lipid ratios influenced by phosphorus availability were quantified in two green microalgae and seven Chromalveolates exposed to phosphorus repletion, deprivation and replenishment. Lipid class cell quota changes in the two green microalgae resembled the currently described pattern of betaine lipids substituting for phospholipids under phosphorus depletion, whereas only two of the studied Chromalveolates showed this pattern. Sulpholipids counterbalanced phosphatidylglycerol only in Picochlorum atomus. In all other species, both lipids decreased simultaneously under phosphorus deprivation, although sulpholipids declined more slowly. Phosphorus deprivation always induced a decrease in digalactosyl-diacylglycerol. However, the ratio of digalactosyl-diacylglycerol to total phospholipids increased in eight species and remained unchanged in Isochrysis galbana. Marine phytoplankton seems to have evolved a diversified mechanism for remodelling its lipid class profile under the influence of phosphorus, with cryptophytes and particularly haptophytes exhibiting previously unobserved lipid responses to phosphorus. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matthews, S. A.; Zharkov, S.; Zharkova, V. V.
2011-10-01
Some of the most challenging observations to explain in the context of existing flare models are those related to the lower atmosphere and below the solar surface. Such observations, including changes in the photospheric magnetic field and seismic emission, indicate the poorly understood connections between energy release in the corona and its impact in the photosphere and the solar interior. Using data from Hinode, TRACE, RHESSI, and GONG we study the temporal and spatial evolution of the 2006 December 14 X-class flare in the chromosphere, photosphere, and the solar interior. We investigate the connections between the emission at various atmosphericmore » depths, including acoustic signatures obtained by time-distance and holography methods from the GONG data. We report the horizontal displacements observed in the photosphere linked to the timing and locations of the acoustic signatures we believe to be associated with this flare, their vertical and horizontal displacement velocities, and their potential implications for current models of flare dynamics.« less
A morphometric assessment and classification of coral reef spur and groove morphology
NASA Astrophysics Data System (ADS)
Duce, S.; Vila-Concejo, A.; Hamylton, S. M.; Webster, J. M.; Bruce, E.; Beaman, R. J.
2016-07-01
Spurs and grooves (SaGs) are a common and important feature of coral reef fore slopes worldwide. However, they are difficult to access and hence their morphodynamics and formation are poorly understood. We use remote sensing, with extensive ground truthing, to measure SaG morphometrics and environmental factors at 11,430 grooves across 17 reefs in the southern Great Barrier Reef, Australia. We revealed strong positive correlations between groove length, orientation and wave exposure with longer, more closely-spaced grooves oriented easterly reflecting the dominant swell regime. Wave exposure was found to be the most important factor controlling SaG distribution and morphology. Gradient of the upper reef slope was also an important limiting factor, with SaGs less likely to develop in steeply sloping (> 5°) areas. We used a subset of the morphometric data (11 reefs) to statistically define four classes of SaG. This classification scheme was tested on the remaining six reefs. SaGs in the four classes differ in morphology, groove substrate and coral cover. These differences provide insights into SaG formation mechanisms with implications to reef platform growth and evolution. We hypothesize SaG formation is dominated by coral growth processes at two classes and erosion processes at one class. A fourth class may represent relic features formed earlier in the Holocene transgression. The classes are comparable with SaGs elsewhere, suggesting the classification could be applied globally with the addition of new classes if necessary. While further research is required, we show remotely sensed SaG morphometrics can provide useful insights into reef platform evolution.
Long non-coding RNAs in cancer metabolism.
Xiao, Zhen-Dong; Zhuang, Li; Gan, Boyi
2016-10-01
Altered cellular metabolism is an emerging hallmark of cancer. Accumulating recent evidence links long non-coding RNAs (lncRNAs), a still poorly understood class of non-coding RNAs, to cancer metabolism. Here we review the emerging findings on the functions of lncRNAs in cancer metabolism, with particular emphasis on how lncRNAs regulate glucose and glutamine metabolism in cancer cells, discuss how lncRNAs regulate various aspects of cancer metabolism through their cross-talk with other macromolecules, explore the mechanistic conceptual framework of lncRNAs in reprogramming metabolism in cancers, and highlight the challenges in this field. A more in-depth understanding of lncRNAs in cancer metabolism may enable the development of novel and effective therapeutic strategies targeting cancer metabolism. © 2016 WILEY Periodicals, Inc.
Laboratory tests for mumps vaccines.
Minor, P D
1997-03-01
The action of live attenuated vaccines against mumps is poorly understood although their clinical efficacy is beyond doubt. The attenuated character of the vaccine is assured by consistency of production related to clinical trials, and limited studies of vaccine seeds in primates. Potency is assessed by infectivity in vitro and is subject to poorly understood sources of variation. Molecular biological studies are at an early stage.
2015-10-01
FORD CLASS AIRCRAFT CARRIER Poor Outcomes Are the Predictable Consequences of the Prevalent Acquisition Culture...2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Ford Class Aircraft Carrier: Poor Outcomes Are the Predictable...This Study The Navy set ambitious goals for the Ford -class program, including an array of new technologies and design features that were intended
Defining Social Class Across Time and Between Groups.
Cohen, Dov; Shin, Faith; Liu, Xi; Ondish, Peter; Kraus, Michael W
2017-11-01
We examined changes over four decades and between ethnic groups in how people define their social class. Changes included the increasing importance of income, decreasing importance of occupational prestige, and the demise of the "Victorian bargain," in which poor people who subscribed to conservative sexual and religious norms could think of themselves as middle class. The period also saw changes (among Whites) and continuity (among Black Americans) in subjective status perceptions. For Whites (and particularly poor Whites), their perceptions of enhanced social class were greatly reduced. Poor Whites now view their social class as slightly but significantly lower than their poor Black and Latino counterparts. For Black respondents, a caste-like understanding of social class persisted, as they continued to view their class standing as relatively independent of their achieved education, income, and occupation. Such achievement indicators, however, predicted Black respondents' self-esteem more than they predicted self-esteem for any other group.
Zha, Hong-Guang; Milne, Richard I; Zhou, Hong-Xia; Chen, Xiang-Yang; Sun, Hang
2016-10-01
Class II and III chitinases belonging to different glycoside hydrolase families were major nectarins in Rhododendron irroratum floral nectar which showed significant chitinolytic activity. Previous studies have demonstrated antimicrobial activity in plant floral nectar, but the molecular basis for the mechanism is still poorly understood. Two chitinases, class II (Rhchi2) and III (Rhchi3), were characterized from alkaline Rhododendron irroratum nectar by both SDS-PAGE and mass spectrometry. Rhchi2 (27 kDa) and Rhchi3 (29 kDa) are glycoside hydrolases (family 19 and 18) with theoretical pI of 8.19 and 7.04. The expression patterns of Rhchi2 and Rhchi3 were analyzed by semi-quantitative RT-PCR. Rhchi2 is expressed in flowers (corolla nectar pouches) and leaves while Rhchi3 is expressed in flowers. Chitinase in concentrated protein and fresh nectar samples was visualised by SDS-PAGE and chitinolytic activity in fresh nectar was determined spectrophotometrically via chitin-azure. Full length gene sequences were cloned with Tail-PCR and RACE. The amino acid sequence deduced from the coding region for these proteins showed high identity with known chitinases and predicted to be located in extracellular space. Fresh R. irroratum floral nectar showed significant chitinolytic activity. Our results demonstrate that class III chitinase (GH 18 family) also exists in floral nectar. The functional relationship between class II and III chitinases and the role of these pathogenesis-related proteins in antimicrobial activity in nectar is suggested.
Blood parasites shape extreme major histocompatibility complex diversity in a migratory passerine.
Biedrzycka, Aleksandra; Bielański, Wojciech; Ćmiel, Adam; Solarz, Wojciech; Zając, Tadeusz; Migalska, Magdalena; Sebastian, Alvaro; Westerdahl, Helena; Radwan, Jacek
2018-06-01
Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen-mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes, and using data from high-throughput MHC genotyping, we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long-term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, that is avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers and possibly also in other passerines where avian malaria is a common disease. © 2018 John Wiley & Sons Ltd.
DeMartini, Kelly S; Fucito, Lisa M
2014-10-01
Sleep disturbance and heavy drinking increase risk of negative consequences in college students. Limited research exists on how they act synergistically, and the overall nature of sleep and sleep-related impairment in college student drinkers is poorly understood. A latent profile analysis was conducted on the sleep characteristics and daytime sleep-related consequences of college student drinkers who were at-risk based on Alcohol Use Disorders Identification Test-Consumption scores. Participants (N = 312, mean age = 18.90 (0.97) years) consumed a mean (SD) of 20.93 (13.04) drinks per week. Scores on the 10 items of the Sleep/Wake Behavior Problems Scale (SWPS) were the class indicators. Four classes best described the sleep and sleep-related consequences of at-risk college drinkers. Classes represented different gradients and types of sleep patterns and sleep-related impairment; nearly half the sample reported late bedtimes and daytime consequences of insufficient sleep. Subsequent validation analyses indicated that these classes were directly correspondent with severity of alcohol consumption, alcohol-related consequences illicit substance use, and perceived health. These findings indicate the presence of significant heterogeneity in college drinkers' sleep patterns and experiences of sleep-related impairment. Class differences significantly impact the level of alcohol and drug use and the consequences members experience. Greater alcohol use and sleep/wake problems are associated with increased risk for negative consequences for certain classes. These results suggest that college drinking interventions could benefit from the incorporation of sleep-related content and the value in adding brief alcohol assessments and interventions to other college health treatments.
Richer, Isabelle; Lee, Jennifer E C; Born, Jennifer
2016-04-07
Heavy drinking increases the risk of injury, adverse physical and mental health outcomes, and loss of productivity. Nonetheless, patterns of alcohol use and related symptomatology among military personnel remain poorly understood. A latent class analysis (LCA) was used to explore the presence of subgroups of alcohol users among Canadian Armed Forces (CAF) Regular Forces members. Correlates of empirically derived subgroups were further explored. Analyses were performed on a subsample of alcohol users who participated in a 2008/09 cross-sectional survey of a stratified random sample of currently serving CAF Regular Force members (N = 1980). Multinomial logistic regression models were conducted to verify physical and mental health differences across subgroups of alcohol users. All analyses were adjusted for complex survey design. A 4-class solution was considered the best fit for the data. Subgroups were labeled as follows: Class 1 - Infrequent drinkers (27.2%); Class 2 - Moderate drinkers (41.5%); Class 3 - Regular binge drinkers with minimal problems (14.8%); and Class 4 - Problem drinkers (16.6%). Significant differences by age, sex, marital status, element, rank, recent serious injuries, chronic conditions, psychological distress, posttraumatic stress disorder, and depression symptoms were found across the subgroups. Problem drinkers demonstrated the most degraded physical and mental health. Findings highlight the heterogeneity of alcohol users and heavy drinkers among CAF members and the need for tailored interventions addressing high-risk alcohol use. Results have the potential to inform prevention strategies and screening efforts. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Farkas, Jerneja; Pahor, Majda; Zaletel-Kragelj, Lijana
2011-02-01
Self-rated health can be influenced by several characteristics of the social environment. The aim of this study was to evaluate the relationship between self-rated health and self-assessed social class in Slovenian adult population. The study was based on the Countrywide Integrated Non-communicable Diseases Intervention Health Monitor database. During 2004, 8,741/15,297 (57.1%) participants aged 25-64 years returned posted self-administered questionnaire. Logistic regression was used to determine unadjusted and adjusted estimates of association between poor self-rated health and self-assessed social class. Poor self-rated health was reported by 9.6% of participants with a decrease from lower to upper-middle/upper self-assessed social class (35.9 vs. 3.7%). Logistic regression showed significant association between self-rated health and all self-assessed social classes. In an adjusted model, poor self-rated health remained associated with self-assessed social class (odds ratio for lower vs. upper-middle/upper self-assessed social class 4.23, 95% confidence interval 2.46-7.25; P < 0.001). Our study confirmed differences in the prevalence of poor self-rated health across self-assessed social classes. Participants from lower self-assessed social class reported poor self-rated health most often and should comprise the focus of multisectoral interventions.
A Tale of Two Classes: The Black Poor and the Black Middle Class.
ERIC Educational Resources Information Center
Lewin, Arthur
1991-01-01
To understand the African-American family, the African-American poor and middle class must be investigated. Extra costs mean that it is much harder for African Americans to reach the middle class. Ways to improve the economic status of African-American families and to increase the middle class are discussed. (SLD)
Gender and the Construction of Class.
ERIC Educational Resources Information Center
Acker, Joan
Only by recognizing that class is not gender neutral can the processes of class formation and reproduction be understood. Class is defined as a process in which human beings take an active part, rather than a structure of categories into which individuals may be inserted. Gender organizes or structures class in many different ways. For example,…
The dynamics of gender and class in access to health care: evidence from rural Karnataka, India.
Iyer, Aditi; Sen, Gita; George, Asha
2007-01-01
In the early 1990s, India embarked upon a course of health sector reform, the impact of which on an already unequal society is now becoming more apparent. This study sought to deepen understanding of equity effects by exploring gender and class dynamics vis-à-vis basic access to health care for self-reported long-term ailments. The authors drew on the results of a cross-sectional household survey in a poor agrarian region of south India to test whether gender bias in treatment-seeking is class-neutral and whether class bias is gender-neutral. They found evidence of "pure gender bias" in non-treatment operating against both non-poor and poor women, and evidence of "rationing bias" in discontinued treatment operating against poor women overall, but with some differences between the poor and poorest households. In poor households, men insulated themselves and passed the entire burden of rationing onto women; but among the poorest, men, like women, were forced to curtail treatment. There were economic class differences in continued, discontinued, and no treatment, but class was a gendered phenomenon operating through women, not men.
Studies of the Coldest Brown Dwarfs With The James Webb Space Telescope
NASA Astrophysics Data System (ADS)
Roellig, Thomas L.; Greene, Thomas P.; Beichman, Charles; Meyer, Michael; Rieke, Marcia
2016-07-01
The coolest T and Y-class Brown Dwarf objects are very faint and are therefore very poorly understood, since they are barely detectable with the current astronomical instrumentation. The upcoming James Webb Space Telescope now in development for a launch in the Fall of 2018 will have vastly increased sensitivity in the near and mid-infrared compared to any current facilities and will not be affected by telluric absorption over its entire wavelength range of operations. As a result it will be an ideal tool to obtain information about the composition and temperature-pressure structure in these objects' atmospheres. This presentation outlines the JWST guaranteed time observing plans for these studies. These plans comprise both spectro-photometric and spectroscopic observations of a selection of late T and Y-dwarf targets.
Alkylation Damage by Lipid Electrophiles Targets Functional Protein Systems*
Codreanu, Simona G.; Ullery, Jody C.; Zhu, Jing; Tallman, Keri A.; Beavers, William N.; Porter, Ned A.; Marnett, Lawrence J.; Zhang, Bing; Liebler, Daniel C.
2014-01-01
Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells treated with lipid electrophile probes. Protein target profiles revealed three damage susceptibility classes, as well as proteins that were highly resistant to alkylation. Damage occurred selectively across functional protein interaction networks, with the most highly alkylation-susceptible proteins mapping to networks involved in cytoskeletal regulation. Proteins with lower damage susceptibility mapped to networks involved in protein synthesis and turnover and were alkylated only at electrophile concentrations that caused significant toxicity. Hierarchical susceptibility of proteome systems to alkylation may allow cells to survive sublethal damage while protecting critical cell functions. PMID:24429493
TMEM150C/Tentonin3 Is a Regulator of Mechano-gated Ion Channels.
Anderson, Evan O; Schneider, Eve R; Matson, Jon D; Gracheva, Elena O; Bagriantsev, Sviatoslav N
2018-04-17
Neuronal mechano-sensitivity relies on mechano-gated ion channels, but pathways regulating their activity remain poorly understood. TMEM150C was proposed to mediate mechano-activated current in proprioceptive neurons. Here, we studied functional interaction of TMEM150C with mechano-gated ion channels from different classes (Piezo2, Piezo1, and the potassium channel TREK-1) using two independent methods of mechanical stimulation. We found that TMEM150C significantly prolongs the duration of the mechano-current produced by all three channels, decreases apparent activation threshold in Piezo2, and induces persistent current in Piezo1. We also show that TMEM150C is co-expressed with Piezo2 in trigeminal neurons, expanding its role beyond proprioceptors. Finally, we cloned TMEM150C from the trigeminal neurons of the tactile-foraging domestic duck and showed that it functions similarly to the mouse ortholog, demonstrating evolutionary conservation among vertebrates. Our studies reveal TMEM150C as a general regulator of mechano-gated ion channels from different classes. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.
A Class of Reactive Acyl-CoA Species Reveals the Non-Enzymatic Origins of Protein Acylation
Wagner, Gregory R.; Bhatt, Dhaval P.; O’Connell, Thomas M.; Thompson, J. Will; Dubois, Laura G.; Backos, Donald S.; Yang, Hao; Mitchell, Grant A.; Ilkayeva, Olga R.; Stevens, Robert D.; Grimsrud, Paul A.; Hirschey, Matthew D.
2017-01-01
SUMMARY The mechanisms underlying the formation of acyl protein modifications remain poorly understood. By investigating the reactivity of endogenous acyl-CoA metabolites, we found a class of acyl-CoAs that undergoes intramolecular catalysis to form reactive intermediates which non-enzymatically modify proteins. Based on this mechanism, we predicted, validated, and characterized a protein modification: 3-hydroxy-3-methylglutaryl(HMG)-lysine. In a model of altered HMG-CoA metabolism, we found evidence of two additional protein modifications: 3-methylglutaconyl(MGc)-lysine and 3-methylglutaryl(MG)-lysine. Using quantitative proteomics, we compared the ‘acylomes’ of two reactive acyl-CoA species, namely HMG-CoA and glutaryl-CoA, which are generated in different pathways. We found proteins that are uniquely modified by each reactive metabolite, as well as common proteins and pathways. We identified the tricarboxylic acid cycle as a pathway commonly regulated by acylation, and validated malate dehydrogenase as a key target. These data uncover a fundamental relationship between reactive acyl-CoA species and proteins, and define a new regulatory paradigm in metabolism. PMID:28380375
B Cells and Humoral Immunity in Atherosclerosis
Tsiantoulas, Dimitrios; Diehl, Cody J.; Witztum, Joseph L.; Binder, Christoph J.
2014-01-01
Insights into the important contribution of inflammation and immune functions in the development and progression of atherosclerosis have greatly improved our understanding of this disease. Although the role of T cells has been extensively studied for decades, only recently has the role of B cells gained more attention. Recent studies have identified differential effects of different B-cell subsets and helped to clarify the still poorly understood mechanisms by which these act. B1 cells have been shown to prevent lesion formation, whereas B2 cells have been suggested to promote it. Natural IgM antibodies, mainly derived from B1 cells, have been shown to mediate atheroprotective effects, but the functional role of other immunoglobulin classes, particularly IgG, still remains elusive. In this review, we will focus on recent insights on the role of B cells and various immunoglobulin classes and how these may mediate their effects in atherosclerotic lesion formation. Moreover, we will highlight potential therapeutic approaches focusing on B-cell depletion that could be used to translate experimental evidence to human disease. PMID:24855199
ERIC Educational Resources Information Center
Hoff, Dominic A.; Andersen, Anette; Holstein, Bjorn E.
2010-01-01
There is little information available on the topic of poor school satisfaction as a risk factor for cannabis use among adolescents. We examined if there was an association between poor school satisfaction, school class cannabis use and individual cannabis use. Further, we investigated if many cannabis users within the school class statistically…
The Unknown City: Lives of Poor and Working-Class Young Adults.
ERIC Educational Resources Information Center
Fine, Michelle; Weis, Lois
The deeply fractured nature of U.S. society is examined, focusing on poor and working class people in cities. Based on data from 154 poor and working class young adults aged 23 to 35, the study reveals the ways in which this urban generation has suffered from social change. The following chapters are included: (1) "Voices of Hope and Despair:…
Xerostomia is associated with old age and poor appetite in patients on chronic hemodialysis.
Bossola, Maurizio; Di Stasio, Enrico; Giungi, Stefania; Vulpio, Carlo; Papa, Valerio; Rosa, Fausto; Tortorelli, Antonio; Tazza, Luigi
2013-11-01
The objective of this study was to assess variables associated with xerostomia in patients on chronic hemodialysis (HD). This was a cross-sectional study of 75 HD patients at an outpatient HD service. Demographic, clinical (renal disease, HD regimen/duration, Charlson comorbidity index, activities of daily living, instrumental activities of daily living [IADL], body mass index), and laboratory (hemoglobin, albumin, interleukin-6 [IL-6], and parathyroid hormone) parameters were recorded. We assessed the appetite through the Hemodialysis Study Appetite questionnaire and xerostomia through the Xerostomia Inventory (XI). A single question ("How often does your mouth feel dry?"; never = Class 1, almost never = Class 2, occasionally = Class 3, often = Class 4, very often = Class 5) was also included in the study questionnaire. The main outcome measure was factors correlated with XI. The median XI score was 18 (min-max = 11-33). Forty patients had an XI score of 18 or less (Group 1) and between 18 and 35 (Group 2). In Group 2, age, Charlson comorbidity index score, and number of patients with poor/very poor appetite were significantly higher. At the univariate analysis, the score of the XI was significantly associated with age, appetite, IADL, Charlson comorbidity index, and serum IL-6 levels. Multiple linear regression analysis showed that the XI was independently associated with age and appetite. Thirty-one patients were in Class 1 to 2, 23 were in Class 3, and 21 were in Class 4 to 5. In Classes 4 to 5, age and the number of patients with poor/very poor appetite were higher (P = .012 and .09, respectively). Xerostomia is associated with old age and poor appetite in patients on chronic HD. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Lahelma, Eero; Laaksonen, Mikko; Aittomäki, Akseli
2009-01-01
While health inequalities among employees are well documented, their variation and determinants among employee subpopulations are poorly understood. We examined variations in occupational class inequalities in health within four employment sectors and the contribution of working conditions to these inequalities. Cross-sectional data from the Helsinki Health Study in 2000-2002 were used. Each year, employees of the City of Helsinki, aged 40-60 years, received a mailed questionnaire (n = 8,960, 80% women, overall response rate for 3 years 67%). The outcome was physical health functioning measured by the overall physical component summary of SF-36. The socioeconomic indicator was occupational social class. Employment sectors studied were health care, education, social welfare and administration (n = 6,557). Physical and mental workload, and job demands and job control were explanatory factors. Inequality indices from logistic regression analysis were calculated. Occupational class inequalities in physical health functioning were slightly larger in education (1.47) than in the other sectors (1.43-1.40). Physical workload explained 95% of inequalities in social welfare and 32-36% in the other sectors. Job control also partly explained health inequalities. However, adjusting for mental workload and job demands resulted in larger health inequalities. Inequalities in physical health functioning were found within each employment sector, with minor variation in their magnitude. Physical workload was the main explanation for these inequalities, but its contribution varied between the sectors. In contrast, considering psychosocial working conditions led to wider inequalities. Improving physical working conditions among the lower occupational classes would help reduce health inequalities within different employment sectors.
1985-09-02
34 among the enemies and any variance of interests among the bourgeoisie of various countries, among groups or types of bourgeoisie within individual...He who has not understood this has not understood a grain of Marxism and of scientific, modern socialism in general.ൣ The activity of the Soviet...and rural workers, intelligentsia, and petty and some middle bourgeoisie took part in it. A special role belonged to the working class, which
Holseter, Christoffer; Dalen, Joakim Døving; Krokstad, Steinar; Eikemo, Terje Andreas
2015-03-10
People with a lower socioeconomic position have a higher the prevalence of most self-rated health problems. In this article we ask whether this may be attributed to self-rated health not reflecting actual health, understood as mortality, in different socioeconomic groups. For the study we used data from the Nord-Trøndelag Health Study 1984-86 (HUNT1), in which the county's entire adult population aged 20 years and above were invited to participate. The association between self-rated health and mortality in different occupational classes and income groups was analysed. The analysis corrected for age, chronic disease, functional impairment and lifestyle factors. The association between self-rated health and mortality was of the same order of magnitude for the occupational classes and income groups, but persons without work/income and with poor self-rated health stood out. Compared with persons in the highest socioeconomic class, unemployed men had a hazard ratio for death that was three times higher in the follow-up period. For women with no income, the ratio was twice as high. INTERPRETATION Self-rated health and mortality largely conform to the different socioeconomic strata. This supports the perception that socioeconomic differences in health are a reality and represent a significant challenge nationally. Our results also increase the credibility of findings from other studies that use self-reported health in surveys to measure differences and identify the mechanisms that create them.
Mohan, Indu; Gupta, Rajeev; Misra, Anoop; Sharma, Krishna Kumar; Agrawal, Aachu; Vikram, Naval K; Sharma, Vinita; Shrivastava, Usha; Pandey, Ravindra M
2016-01-01
Urbanization is an important determinant of cardiovascular disease (CVD) risk. To determine location-based differences in CVD risk factors in India we performed studies among women in rural, urban-poor and urban middle-class locations. Population-based cross-sectional studies in rural, urban-poor, and urban-middle class women (35-70 y) were performed at multiple sites. We evaluated 6853 women (rural 2616, 5 sites; urban-poor 2008, 4 sites; urban middle-class 2229, 11 sites) for socioeconomic, lifestyle, anthropometric and biochemical risk factors. Descriptive statistics are reported. Mean levels of body mass index (BMI), waist circumference, waist-hip ratio (WHR), systolic BP, fasting glucose and cholesterol in rural, urban-poor and urban-middle class women showed significantly increasing trends (ANOVAtrend, p <0.001). Age-adjusted prevalence of diabetes and risk factors among rural, urban-poor and urban-middle class women, respectively was, diabetes (2.2, 9.3, 17.7%), overweight BMI ≥25 kg/m2 (22.5, 45.6, 57.4%), waist >80 cm (28.3, 63.4, 61.9%), waist >90 cm (8.4, 31.4, 38.2%), waist hip ratio (WHR) >0.8 (60.4, 90.7, 88.5), WHR>0.9 (13.0, 44.3, 56.1%), hypertension (31.6, 48.2, 59.0%) and hypercholesterolemia (13.5, 27.7, 37.4%) (Mantel Haenszel X2 ptrend <0.01). Inverse trend was observed for tobacco use (41.6, 19.6, 9.4%). There was significant association of hypertension, hypercholesterolemia and diabetes with overweight and obesity (adjusted R2 0.89-0.99). There are significant location based differences in cardiometabolic risk factors in India. The urban-middle class women have the highest risk compared to urban-poor and rural.
Mohan, Indu; Gupta, Rajeev; Misra, Anoop; Sharma, Krishna Kumar; Agrawal, Aachu; Vikram, Naval K.; Sharma, Vinita; Shrivastava, Usha; Pandey, Ravindra M.
2016-01-01
Objective Urbanization is an important determinant of cardiovascular disease (CVD) risk. To determine location-based differences in CVD risk factors in India we performed studies among women in rural, urban-poor and urban middle-class locations. Methods Population-based cross-sectional studies in rural, urban-poor, and urban-middle class women (35–70y) were performed at multiple sites. We evaluated 6853 women (rural 2616, 5 sites; urban-poor 2008, 4 sites; urban middle-class 2229, 11 sites) for socioeconomic, lifestyle, anthropometric and biochemical risk factors. Descriptive statistics are reported. Results Mean levels of body mass index (BMI), waist circumference, waist-hip ratio (WHR), systolic BP, fasting glucose and cholesterol in rural, urban-poor and urban-middle class women showed significantly increasing trends (ANOVAtrend, p <0.001). Age-adjusted prevalence of diabetes and risk factors among rural, urban-poor and urban-middle class women, respectively was, diabetes (2.2, 9.3, 17.7%), overweight BMI ≥25 kg/m2 (22.5, 45.6, 57.4%), waist >80 cm (28.3, 63.4, 61.9%), waist >90 cm (8.4, 31.4, 38.2%), waist hip ratio (WHR) >0.8 (60.4, 90.7, 88.5), WHR>0.9 (13.0, 44.3, 56.1%), hypertension (31.6, 48.2, 59.0%) and hypercholesterolemia (13.5, 27.7, 37.4%) (Mantel Haenszel X2 ptrend <0.01). Inverse trend was observed for tobacco use (41.6, 19.6, 9.4%). There was significant association of hypertension, hypercholesterolemia and diabetes with overweight and obesity (adjusted R2 0.89–0.99). Conclusions There are significant location based differences in cardiometabolic risk factors in India. The urban-middle class women have the highest risk compared to urban-poor and rural. PMID:26881429
A Medium-Scale Traveling Ionospheric Disturbance Observed from the Ground and from Space
NASA Astrophysics Data System (ADS)
Watts, C.; Dymond, K. F.; Coker, C.; Budzien, S.; Bernhardt, P.; Kassim, N.; Lazio, J.; Cohen, A.; Weiler, K.; Crane, P.; Clarke, T.; Rickard, L. J.; Taylor, G. B.; Schinzel, F.; Philstrom, Y.; Kuniyoshi, M.; Close, S.; Colestock, P.; Myers, S.; Datta, A.
2008-12-01
We report the first optical observations from space of a Medium-scale Traveling Ionospheric Disturbance (MSTID) of the Traveling Wave Packet type. The observations were made during the Combined Radio Interferometry and COSMIC Experiment in Tomography Campaign (CRICKET) held on September 15, 2007 at ~0830 UT. The experiment used a Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC also known as FORMOSAT-3) satellite in conjunction with the Very Large Array (VLA) radio telescope, located near Socorro, NM, to study the ionosphere from the global scale down to the regional scale while the TIDs propagated through it. The COSMIC/FORMOSAT-3 satellite measured the ionosphere both horizontally and with altitude while the VLA measured the directions and speed of the TIDs. Our observations provide new information on this poorly understood class of TID
ERIC Educational Resources Information Center
Pittelman, Susan D.; And Others
A study investigated whether semantic mapping is more effective for poor readers instructed in a small group of poor readers or in a class of students with mixed reading abilities. Students in five fourth-grade classes served as the control, receiving no semantic mapping instruction. Subjects, 39 fourth-grade poor readers, were presented semantic…
2011-01-01
Background Intersectionality theory, a way of understanding social inequalities by race, gender, class, and sexuality that emphasizes their mutually constitutive natures, possesses potential to uncover and explicate previously unknown health inequalities. In this paper, the intersectionality principles of "directionality," "simultaneity," "multiplicativity," and "multiple jeopardy" are applied to inequalities in self-rated health by race, gender, class, and sexual orientation in a Canadian sample. Methods The Canadian Community Health Survey 2.1 (N = 90,310) provided nationally representative data that enabled binary logistic regression modeling on fair/poor self-rated health in two analytical stages. The additive stage involved regressing self-rated health on race, gender, class, and sexual orientation singly and then as a set. The intersectional stage involved consideration of two-way and three-way interaction terms between the inequality variables added to the full additive model created in the previous stage. Results From an additive perspective, poor self-rated health outcomes were reported by respondents claiming Aboriginal, Asian, or South Asian affiliations, lower class respondents, and bisexual respondents. However, each axis of inequality interacted significantly with at least one other: multiple jeopardy pertained to poor homosexuals and to South Asian women who were at unexpectedly high risks of fair/poor self-rated health and mitigating effects were experienced by poor women and by poor Asian Canadians who were less likely than expected to report fair/poor health. Conclusions Although a variety of intersections between race, gender, class, and sexual orientation were associated with especially high risks of fair/poor self-rated health, they were not all consistent with the predictions of intersectionality theory. I conclude that an intersectionality theory well suited for explicating health inequalities in Canada should be capable of accommodating axis intersections of multiple kinds and qualities. PMID:21241506
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peter Daum
2008-10-06
Brookhaven researcher Peter Daum discusses an international field experiment designed to make observations of critical components of the climate system of the southeastern Pacific. Because elements of this system are poorly understood and poorly represent
Peter Daum
2017-12-09
Brookhaven researcher Peter Daum discusses an international field experiment designed to make observations of critical components of the climate system of the southeastern Pacific. Because elements of this system are poorly understood and poorly represent
Quinn, Laura L.; Williams, Luke R.; White, Claire; Forrest, Calum; Rowe, Martin
2015-01-01
ABSTRACT The ability of Epstein-Barr virus (EBV) to spread and persist in human populations relies on a balance between host immune responses and EBV immune evasion. CD8+ cells specific for EBV late lytic cycle antigens show poor recognition of target cells compared to immediate early and early antigen-specific CD8+ cells. This phenomenon is due in part to the early EBV protein BILF1, whose immunosuppressive activity increases with lytic cycle progression. However, published data suggest the existence of a hitherto unidentified immune evasion protein further enhancing protection against late EBV antigen-specific CD8+ cells. We have now identified the late lytic BDLF3 gene as the missing link accounting for efficient evasion during the late lytic cycle. Interestingly, BDLF3 also contributes to evasion of CD4+ cell responses to EBV. We report that BDLF3 downregulates expression of surface major histocompatibility complex (MHC) class I and class II molecules in the absence of any effect upon other surface molecules screened, including CD54 (ICAM-1) and CD71 (transferrin receptor). BDLF3 both enhanced internalization of surface MHC molecules and reduced the rate of their appearance at the cell surface. The reduced expression of surface MHC molecules correlated with functional protection against CD8+ and CD4+ T cell recognition. The molecular mechanism was identified as BDLF3-induced ubiquitination of MHC molecules and their subsequent downregulation in a proteasome-dependent manner. IMPORTANCE Immune evasion is a necessary feature of viruses that establish lifelong persistent infections in the face of strong immune responses. EBV is an important human pathogen whose immune evasion mechanisms are only partly understood. Of the EBV immune evasion mechanisms identified to date, none could explain why CD8+ T cell responses to late lytic cycle genes are so infrequent and, when present, recognize lytically infected target cells so poorly relative to CD8+ T cells specific for early lytic cycle antigens. The present work identifies an additional immune evasion protein, BDLF3, that is expressed late in the lytic cycle and impairs CD8+ T cell recognition by targeting cell surface MHC class I molecules for ubiquitination and proteasome-dependent downregulation. Interestingly, BDLF3 also targets MHC class II molecules to impair CD4+ T cell recognition. BDLF3 is therefore a rare example of a viral protein that impairs both the MHC class I and class II antigen-presenting pathways. PMID:26468525
Quinn, Laura L; Williams, Luke R; White, Claire; Forrest, Calum; Zuo, Jianmin; Rowe, Martin
2016-01-01
The ability of Epstein-Barr virus (EBV) to spread and persist in human populations relies on a balance between host immune responses and EBV immune evasion. CD8(+) cells specific for EBV late lytic cycle antigens show poor recognition of target cells compared to immediate early and early antigen-specific CD8(+) cells. This phenomenon is due in part to the early EBV protein BILF1, whose immunosuppressive activity increases with lytic cycle progression. However, published data suggest the existence of a hitherto unidentified immune evasion protein further enhancing protection against late EBV antigen-specific CD8(+) cells. We have now identified the late lytic BDLF3 gene as the missing link accounting for efficient evasion during the late lytic cycle. Interestingly, BDLF3 also contributes to evasion of CD4(+) cell responses to EBV. We report that BDLF3 downregulates expression of surface major histocompatibility complex (MHC) class I and class II molecules in the absence of any effect upon other surface molecules screened, including CD54 (ICAM-1) and CD71 (transferrin receptor). BDLF3 both enhanced internalization of surface MHC molecules and reduced the rate of their appearance at the cell surface. The reduced expression of surface MHC molecules correlated with functional protection against CD8(+) and CD4(+) T cell recognition. The molecular mechanism was identified as BDLF3-induced ubiquitination of MHC molecules and their subsequent downregulation in a proteasome-dependent manner. Immune evasion is a necessary feature of viruses that establish lifelong persistent infections in the face of strong immune responses. EBV is an important human pathogen whose immune evasion mechanisms are only partly understood. Of the EBV immune evasion mechanisms identified to date, none could explain why CD8(+) T cell responses to late lytic cycle genes are so infrequent and, when present, recognize lytically infected target cells so poorly relative to CD8(+) T cells specific for early lytic cycle antigens. The present work identifies an additional immune evasion protein, BDLF3, that is expressed late in the lytic cycle and impairs CD8(+) T cell recognition by targeting cell surface MHC class I molecules for ubiquitination and proteasome-dependent downregulation. Interestingly, BDLF3 also targets MHC class II molecules to impair CD4(+) T cell recognition. BDLF3 is therefore a rare example of a viral protein that impairs both the MHC class I and class II antigen-presenting pathways. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Delivering phonological and phonics training within whole-class teaching.
Shapiro, Laura R; Solity, Jonathan
2008-12-01
Early, intensive phonological awareness and phonics training is widely held to be beneficial for children with poor phonological awareness. However, most studies have delivered this training separately from children's normal whole-class reading lessons. We examined whether integrating this training into whole class, mixed-ability reading lessons could impact on children with poor phonological awareness, whilst also benefiting normally developing readers. Teachers delivered the training within a broad reading programme to whole classes of children from Reception to the end of Year 1 (N=251). A comparison group of children received standard teaching methods (N=213). Children's literacy was assessed at the beginning of Reception, and then at the end of each year until 1 year post-intervention. The strategy significantly impacted on reading performance for normally developing readers and those with poor phonological awareness, vastly reducing the incidence of reading difficulties from 20% in comparison schools to 5% in intervention schools. Phonological and phonics training is highly effective for children with poor phonological awareness, even when incorporated into whole-class teaching.
The Effect of Antidepressants on Mesenchymal Stem Cell Differentiation.
Kruk, Jeffrey S; Bermeo, Sandra; Skarratt, Kristen K; Fuller, Stephen J; Duque, Gustavo
2018-02-01
Use of antidepressant medications has been linked to detrimental impacts on bone mineral density and osteoporosis; however, the cellular basis behind these observations remains poorly understood. The effect does not appear to be homogeneous across the whole class of drugs and may be linked to affinity for the serotonin transporter system. In this study, we hypothesized that antidepressants have a class- and dose-dependent effect on mesenchymal stem cell (MSC) differentiation, which may affect bone metabolism. Human MSCs (hMSCs) were committed to differentiate when either adipogenic or osteogenic media was added, supplemented with five increasing concentrations of amitriptyline (0.001-10 µM), venlafaxine (0.01-25 µM), or fluoxetine (0.001-10 µM). Alizarin red staining (mineralization), alkaline phosphatase (osteoblastogenesis), and oil red O (adipogenesis) assays were performed at timed intervals. In addition, cell viability was assessed using a MTT. We found that fluoxetine had a significant inhibitory effect on mineralization. Furthermore, adipogenic differentiation of hMSC was affected by the addition of amitriptyline, venlafaxine, and fluoxetine to the media. Finally, none of the tested medications significantly affected cell survival. This study showed a divergent effect of three antidepressants on hMSC differentiation, which appears to be independent of class and dose. As fluoxetine and amitriptyline, but not venlafaxine, affected both osteoblastogenesis and adipogenesis, this inhibitory effect could be associated to the high affinity of fluoxetine to the serotonin transporter system.
From Discovery to Function: The Expanding Roles of Long NonCoding RNAs in Physiology and Disease
Sun, Miao
2015-01-01
Long noncoding RNAs (lncRNAs) are a relatively poorly understood class of RNAs with little or no coding capacity transcribed from a set of incompletely annotated genes. They have received considerable attention in the past few years and are emerging as potentially important players in biological regulation. Here we discuss the evolving understanding of this new class of molecular regulators that has emerged from ongoing research, which continues to expand our databases of annotated lncRNAs and provide new insights into their physical properties, molecular mechanisms of action, and biological functions. We outline the current strategies and approaches that have been employed to identify and characterize lncRNAs, which have been instrumental in revealing their multifaceted roles ranging from cis- to trans-regulation of gene expression and from epigenetic modulation in the nucleus to posttranscriptional control in the cytoplasm. In addition, we highlight the molecular and biological functions of some of the best characterized lncRNAs in physiology and disease, especially those relevant to endocrinology, reproduction, metabolism, immunology, neurobiology, muscle biology, and cancer. Finally, we discuss the tremendous diagnostic and therapeutic potential of lncRNAs in cancer and other diseases. PMID:25426780
Crystal structure of a gammadelta T-cell receptor specific for the human MHC class I homolog MICA.
Xu, Bin; Pizarro, Juan C; Holmes, Margaret A; McBeth, Christine; Groh, Veronika; Spies, Thomas; Strong, Roland K
2011-02-08
γδ T cells play important roles in bridging innate and adaptive immunity, but their recognition mechanisms remain poorly understood. Human γδ T cells of the V(δ)1 subset predominate in intestinal epithelia and respond to MICA and MICB (MHC class I chain-related, A and B; MIC) self-antigens, mediating responses to tumorigenesis or viral infection. The crystal structure of an MIC-reactive V(δ)1 γδ T-cell receptor (TCR) showed expected overall structural homology to antibodies, αβ, and other γδ TCRs, but complementary determining region conformations and conservation of V(δ)1 use revealed an uncharacteristically flat potential binding surface. MIC, likewise, serves as a ligand for the activating immunoreceptor natural killer group 2, D (NKG2D), also expressed on γδ T cells. Although MIC recognition drives both the TCR-dependent stimulatory and NKG2D-dependent costimulatory signals necessary for activation, interaction analyses showed that MIC binding by the two receptors was mutually exclusive. Analysis of relative binding kinetics suggested sequential recognition, defining constraints for the temporal organization of γδ T-cell/target cell interfaces.
From discovery to function: the expanding roles of long noncoding RNAs in physiology and disease.
Sun, Miao; Kraus, W Lee
2015-02-01
Long noncoding RNAs (lncRNAs) are a relatively poorly understood class of RNAs with little or no coding capacity transcribed from a set of incompletely annotated genes. They have received considerable attention in the past few years and are emerging as potentially important players in biological regulation. Here we discuss the evolving understanding of this new class of molecular regulators that has emerged from ongoing research, which continues to expand our databases of annotated lncRNAs and provide new insights into their physical properties, molecular mechanisms of action, and biological functions. We outline the current strategies and approaches that have been employed to identify and characterize lncRNAs, which have been instrumental in revealing their multifaceted roles ranging from cis- to trans-regulation of gene expression and from epigenetic modulation in the nucleus to posttranscriptional control in the cytoplasm. In addition, we highlight the molecular and biological functions of some of the best characterized lncRNAs in physiology and disease, especially those relevant to endocrinology, reproduction, metabolism, immunology, neurobiology, muscle biology, and cancer. Finally, we discuss the tremendous diagnostic and therapeutic potential of lncRNAs in cancer and other diseases.
ERIC Educational Resources Information Center
Newman, Katherine S.; Tan Chen, Victor
2007-01-01
This article focuses on the "missing class," the near poor whose incomes place them above the poverty line, but well below the middle class. Near-poor families with two parents and two children subsist on $20,000 to $40,000 a year, which disqualifies them for virtually all public subsidies, but is a far cry from what they need to be…
Cavasin, Maria A.; Demos-Davies, Kim; Horn, Todd R.; Walker, Lori A.; Lemon, Douglas D.; Birdsey, Nicholas; Weiser-Evans, Mary C. M.; Harral, Jules; Irwin, David C.; Anwar, Adil; Yeager, Michael E.; Li, Min; Watson, Peter A.; Nemenoff, Raphael A.; Buttrick, Peter M.; Stenmark, Kurt R.; McKinsey, Timothy A.
2012-01-01
Rationale Histone deacetylase (HDAC) inhibitors are efficacious in models of hypertension-induced left ventricular (LV) heart failure. The consequences of HDAC inhibition in the context of pulmonary hypertension (PH) with associated right ventricular (RV) cardiac remodeling are poorly understood. Objective This study was performed to assess the utility of selective small molecule inhibitors of class I HDACs in a pre-clinical model of PH. Methods and Results Rats were exposed to hypobaric hypoxia for 3 weeks in the absence or presence of a benzamide HDAC inhibitor, MGCD0103, which selectively inhibits class I HDACs −1, −2 and −3. The compound reduced pulmonary arterial pressure (PAP) more dramatically than tadalafil, a standard-of-care therapy for human PH that functions as a vasodilator. MGCD0103 improved pulmonary artery (PA) acceleration time (PAAT) and reduced systolic notching of the PA flow envelope, suggesting a positive impact of the HDAC inhibitor on pulmonary vascular remodeling and stiffening. Similar results were obtained with an independent class I HDAC-selective inhibitor, MS-275. Reduced PAP in MGCD0103-treated animals was associated with blunted pulmonary arterial wall thickening due to suppression of smooth muscle cell proliferation. RV function was maintained in MGCD0103 treated animals. Although the class I HDAC inhibitor only modestly reduced RV hypertrophy, it had multiple beneficial effects on the RV, which included suppression of pathological gene expression, inhibition of pro-apoptotic caspase activity, and repression of pro-inflammatory protein expression. Conclusions By targeting distinct pathogenic mechanisms, isoform-selective HDAC inhibitors have potential as novel therapeutics for PH that will complement vasodilator standards-of-care. PMID:22282194
The Role of Diet in Shaping the Chemical Signal Design of Lacertid Lizards.
Baeckens, Simon; García-Roa, Roberto; Martín, José; Van Damme, Raoul
2017-09-01
Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall, diet appears a relatively poor predictor of interspecific differences in the broad chemical profiles of secretions of lacertid lizards.
Pattenden, Jonathan
2010-01-01
This paper notes the prominence of self-help groups (SHGs) within current anti-poverty policy in India, and analyses the impacts of government- and NGO-backed SHGs in rural North Karnataka. It argues that self-help groups represent a partial neoliberalisation of civil society in that they address poverty through low-cost methods that do not challenge the existing distribution of power and resources between the dominant class and the labouring class poor. It finds that intra-group savings and loans and external loans/subsidies can provide marginal economic and political gains for members of the dominant class and those members of the labouring classes whose insecure employment patterns currently provide above poverty line consumption levels, but provide neither material nor political gains for the labouring class poor. Target-oriented SHG catalysts are inattentive to how the social relations of production reproduce poverty and tend to overlook class relations and socio-economic and political differentiation within and outside of groups, which are subject to interference by dominant class local politicians and landowners.
Hagen, Kåre Birger; Tambs, Kristian; Bjerkedal, Tor
2006-09-01
Low education is consistently associated with an increased risk of back pain disability, but the underlying mechanisms for this relationship are poorly understood. In a seven-year prospective observational study of 38,426 employed men and women between 25 and 59 years in Norway, we investigated to what extent occupational class, working conditions and individual lifestyle mediated the effect of formal education on disability pensioning from back pain. Each additional year of formal education was associated with decreased risk for disability pensioning from back pain for both men [age adjusted Hazard Ratio (HR) 0.77; (95% Confidence Interval, 0.72-0.82)] and women [HR 0.76(0.71-0.82)]. Adjustment for occupational class and factors related to working conditions (authority to plan own work, physically demanding work, concentration and attention and job satisfaction) and individual lifestyle (smoking, body mass index, physical exercise and alcohol consumption) reduced the effect of education by 39% [HR 0.86(0.79-0.93)] for men and by 21% [HR 0.81(0.73-0.89)] for women. Working conditions contributed most to the explanation for men, while occupational class, working conditions and life style factors contributed equally for women. Subgroup analyses indicate small differences between full-time and part-time employees, while some differences were found between subcategories of back diseases. The study indicates that there is a strong and unexplained effect of education on back pain disability pensioning, which is not mediated by occupational class, working conditions or individual lifestyle.
First Magnetic Field Detection on a Class I Protostar
NASA Astrophysics Data System (ADS)
Johns-Krull, Christopher M.; Greene, Thomas P.; Doppmann, Greg W.; Covey, Kevin R.
2009-08-01
Strong stellar magnetic fields are believed to truncate the inner accretion disks around young stars, redirecting the accreting material to the high latitude regions of the stellar surface. In the past few years, observations of strong stellar fields on T Tauri stars with field strengths in general agreement with the predictions of magnetospheric accretion theory have bolstered this picture. Currently, nothing is known about the magnetic field properties of younger, more embedded Class I young stellar objects. It is believed that protostars accrete much of their final mass during the Class I phase, but the physics governing this process remains poorly understood. Here, we use high-resolution near-infrared spectra obtained with NIRSPEC on Keck and with Phoenix on Gemini South to measure the magnetic field properties of the Class I protostar WL 17. We find clear signatures of a strong stellar magnetic field. Analysis of this data suggests a surface average field strength of 2.9 ± 0.43 kG on WL 17. We present our field measurements and discuss how they fit with the general model of magnetospheric accretion in young stars. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and SECYT (Argentina). The Phoenix data were obtained under the program: GS-2006A-C-12.
Population Pulsation Resonances of Excitons in Monolayer MoSe 2 with Sub-1 μeV Linewidths
Schaibley, John R.; Karin, Todd; Yu, Hongyi; ...
2015-04-01
Monolayer transition metal dichalcogenides, a new class of atomically thin semiconductors, possess optically coupled 2D valley excitons. The nature of exciton relaxation in these systems is currently poorly understood. In this paper, we investigate exciton relaxation in monolayer MoSe 2 using polarization-resolved coherent nonlinear optical spectroscopy with high spectral resolution. We report strikingly narrow population pulsation resonances with two different characteristic linewidths of 1 and <0.2 μeV at low temperature. These linewidths are more than 3 orders of magnitude narrower than the photoluminescence and absorption linewidth, and indicate that a component of the exciton relaxation dynamics occurs on time scalesmore » longer than 1 ns. Finally, the ultranarrow resonance (<0.2 μeV) emerges with increasing excitation intensity, and implies the existence of a long-lived state whose lifetime exceeds 6 ns.« less
Memory retrieval and the parietal cortex: a review of evidence from a dual-process perspective.
Vilberg, Kaia L; Rugg, Michael D
2008-01-01
Although regions of the parietal cortex have been consistently implicated in episodic memory retrieval, the functional roles of these regions remain poorly understood. The present review presents a meta-analysis of findings from event-related fMRI studies reporting the loci of retrieval effects associated with familiarity- and recollection-related recognition judgments. The results of this analysis support previous suggestions that retrieval-related activity in lateral parietal cortex dissociates between superior regions, where activity likely reflects the task relevance of different classes of recognition test items, and more inferior regions where retrieval-related activity appears closely linked to successful recollection. It is proposed that inferior lateral parietal cortex forms part of a neural network supporting the 'episodic buffer' [Baddeley, A. D. (2000). The episodic buffer: A new component of working memory? Trends in Cognitive Sciences, 4, 417-423].
Hepworth, Matthew R.; Fung, Thomas C.; Masur, Samuel H.; Kelsen, Judith R.; McConnell, Fiona M.; Dubrot, Juan; Withers, David R.; Hugues, Stephanie; Farrar, Michael A.; Reith, Walter; Eberl, Gerard; Baldassano, Robert N.; Laufer, Terri M.; Elson, Charles O.; Sonnenberg, Gregory F.
2015-01-01
Inflammatory CD4+ T cell responses to self or commensal bacteria underlie the pathogenesis of autoimmunity and inflammatory bowel disease (IBD), respectively. While selection of self-specific T cells in the thymus limits responses to tissue antigens, the mechanisms that control selection of commensal bacteria-specific T cells remain poorly understood. Here we demonstrate that group 3 innate lymphoid cell (ILC3)-intrinsic expression of major histocompatibility complex class II (MHCII) is regulated similarly to thymic epithelial cells, and that MHCII+ ILC3s directly induce cell death of activated commensal bacteria-specific T cells. Further, MHCII on human colonic ILC3s was reduced in pediatric IBD patients. Collectively, these results define a selection pathway for commensal bacteria-specific CD4+ T cells in the intestine, and suggest that this process is dysregulated in human IBD. PMID:25908663
A medium-scale traveling ionospheric disturbance observed from the ground and from space
NASA Astrophysics Data System (ADS)
Dymond, K. F.; Watts, C.; Coker, C.; Budzien, S. A.; Bernhardt, P. A.; Kassim, N.; Lazio, T. J.; Weiler, K.; Crane, P. C.; Ray, P. S.; Cohen, A.; Clarke, T.; Rickard, L. J.; Taylor, G. B.; Schinzel, F.; Pihlstrom, Y.; Kuniyoshi, M.; Close, S.; Colestock, P.; Myers, S.; Datta, A.
2011-10-01
We report ultraviolet optical observations from space of a Medium-Scale Traveling Ionospheric Disturbance (MSTID) made during the Combined Radio Interferometry and COSMIC Experiment in Tomography Campaign (CRICKET) held on September 15, 2007 at ˜8:30 UT. The experiment used a Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC also known as FORMOSAT-3) satellite in conjunction with the Very Large Array (VLA) radio telescope, located near Socorro, NM, to study the ionosphere from the global scale down to the regional scale while the TIDs propagated through it. The COSMIC/FORMOSAT-3 satellite measured the F region electron density both horizontally and with altitude while the VLA measured the directions and speeds of the TIDs. These observations provide new information on this poorly understood class of TID and demonstrate the possibility of studying MSTIDs using space-based optical instruments.
Characterizing Chain Processes in Visible Light Photoredox Catalysis
Cismesia, Megan A.
2015-01-01
The recognition that Ru(bpy)32+ andsimilar visible light absorbing transition metal complexes can be photocatalysts for a variety of synthetically useful organic reactions has resulted in a recent resurgence of interest in photoredox catalysis. However, many of the critical mechanistic aspects of this class of reactions remain poorly understood. In particular, the degree to which visible light photoredox reactions involve radical chain processes has been a point of some disagreement that has not been subjected to systematic analysis. We have now performed quantum yield measurements to demonstrate that threerepresentative, mechanistically distinct photoredox processes involve product-forming chain reactions. Moreover, we show that the combination of quantum yield and luminescence quenching experiments provides a rapid method to estimate the length of these chains. Together, these measurements constitute a robust, operationally facile strategy for characterizing chain processes in a wide range of visible light photoredox reactions. PMID:26668708
Impaired IL-13-mediated functions of macrophages in STAT6-deficient mice.
Takeda, K; Kamanaka, M; Tanaka, T; Kishimoto, T; Akira, S
1996-10-15
IL-13 shares many biologic responses with IL-4. In contrast to well-characterized IL-4 signaling pathways, which utilize STAT6 and 4PS/IRS2, IL-13 signaling pathways are poorly understood. Recent studies performed with STAT6-deficient mice have demonstrated that STAT6 plays an essential role in IL-4 signaling. In this study, the functions of peritoneal macrophages of STAT6-deficient mice in response to IL-13 were analyzed. In STAT6-deficient mice, neither morphologic changes nor augmentation of MHC class II expression in response to IL-13 was observed. In addition, IL-13 did not decrease the nitric oxide production by activated macrophages. Taken together, these results suggest that the macrophage functions in response to IL-13 were impaired in STAT6-deficient mice, indicating that IL-13 and IL-4 share the signaling pathway via STAT6.
Central auditory neurons have composite receptive fields.
Kozlov, Andrei S; Gentner, Timothy Q
2016-02-02
High-level neurons processing complex, behaviorally relevant signals are sensitive to conjunctions of features. Characterizing the receptive fields of such neurons is difficult with standard statistical tools, however, and the principles governing their organization remain poorly understood. Here, we demonstrate multiple distinct receptive-field features in individual high-level auditory neurons in a songbird, European starling, in response to natural vocal signals (songs). We then show that receptive fields with similar characteristics can be reproduced by an unsupervised neural network trained to represent starling songs with a single learning rule that enforces sparseness and divisive normalization. We conclude that central auditory neurons have composite receptive fields that can arise through a combination of sparseness and normalization in neural circuits. Our results, along with descriptions of random, discontinuous receptive fields in the central olfactory neurons in mammals and insects, suggest general principles of neural computation across sensory systems and animal classes.
Mondal, Samiran; Begum, Nasim A; Hu, Wenjun; Honjo, Tasuku
2016-03-15
Activation-induced cytidine deaminase (AID) is essential for the somatic hypermutation (SHM) and class-switch recombination (CSR) of Ig genes. Although both the N and C termini of AID have unique functions in DNA cleavage and recombination, respectively, during SHM and CSR, their molecular mechanisms are poorly understood. Using a bimolecular fluorescence complementation (BiFC) assay combined with glycerol gradient fractionation, we revealed that the AID C terminus is required for a stable dimer formation. Furthermore, AID monomers and dimers form complexes with distinct heterogeneous nuclear ribonucleoproteins (hnRNPs). AID monomers associate with DNA cleavage cofactor hnRNP K whereas AID dimers associate with recombination cofactors hnRNP L, hnRNP U, and Serpine mRNA-binding protein 1. All of these AID/ribonucleoprotein associations are RNA-dependent. We propose that AID's structure-specific cofactor complex formations differentially contribute to its DNA-cleavage and recombination functions.
NASA Astrophysics Data System (ADS)
Raegen, Adam; Dion, Alexander; Reiter, Kyle; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John
2014-03-01
The use of cellulosic ethanol, a promising emerging energy source, is limited by the energy intensive and costly step of first converting the cellulose fibers into their constituent glucose monomers. Industrial processes mimic those that occur in nature, using mixtures or ``cocktails'' of different classes of cellulolytic enzymes derived from fungi. Despite several decades of investigation, the molecular mechanisms for enzyme synergy remain poorly understood. To gain additional insight, we have used a custom angle-scanning surface plasmon resonance (SPR) imaging apparatus to obtain a sensitive measure of enzymatic degradation. By implementing a novel SPR data analysis procedure, we have been able to track the thickness and roughness of laterally heterogeneous cellulose microfibril-coated substrates as enzymatic degradation proceeds. This has allowed us to measure the synergistic actions of the different enzymes, providing data that are directly relevant to the cellulosic ethanol industry.
Meta-Analysis of the Core Aroma Components of Grape and Wine Aroma
Ilc, Tina; Werck-Reichhart, Danièle; Navrot, Nicolas
2016-01-01
Wine aroma strongly influences wine quality, yet its composition and its evolution during the winemaking process are poorly understood. Volatile compounds that constitute wine aroma are traditionally divided into three classes according to their origin: grape, fermentation, and maturation aroma. We challenge this view with meta-analysis and review of grape and wine volatiles and their precursors from 82 profiling experiments. We compiled a list of 141 common grape and wine volatiles and quantitatively compared 43 of them. Our work offers insight into complex relationships between biosynthesis of aroma in grapes and the changes during the winemaking process. Monoterpenes are one of the largest and most researched wine aroma compounds. We show that their diversity in wines is mainly due to the oxidative metabolism of linalool in grapes. Furthermore, we demonstrate that most of the linalool produced in grapes is converted to these oxidized derivatives. PMID:27746799
The alignment of molecular cloud magnetic fields with the spiral arms in M33.
Li, Hua-bai; Henning, Thomas
2011-11-16
The formation of molecular clouds, which serve as stellar nurseries in galaxies, is poorly understood. A class of cloud formation models suggests that a large-scale galactic magnetic field is irrelevant at the scale of individual clouds, because the turbulence and rotation of a cloud may randomize the orientation of its magnetic field. Alternatively, galactic fields could be strong enough to impose their direction upon individual clouds, thereby regulating cloud accumulation and fragmentation, and affecting the rate and efficiency of star formation. Our location in the disk of the Galaxy makes an assessment of the situation difficult. Here we report observations of the magnetic field orientation of six giant molecular cloud complexes in the nearby, almost face-on, galaxy M33. The fields are aligned with the spiral arms, suggesting that the large-scale field in M33 anchors the clouds. ©2011 Macmillan Publishers Limited. All rights reserved
Predicting the dissolution kinetics of silicate glasses using machine learning
NASA Astrophysics Data System (ADS)
Anoop Krishnan, N. M.; Mangalathu, Sujith; Smedskjaer, Morten M.; Tandia, Adama; Burton, Henry; Bauchy, Mathieu
2018-05-01
Predicting the dissolution rates of silicate glasses in aqueous conditions is a complex task as the underlying mechanism(s) remain poorly understood and the dissolution kinetics can depend on a large number of intrinsic and extrinsic factors. Here, we assess the potential of data-driven models based on machine learning to predict the dissolution rates of various aluminosilicate glasses exposed to a wide range of solution pH values, from acidic to caustic conditions. Four classes of machine learning methods are investigated, namely, linear regression, support vector machine regression, random forest, and artificial neural network. We observe that, although linear methods all fail to describe the dissolution kinetics, the artificial neural network approach offers excellent predictions, thanks to its inherent ability to handle non-linear data. Overall, we suggest that a more extensive use of machine learning approaches could significantly accelerate the design of novel glasses with tailored properties.
Mondal, Samiran; Begum, Nasim A.; Hu, Wenjun; Honjo, Tasuku
2016-01-01
Activation-induced cytidine deaminase (AID) is essential for the somatic hypermutation (SHM) and class-switch recombination (CSR) of Ig genes. Although both the N and C termini of AID have unique functions in DNA cleavage and recombination, respectively, during SHM and CSR, their molecular mechanisms are poorly understood. Using a bimolecular fluorescence complementation (BiFC) assay combined with glycerol gradient fractionation, we revealed that the AID C terminus is required for a stable dimer formation. Furthermore, AID monomers and dimers form complexes with distinct heterogeneous nuclear ribonucleoproteins (hnRNPs). AID monomers associate with DNA cleavage cofactor hnRNP K whereas AID dimers associate with recombination cofactors hnRNP L, hnRNP U, and Serpine mRNA-binding protein 1. All of these AID/ribonucleoprotein associations are RNA-dependent. We propose that AID’s structure-specific cofactor complex formations differentially contribute to its DNA-cleavage and recombination functions. PMID:26929374
The White Working Class, Racism and Respectability: Victims, Degenerates and Interest-Convergence
ERIC Educational Resources Information Center
Gillborn, David
2010-01-01
This paper argues that race and class inequalities cannot be fully understood in isolation: their intersectional quality is explored through an analysis of how the White working class were portrayed in popular and political discourse during late 2008 (the timing is highly significant). While global capitalism reeled on the edge of financial…
Unveiling a phytoplankton hotspot at a narrow boundary between coastal and offshore waters
Ribalet, Francois; Marchetti, Adrian; Hubbard, Katherine A.; Brown, Kristina; Durkin, Colleen A.; Morales, Rhonda; Robert, Marie; Swalwell, Jarred E.; Tortell, Philippe D.; Armbrust, E. Virginia
2010-01-01
In terrestrial ecosystems, transitional areas between different plant communities (ecotones) are formed by steep environmental gradients and are commonly characterized by high species diversity and primary productivity, which in turn influences the foodweb structure of these regions. Whether comparable zones of elevated diversity and productivity characterize ecotones in the oceans remains poorly understood. Here we describe a previously hidden hotspot of phytoplankton diversity and productivity in a narrow but seasonally persistent transition zone at the intersection of iron-poor, nitrate-rich offshore waters and iron-rich, nitrate-poor coastal waters of the Northeast Pacific Ocean. Novel continuous measurements of phytoplankton cell abundance and composition identified a complex succession of blooms of five distinct size classes of phytoplankton populations within a 100-km–wide transition zone. The blooms appear to be fueled by natural iron enrichment of offshore communities as they are transported toward the coast. The observed succession of phytoplankton populations is likely driven by spatial gradients in iron availability or time since iron enrichment. Regardless of the underlying mechanism, the resulting communities have a strong impact on the regional biogeochemistry as evidenced by the low partial pressure of CO2 and the nearly complete depletion of nutrients. Enhanced phytoplankton productivity and diversity associated with steep environmental gradients are expected wherever water masses with complementary nutrient compositions mix to create a region more favorable for phytoplankton growth. The ability to detect and track these important but poorly characterized marine ecotones is critical for understanding their impact on productivity and ecosystem structure in the oceans. PMID:20823224
Unveiling a phytoplankton hotspot at a narrow boundary between coastal and offshore waters.
Ribalet, Francois; Marchetti, Adrian; Hubbard, Katherine A; Brown, Kristina; Durkin, Colleen A; Morales, Rhonda; Robert, Marie; Swalwell, Jarred E; Tortell, Philippe D; Armbrust, E Virginia
2010-09-21
In terrestrial ecosystems, transitional areas between different plant communities (ecotones) are formed by steep environmental gradients and are commonly characterized by high species diversity and primary productivity, which in turn influences the foodweb structure of these regions. Whether comparable zones of elevated diversity and productivity characterize ecotones in the oceans remains poorly understood. Here we describe a previously hidden hotspot of phytoplankton diversity and productivity in a narrow but seasonally persistent transition zone at the intersection of iron-poor, nitrate-rich offshore waters and iron-rich, nitrate-poor coastal waters of the Northeast Pacific Ocean. Novel continuous measurements of phytoplankton cell abundance and composition identified a complex succession of blooms of five distinct size classes of phytoplankton populations within a 100-km-wide transition zone. The blooms appear to be fueled by natural iron enrichment of offshore communities as they are transported toward the coast. The observed succession of phytoplankton populations is likely driven by spatial gradients in iron availability or time since iron enrichment. Regardless of the underlying mechanism, the resulting communities have a strong impact on the regional biogeochemistry as evidenced by the low partial pressure of CO(2) and the nearly complete depletion of nutrients. Enhanced phytoplankton productivity and diversity associated with steep environmental gradients are expected wherever water masses with complementary nutrient compositions mix to create a region more favorable for phytoplankton growth. The ability to detect and track these important but poorly characterized marine ecotones is critical for understanding their impact on productivity and ecosystem structure in the oceans.
Horodynski, Mildred A; Brophy-Herb, Holly E; Martoccio, Tiffany L; Contreras, Dawn; Peterson, Karen; Shattuck, Mackenzie; Senehi, Neda; Favreau, Zachary; Miller, Alison L; Sturza, Julie; Kaciroti, Niko; Lumeng, Julie C
2018-04-01
Early child weight gain predicts adolescent and adult obesity, underscoring the need to determine early risk factors affecting weight status and how risk factors might be mitigated. Socioeconomic status, food insecurity, caregiver depressive symptomology, single parenthood, and dysfunctional parenting each have been linked to early childhood weight status. However, the associations between these risk factors and children's weight status may be moderated by caregiver feeding styles (CFS). Examining modifiable factors buffering risk could provide key information to guide early obesity intervention efforts. This analysis used baseline data from the Growing Healthy project that recruited caregivers/child dyads (N = 626) from Michigan Head Start programs. Caregivers were primarily non-Hispanic white (62%) and African American (30%). After using latent class analysis to identify classes of familial psychosocial risk, CFS was tested as a moderator of the association between familial psychosocial risk class and child body mass index (BMI) z-score. Latent class analysis identified three familial psychosocial risk classes: (1) poor, food insecure and depressed families; (2) poor, single parent families; and (3) low risk families. Interactive effects for uninvolved feeding styles and risk group indicated that children in poor, food insecure, and depressed families had higher BMI z-scores compared to children in the low risk group. Authoritative feeding styles in low risk and poor, food insecure, and depressed families showed lower child BMI z-scores relative to poor, single parent families with authoritative feeding styles. Uninvolved feeding styles intensified the risk and an authoritative feeding style muted the risk conferred by living in a poor, food-insecure, and depressed family. Interventions that promote responsive feeding practices could help decrease the associations of familial psychosocial risks with early child weight outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.
The Relationship Between Infrared Dark Cloud and Stellar Properties
NASA Astrophysics Data System (ADS)
Calahan, Jenny; Hora, Joseph L.
2018-01-01
Massive stars are known to form within infrared dark clouds (IRDCs), but many details about how molecular clouds collapse and form stars remain poorly understood.We determine the relationship between the dark cloud mass and the population of young stellar objects (YSOs) associated with the cloud to shed light on the physical processes occurring within these star forming regions. We chose to use a sample of IRDCs and YSOs within the Cygnus-X region, a close-by giant star formation complex that has every stage of star formation represented. Using observations from IRAC, MIPS, PACS, and SPIRE on Spitzer and Herschel we identified a sample of 30,903 YSOs and 167 IRDCs. We derived the class of each YSO as well as the mass of YSO and IRDCs from the flux information. Using these parameters, as well as their locations in the cloud, we were sorted IRDC fragments into larger filaments and associate a set of YSOs with each IRDC. By measuring and comparing parameters such as YSO total mass, number of YSOs, Class 0, Class I, and Class II populations, distance from host filament, and filament mass we tested for correlations between the YSO and IRDC parameters. Using this treasure trove of information, we find that Class 0 and I objects are located more closely to their host IRDC than their Class II counterparts. We also find that high-density IRDCs are better environments for star formation than low-density IRDCs. However, we find no correlation between the total mass of the IRDC and the largest YSO mass in the IRDC, suggesting that IRDCs of any mass can have massive YSOs associated with them.The SAO REU program is funded by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant AST-1659473, and by the Smithsonian Institution.
An Artificial Intelligence Classification Tool and Its Application to Gamma-Ray Bursts
NASA Technical Reports Server (NTRS)
Hakkila, Jon; Haglin, David J.; Roiger, Richard J.; Giblin, Timothy; Paciesas, William S.; Pendleton, Geoffrey N.; Mallozzi, Robert S.
2004-01-01
Despite being the most energetic phenomenon in the known universe, the astrophysics of gamma-ray bursts (GRBs) has still proven difficult to understand. It has only been within the past five years that the GRB distance scale has been firmly established, on the basis of a few dozen bursts with x-ray, optical, and radio afterglows. The afterglows indicate source redshifts of z=1 to z=5, total energy outputs of roughly 10(exp 52) ergs, and energy confined to the far x-ray to near gamma-ray regime of the electromagnetic spectrum. The multi-wavelength afterglow observations have thus far provided more insight on the nature of the GRB mechanism than the GRB observations; far more papers have been written about the few observed gamma-ray burst afterglows in the past few years than about the thousands of detected gamma-ray bursts. One reason the GRB central engine is still so poorly understood is that GRBs have complex, overlapping characteristics that do not appear to be produced by one homogeneous process. At least two subclasses have been found on the basis of duration, spectral hardness, and fluence (time integrated flux); Class 1 bursts are softer, longer, and brighter than Class 2 bursts (with two second durations indicating a rough division). A third GRB subclass, overlapping the other two, has been identified using statistical clustering techniques; Class 3 bursts are intermediate between Class 1 and Class 2 bursts in brightness and duration, but are softer than Class 1 bursts. We are developing a tool to aid scientists in the study of GRB properties. In the process of developing this tool, we are building a large gamma-ray burst classification database. We are also scientifically analyzing some GRB data as we develop the tool. Tool development thus proceeds in tandem with the dataset for which it is being designed. The tool invokes a modified KDD (Knowledge Discovery in Databases) process, which is described as follows.
Zammit, Andrea R; Hall, Charles B; Lipton, Richard B; Katz, Mindy J; Muniz-Terrera, Graciela
2018-05-01
The aim of this study was to identify natural subgroups of older adults based on cognitive performance, and to establish each subgroup's characteristics based on demographic factors, physical function, psychosocial well-being, and comorbidity. We applied latent class (LC) modeling to identify subgroups in baseline assessments of 1345 Einstein Aging Study (EAS) participants free of dementia. The EAS is a community-dwelling cohort study of 70+ year-old adults living in the Bronx, NY. We used 10 neurocognitive tests and 3 covariates (age, sex, education) to identify latent subgroups. We used goodness-of-fit statistics to identify the optimal class solution and assess model adequacy. We also validated our model using two-fold split-half cross-validation. The sample had a mean age of 78.0 (SD=5.4) and a mean of 13.6 years of education (SD=3.5). A 9-class solution based on cognitive performance at baseline was the best-fitting model. We characterized the 9 identified classes as (i) disadvantaged, (ii) poor language, (iii) poor episodic memory and fluency, (iv) poor processing speed and executive function, (v) low average, (vi) high average, (vii) average, (viii) poor executive and poor working memory, (ix) elite. The cross validation indicated stable class assignment with the exception of the average and high average classes. LC modeling in a community sample of older adults revealed 9 cognitive subgroups. Assignment of subgroups was reliable and associated with external validators. Future work will test the predictive validity of these groups for outcomes such as Alzheimer's disease, vascular dementia and death, as well as markers of biological pathways that contribute to cognitive decline. (JINS, 2018, 24, 511-523).
The Effect of Antidepressants on Mesenchymal Stem Cell Differentiation
Kruk, Jeffrey S.; Bermeo, Sandra; Skarratt, Kristen K.; Fuller, Stephen J.
2018-01-01
Background Use of antidepressant medications has been linked to detrimental impacts on bone mineral density and osteoporosis; however, the cellular basis behind these observations remains poorly understood. The effect does not appear to be homogeneous across the whole class of drugs and may be linked to affinity for the serotonin transporter system. In this study, we hypothesized that antidepressants have a class- and dose-dependent effect on mesenchymal stem cell (MSC) differentiation, which may affect bone metabolism. Methods Human MSCs (hMSCs) were committed to differentiate when either adipogenic or osteogenic media was added, supplemented with five increasing concentrations of amitriptyline (0.001–10 µM), venlafaxine (0.01–25 µM), or fluoxetine (0.001–10 µM). Alizarin red staining (mineralization), alkaline phosphatase (osteoblastogenesis), and oil red O (adipogenesis) assays were performed at timed intervals. In addition, cell viability was assessed using a MTT. Results We found that fluoxetine had a significant inhibitory effect on mineralization. Furthermore, adipogenic differentiation of hMSC was affected by the addition of amitriptyline, venlafaxine, and fluoxetine to the media. Finally, none of the tested medications significantly affected cell survival. Conclusions This study showed a divergent effect of three antidepressants on hMSC differentiation, which appears to be independent of class and dose. As fluoxetine and amitriptyline, but not venlafaxine, affected both osteoblastogenesis and adipogenesis, this inhibitory effect could be associated to the high affinity of fluoxetine to the serotonin transporter system. PMID:29564305
Ha, Eun Kyo; Baek, Ji Hyeon; Lee, So-Yeon; Park, Yong Mean; Kim, Woo Kyung; Sheen, Youn Ho; Lee, Seung Jin; Bae, Youngoh; Kim, Jihyeon; Lee, Kee-Jae; Ahn, Kangmo; Kwon, Ho-Jang; Han, Man Yong
2016-01-01
Aeroallergen sensitization is related to the coexistence of allergic diseases, but the nature of this relationship is poorly understood. The aim of this study was to clarify the relationship of polysensitization with allergic multimorbidities and the severity of allergic diseases. This study is a cross-sectional analysis of 3,368 Korean children aged 6-7 years-old. We defined IgE-mediated allergic diseases based on structured questionnaires, and classified the sensitivity to 18 aeroallergens by logistic regression and the Ward hierarchical clustering method. The relationship of polysensitization (positive IgE responses against 2 or more aeroallergens classes) with allergic multimorbidities (coexistence of 2 or more of the following allergic diseases: asthma, rhinitis, eczema, and conjunctivitis) and severity of allergic diseases was determined by ordinal logistic regression analysis. The rate of polysensitization was 13.6% (n = 458, 95% CI 12.4-14.8) and that of allergic multimorbidity was 23.5% (n = 790, 95% CI 22.0-24.9). Children sensitized to more aeroallergens tended to have more allergic diseases (rho = 0.248, p < 0.001), although the agreement between polysensitization and multimorbidity was poor (kappa = 0.11, p < 0.001). The number allergen classes to which a child was sensitized increased the risk of wheezing attacks (1 allergen: adjusted odds ratio [aOR] 2.22, 4 or more allergens: aOR 9.39), absence from school (1 allergen: aOR 1.96, 3 allergens: aOR 2.08), and severity of nasal symptoms (1 allergen: aOR 1.61, 4 or more allergens: aOR 4.38). Polysensitization was weakly related to multimorbidity. However, the number of allergens to which a child is sensitized is related to the severity of IgE-mediated symptoms. © 2017 S. Karger AG, Basel.
Rhyne, Ragan
2004-01-01
While drag is primarily understood as a performance of gender, other performative categories such as race, class, and sexuality create drag meaning as well. Though other categories of identification are increasingly understood as essential elements of drag by performers of color, whiteness remains an unmarked category in the scholarship on drag performances by white queens. In this paper, I argue that drag by white queens must be understood as a performance of race as well as gender and that codes of gender excess are specifically constructed through the framework of these other axes of identity. This essay asks whether white performance by white queens necessarily reinscribes white supremacy through the performance of an unmarked white femininity, or might drag performance complicate (though not necessarily subvert) categories of race as well as gender? In this essay, I will suggest that camp drag performances, through the deployment of class as a crucial category of performative femininity, might indeed be a key site through which whiteness is denaturalized and its power challenged. Specifically, I will read on camp as a politicized mode of race, class and gender performance, focusing on the intersections of these categories of identity in the drag performance of Divine.
Poor Women in Psychological Research: Shut Up and Shut Out.
ERIC Educational Resources Information Center
Reid, Pamela Trotman
1993-01-01
Raises the issue of recognizing the diversity of poor women in psychological research, focusing on the need to disentangle ethnicity and class and the limitations of adopting a middle-class white perspective. Possible causes of exclusion in addition to racism and suggestions for achieving feminist goals are considered. (SLD)
Research Review: The Neurobiology and Genetics of Maltreatment and Adversity
ERIC Educational Resources Information Center
McCrory, Eamon; De Brito, Stephane A.; Viding, Essi
2010-01-01
The neurobiological mechanisms by which childhood maltreatment heightens vulnerability to psychopathology remain poorly understood. It is likely that a complex interaction between environmental experiences (including poor caregiving) and an individual's genetic make-up influence neurobiological development across infancy and childhood, which in…
Rahaman, Abdur; Miao, Wei; Turkewitz, Aaron P.
2009-01-01
Dense core granules (DCGs) in Tetrahymena thermophila contain two protein classes. Proteins in the first class, called granule lattice (Grl), coassemble to form a crystalline lattice within the granule lumen. Lattice expansion acts as a propulsive mechanism during DCG release, and Grl proteins are essential for efficient exocytosis. The second protein class, defined by a C-terminal β/γ-crystallin domain, is poorly understood. Here, we have analyzed the function and sorting of Grt1p (granule tip), which was previously identified as an abundant protein in this family. Cells lacking all copies of GRT1, together with the closely related GRT2, accumulate wild-type levels of docked DCGs. Unlike cells disrupted in any of the major GRL genes, ΔGRT1 ΔGRT2 cells show no defect in secretion, indicating that neither exocytic fusion nor core expansion depends on GRT1. These results suggest that Grl protein sorting to DCGs is independent of Grt proteins. Consistent with this, the granule core lattice in ΔGRT1 ΔGRT2 cells appears identical to that in wild-type cells by electron microscopy, and the only biochemical component visibly absent is Grt1p itself. Moreover, gel filtration showed that Grl and Grt proteins in cell homogenates exist in nonoverlapping complexes, and affinity-isolated Grt1p complexes do not contain Grl proteins. These data demonstrate that two major classes of proteins in Tetrahymena DCGs are likely to be independently transported during DCG biosynthesis and play distinct roles in granule function. The role of Grt1p may primarily be postexocytic; consistent with this idea, DCG contents from ΔGRT1 ΔGRT2 cells appear less adhesive than those from the wild type. PMID:19684282
Rahaman, Abdur; Miao, Wei; Turkewitz, Aaron P
2009-10-01
Dense core granules (DCGs) in Tetrahymena thermophila contain two protein classes. Proteins in the first class, called granule lattice (Grl), coassemble to form a crystalline lattice within the granule lumen. Lattice expansion acts as a propulsive mechanism during DCG release, and Grl proteins are essential for efficient exocytosis. The second protein class, defined by a C-terminal beta/gamma-crystallin domain, is poorly understood. Here, we have analyzed the function and sorting of Grt1p (granule tip), which was previously identified as an abundant protein in this family. Cells lacking all copies of GRT1, together with the closely related GRT2, accumulate wild-type levels of docked DCGs. Unlike cells disrupted in any of the major GRL genes, DeltaGRT1 DeltaGRT2 cells show no defect in secretion, indicating that neither exocytic fusion nor core expansion depends on GRT1. These results suggest that Grl protein sorting to DCGs is independent of Grt proteins. Consistent with this, the granule core lattice in DeltaGRT1 DeltaGRT2 cells appears identical to that in wild-type cells by electron microscopy, and the only biochemical component visibly absent is Grt1p itself. Moreover, gel filtration showed that Grl and Grt proteins in cell homogenates exist in nonoverlapping complexes, and affinity-isolated Grt1p complexes do not contain Grl proteins. These data demonstrate that two major classes of proteins in Tetrahymena DCGs are likely to be independently transported during DCG biosynthesis and play distinct roles in granule function. The role of Grt1p may primarily be postexocytic; consistent with this idea, DCG contents from DeltaGRT1 DeltaGRT2 cells appear less adhesive than those from the wild type.
Bartho, Joseph D.; Bellini, Dom; Wuerges, Jochen; Demitri, Nicola; Toccafondi, Mirco; Schmitt, Armin O.; Zhao, Youfu; Walsh, Martin A.
2017-01-01
AmyR is a stress and virulence associated protein from the plant pathogenic Enterobacteriaceae species Erwinia amylovora, and is a functionally conserved ortholog of YbjN from Escherichia coli. The crystal structure of E. amylovora AmyR reveals a class I type III secretion chaperone-like fold, despite the lack of sequence similarity between these two classes of protein and lacking any evidence of a secretion-associated role. The results indicate that AmyR, and YbjN proteins in general, function through protein-protein interactions without any enzymatic action. The YbjN proteins of Enterobacteriaceae show remarkably low sequence similarity with other members of the YbjN protein family in Eubacteria, yet a high level of structural conservation is observed. Across the YbjN protein family sequence conservation is limited to residues stabilising the protein core and dimerization interface, while interacting regions are only conserved between closely related species. This study presents the first structure of a YbjN protein from Enterobacteriaceae, the most highly divergent and well-studied subgroup of YbjN proteins, and an in-depth sequence and structural analysis of this important but poorly understood protein family. PMID:28426806
Bartho, Joseph D; Bellini, Dom; Wuerges, Jochen; Demitri, Nicola; Toccafondi, Mirco; Schmitt, Armin O; Zhao, Youfu; Walsh, Martin A; Benini, Stefano
2017-01-01
AmyR is a stress and virulence associated protein from the plant pathogenic Enterobacteriaceae species Erwinia amylovora, and is a functionally conserved ortholog of YbjN from Escherichia coli. The crystal structure of E. amylovora AmyR reveals a class I type III secretion chaperone-like fold, despite the lack of sequence similarity between these two classes of protein and lacking any evidence of a secretion-associated role. The results indicate that AmyR, and YbjN proteins in general, function through protein-protein interactions without any enzymatic action. The YbjN proteins of Enterobacteriaceae show remarkably low sequence similarity with other members of the YbjN protein family in Eubacteria, yet a high level of structural conservation is observed. Across the YbjN protein family sequence conservation is limited to residues stabilising the protein core and dimerization interface, while interacting regions are only conserved between closely related species. This study presents the first structure of a YbjN protein from Enterobacteriaceae, the most highly divergent and well-studied subgroup of YbjN proteins, and an in-depth sequence and structural analysis of this important but poorly understood protein family.
D14-SCFD3-dependent degradation of D53 regulates strigolactone signaling
Zhou, Feng; Lin, Qibing; Zhu, Lihong; Ren, Yulong; Zhou, Kunneng; Shabek, Nitzan; Wu, Fuqing; Mao, Haibin; Dong, Wei; Gan, Lu; Ma, Weiwei; Gao, He; Chen, Jun; Yang, Chao; Wang, Dan; Tan, Junjie; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Jiang, Ling; Liu, Xi; Chen, Weiqi; Chu, Jinfang; Yan, Cunyu; Ueno, Kotomi; Ito, Shinsaku; Asami, Tadao; Cheng, Zhijun; Wang, Jie; Lei, Cailin; Zhai, Huqu; Wu, Chuanyin; Wang, Haiyang; Zheng, Ning; Wan, Jianmin
2014-01-01
Strigolactones (SLs) are a new class of carotenoid-derived phytohormones essential for developmental processes shaping plant architecture and interactions with parasitic weeds and symbiotic arbuscular mycorrhizal fungi. Despite the rapid progress in elucidating the SL biosynthetic pathway, the perception and signaling mechanisms of SL remain poorly understood. Here we show that DWARF53 (D53) acts as a repressor of SL signaling and SLs induce its degradation. We found that the rice d53 mutant, which produces an exaggerated number of tillers compared to wild type plants, is caused by a gain-of-function mutation and is insensitive to exogenous SL treatment. The D53 gene product shares predicted features with the class I Clp ATPase proteins and can form a complex with the α/β hydrolase protein DWARF14 (D14) and the F-box protein DWARF3 (D3), two previously identified signaling components potentially responsible for SL perception. We demonstrate that, in a D14- and D3-dependent manner, SLs induce D53 degradation by the proteasome and abrogate its activity in promoting axillary bud outgrowth. Our combined genetic and biochemical data reveal that D53 acts as a repressor of the SL signaling pathway, whose hormone-induced degradation represents a key molecular link between SL perception and responses. PMID:24336215
La parole, vue et prise par les etudiants (Speech as Seen and Understood by Student).
ERIC Educational Resources Information Center
Gajo, Laurent, Ed.; Jeanneret, Fabrice, Ed.
1998-01-01
Articles on speech and second language learning include: "Les sequences de correction en classe de langue seconde: evitement du 'non' explicite" ("Error Correction Sequences in Second Language Class: Avoidance of the Explicit 'No'") (Anne-Lise de Bosset); "Analyse hierarchique et fonctionnelle du discours: conversations…
Newby, Danielle; Freitas, Alex A; Ghafourian, Taravat
2015-01-27
Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Astrobiology: A pathway to adult science literacy?
NASA Astrophysics Data System (ADS)
Oliver, C. A.; Fergusson, J.
2007-10-01
Adult science illiteracy is widespread. This is concerning for astrobiology, or indeed any other area of science in the communication of science to public audiences. Where and how does this scientific illiteracy arise in the journey to adulthood? Two astrobiology education projects have hinted that science illiteracy may begin in high school. This relationship between high school science education and the public understanding of science is poorly understood. Do adults forget their science education, or did they never grasp it in the first place? A 2003 science education project raised these questions when 24 16-year-olds from 10 Sydney high schools were brought into contact with real science. The unexpected results suggested that even good high school science students have a poor understanding of how science is really undertaken in the field and in the laboratory. This concept is being further tested in a new high school science education project, aimed at the same age group, using authentic astrobiology cutting-edge data, NASA Learning Technologies tools, a purpose-built research Information and Communication Technology-aided learning facility and a collaboration that spans three continents. In addition, a first year university class will be tested for evidence of science illiteracy immediately after high school among non-science oriented but well-educated students.
Of all foods bread is the most noble: Carl von Linné (Carl Linneaus) on bread1
Räsänen, Leena
2007-01-01
Carl von Linné was interested in dietetics, which in his time covered all aspects of a healthy life. As a utilitarian he understood the importance of private economy and paid attention to bread in many of his publications. Two texts, Ceres noverca arctoum and De pane diaetetico, were wholly devoted to bread and bread-making. Linné classified different types of bread, and described their nutritional value and health-related aspects, as well as milling, baking and storing, in detail. While discussing the food habits of social classes Linné accepted as a fact that the peasants and the poor should eat less tasty bread than the rich. The less palatable bread had, however, many nutritional and health advantages. Linné paid much attention to substitutes for grain to be used in times of famine, an important topic in eighteenth century Sweden. He regarded flour made of pine bark or water arum roots as excellent famine food, was enthusiastic about the new plant, maize, but considered potato only as a poor substitute for grain. Linné and his followers praised bread not only as the core component of diet, but also for its versatile role both in health and in disease.
NASA Aims to Create First-Ever Space-Based Sodium Lidar to Study Poorly Understood Mesosphere
2017-12-08
Caption: Mike Krainak (left) and Diego Janches recently won NASA follow-on funding to advance a spaceborne sodium lidar needed to probe Earth’s poorly understood mesosphere. Credits: NASA/W. Hrybyk More: A team of NASA scientists and engineers now believes it can leverage recent advances in a greenhouse-detecting instrument to build the world’s first space-based sodium lidar to study Earth’s poorly understood mesosphere. Scientist Diego Janches and laser experts Mike Krainak and Tony Yu, all of whom work at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are leading a research-and-development effort to further advance the sodium lidar, which the group plans to deploy on the International Space Station if it succeeds in proving its flightworthiness. Read more: go.nasa.gov/2rcGpSM NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram
Do Middle-Class Students Perceive Poor Women and Poor Men Differently?
ERIC Educational Resources Information Center
Cozzarelli, Catherine; Tagler, Michael J.; Wilkinson, Anna V.
2002-01-01
Examined college students' attitudes and stereotypes regarding poor women, attributions for their poverty, and whether those thoughts and feelings differed from those about poor men. Attitudes and stereotypes were significantly more positive regarding poor women than poor men. Participants endorsed internal attributions for both women's and men's…
Auditory Processing Disorders: Acquisition and Treatment
ERIC Educational Resources Information Center
Moore, David R.
2007-01-01
Auditory processing disorder (APD) describes a mixed and poorly understood listening problem characterised by poor speech perception, especially in challenging environments. APD may include an inherited component, and this may be major, but studies reviewed here of children with long-term otitis media with effusion (OME) provide strong evidence…
Linking Carbonic Anhydrase Abundance and Diversity in Soils to Ecological Function
NASA Astrophysics Data System (ADS)
Pang, E.; Meredith, L. K.; Welander, P. V.
2015-12-01
Carbonic anhydrase (CA) is an ancient enzyme widespread among bacteria, archaea, and eukarya that catalyzes the following reaction: CO2 + H2O ⇌ HCO3- + H+. Its functions are critical for key cellular processes such as concentrating CO2 for autotrophic growth, pH regulation, and pathogen survival in hosts. Currently, there are six known CA classes (α, β, γ, δ, η, ζ) arising from several distinct evolutionary lineages. CA are widespread in sequenced genomes, with many organisms containing multiple classes of CA or multiple CA of the same class. Soils host rich microbial communities with diverse and important ecological functions, but the diversity and abundance of CA in soils has not been explored. CA appears to play an important, but poorly understood, role in some biogeochemical cycles such as those of CO2 and its oxygen isotope composition and also carbonyl sulfide (COS), which are potential tracers in predictive carbon cycle models. Recognizing the prevalence and functional significance of CA in soils, we used a combined bioinformatics and molecular biology approach to address fundamental questions regarding the abundance, diversity, and function of CA in soils. To characterize the abundance and diversity of the different CA classes in soils, we analyzed existing soil metagenomic and metatranscriptomic data from the DOE Joint Genome Institute databases. Out of the six classes of CA, we only found the α, β, and γ classes to be present in soils, with the β class being the most abundant. We also looked at genomes of sequenced soil microorganisms to learn what combination of CA classes they contain, from which we can begin to predict the physiological role of CA. To characterize the functional roles of the different CA classes in soils, we collected soil samples from a variety of biomes with diverse chemical and physical properties and quantified the rate of two CA-mediated processes: soil uptake of COS and acceleration of the oxygen isotope exchange between CO2 and H2O. We employed PCR-based methods to quantify the abundance and diversity of CA encoding genes and their expression in our samples to link CA classes to the gas flux data. These studies provide the first survey of CA in soils, a step towards understanding CA's potentially significant role in microbial survival and microbe-mediated biogeochemical cycles.
ERIC Educational Resources Information Center
Van Galen, Jane
2008-01-01
In this article, I argue for a closer read of the daily "class work" of teachers, as posited by Reay, 1998. In developing exploratory class portraits of four teachers who occupy distinctive social positions (two from working-class homes now teaching upper-middle-class children and two from upper-middle-class homes now teaching poor children), I…
Tan, Jacinth J X; Kraus, Michael W
2015-03-01
The economic conditions of one's life can profoundly and systematically influence health outcomes over the life course. Our present research demonstrates that rejecting the notion that social class categories are biologically determined-a nonessentialist belief-buffers lower-class individuals from poor self-rated health and negative affect, whereas conceiving of social class categories as rooted in biology-an essentialist belief-does not. In Study 1, lower-class individuals self-reported poorer health than upper-class individuals when they endorsed essentialist beliefs but showed no such difference when they rejected such beliefs. Exposure to essentialist theories of social class also led lower-class individuals to report greater feelings of negative self-conscious emotions (Studies 2 and 3), and perceive poorer health (Study 3) than upper-class individuals, whereas exposure to nonessentialist theories did not lead to such differences. Discussion considers how lay theories of social class potentially shape long-term trajectories of health and affect of lower-class individuals. © 2015 by the Society for Personality and Social Psychology, Inc.
Searching for chemical classes among metal-poor stars using medium-resolution spectroscopy
NASA Astrophysics Data System (ADS)
Cruz, Monique A.; Cogo-Moreira, Hugo; Rossi, Silvia
2018-04-01
Astronomy is in the era of large spectroscopy surveys, with the spectra of hundreds of thousands of stars in the Galaxy being collected. Although most of these surveys have low or medium resolution, which makes precise abundance measurements not possible, there is still important information to be extracted from the available data. Our aim is to identify chemically distinct classes among metal-poor stars, observed by the Sloan Digital Sky Survey, using line indices. The present work focused on carbon-enhanced metal-poor (CEMP) stars and their subclasses. We applied the latent profile analysis technique to line indices for carbon, barium, iron and europium, in order to separate the sample into classes with similar chemical signatures. This technique provides not only the number of possible groups but also the probability of each object to belong to each class. The method was able to distinguish at least two classes among the observed sample, with one of them being probable CEMP stars enriched in s-process elements. However, it was not able to separate CEMP-no stars from the rest of the sample. Latent profile analysis is a powerful model-based tool to be used in the identification of patterns in astrophysics. Our tests show the potential of the technique for the attainment of additional chemical information from `poor' data.
The Class I HDAC Inhibitor RGFP963 Enhances Consolidation of Cued Fear Extinction
ERIC Educational Resources Information Center
Bowers, Mallory E.; Xia, Bing; Carreiro, Samantha; Ressler, Kerry J.
2015-01-01
Evidence indicates that broad, nonspecific histone deacetylase (HDAC) inhibition enhances learning and memory, however, the contribution of the various HDACs to specific forms of learning is incompletely understood. Here, we show that the Class I HDAC inhibitor, RGFP963, enhances consolidation of cued fear extinction. However, RGFP966, a strong…
Transient Analysis Generator /TAG/ simulates behavior of large class of electrical networks
NASA Technical Reports Server (NTRS)
Thomas, W. J.
1967-01-01
Transient Analysis Generator program simulates both transient and dc steady-state behavior of a large class of electrical networks. It generates a special analysis program for each circuit described in an easily understood and manipulated programming language. A generator or preprocessor and a simulation system make up the TAG system.
Learning about Whole-Class Scaffolding from a Teacher Professional Development Study
ERIC Educational Resources Information Center
Visnovska, Jana; Cobb, Paul
2015-01-01
The importance of teachers developing adaptive instructional practices consistent with metaphor of whole-class scaffolding has been well documented. However, teachers' development of such practices is currently not well understood. We draw on a 5-year professional development (PD) design experiment in which a group of middle school mathematics…
ERIC Educational Resources Information Center
Oldfield, Kenneth
2012-01-01
In 2007, "About Campus" published the author's article "Humble and Hopeful: Welcoming First-Generation Poor and Working-Class Students to College." It has been used as a handout in various student orientations, included as a chapter in Teresa Heinz Housel and Vickie Harvey's "The Invisibility Factor: Administrators and…
ERIC Educational Resources Information Center
Jones, Stephanie
2012-01-01
Drawing from a larger ethnographic study, this article engages post-structural theories of language and critical feminist theories of social class to examine two fourth-grade, White, working-poor girls' narratives about their urban neighbourhood in the United States. The author argues that young girls should be perceived as social theorists…
Drug carrier systems for solubility enhancement of BCS class II drugs: a critical review.
Kumar, Sumit; Bhargava, Deepak; Thakkar, Arti; Arora, Saahil
2013-01-01
Poor aqueous solubility impedes a drug's bioavailability and challenges its pharmaceutical development. Pharmaceutical development of drugs with poor water solubility requires the establishment of a suitable formulation layout among various techniques. Various approaches have been investigated extensively to improve the aqueous solubility and poor dissolution rate of BCS class II and IV drugs. In this literature review, novel formulation options, particularly for class II drugs designed for applications such as micronization, self-emulsification, cyclodextrin complexation, co-crystallisation, super critical fluid technology, solubilisation by change in pH, salt formation, co-solvents, melt granulation, and solid dispersion, liposomal/niosomal formulations, are discussed in detail to introduce biopharmaceutical challenges and recent approaches to facilitate more efficient drug formulation and development.
ERIC Educational Resources Information Center
Rothman, Sheila M.
1977-01-01
Suggests that freedom for the middle classes may mean vulnerability for the poor. The enthusiasm for sterilization may be so intense as to deprive the poor of their right not to be sterilized. (Author/AM)
[Non-LTR retrotransposons: LINEs and SINEs in plant genome].
Cheng, Xu-Dong; Ling, Hong-Qing
2006-06-01
Retrotransposons are one of the drivers of genome evolution. They include LTR (long terminal repeat) retrotransposons, which widespread in Eukaryotagenomes, show structural similarity to retroviruses. Non-LTR retrotransposons were first discovered in animal genomes and then identified as ubiquitous components of nuclear genomes in many species across the plant kingdom. They constitute a large fraction of the repetitive DNA. Non-LTR retrotransposons are divided into LINEs (long interspersed nuclear elements) and SINEs (short interspersed nuclear elements). Transposition of non-LTR retrotransposons is rarely observed in plants indicating that most of them are inactive and/or under regulation of the host genome. Transposition is poorly understood, but experimental evidence from other genetic systems shows that LINEs are able to transpose autonomously while non-autonomous SINEs depend on the reverse transcription machinery of other retrotransposons. Phylogenic analysis shows LINEs are probably the most ancient class of retrotransposons in plant genomes, while the origin of SINEs is unknown. This review sums up the above data and wants to show readers a clear picture of non-LTR retrotransposons.
Design of crystal-like aperiodic solids with selective disorder–phonon coupling
Overy, Alistair R.; Cairns, Andrew B.; Cliffe, Matthew J.; Simonov, Arkadiy; Tucker, Matthew G.; Goodwin, Andrew L.
2016-01-01
Functional materials design normally focuses on structurally ordered systems because disorder is considered detrimental to many functional properties. Here we challenge this paradigm by showing that particular types of strongly correlated disorder can give rise to useful characteristics that are inaccessible to ordered states. A judicious combination of low-symmetry building unit and high-symmetry topological template leads to aperiodic ‘procrystalline' solids that harbour this type of disorder. We identify key classes of procrystalline states together with their characteristic diffraction behaviour, and establish mappings onto known and target materials. The strongly correlated disorder found in these systems is associated with specific sets of modulation periodicities distributed throughout the Brillouin zone. Lattice dynamical calculations reveal selective disorder-driven phonon broadening that resembles the poorly understood ‘waterfall' effect observed in relaxor ferroelectrics. This property of procrystalline solids suggests a mechanism by which strongly correlated topological disorder might allow independently optimized thermal and electronic transport behaviour, such as required for high-performance thermoelectrics. PMID:26842772
Edge, Sara; Newbold, Bruce
2013-02-01
Research and practice increasingly suggests discrimination compromises health. Yet the unique experiences and effects facing immigrant and refugee populations remain poorly understood in Canada and abroad. We review current knowledge on discrimination against newcomers in Canada, emphasizing impacts upon health status and service access to identify gaps and research needs. Existing knowledge centers around experiences within health-care settings, differences in perception and coping, mental health impacts, and debates about "non-discriminatory" health-care. There is need for comparative analyses within and across ethno-cultural groups and newcomer classes to better understand factors shaping how discrimination and its health effects are differentially experienced. Women receive greater attention in the literature given their compounded vulnerability. While this must continue, little is known about the experiences of youth and men. Governance and policy discourse analyses would elucidate how norms, institutions and practices shape discriminatory attitudes and responses. Finally, "non-discriminatory health-care" interventions require critical evaluation to determine their effectiveness.
Qian, Ying; Shirasawa, Senji; Chen, Chih-Li; Cheng, Leping; Ma, Qiufu
2002-01-01
Trigeminal nuclei and the dorsal spinal cord are first-order relay stations for processing somatic sensory information such as touch, pain, and temperature. The origins and development of these neurons are poorly understood. Here we show that relay somatic sensory neurons and D2/D4 dorsal interneurons likely derive from Mash1-positive neural precursors, and depend on two related homeobox genes, Rnx and Tlx-1, for proper formation. Rnx and Tlx-1 maintain expression of Drg11, a homeobox gene critical for the development of pain circuitry, and are essential for the ingrowth of trkA+ nociceptive/thermoceptive sensory afferents to their central targets. We showed previously that Rnx is necessary for proper formation of the nucleus of solitary tract, the target for visceral sensory afferents. Together, our studies demonstrate a central role for Rnx and Tlx-1 in the development of two major classes of relay sensory neurons, somatic and visceral. PMID:12023301
Qian, Ying; Shirasawa, Senji; Chen, Chih-Li; Cheng, Leping; Ma, Qiufu
2002-05-15
Trigeminal nuclei and the dorsal spinal cord are first-order relay stations for processing somatic sensory information such as touch, pain, and temperature. The origins and development of these neurons are poorly understood. Here we show that relay somatic sensory neurons and D2/D4 dorsal interneurons likely derive from Mash1-positive neural precursors, and depend on two related homeobox genes, Rnx and Tlx-1, for proper formation. Rnx and Tlx-1 maintain expression of Drg11, a homeobox gene critical for the development of pain circuitry, and are essential for the ingrowth of trkA+ nociceptive/thermoceptive sensory afferents to their central targets. We showed previously that Rnx is necessary for proper formation of the nucleus of solitary tract, the target for visceral sensory afferents. Together, our studies demonstrate a central role for Rnx and Tlx-1 in the development of two major classes of relay sensory neurons, somatic and visceral.
Hantaviruses induce cell type- and viral species-specific host microRNA expression signatures
Shin, Ok Sarah; Kumar, Mukesh; Yanagihara, Richard; Song, Jin-Won
2014-01-01
The mechanisms of hantavirus-induced modulation of host cellular immunity remain poorly understood. Recently, microRNAs (miRNAs) have emerged as a class of essential regulators of host immune response genes. To ascertain if differential host miRNA expression toward representative hantavirus species correlated with immune response genes, miRNA expression profiles were analyzed in human endothelial cells, macrophages and epithelial cells infected with pathogenic and nonpathogenic rodent- and shrew-borne hantaviruses. Distinct miRNA expression profiles were observed in a cell type- and viral species-specific pattern. A subset of miRNAs, including miR-151-5p and miR-1973, were differentially expressed between Hantaan virus and Prospect Hill virus. Pathway analyses confirmed that the targets of selected miRNAs were associated with inflammatory responses and innate immune receptor-mediated signaling pathways. Our data suggest that differential immune responses following hantavirus infection may be regulated in part by cellular miRNA through dysregulation of genes critical to the inflammatory process. PMID:24074584
McCreless, Erin E.; Huff, David D.; Croll, Donald A.; Tershy, Bernie R.; Spatz, Dena R.; Holmes, Nick D.; Butchart, Stuart H. M.; Wilcox, Chris
2016-01-01
Invasive mammals on islands pose severe, ongoing threats to global biodiversity. However, the severity of threats from different mammals, and the role of interacting biotic and abiotic factors in driving extinctions, remain poorly understood at a global scale. Here we model global extirpation patterns for island populations of threatened and extinct vertebrates. Extirpations are driven by interacting factors including invasive rats, cats, pigs, mustelids and mongooses, native species taxonomic class and volancy, island size, precipitation and human presence. We show that controlling or eradicating the relevant invasive mammals could prevent 41–75% of predicted future extirpations. The magnitude of benefits varies across species and environments; for example, managing invasive mammals on small, dry islands could halve the extirpation risk for highly threatened birds and mammals, while doing so on large, wet islands may have little benefit. Our results provide quantitative estimates of conservation benefits and, when combined with costs in a return-on-investment framework, can guide efficient conservation strategies. PMID:27535095
Gender, Contraceptives and Individual Metabolic Predisposition Shape a Healthy Plasma Lipidome.
Sales, Susanne; Graessler, Juergen; Ciucci, Sara; Al-Atrib, Rania; Vihervaara, Terhi; Schuhmann, Kai; Kauhanen, Dimple; Sysi-Aho, Marko; Bornstein, Stefan R; Bickle, Marc; Cannistraci, Carlo V; Ekroos, Kim; Shevchenko, Andrej
2016-06-14
Lipidomics of human blood plasma is an emerging biomarker discovery approach that compares lipid profiles under pathological and physiologically normal conditions, but how a healthy lipidome varies within the population is poorly understood. By quantifying 281 molecular species from 27 major lipid classes in the plasma of 71 healthy young Caucasians whose 35 clinical blood test and anthropometric indices matched the medical norm, we provided a comprehensive, expandable and clinically relevant resource of reference molar concentrations of individual lipids. We established that gender is a major lipidomic factor, whose impact is strongly enhanced by hormonal contraceptives and mediated by sex hormone-binding globulin. In lipidomics epidemiological studies should avoid mixed-gender cohorts and females taking hormonal contraceptives should be considered as a separate sub-cohort. Within a gender-restricted cohort lipidomics revealed a compositional signature that indicates the predisposition towards an early development of metabolic syndrome in ca. 25% of healthy male individuals suggesting a healthy plasma lipidome as resource for early biomarker discovery.
MicroRNAs and intellectual disability (ID) in Down syndrome, X-linked ID, and Fragile X syndrome
Siew, Wei-Hong; Tan, Kai-Leng; Babaei, Maryam Abbaspour; Cheah, Pike-See; Ling, King-Hwa
2013-01-01
Intellectual disability (ID) is one of the many features manifested in various genetic syndromes leading to deficits in cognitive function among affected individuals. ID is a feature affected by polygenes and multiple environmental factors. It leads to a broad spectrum of affected clinical and behavioral characteristics among patients. Until now, the causative mechanism of ID is unknown and the progression of the condition is poorly understood. Advancement in technology and research had identified various genetic abnormalities and defects as the potential cause of ID. However, the link between these abnormalities with ID is remained inconclusive and the roles of many newly discovered genetic components such as non-coding RNAs have not been thoroughly investigated. In this review, we aim to consolidate and assimilate the latest development and findings on a class of small non-coding RNAs known as microRNAs (miRNAs) involvement in ID development and progression with special focus on Down syndrome (DS) and X-linked ID (XLID) [including Fragile X syndrome (FXS)]. PMID:23596395
High frequency, spontaneous motA mutations in Campylobacter jejuni strain 81-176.
Mohawk, Krystle L; Poly, Frédéric; Sahl, Jason W; Rasko, David A; Guerry, Patricia
2014-01-01
Campylobacter jejuni is an important cause of bacterial diarrhea worldwide. The pathogenesis of C. jejuni is poorly understood and complicated by phase variation of multiple surface structures including lipooligosaccharide, capsule, and flagellum. When C. jejuni strain 81-176 was plated on blood agar for single colonies, the presence of translucent, non-motile colonial variants was noted among the majority of opaque, motile colonies. High-throughput genomic sequencing of two flagellated translucent and two opaque variants as well as the parent strain revealed multiple genetic changes compared to the published genome. However, the only mutated open reading frame common between the two translucent variants and absent from the opaque variants and the parent was motA, encoding a flagellar motor protein. A total of 18 spontaneous motA mutations were found that mapped to four distinct sites in the gene, with only one class of mutation present in a phase variable region. This study exemplifies the mutative/adaptive properties of C. jejuni and demonstrates additional variability in C. jejuni beyond phase variation.
Cardiac Cachexia: Perspectives for Prevention and Treatment.
Okoshi, Marina Politi; Capalbo, Rafael Verardino; Romeiro, Fernando G; Okoshi, Katashi
2017-01-01
Cachexia is a prevalent pathological condition associated with chronic heart failure. Its occurrence predicts increased morbidity and mortality independent of important clinical variables such as age, ventricular function, or heart failure functional class. The clinical consequences of cachexia are dependent on both weight loss and systemic inflammation, which accompany cachexia development. Skeletal muscle wasting is an important component of cachexia; it often precedes cachexia development and predicts poor outcome in heart failure. Cachexia clinically affects several organs and systems. It is a multifactorial condition where underlying pathophysiological mechanisms are not completely understood making it difficult to develop specific prevention and treatment therapies. Preventive strategies have largely focused on muscle mass preservation. Different treatment options have been described, mostly in small clinical studies or experimental settings. These include nutritional support, neurohormonal blockade, reducing intestinal bacterial translocation, anemia and iron deficiency treatment, appetite stimulants, immunomodulatory agents, anabolic hormones, and physical exercise regimens. Currently, nonpharmacological therapy such as nutritional support and physical exercise are considered central to cachexia prevention and treatment.
Baggott, Matthew J; Coyle, Jeremy R; Siegrist, Jennifer D; Garrison, Kathleen J; Galloway, Gantt P; Mendelson, John E
2016-04-01
The drug 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy", "molly") is a widely used illicit drug and experimental adjunct to psychotherapy. MDMA has unusual, poorly understood socioemotional effects, including feelings of interpersonal closeness and sociability. To better understand these effects, we conducted a small (n=12) within-subjects double-blind placebo controlled study of the effects of 1.5 mg/kg oral MDMA on social emotions and autobiographical disclosure in a controlled setting. MDMA displayed both sedative- and stimulant-like effects, including increased self-report anxiety. At the same time, MDMA positively altered evaluation of the self (i.e. increasing feelings of authenticity) while decreasing concerns about negative evaluation by others (i.e. decreasing social anxiety). Consistent with these feelings, MDMA increased how comfortable participants felt describing emotional memories. Overall, MDMA produced a prosocial syndrome that seemed to facilitate emotional disclosure and that appears consistent with the suggestion that it represents a novel pharmacological class. © The Author(s) 2016.
Gou, Qiheng; Gao, Linbo; Nie, Xinwen; Pu, Wenchen; Zhu, Jingqiang; Wang, Yichao; Liu, Xuesha; Tan, Shuangyan; Zhou, Jian-Kang; Gong, Yanqiu; He, Juan; Wu, Ke; Xie, Yuxin; Zhao, Wanjun; Dai, Lunzhi; Liu, Lunxu; Xiang, Rong; Wei, Yu-Quan; Zhang, Lin; Peng, Yong
2018-05-07
Long noncoding RNAs (lncRNAs) are emerging as a novel class of regulators in gene expression associated with tumorigenesis. However, the role of lncRNAs in papillary thyroid carcinoma (PTC) is poorly understood. Here we conducted global lncRNA profiling and identified lncRNA AB074169 (lncAB) as significantly downregulated in PTC. Decreased expression of lncAB in PTC was caused by CpG hypermethylation within its gene promoter. Functional studies showed that lncAB overexpression led to cell cycle arrest and tumor growth inhibition in vitro and in vivo, whereas lncAB knockdown promoted cell proliferation. Mechanistic analyses revealed that lncAB bound KH-type splicing regulatory protein (KHSRP) and also decreased expression of KHSRP, thus increasing CDKN1a (p21) expression and decreasing CDK2 expression to repress cell proliferation. Taken together, these findings demonstrate that lncAB functions as a tumor suppressor during PTC tumorigenesis. Copyright ©2018, American Association for Cancer Research.
Dynamic ASXL1 Exon Skipping and Alternative Circular Splicing in Single Human Cells
Natarajan, Sivaraman; Carter, Robert; Brown, Patrick O.
2016-01-01
Circular RNAs comprise a poorly understood new class of noncoding RNA. In this study, we used a combination of targeted deletion, high-resolution splicing detection, and single-cell sequencing to deeply probe ASXL1 circular splicing. We found that efficient circular splicing required the canonical transcriptional start site and inverted AluSx elements. Sequencing-based interrogation of isoforms after ASXL1 overexpression identified promiscuous linear splicing between all exons, with the two most abundant non-canonical linear products skipping the exons that produced the circular isoforms. Single-cell sequencing revealed a strong preference for either the linear or circular ASXL1 isoforms in each cell, and found the predominant exon skipping product is frequently co-expressed with its reciprocal circular isoform. Finally, absolute quantification of ASXL1 isoforms confirmed our findings and suggests that standard methods overestimate circRNA abundance. Taken together, these data reveal a dynamic new view of circRNA genesis, providing additional framework for studying their roles in cellular biology. PMID:27736885
Pitchiaya, Sethuramasundaram; Krishnan, Vishalakshi; Custer, Thomas C.; Walter, Nils G.
2013-01-01
Non-coding RNAs (ncRNAs) recently were discovered to outnumber their protein-coding counterparts, yet their diverse functions are still poorly understood. Here we report on a method for the intracellular Single-molecule High Resolution Localization and Counting (iSHiRLoC) of microRNAs (miRNAs), a conserved, ubiquitous class of regulatory ncRNAs that controls the expression of over 60% of all mammalian protein coding genes post-transcriptionally, by a mechanism shrouded by seemingly contradictory observations. We present protocols to execute single particle tracking (SPT) and single-molecule counting of functional microinjected, fluorophore-labeled miRNAs and thereby extract diffusion coefficients and molecular stoichiometries of micro-ribonucleoprotein (miRNP) complexes from living and fixed cells, respectively. This probing of miRNAs at the single molecule level sheds new light on the intracellular assembly/disassembly of miRNPs, thus beginning to unravel the dynamic nature of this important gene regulatory pathway and facilitating the development of a parsimonious model for their obscured mechanism of action. PMID:23820309
Regulation of Strigolactone Biosynthesis by Gibberellin Signaling.
Ito, Shinsaku; Yamagami, Daichi; Umehara, Mikihisa; Hanada, Atsushi; Yoshida, Satoko; Sasaki, Yasuyuki; Yajima, Shunsuke; Kyozuka, Junko; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Shirasu, Ken; Yamaguchi, Shinjiro; Asami, Tadao
2017-06-01
Strigolactones (SLs) are a class of plant hormones that regulate diverse physiological processes, including shoot branching and root development. They also act as rhizosphere signaling molecules to stimulate the germination of root parasitic weeds and the branching of arbuscular mycorrhizal fungi. Although various types of cross talk between SLs and other hormones have been reported in physiological analyses, the cross talk between gibberellin (GA) and SLs is poorly understood. We screened for chemicals that regulate the level of SLs in rice ( Oryza sativa ) and identified GA as, to our knowledge, a novel SL-regulating molecule. The regulation of SL biosynthesis by GA is dependent on the GA receptor GID1 and F-box protein GID2. GA treatment also reduced the infection of rice plants by the parasitic plant witchers weed ( Striga hermonthica ). These data not only demonstrate, to our knowledge, the novel plant hormone cross talk between SL and GA, but also suggest that GA can be used to control parasitic weed infections. © 2017 American Society of Plant Biologists. All Rights Reserved.
Regulation of Strigolactone Biosynthesis by Gibberellin Signaling1[OPEN
Ito, Shinsaku; Yamagami, Daichi; Umehara, Mikihisa; Hanada, Atsushi; Sasaki, Yasuyuki; Yajima, Shunsuke; Kyozuka, Junko; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Yamaguchi, Shinjiro
2017-01-01
Strigolactones (SLs) are a class of plant hormones that regulate diverse physiological processes, including shoot branching and root development. They also act as rhizosphere signaling molecules to stimulate the germination of root parasitic weeds and the branching of arbuscular mycorrhizal fungi. Although various types of cross talk between SLs and other hormones have been reported in physiological analyses, the cross talk between gibberellin (GA) and SLs is poorly understood. We screened for chemicals that regulate the level of SLs in rice (Oryza sativa) and identified GA as, to our knowledge, a novel SL-regulating molecule. The regulation of SL biosynthesis by GA is dependent on the GA receptor GID1 and F-box protein GID2. GA treatment also reduced the infection of rice plants by the parasitic plant witchers weed (Striga hermonthica). These data not only demonstrate, to our knowledge, the novel plant hormone cross talk between SL and GA, but also suggest that GA can be used to control parasitic weed infections. PMID:28404726
Leek, Jeffrey T.; Maier, Ronald V.; Tompkins, Ronald G.; Storey, John D.
2011-01-01
Background Trauma is the number one killer of individuals 1–44 y of age in the United States. The prognosis and treatment of inflammatory complications in critically injured patients continue to be challenging, with a history of failed clinical trials and poorly understood biology. New approaches are therefore needed to improve our ability to diagnose and treat this clinical condition. Methods and Findings We conducted a large-scale study on 168 blunt-force trauma patients over 28 d, measuring ∼400 clinical variables and longitudinally profiling leukocyte gene expression with ∼800 microarrays. Marshall MOF (multiple organ failure) clinical score trajectories were first utilized to organize the patients into five categories of increasingly poor outcomes. We then developed an analysis framework modeling early within-patient expression changes to produce a robust characterization of the genomic response to trauma. A quarter of the genome shows early expression changes associated with longer-term post-injury complications, captured by at least five dynamic co-expression modules of functionally related genes. In particular, early down-regulation of MHC-class II genes and up-regulation of p38 MAPK signaling pathway were found to strongly associate with longer-term post-injury complications, providing discrimination among patient outcomes from expression changes during the 40–80 h window post-injury. Conclusions The genomic characterization provided here substantially expands the scope by which the molecular response to trauma may be characterized and understood. These results may be instrumental in furthering our understanding of the disease process and identifying potential targets for therapeutic intervention. Additionally, the quantitative approach we have introduced is potentially applicable to future genomics studies of rapidly progressing clinical conditions. Trial Registration ClinicalTrials.gov NCT00257231 Please see later in the article for the Editors' Summary PMID:21931541
2011-01-01
Background How youth perceive marketing messages in sports is poorly understood. We evaluated whether youth perceive that the imagery of a specific sports marketing advertisement contained smoking-related messages. Methods Twenty grade 7 to 11 classes (397 students) from two high schools in Montréal, Canada were recruited to participate in a cluster randomised single-blind controlled trial. Classes were randomly allocated to either a NIKE advertisement containing the phrase 'LIGHT IT UP' (n = 205) or to a neutral advertisement with smoking imagery reduced and the phrase replaced by 'GO FOR IT' (n = 192). The NIKE logo was removed from both advertisements. Students responded in class to a questionnaire asking open-ended questions about their perception of the messages in the ad. Reports relating to the appearance and text of the ad, and the product being promoted were evaluated. Results Relative to the neutral ad, more students reported that the phrase 'LIGHT IT UP' was smoking-related (37.6% vs. 0.5%) and that other parts of the ad resembled smoking-related products (50.7% vs. 10.4%). The relative risk of students reporting that the NIKE ad promoted cigarettes was 4.41 (95% confidence interval: 2.64-7.36; P < 0.001). Conclusions The unbranded imagery of an advertisement in a specific campaign aimed at promoting NIKE hockey products appears to have contained smoking-related messages. This particular marketing campaign may have promoted smoking. This suggests that the regulation of marketing to youth may need to be more tightly controlled. PMID:21477307
Nagy, László G; Riley, Robert; Tritt, Andrew; Adam, Catherine; Daum, Chris; Floudas, Dimitrios; Sun, Hui; Yadav, Jagjit S; Pangilinan, Jasmyn; Larsson, Karl-Henrik; Matsuura, Kenji; Barry, Kerrie; Labutti, Kurt; Kuo, Rita; Ohm, Robin A; Bhattacharya, Sukanta S; Shirouzu, Takashi; Yoshinaga, Yuko; Martin, Francis M; Grigoriev, Igor V; Hibbett, David S
2016-04-01
Evolution of lignocellulose decomposition was one of the most ecologically important innovations in fungi. White-rot fungi in the Agaricomycetes (mushrooms and relatives) are the most effective microorganisms in degrading both cellulose and lignin components of woody plant cell walls (PCW). However, the precise evolutionary origins of lignocellulose decomposition are poorly understood, largely because certain early-diverging clades of Agaricomycetes and its sister group, the Dacrymycetes, have yet to be sampled, or have been undersampled, in comparative genomic studies. Here, we present new genome sequences of ten saprotrophic fungi, including members of the Dacrymycetes and early-diverging clades of Agaricomycetes (Cantharellales, Sebacinales, Auriculariales, and Trechisporales), which we use to refine the origins and evolutionary history of the enzymatic toolkit of lignocellulose decomposition. We reconstructed the origin of ligninolytic enzymes, focusing on class II peroxidases (AA2), as well as enzymes that attack crystalline cellulose. Despite previous reports of white rot appearing as early as the Dacrymycetes, our results suggest that white-rot fungi evolved later in the Agaricomycetes, with the first class II peroxidases reconstructed in the ancestor of the Auriculariales and residual Agaricomycetes. The exemplars of the most ancient clades of Agaricomycetes that we sampled all lack class II peroxidases, and are thus concluded to use a combination of plesiomorphic and derived PCW degrading enzymes that predate the evolution of white rot. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Endophytic fungi associated with Macrosolen tricolor and its host Camellia oleifera.
Sheng-Liang, Zhou; Shu-Zhen, Yan; Zhen-Ying, Wu; Shuang-Lin, Chen
2014-06-01
Endophytic fungi play an important role in terrestrial ecosystem, while little is known about those in hemi-parasitic plants, a group of special plants which absorb nutrients from its hosts by haustoria. The relationship of the endophytes in the two parts of the bipartite systems (hemiparasites together with their hosts) is also poorly understood. Endophytic fungi of a hemi-parasitic plant Macrosolen tricolor, and its host plant Camellia oleifera were investigated and compared in this study. M. tricolor contained rich and diversified endophytic fungi (H' = 2.829), which consisted mainly of ascomycetes, distributed in more than ten orders of four classes (Sordariomycetes, Dothideomycetes, Leotiomycetes and Eurotiomycetes) besides Incertae sedis strains (23.2 % of total). In addition, 2.2 % of isolates were identified to be Basidiomycota, all of which belonged to Agaricomycetes. Obvious differences were observed between the endophytic fungal assembles in the leaves and those in the branches of M. tricolor. The endophytic fungi isolated from C. oleifera distributed in nearly same orders of the four classes of Ascomycota and one class (Agaricomycetes) of Basidiomycota as those from M. tricolor with similar proportion. For both M. tricolor and C. oleifera, Valsa sp. was the dominant endophyte species in the leaves, Torula sp. 1 and Fusarium sp. 1 were the dominant endophytic fungi in the branches. The similarity coefficient of the endophyte assembles in the two host was 64.4 %. Canonical correspondence analysis showed that the endophyte assembles of M. tricolor and C. oleifera were significantly different (p < 0.01).
Goff, Kira L; Peru, Kerry; Wilson, Kenneth E; Headley, John V
2014-08-01
Industrial activity associated with oil-sands extraction in Canada's Athabasca region produces a variety of contaminants of concern, including naphthenic acid fraction components (NAFCs). NAFCs are a complex mixture of organic compounds that are poorly understood both in terms of their chemical composition and effects on the environment. NAFC toxicity in the unicellular green algae Chlamydomonas reinhardtii P.A.Dangeard was correlated with the presence of the algal cell wall. It was suggested that the toxicity of NAFCs in C. reinhardtii was due to surfactant effects. Surfactant-cell wall interactions are specific and governed by the compound class and structure, and by the nature of the biological material. Here, we investigate the effects of wildtype (WT) C. reinhardtii and two cell-wall mutants on specific classes of NAFCs when growing cultures were treated with a 100 mg · L(-1) solution of NAFCs. Changes in the NAFC composition in the media were examined using high resolution mass spectrometry over a period of 4 d. Algal mediated changes in the NAFCs were limited to specific classes of NAFCs. In particular, the removal of large, classical naphthenic acids, with a double bond equivalent of 8, was observed in WT C. reinhardtii cultures. The observed algal mediated changes in NAFC composition would have been masked by low resolution mass spectrometry and highlight the importance of this tool in examining bioremediation of complex mixtures of NAFCs. © 2014 Phycological Society of America.
Ruzzenente, Andrea; Bagante, Fabio; Bertuzzo, Francesca; Aldrighetti, Luca; Ercolani, Giorgio; Giuliante, Felice; Ferrero, Alessandro; Torzilli, Guido; Grazi, Gian Luca; Ratti, Francesca; Cucchetti, Alessandro; De Rose, Agostino M; Russolillo, Nadia; Cimino, Matteo; Perri, Pasquale; Cataldo, Ivana; Scarpa, Aldo; Guglielmi, Alfredo; Iacono, Calogero
2017-01-01
Even though surgery remains the only potentially curative option for patients with neuroendocrine liver metastases, the factors determining a patient's prognosis following hepatectomy are poorly understood. Using a multicentric database including patients who underwent hepatectomy for NELMs at seven tertiary referral hepato-biliary-pancreatic centers between January 1990 and December 2014, we sought to identify the predictors of survival and develop a clinical tool to predict patient's prognosis after liver resection for NELMs. The median age of the 238 patients included in the study was 61.9 years (interquartile range 51.5-70.1) and 55.9 % (n = 133) of patients were men. The number of NELMs (hazard ratio = 1.05), tumor size (HR = 1.01), and Ki-67 index (HR = 1.07) were the predictors of overall survival. These variables were used to develop a nomogram able to predict survival. According to the predicted 5-year OS, patients were divided into three different risk classes: 19.3, 55.5, and 25.2 % of patients were in low (>80 % predicted 5-year OS), medium (40-80 % predicted 5-year OS), and high (<40 % predicted 5-year OS) risk classes. The 10-year OS was 97.0, 55.9, and 20.0 % in the low, medium, and high-risk classes, respectively (p < 0.001). We developed a novel nomogram that accurately (c-index >70 %) staged and predicted the prognosis of patients undergoing liver resection for NELMs.
Auger, Nathalie; Daniel, Mark; Knäuper, Bärbel; Raynault, Marie-France; Pless, Barry
2011-04-08
How youth perceive marketing messages in sports is poorly understood. We evaluated whether youth perceive that the imagery of a specific sports marketing advertisement contained smoking-related messages. Twenty grade 7 to 11 classes (397 students) from two high schools in Montréal, Canada were recruited to participate in a cluster randomised single-blind controlled trial. Classes were randomly allocated to either a NIKE advertisement containing the phrase 'LIGHT IT UP' (n = 205) or to a neutral advertisement with smoking imagery reduced and the phrase replaced by 'GO FOR IT' (n = 192). The NIKE logo was removed from both advertisements. Students responded in class to a questionnaire asking open-ended questions about their perception of the messages in the ad. Reports relating to the appearance and text of the ad, and the product being promoted were evaluated. Relative to the neutral ad, more students reported that the phrase 'LIGHT IT UP' was smoking-related (37.6% vs. 0.5%) and that other parts of the ad resembled smoking-related products (50.7% vs. 10.4%). The relative risk of students reporting that the NIKE ad promoted cigarettes was 4.41 (95% confidence interval: 2.64-7.36; P < 0.001). The unbranded imagery of an advertisement in a specific campaign aimed at promoting NIKE hockey products appears to have contained smoking-related messages. This particular marketing campaign may have promoted smoking. This suggests that the regulation of marketing to youth may need to be more tightly controlled.
Isotopic signals of summer denitrification in a northern hardwood forested catchment
Sarah K. Wexler; Christine L. Goodale; Kevin J. McGuire; Scott W. Bailey; Peter M. Groffman
2014-01-01
Despite decades of measurements, the nitrogen balance of temperate forest catchments remains poorly understood. Atmospheric nitrogen deposition often greatly exceeds streamwater nitrogen losses; the fate of the remaining nitrogen is highly uncertain. Gaseous losses of nitrogen to denitrification are especially poorly documented and are often ignored. Here, we provide...
Punishment and Welfare: Paternal Incarceration and Families' Receipt of Public Assistance
ERIC Educational Resources Information Center
Sugie, Naomi F.
2012-01-01
The United States criminal justice and welfare systems are two important government institutions in the lives of the poor. Despite many theoretical discussions about their relationship, their operation at the level of offenders and families remains poorly understood. This paper utilizes Fragile Families and Child Wellbeing data to examine how…
ERIC Educational Resources Information Center
Gilman, Amy
1984-01-01
Vast changes took place in urban benevolence toward poor females in the first half of the nineteenth century. Agencies started by upper-class women as private organizations to support needy women became agencies run by salaried, professional, male charity workers whose job it was to train and discipline poor females. (RM)
Transforming the University through Community Engagement
ERIC Educational Resources Information Center
Yapa, Lakshman
2009-01-01
The universal belief that poverty is a matter of low income and correctable through economic growth, more jobs, and increased income is precisely why poverty has persisted in the United States and elsewhere. We view the poor as those not yet in the middle class, but it can be shown that not all the poor can join the middle class, even in the…
ERIC Educational Resources Information Center
Chessin, Debby; Zander, Mary Jane
2006-01-01
A Mrs. Jefferson, a sixth-grade lead science teacher, wandered through her students' art show, she enjoyed the creative drawings that her students did in art class. Next year, due to budget cuts, the art teacher would be shared with several other schools and would not have time for weekly art classes for every grade. The principal understood the…
Ag Bendech, M; Chauliac, M; Gerbouin-Rerolle, P; Kante, N; Malvy, D J
1997-01-01
This survey, conducted in 1996, evaluated changes in the way families feed themselves caused by the effects of devaluation of the CFA franc. It involved semi-directed interviews with 64 subjects from various socio-economic backgrounds (affluent, middle-class, poor). The subjects spoke of the difficulties of daily life, lack of money and rapid, unpredictable rises in the prices of essential goods caused by the devaluation. They did not understand the reasons for the devaluation, which has caused rapid changes in the social conditions and nutrition of urban families and has exacerbated the inequality of access to foodstuffs. Affluent families have adopted strategies that increase the family food budget, compensating for price increases. The meals of poor and middle-class families have been directly affected in both structure and content. Poor families have been particularly badly affected. All the changes in strategy, and substitutions of one product for another described by middle-class families were already being used by the poor families before devaluation.
Sen, Gita; Iyer, Aditi
2012-06-01
This paper argues that a focus on the middle groups in a multi-dimensional socioeconomic ordering can provide valuable insights into how different axes of advantage and disadvantage intersect with each other. It develops the elements of a framework to analyse the middle groups through an intersectional analysis, and uses it to explore how such groups leverage economic class or gender advantages to secure entitlements to treatment for long-term illness. The study draws upon household survey data on health-seeking for long-term ailments from 60 villages of Koppal district, Karnataka (India). The survey was designed to capture gender, economic class, caste, age and life stage-based inequalities in access to health care during pregnancy and for short and long-term illnesses. There were striking similarities between two important middle groups--non-poor women and poor men--in some key outcomes: their rates of non-treatment when ill, treatment discontinuation and treatment continuation, and the amounts they spent for treatment. These two groups are the obverse of each other in terms of gender and economic class advantage and disadvantage. Non-poor women have an economic advantage and a gender disadvantage, while poor men have the exact opposite. However, despite the similarities in outcomes, the processes by which gender and class advantage were leveraged by each of the groups varied sharply. Similar patterns held for the poorest men except that the class disadvantage they had to overcome was greater, and the results are modified by this. Copyright © 2011 Elsevier Ltd. All rights reserved.
Narrating the 1980s and 1990s: Voices of Poor and Working-Class White and African American Men.
ERIC Educational Resources Information Center
Weis, Lois; Fine, Michelle
1996-01-01
The divergent views of poor and working-class African-American and White men regarding the causes of their current condition are presented. Different "biographies of race" encourage African-American men to blame the economy and racism but White men to blame Black males for the economic plight of White men. The ways in which the two…
Evolution of a sediment wave in an experimental channel
Thomas E. Lisle; James E. Pizzuto; Hiroshi Ikeda; Fujiko Iseya; Yoshinori Kodama
1997-01-01
Abstract - The routing of bed material through channels is poorly understood. We approach the problem by observing and modeling the fate of a low-amplitude sediment wave of poorly sorted sand that we introduced into an experimental channel transporting sediment identical to that of the introduced wave. The wave essentially dispersed upstream and downstream without...
Independent Learning--What We Do When You're Not There
ERIC Educational Resources Information Center
Hockings, Christine; Thomas, Liz; Ottaway, Jim; Jones, Rob
2018-01-01
Independent learning is one of the cornerstones of UK higher education yet it is poorly understood by students and is seen by politicians as a poor substitute for face to face teaching. This paper explores students' understandings, approaches and experiences of independent learning and how they may become more effective independent learners. This…
The role of bedrock groundwater in rainfall-runoff response at hillslope and catchment scales
C. Gabrielli; J.J. McDonnell; W.T. Jarvis
2012-01-01
Bedrock groundwater dynamics in headwater catchments are poorly understood and poorly characterized. Direct hydrometric measurements have been limited due to the logistical challenges associated with drilling through hard rock in steep, remote and often roadless terrain. We used a new portable bedrock drilling system to explore bedrock groundwater dynamics aimed at...
Asian and Pacific Islander American Poverty: The Working Poor and the Jobless Poor.
ERIC Educational Resources Information Center
Toji, Dean S.; Johnson, James H.
1992-01-01
Assesses the incidence of Asian-American and Pacific Islander-American poverty, and offers a theoretical explanation for its existence. It is argued that poverty of Americans of Asian and Pacific Island descent is best understood in the context of the linkage of labor migration and U.S. labor market segmentation. (SLD)
Interannual Variation in Phytoplankton Class-specific Primary Production at a Global Scale
NASA Technical Reports Server (NTRS)
Rousseaux, Cecile; Gregg, Watson
2014-01-01
Phytoplankton is responsible for over half of the net primary production on earth. The knowledge on the contribution of various phytoplankton groups to the total primary production is still poorly understood. Data from satellite observations suggest that for upwelling regions, photosynthetic rates by microplankton is higher than that of nanoplankton but that when the spatial extent is considered, the production by nanoplankton is comparable or even larger than microplankton. Here, we used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. Globally, diatoms were the group that contributed the most to the total phytoplankton production (approx. 50%) followed by coccolithophores and chlorophytes. Primary production by diatoms was highest in high latitude (>45 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nino Index, MEI) and 'regional' climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability. These results provide a modeling and data assimilation perspective to phytoplankton partitioning of primary production and contribute to our understanding of the dynamics of the carbon cycle in the oceans at a global scale.
Impaired capacity for upregulation of MHC class II in tumor-associated microglia.
Schartner, Jill M; Hagar, Aaron R; Van Handel, Michelle; Zhang, Leying; Nadkarni, Nivedita; Badie, Behnam
2005-09-01
Immunotherapy for malignant gliomas is being studied as a possible adjunctive therapy for this highly fatal disease. Thus far, inadequate understanding of brain tumor immunology has hindered the design of such therapies. For instance, the role of microglia and macrophages, which comprise a significant proportion of tumor-infiltrating inflammatory cells, in the regulation of the local anti-tumor immune response is poorly understood. To study the response of microglia and macrophages to known activators in brain tumors, we injected CpG oligodeoxynucleotide (ODN), interferon-gamma (IFN-gamma), and IFN-gamma/LPS into normal and intracranial RG2 glioma-bearing rodents. Microglia/macrophage infiltration and their surface expression of MHC class II B7.1 and B7.2 was examined by flow cytometry. Each agent evaluated yielded a distinct microglia/macrophage response: CpG ODN was the most potent inducer of microglia/macrophage infiltration and B7.1 expression, while IFN-gamma resulted in the highest MHC-II expression in both normal and tumors. Regardless of the agent injected, however, MHC-II induction was significantly muted in tumor microglia/macrophage as compared with normal brain. These data suggest that microglia/macrophage responsiveness to activators can vary in brain tumors when compared with normal brain. Understanding the mechanism of these differences may be critical in the development of novel immunotherapies for malignant glioma. (c) 2005 Wiley-Liss, Inc.
Near-infrared counterparts of three transient very faint neutron star X-ray binaries
NASA Astrophysics Data System (ADS)
Shaw, A. W.; Heinke, C. O.; Degenaar, N.; Wijnands, R.; Kaur, R.; Forestell, L. M.
2017-10-01
We present near-infrared (NIR) imaging observations of three transient neutron star X-ray binaries, SAX J1753.5-2349, SAX J1806.5-2215 and AX J1754.2-2754. All three sources are members of the class of 'very faint' X-ray transients which exhibit X-ray luminosities LX ≲ 1036 erg s-1. The nature of this class of sources is still poorly understood. We detect NIR counterparts for all three systems and perform multiband photometry for both SAX J1753.5-2349 and SAX J1806.5-2215, including narrow-band Br γ photometry for SAX J1806.5-2215. We find that SAX J1753.5-2349 is significantly redder than the field population, indicating that there may be absorption intrinsic to the system, or perhaps a jet is contributing to the infrared emission. SAX J1806.5-2215 appears to exhibit absorption in Br γ, providing evidence for hydrogen in the system. Our observations of AX J1754.2-2754 represent the first detection of an NIR counterpart for this system. We find that none of the measured magnitudes are consistent with the expected quiescent magnitudes of these systems. Assuming that the infrared radiation is dominated by either the disc or the companion star, the observed magnitudes argue against an ultracompact nature for all three systems.
Diversity of the Epsilonproteobacteria Dsb (disulfide bond) systems
Bocian-Ostrzycka, Katarzyna M.; Grzeszczuk, Magdalena J.; Dziewit, Lukasz; Jagusztyn-Krynicka, Elżbieta K.
2015-01-01
The bacterial proteins of the Dsb family—important components of the post-translational protein modification system—catalyze the formation of disulfide bridges, a process that is crucial for protein structure stabilization and activity. Dsb systems play an essential role in the assembly of many virulence factors. Recent rapid advances in global analysis of bacteria have thrown light on the enormous diversity among bacterial Dsb systems. While the Escherichia coli disulfide bond-forming system is quite well understood, the mechanisms of action of Dsb systems in other bacteria, including members of class Epsilonproteobacteria that contain pathogenic and non-pathogenic bacteria colonizing extremely diverse ecological niches, are poorly characterized. Here we present a review of current knowledge on Epsilonproteobacteria Dsb systems. We have focused on the Dsb systems of Campylobacter spp. and Helicobacter spp. because our knowledge about Dsb proteins of Wolinella and Arcobacter spp. is still scarce and comes mainly from bioinformatic studies. Helicobacter pylori is a common human pathogen that colonizes the gastric epithelium of humans with severe consequences. Campylobacter spp. is a leading cause of zoonotic enteric bacterial infections in most developed and developing nations. We focus on various aspects of the diversity of the Dsb systems and their influence on pathogenicity, particularly because Dsb proteins are considered as potential targets for a new class of anti-virulence drugs to treat human infections by Campylobacter or Helicobacter spp. PMID:26106374
Gao, Dongying; Jiang, Ning; Wing, Rod A.; Jiang, Jiming; Jackson, Scott A.
2015-01-01
Centromeres are important chromosomal regions necessary for eukaryotic cell segregation and replication. Due to high amounts of tandem repeats and transposons, centromeres have been difficult to sequence in most multicellular organisms, thus their sequence structure and evolution are poorly understood. In this study, we analyzed transposons in the centromere 8 (Cen8) from the African cultivated rice (O. glaberrima) and two subspecies of the Asian cultivated rice (O. sativa), indica and japonica. We detected much higher transposon contents (>69%) in centromere regions than in the whole genomes of O. sativa ssp. japonica and O. glaberrima (~35%). We compared the three Cen8s and identified numerous recent insertions of transposons that were frequently organized into multiple-layer nested blocks, similar to nested transposons in maize. Except for the Hopi retrotransposon, all LTR retrotransposons were shared but exhibit different abundances amongst the three Cen8s. Even though a majority of the transposons were located in intergenic regions, some gene-related transposons were found and may be involved in gene diversification. Chromatin immunoprecipitated (ChIP) data analysis revealed that 165 families from both Class I and Class II transposons were found in CENH3-associated chromatin sequences. These results indicate essential roles for transposons in centromeres and that the rapid divergence of the Cen8 sequences between the two cultivated rice species was primarily caused by recent transposon insertions. PMID:25904926
Gao, Dongying; Jiang, Ning; Wing, Rod A; Jiang, Jiming; Jackson, Scott A
2015-01-01
Centromeres are important chromosomal regions necessary for eukaryotic cell segregation and replication. Due to high amounts of tandem repeats and transposons, centromeres have been difficult to sequence in most multicellular organisms, thus their sequence structure and evolution are poorly understood. In this study, we analyzed transposons in the centromere 8 (Cen8) from the African cultivated rice (O. glaberrima) and two subspecies of the Asian cultivated rice (O. sativa), indica and japonica. We detected much higher transposon contents (>69%) in centromere regions than in the whole genomes of O. sativa ssp. japonica and O. glaberrima (~35%). We compared the three Cen8s and identified numerous recent insertions of transposons that were frequently organized into multiple-layer nested blocks, similar to nested transposons in maize. Except for the Hopi retrotransposon, all LTR retrotransposons were shared but exhibit different abundances amongst the three Cen8s. Even though a majority of the transposons were located in intergenic regions, some gene-related transposons were found and may be involved in gene diversification. Chromatin immunoprecipitated (ChIP) data analysis revealed that 165 families from both Class I and Class II transposons were found in CENH3-associated chromatin sequences. These results indicate essential roles for transposons in centromeres and that the rapid divergence of the Cen8 sequences between the two cultivated rice species was primarily caused by recent transposon insertions.
2013-01-01
Background Pluripotency is a fundamental property of early mammalian development but it is currently unclear to what extent its cellular mechanisms are conserved in vertebrates or metazoans. POU5F1 and POU2 are the two principle members constituting the class V POU domain family of transcription factors, thought to have a conserved role in the regulation of pluripotency in vertebrates as well as germ cell maintenance and neural patterning. They have undergone a complex pattern of evolution which is poorly understood and controversial. Results By analyzing the sequences of POU5F1, POU2 and their flanking genes, we provide strong indirect evidence that POU5F1 originated at least as early as a common ancestor of gnathostomes but became extinct in a common ancestor of teleost fishes, while both POU5F1 and POU2 survived in the sarcopterygian lineage leading to tetrapods. Less divergent forms of POU5F1 and POU2 appear to have persisted among cartilaginous fishes. Conclusions Our study resolves the controversial evolutionary relationship between teleost pou2 and tetrapod POU2 and POU5F1, and shows that class V POU transcription factors have existed at least since the common ancestor of gnathostome vertebrates. It provides a framework for elucidating the basis for the lineage-specific extinctions of POU2 and POU5F1. PMID:23659605
ANALYTICAL CHEMISTRY RESEARCH NEEDS FOR ...
The consensus among environmental scientists and risk assessors is that the fate and effects of pharmaceutical and personal care products (PPCPS) in the environment are poorly understood. Many classes of PPCPs have yet to be investigated. Acquisition of trends data for a suite of PPCPs (representatives from each of numerous significant classes), shown to recur amongst municipal wastewater treatment plants across the country, may prove of key importance. The focus of this paper is an overview of some of the analytical methods being developed at the Environmenental Protection Agency and their application to wastewater and surface water samples. Because PPCPs are generally micro-pollutants, emphasis is on development of enrichment and pre- concentration techniques using various means of solid-phase extraction. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCP
"I Did Not Miss Any, Only When I Had a Valid Reason": Accounting for Absences from Sociology Classes
ERIC Educational Resources Information Center
O'Sullivan, Sara; McMahon, Léan; Moore, Gemma; Nititham, Diane Sabenacio; Slevin, Amanda; Kelly, Christina; Wixted, Lisa
2015-01-01
In this study we explore how absence from sociology classes is understood by undergraduate students at University College Dublin. The authors use Scott and Lyman's (1968) concept of accounts to explore absence sociologically. Drawing on data generated via focus groups, an open-ended questionnaire, and an online survey with students, we outline the…
Shen, Chao-qin; Yan, Ting-Ting; Liu, Wei; Zhu, Xiao-qiang; Tian, Xiang-long; Fu, Xue-liang; Hua, Rong; Zhang, Jun-feng; Huo, Yan-miao; Liu, De-jun; Yang, Jian-yu; Sun, Yong-Wei; Fang, Jing-Yuan; Chen, Hao-Yan; Hong, Jie
2017-01-01
FAM83B (family with sequence similarity 83, member B) seems to emerge as a new class of players involved in the development of a variety of malignant tumors. Yet the molecular mechanisms are not well understood. The present study is intended to investigate the expression and function of FAM83B in pancreatic ductal adenocarcinoma (PDAC). In this study, we found that the expression of FAM83B was significantly increased both in PDAC cell lines and PDAC tumor tissues. FAM83B expression was positively related with advanced clinical stage and poor vital status. Higher FAM83B expression predicted shorter overall survival in PDAC patients, regardless of lymphatic metastasis status and histological differentiation. Actually, FAM83B may act as an independent prognostic indicator as well. What's more, down-regulation of FAM83B in PDAC cells contributed to G0/G1 phase arrest and inhibition of cell proliferation. Finally, a subcutaneous xenograft model indicated that knockdown of FAM83B significantly reduced the tumor volume in vivo. Our findings have provided supporting evidence for the potential molecular biomarker role of FAM83B in PDAC. It's of great interest and broad significance to target FAM83B in PDAC, which may conduce to develop a meaningful and effective strategy in the diagnosis and treatment of PDAC. PMID:29158787
Zeppa, Joseph J.; Kasper, Katherine J.; Mohorovic, Ivor; Mazzuca, Delfina M.
2017-01-01
The globally prominent pathogen Streptococcus pyogenes secretes potent immunomodulatory proteins known as superantigens (SAgs), which engage lateral surfaces of major histocompatibility class II molecules and T-cell receptor (TCR) β-chain variable domains (Vβs). These interactions result in the activation of numerous Vβ-specific T cells, which is the defining activity of a SAg. Although streptococcal SAgs are known virulence factors in scarlet fever and toxic shock syndrome, mechanisms by how SAgs contribute to the life cycle of S. pyogenes remain poorly understood. Herein, we demonstrate that passive immunization against the Vβ8-targeting SAg streptococcal pyrogenic exotoxin A (SpeA), or active immunization with either wild-type or a nonfunctional SpeA mutant, protects mice from nasopharyngeal infection; however, only passive immunization, or vaccination with inactive SpeA, resulted in high-titer SpeA-specific antibodies in vivo. Mice vaccinated with wild-type SpeA rendered Vβ8+ T cells poorly responsive, which prevented infection. This phenotype was reproduced with staphylococcal enterotoxin B, a heterologous SAg that also targets Vβ8+ T cells, and rendered mice resistant to infection. Furthermore, antibody-mediated depletion of T cells prevented nasopharyngeal infection by S. pyogenes, but not by Streptococcus pneumoniae, a bacterium that does not produce SAgs. Remarkably, these observations suggest that S. pyogenes uses SAgs to manipulate Vβ-specific T cells to establish nasopharyngeal infection. PMID:28794279
NASA Astrophysics Data System (ADS)
Jones, Alan M.; Westwood, Isaac M.; Osborne, James D.; Matthews, Thomas P.; Cheeseman, Matthew D.; Rowlands, Martin G.; Jeganathan, Fiona; Burke, Rosemary; Lee, Diane; Kadi, Nadia; Liu, Manjuan; Richards, Meirion; McAndrew, Craig; Yahya, Norhakim; Dobson, Sarah E.; Jones, Keith; Workman, Paul; Collins, Ian; van Montfort, Rob L. M.
2016-10-01
The heat shock protein 70s (HSP70s) are molecular chaperones implicated in many cancers and of significant interest as targets for novel cancer therapies. Several HSP70 inhibitors have been reported, but because the majority have poor physicochemical properties and for many the exact mode of action is poorly understood, more detailed mechanistic and structural insight into ligand-binding to HSP70s is urgently needed. Here we describe the first comprehensive fragment-based inhibitor exploration of an HSP70 enzyme, which yielded an amino-quinazoline fragment that was elaborated to a novel ATP binding site ligand with different physicochemical properties to known adenosine-based HSP70 inhibitors. Crystal structures of amino-quinazoline ligands bound to the different conformational states of the HSP70 nucleotide binding domain highlighted the challenges of a fragment-based approach when applied to this particular flexible enzyme class with an ATP-binding site that changes shape and size during its catalytic cycle. In these studies we showed that Ser275 is a key residue in the selective binding of ATP. Additionally, the structural data revealed a potential functional role for the ATP ribose moiety in priming the protein for the formation of the ATP-bound pre-hydrolysis complex by influencing the conformation of one of the phosphate binding loops.
ERIC Educational Resources Information Center
Silva, Janelle M.; Langhout, Regina Day
2016-01-01
Empowering settings are important places for people to develop leadership skills in order to enact social change. Yet, due to socio-cultural constructions of childhood in the US, especially constructions around working class and working poor children of Color, they are often not seen as capable or competent change agents, or in need of being in…
Antenatal psychosocial risk factors associated with adverse postpartum family outcomes.
Wilson, L M; Reid, A J; Midmer, D K; Biringer, A; Carroll, J C; Stewart, D E
1996-01-01
OBJECTIVE: To determine the strength of the association between antenatal psychosocial risk factors and adverse postpartum outcomes in the family, such as assault of women by their partner, child abuse, postpartum depression, marital dysfunction and physical illness. DATA SOURCES: MEDLINE, Cinahl, Famli, Psych Abstracts and the Oxford Database of Perinatal Trials were searched from relevant articles published from Jan. 1, 1980, to Dec. 31, 1993, with the use of MeSH terms "depression, involutional," "child abuse," "child neglect," "domestic violence," "family," "marital adjustment," "family health," "newborn health," "child health," "physical illness," "social support," "psychosocial risk," "prediction," "risk factors," "obstetrics" and "prenatal care." Further articles were identified from bibliographies. STUDY SELECTION: Of the 370 articles identified through the search, 118 were included for review. Studies were included if they examined the association between psychosocial risk factors and the outcomes of interest. Articles were excluded if they were reviews of poor quality or they had one or more of the following features: insufficient description of the sample, a high attrition rate, a lack of standardized outcome measures, outcomes other than the ones of interest or results that had already been reported in a previous study. DATA EXTRACTION: The strength of evidence of each study was evaluated. On the basis of the evidence, each risk factor was assigned a rating of the strength of its association with each of the postpartum outcomes. The ratings were class A (good evidence of association), class B (fair evidence) and class C (no clear evidence). Of the 129 antenatal psychosocial risk factors studied, 15 were found to have a class A association with at least one of the postpartum outcomes. DATA SYNTHESIS: Child abuse and abuse of the mother by her partner were most strongly correlated (class A evidence) with a history of lack of social support, recent life stressors, psychiatric disturbance in the mother and an unwanted pregnancy. Child abuse was also strongly associated with a history of childhood violence in the mother or her partner, previous child abuse by the mother's partner, a poor relationship between the mother and her parents, low self-esteem in the mother and lack of attendance at prenatal classes. Postpartum abuse of the mother was also associated with a history of abuse of the mother, prenatal care not started until the third trimester and alcohol or drug abuse by the mother or her partner (class A evidence). Child abuse had a fair (class B) association with poor marital adjustment or satisfaction, current or past abuse of the mother and alcohol or drug abuse by the mother or her partner. There was class B evidence supporting an association between abuse of the mother and poor marital adjustment, traditional sex-role expectations, a history of childhood violence in the mother or her partner and low self-esteem in the mother. Postpartum depression was most strongly associated with poor marital adjustment, recent life stressors, antepartum depression (class A evidence), but was also associated with lack of social support, abuse of the mother and a history of psychiatric disorder in the mother (class B evidence). Marital dysfunction was associated with poor marital adjustment before the birth and traditional sex-role expectations (class A evidence), and physical illness was correlated with recent life stressors (class B evidence). CONCLUSIONS: Psychosocial risk factors during the antenatal period may herald postpartum morbidity. Research is required to determine whether detection of these risk factors may lead to interventions that improve postpartum family outcomes. PMID:8634957
Patterns of Chronic Conditions and Their Associations With Behaviors and Quality of Life, 2010
Mitchell, Sandra A.; Thompson, William W.; Zack, Matthew M.; Reeve, Bryce B.; Cella, David; Smith, Ashley Wilder
2015-01-01
Introduction Co-occurring chronic health conditions elevate the risk of poor health outcomes such as death and disability, are associated with poor quality of life, and magnify the complexities of self-management, care coordination, and treatment planning. This study assessed patterns of both singular and multiple chronic conditions, behavioral risk factors, and quality of life in a population-based sample. Methods In a national survey, adults (n = 4,184) answered questions about the presence of 27 chronic conditions. We used latent class analysis to identify patterns of chronic conditions and to explore associations of latent class membership with sociodemographic characteristics, behavioral risk factors, and health. Results Latent class analyses indicated 4 morbidity profiles: a healthy class (class 1), a class with predominantly physical health conditions (class 2), a class with predominantly mental health conditions (class 3), and a class with both physical and mental health conditions (class 4). Class 4 respondents reported significantly worse physical health and well-being and more days of activity limitation than those in the other latent classes. Class 4 respondents were also more likely to be obese and sedentary, and those with predominantly mental health conditions were most likely to be current smokers. Conclusions Subgroups with distinct patterns of chronic conditions can provide direction for screening and surveillance, guideline development, and the delivery of complex care services. PMID:26679491
The Lay Public's Understanding and Perception of Dementia in a Developed Asian Nation
Tan, Wai Jia; Hong, Song-Iee; Luo, Nan; Lo, Tong Jen; Yap, Philip
2012-01-01
Background Early detection of dementia aims to improve treatment outcomes. However, poor perception and understanding of dementia are significant barriers. We aim to investigate the public's perception of dementia and identify variables associated with the different profiles of public perception. Methods A custom-designed questionnaire was used to assess laypersons’ knowledge and perception of dementia during a health fair at a public hospital in Singapore, a developed Asian nation. Out of a sample of 370 subjects, 32 declined to participate (response rate = 91.4%). Latent class analysis (LCA) was used to identify meaningful subgroups of subjects from significant associations with multiple indicators of dementia awareness. Multinomial logistic regression was performed exploring variables associated with each of the subgroups derived from LCA. Results The majority of the study participants were female (66.9%), 65 years or older (71.1%), and ethnic Chinese (88.1%). LCA classified the study participants into 3 subgroups: Class 1 (good knowledge, good attitude), Class 2 (good knowledge, poor attitude), and Class 3 (poor knowledge, poor attitude), in proportions of 14.28, 63.83, and 21.88%, respectively. Compared to other classes, participants with good knowledge and good attitude towards dementia (Class 1) were more likely to know someone with dementia and understand the effects of the disease, be married, live in private housing, receive higher monthly income, and not profess belief in Buddhism, Taoism, or Hinduism. Conclusion Our results show that the public in Singapore may not be ready for screening initiatives and early dementia diagnosis. Education efforts should be targeted at lower socioeconomic groups, singles, and those of certain oriental religions. PMID:23139688
Liangjun Hu; Qinfeng Guo
2013-01-01
How species diversity relates to productivity remains a major debate. To date, however, the underlying mechanisms that regulate the ecological processes involved are still poorly understood. Three major issues persist in early efforts at resolution. First, in the context that productivity drives species diversity, how the pathways operate is poorly-explained. Second,...
USDA-ARS?s Scientific Manuscript database
Stunting affects ~25% of children <5 y of age and is associated with impaired cognitive and motor development and increased morbidity and mortality. The pathogenesis of stunting is poorly understood. The purpose of this study was to identify altered metabolic pathways associated with child stunting...
Horton, Leslie E; Tarbox, Sarah I; Olino, Thomas M; Haas, Gretchen L
2015-06-30
Evidence of social and behavioral problems preceding the onset of schizophrenia-spectrum psychoses is consistent with a neurodevelopmental model of these disorders. Here we predict that individuals with a first episode of schizophrenia-spectrum psychoses will evidence one of three patterns of premorbid adjustment: an early deficit, a deteriorating pattern, or adequate or good social adjustment. Participants were 164 (38% female; 31% black) individuals ages 15-50 with a first episode of schizophrenia-spectrum psychoses. Premorbid adjustment was assessed using the Cannon-Spoor Premorbid Adjustment Scale. We compared the fit of a series of growth mixture models to examine premorbid adjustment trajectories, and found the following 3-class model provided the best fit with: a "stable-poor" adjustment class (54%), a "stable-good" adjustment class (39%), and a "deteriorating" adjustment class (7%). Relative to the "stable-good" class, the "stable-poor" class experienced worse negative symptoms at 1-year follow-up, particularly in the social amotivation domain. This represents the first known growth mixture modeling study to examine premorbid functioning patterns in first-episode schizophrenia-spectrum psychoses. Given that the stable-poor adjustment pattern was most prevalent, detection of social and academic maladjustment as early as childhood may help identify people at increased risk for schizophrenia-spectrum psychoses, potentially increasing feasibility of early interventions. Published by Elsevier Ireland Ltd.
Strategic Note-Taking for Middle-School Students with Learning Disabilities in Science Classes
ERIC Educational Resources Information Center
Boyle, Joseph R.
2010-01-01
While today's teachers use a variety of teaching methods in middle-school science classes, lectures and note-taking still comprise a major portion of students' class time. To be successful in these classes, middle-school students need effective listening and note-taking skills. Students with learning disabilities (LD) are poor note-takers, which…
Social Class, Solipsism, and Contextualism: How the Rich Are Different from the Poor
ERIC Educational Resources Information Center
Kraus, Michael W.; Piff, Paul K.; Mendoza-Denton, Rodolfo; Rheinschmidt, Michelle L.; Keltner, Dacher
2012-01-01
Social class is shaped by an individual's material resources as well as perceptions of rank vis-a-vis others in society, and in this article, we examine how class influences behavior. Diminished resources and lower rank create contexts that constrain social outcomes for lower-class individuals and enhance contextualist tendencies--that is, a focus…
ERIC Educational Resources Information Center
Reed, Rebecca
2017-01-01
Social class encompasses the preferences, lifestyles, and behaviors of people in various social class groups in conjunction with the structural privileges that accompany certain social locations (Smith, 2010). Class-privileged college students typically come to campus with greater amounts of cultural capital (Bourdieu, 1980) that afford them the…
"The University for the Poor": Portrayals of Class in Translated Children's Literature
ERIC Educational Resources Information Center
Forest, Danielle E.; Garrison, Kasey L.; Kimmel, Sue C.
2015-01-01
Background: Scholars of children's literature have been investigating portrayals of females and racial groups for several decades, yet few have examined depictions of social class. Research on social class depictions in children's literature is needed in order to identify books that affirm children's class identities and offer…
Boyle, Keith B; Gyori, David; Sindrilaru, Anca; Scharffetter-Kochanek, Karin; Taylor, Philip R; Mócsai, Attila; Stephens, Len R; Hawkins, Phillip T
2011-03-01
An effective immune response to the ubiquitous fungus Aspergillus fumigatus is dependent upon production of reactive oxygen species (ROS) by the NADPH oxidase. This is evidenced by the acute sensitivity of oxidase-deficient humans and mice to invasive aspergillosis. Neutrophils are recruited to the lungs shortly postinfection and respond by phagocytosing conidia and mediating extracellular killing of germinated hyphae in a ROS-dependent manner. However, the signaling mechanisms regulating the generation of ROS in response to hyphae are poorly understood. PI3Ks are important regulators of numerous cellular processes, with much recent work describing unique roles for the different class I PI3K isoforms. We showed by live-cell imaging that the lipid products of class I PI3Ks accumulated at the hyphal-bound neutrophil plasma membrane. Further, we used pharmacological and genetic approaches to demonstrate essential, but overlapping, roles for PI3Kβ and PI3Kδ in the ROS and spreading responses of murine neutrophils to Aspergillus hyphae. Hyphal-induced ROS responses were substantially inhibited by deletion of the common β2-integrin subunit CD18, with only a minor, redundant role for Dectin-1. However, addition of soluble algal glucans plus the genetic deletion of CD18 were required to significantly inhibit activation of the PI3K-effector protein kinase B. Hyphal ROS responses were also totally dependent on the presence of Syk, but not its ITAM-containing adaptor proteins FcRγ or DAP12, and the Vav family of Rac-guanine nucleotide exchange factors. These results start to define the signaling network controlling neutrophil ROS responses to A. fumigatus hyphae.
Zhang, Dapeng; Burroughs, A. Maxwell; Vidal, Newton D.; Iyer, Lakshminarayan M.; Aravind, L.
2016-01-01
Enzymatic effectors targeting nucleic acids, proteins and other cellular components are the mainstay of conflicts across life forms. Using comparative genomics we identify a large class of eukaryotic proteins, which include effectors from oomycetes, fungi and other parasites. The majority of these proteins have a characteristic domain architecture with one of several N-terminal ‘Header’ domains, which are predicted to play a role in trafficking of these effectors, including a novel version of the Ubiquitin fold. The Headers are followed by one or more diverse C-terminal domains, such as restriction endonuclease (REase), protein kinase, HNH endonuclease, LK-nuclease (a RNase) and multiple distinct peptidase domains, which are predicted to carry their toxicity determinants. The most common types of these proteins appear to have originated from prokaryotic transposases (e.g. TN7 and Mu) and combine a CDC6/ORC1-STAND clade NTPase domain with a C-terminal REase domain. Other than the so-called Crinkler effectors of oomycetes and fungi, these effectors are encoded by other eukaryotic parasites such as trypanosomatids (the RHS proteins) and the rhizarian Plasmodiophora, and symbionts like Capsaspora. Remarkably, we also find these proteins in free-living eukaryotes, including several viridiplantae, fungi, amoebozoans and animals. These versions might either still be transposons or function in other poorly understood eukaryote-specific inter-organismal and inter-genomic conflicts. These include the Medea1 selfish element of Tribolium that spreads via post-zygotic killing. We present a unified mechanism for the recombination-dependent diversification and action of this widespread class of molecular weaponry deployed across diverse conflicts ranging from parasitic to free-living forms. PMID:27060143
Zhao, Wen-Ning; Ghosh, Balaram; Tyler, Marshall; Lalonde, Jasmin; Joseph, Nadine F; Kosaric, Nina; Fass, Daniel M; Tsai, Li-Huei; Mazitschek, Ralph; Haggarty, Stephen J
2018-06-22
Through epigenetic and other regulatory functions, the histone deacetylase (HDAC) family of enzymes has emerged as a promising therapeutic target for central nervous system and other disorders. Here we report on the synthesis and functional characterization of new HDAC inhibitors based structurally on tianeptine, a drug used primarily to treat major depressive disorder (MDD) that has a poorly understood mechanism of action. Since the chemical structure of tianeptine resembles certain HDAC inhibitors, we profiled the in vitro HDAC inhibitory activity of tianeptine and demonstrated its ability to inhibit the lysine deacetylase activity of a subset of class I HDACs. Consistent with a model of active site Zn 2+ chelation by the carboxylic acid present in tianeptine, newly synthesized analogues containing either a hydroxamic acid or ortho-aminoanilide exhibited increased potency and selectivity among the HDAC family. This in vitro potency translated to improved efficacy in a panel of high-content imaging assays designed to assess HDAC target engagement and functional effects on critical pathways involved in neuroplasticity in both primary mouse neurons and, for the first time, human neurons differentiated from pluripotent stem cells. Most notably, tianeptinaline, a class I HDAC-selective analogue of tianeptine, but not tianeptine itself, increased histone acetylation, and enhanced CREB-mediated transcription and the expression of Arc (activity-regulated cytoskeleton-associated protein). Systemic in vivo administration of tianeptinaline to mice confirmed its brain penetration and was found to enhance contextual fear conditioning, a behavioral test of hippocampal-dependent memory. Tianeptinaline and its derivatives provide new pharmacological tools to dissect chromatin-mediated neuroplasticity underlying memory and other epigenetically related processes implicated in health and disease.
Sitnik, Jessica L; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F; Callaerts, Patrick
2014-03-01
Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family's function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates.
Sitnik, Jessica L.; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F.; Callaerts, Patrick
2014-01-01
Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family’s function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates. PMID:24395329
Active output state of the Synechococcus Kai circadian oscillator
Paddock, Mark L.; Boyd, Joseph S.; Adin, Dawn M.; Golden, Susan S.
2013-01-01
The mechanisms by which cellular oscillators keep time and transmit temporal information are poorly understood. In cyanobacteria, the timekeeping aspect of the circadian oscillator, composed of the KaiA, KaiB, and KaiC proteins, involves a cyclic progression of phosphorylation states at Ser431 and Thr432 of KaiC. Elucidating the mechanism that uses this temporal information to modulate gene expression is complicated by unknowns regarding the number, structure, and regulatory effects of output components. To identify oscillator signaling states without a complete description of the output machinery, we defined a simple metric, Kai-complex output activity (KOA), that represents the difference in expression of reporter genes between strains that carry specific variants of KaiC and baseline strains that lack KaiC. In the absence of the oscillator, expression of the class 1 paradigm promoter PkaiBC was locked at its usual peak level; conversely, that of the class 2 paradigm promoter PpurF was locked at its trough level. However, for both classes of promoters, peak KOA in wild-type strains coincided late in the circadian cycle near subjective dawn, when KaiC-pST becomes most prevalent (Ser431 is phosphorylated and Thr432 is not). Analogously, peak KOA was detected specifically for the phosphomimetic of KaiC-pST (KaiC-ET). Notably, peak KOA required KaiB, indicating that a KaiBC complex is involved in the output activity. We also found evidence that phosphorylated RpaA (regulator of phycobilisome associated) represses an RpaA-independent output of KOA. A simple mathematical expression successfully simulated two key features of the oscillator—the time of peak KOA and the peak-to-trough amplitude changes. PMID:24043774
Active output state of the Synechococcus Kai circadian oscillator.
Paddock, Mark L; Boyd, Joseph S; Adin, Dawn M; Golden, Susan S
2013-10-01
The mechanisms by which cellular oscillators keep time and transmit temporal information are poorly understood. In cyanobacteria, the timekeeping aspect of the circadian oscillator, composed of the KaiA, KaiB, and KaiC proteins, involves a cyclic progression of phosphorylation states at Ser431 and Thr432 of KaiC. Elucidating the mechanism that uses this temporal information to modulate gene expression is complicated by unknowns regarding the number, structure, and regulatory effects of output components. To identify oscillator signaling states without a complete description of the output machinery, we defined a simple metric, Kai-complex output activity (KOA), that represents the difference in expression of reporter genes between strains that carry specific variants of KaiC and baseline strains that lack KaiC. In the absence of the oscillator, expression of the class 1 paradigm promoter P(kaiBC) was locked at its usual peak level; conversely, that of the class 2 paradigm promoter P(purF) was locked at its trough level. However, for both classes of promoters, peak KOA in wild-type strains coincided late in the circadian cycle near subjective dawn, when KaiC-pST becomes most prevalent (Ser431 is phosphorylated and Thr432 is not). Analogously, peak KOA was detected specifically for the phosphomimetic of KaiC-pST (KaiC-ET). Notably, peak KOA required KaiB, indicating that a KaiBC complex is involved in the output activity. We also found evidence that phosphorylated RpaA (regulator of phycobilisome associated) represses an RpaA-independent output of KOA. A simple mathematical expression successfully simulated two key features of the oscillator-the time of peak KOA and the peak-to-trough amplitude changes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McLachlan, M.S.
The digestive tract absorption of environmental contaminants is an important but poorly understood parameter in contaminant is an important but poorly understood parameter in contaminant risk assessments. The net absorption of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in a nursing infant was measured under natural conditions over 12 days. The levels of the substances in the mother's milk were typical for Germany. It was found that for almost all congeners over 90% of the ingested compound was absorbed. This indicates that the common assumption of 100% absorption in nursing infants is reasonable. No firm conclusions could be drawn regarding the absorptionmore » of Cl7- and Cl8DD/F due to high blank levels in the cotton diapers used.« less
Poorly Understood Aspects of Striated Muscle Contraction
Månsson, Alf
2015-01-01
Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs. PMID:25961006
Poorly understood aspects of striated muscle contraction.
Månsson, Alf; Rassier, Dilson; Tsiavaliaris, Georgios
2015-01-01
Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs.
Linking Early Environmental Exposures to Adult Diseases
... diseases. Given that many disorders arise during fetal development from disruptions in the dynamic but still poorly understood interplay of genes, environment and nutrition, prevention may have to occur decades ...
An inexpensive and portable drill rig for bedrock groundwater studies in headwater catchments
C. Gabrielli; J.J. McDonnell
2011-01-01
Bedrock groundwater dynamics in headwater catchments are poorly understood and poorly characterized. Here, we present an inexpensive and portable bedrock drilling system designed for use in remote locations. Our system is capable of drilling bedrock wells up to 11 m deep and 38 mm in diameter in a wide range of bedrock types. The drill consists of a lawn mower engine...
Researchers Realize Major Breakthrough in Understanding Endometriosis
... a rarely studied and poorly understood disease that affects many, many women.” Health Terms: Women's Health RELATED LINKS RSS LISTSERV YOUTUBE FACEBOOK TWITTER GOOGLE+ NIH...T URNING D ISCOVERY I ...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hampton, J.
1974-07-01
The percent of total annual income spent on energy by US poor income status families is 19.89%. in comparison upper-middle income families spend 5.95% of total annual income on energy. Governmental policy can either emphasize the needs of corporations or the needs of people. The trickle down concept of social welfare, which actually lines the wallets of middle class pickpockets, must be replaced by a policy that does not forever doom the poor to second-class citizenship. (1 table)
Latent class analysis of lifestyle characteristics and health risk behaviors among college youth.
Laska, Melissa Nelson; Pasch, Keryn E; Lust, Katherine; Story, Mary; Ehlinger, Ed
2009-12-01
Few studies have examined the context of a wide range of risk behaviors among emerging adults (ages 18-25 years), approximately half of whom in the USA enroll in post-secondary educational institutions. The objective of this research was to examine behavioral patterning in weight behaviors (diet and physical activity), substance use, sexual behavior, stress, and sleep among undergraduate students. Health survey data were collected among undergraduates attending a large, public US university (n = 2,026). Latent class analysis was used to identify homogeneous, mutually exclusive "classes" (patterns) of ten leading risk behaviors. Resulting classes differed for males and females. Female classes were defined as: (1) poor lifestyle (diet, physical activity, sleep), yet low-risk behaviors (e.g., smoking, binge drinking, sexual risk, drunk driving; 40.0% of females), (2) high risk (high substance use, intoxicated sex, drunk driving, poor diet, inadequate sleep) (24.3%), (3) moderate lifestyle, few risk behaviors (20.4%), (4) "health conscious" (favorable diet/physical activity with some unhealthy weight control; 15.4%). Male classes were: (1) poor lifestyle, low risk (with notably high stress, insufficient sleep, 9.2% of males), (2) high risk (33.6% of males, similar to class 2 in females), (3) moderate lifestyle, low risk (51.0%), and (4) "classic jocks" (high physical activity, binge drinking, 6.2%). To our knowledge, this is among the first research to examine complex lifestyle patterning among college youth, particularly with emphasis on the role of weight-related behaviors. These findings have important implications for targeting much needed health promotion strategies among emerging adults and college youth.
Transcriptional activation of short interspersed elements by DNA-damaging agents.
Rudin, C M; Thompson, C B
2001-01-01
Short interspersed elements (SINEs), typified by the human Alu repeat, are RNA polymerase III (pol III)-transcribed sequences that replicate within the genome through an RNA intermediate. Replication of SINEs has been extensive in mammalian evolution: an estimated 5% of the human genome consists of Alu repeats. The mechanisms regulating transcription, reverse transcription, and reinsertion of SINE elements in genomic DNA are poorly understood. Here we report that expression of murine SINE transcripts of both the B1 and B2 classes is strongly upregulated after prolonged exposure to cisplatin, etoposide, or gamma radiation. A similar induction of Alu transcripts in human cells occurs under these conditions. This induction is not due to a general upregulation of pol III activity in either species. Genotoxic treatment of murine cells containing an exogenous human Alu element induced Alu transcription. Concomitant with the increased expression of SINEs, an increase in cellular reverse transcriptase was observed after exposure to these same DNA-damaging agents. These findings suggest that genomic damage may be an important activator of SINEs, and that SINE mobility may contribute to secondary malignancy after exposure to DNA-damaging chemotherapy.
Lyons, Kady; Carlisle, Aaron B; Lowe, Christopher G
2017-09-01
Mercury tissue distribution and its dynamics are poorly understood in elasmobranchs. Total mercury was measured in liver and muscle of male Round Stingrays (Urobatis halleri) from Seal Beach, California, an anthropogenically impacted site, and from the offshore island of Santa Catalina, a less impacted site. Stable isotope analysis was also performed on the muscle and red blood cells (RBCs) of a subset of rays over a range of age classes to investigate mercury accumulation with respect to trophic ecology. Mercury in both tissues was found to be significantly greater in adults than juveniles in mainland rays; however, liver mercury accumulation drastically increased after maturity and was significantly greater in mainland adult rays than Catalina rays. There were no patterns in δ 15 N or δ 13 C with size in muscle; however, there were indications of seasonal changes in RBC δ 15 N, suggesting short term shifts in diet or behavior is likely linked to reproductive status as is mercury accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection
NASA Astrophysics Data System (ADS)
Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.
2014-01-01
The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.
Wu, Weihua; Tran, William; Taatjes, Craig A.; ...
2016-02-17
Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs)more » derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS. Lastly, out of the 26 TPS’s profiled, 12 TPS’s were functional, with the majority of them exhibiting both monoterpene and sesquiterpene synthase activity.« less
A physical perspective on cytoplasmic streaming
Goldstein, Raymond E.; van de Meent, Jan-Willem
2015-01-01
Organisms show a remarkable range of sizes, yet the dimensions of a single cell rarely exceed 100 µm. While the physical and biological origins of this constraint remain poorly understood, exceptions to this rule give valuable insights. A well-known counterexample is the aquatic plant Chara, whose cells can exceed 10 cm in length and 1 mm in diameter. Two spiralling bands of molecular motors at the cell periphery drive the cellular fluid up and down at speeds up to 100 µm s−1, motion that has been hypothesized to mitigate the slowness of metabolite transport on these scales and to aid in homeostasis. This is the most organized instance of a broad class of continuous motions known as ‘cytoplasmic streaming’, found in a wide range of eukaryotic organisms—algae, plants, amoebae, nematodes and flies—often in unusually large cells. In this overview of the physics of this phenomenon, we examine the interplay between streaming, transport and cell size and discuss the possible role of self-organization phenomena in establishing the observed patterns of streaming. PMID:26464789
The effect of shear flow on the rotational diffusivity of a single axisymmetric particle
NASA Astrophysics Data System (ADS)
Leahy, Brian; Koch, Donald; Cohen, Itai
2014-11-01
Colloidal suspensions of nonspherical particles abound in the world around us, from red blood cells in arteries to kaolinite discs in clay. Understanding the orientation dynamics of these particles is important for suspension rheology and particle self-assembly. However, even for the simplest case of dilute suspensions in simple shear flow, the orientation dynamics of Brownian nonspherical particles are poorly understood at large shear rates. Here, we analytically calculate the time-dependent orientation distributions of particles confined to the flow-gradient plane when the rotary diffusion is small but nonzero. For both startup and oscillatory shear flows, we find a coordinate change that maps the convection-diffusion equation to a simple diffusion equation with an enhanced diffusion constant, simplifying the orientation dynamics. For oscillatory shear, this enhanced diffusion drastically alters the quasi-steady orientation distributions. Our theory of the unsteady orientation dynamics provides an understanding of a nonspherical particle suspension's rheology for a large class of unsteady flows. For particles with aspect ratio 10 under oscillatory shear, the rotary diffusion and intrinsic viscosity vary with amplitude by a factor of ~ 40 and ~ 2 , respectively.
Pyroptosis drives CD4 T-cell depletion in HIV-1 infection
Doitsh, Gilad; Galloway, Nicole LK; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.
2014-01-01
The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood. Apoptosis has been proposed as the key mechanism for CD4 T-cell loss. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of productively infected cells. The remaining >95% of quiescent lymphoid CD4 T-cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death where cytoplasmic contents and pro-inflammatory cytokines including IL-1β, are released. This death pathway thus links the two signature events in HIV infection––CD4 T-cell depletion and chronic inflammation––and creates a vicious pathogenic cycle where dying CD4 T-cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase-1 inhibitors shown to be safe in humans, raising the possibility of a new class of “anti-AIDS” therapeutics targeting the host rather than the virus. PMID:24356306
Lee, Chih-Yung Sean; Lu, Tu
2017-01-01
Nanos RNA-binding proteins are required for germline development in metazoans, but the underlying mechanisms remain poorly understood. We have profiled the transcriptome of primordial germ cells (PGCs) lacking the nanos homologs nos-1 and nos-2 in C. elegans. nos-1nos-2 PGCs fail to silence hundreds of transcripts normally expressed in oocytes. We find that this misregulation is due to both delayed turnover of maternal transcripts and inappropriate transcriptional activation. The latter appears to be an indirect consequence of delayed turnover of the maternally-inherited transcription factor LIN-15B, a synMuvB class transcription factor known to antagonize PRC2 activity. PRC2 is required for chromatin reprogramming in the germline, and the transcriptome of PGCs lacking PRC2 resembles that of nos-1nos-2 PGCs. Loss of maternal LIN-15B restores fertility to nos-1nos-2 mutants. These findings suggest that Nanos promotes germ cell fate by downregulating maternal RNAs and proteins that would otherwise interfere with PRC2-dependent reprogramming of PGC chromatin. PMID:29111977
Lee, Chih-Yung Sean; Lu, Tu; Seydoux, Geraldine
2017-11-07
Nanos RNA-binding proteins are required for germline development in metazoans, but the underlying mechanisms remain poorly understood. We have profiled the transcriptome of primordial germ cells (PGCs) lacking the nanos homologs nos-1 and nos-2 in C. elegans. nos-1nos-2 PGCs fail to silence hundreds of transcripts normally expressed in oocytes. We find that this misregulation is due to both delayed turnover of maternal transcripts and inappropriate transcriptional activation. The latter appears to be an indirect consequence of delayed turnover of the maternally-inherited transcription factor LIN-15B, a synMuvB class transcription factor known to antagonize PRC2 activity. PRC2 is required for chromatin reprogramming in the germline, and the transcriptome of PGCs lacking PRC2 resembles that of nos-1nos-2 PGCs. Loss of maternal LIN-15B restores fertility to nos-1nos-2 mutants. These findings suggest that Nanos promotes germ cell fate by downregulating maternal RNAs and proteins that would otherwise interfere with PRC2-dependent reprogramming of PGC chromatin.
Peh, Wendy Y X; Roberts, Todd F; Mooney, Richard
2015-04-08
Vocal communication depends on the coordinated activity of sensorimotor neurons important to vocal perception and production. How vocalizations are represented by spatiotemporal activity patterns in these neuronal populations remains poorly understood. Here we combined intracellular recordings and two-photon calcium imaging in anesthetized adult zebra finches (Taeniopygia guttata) to examine how learned birdsong and its component syllables are represented in identified projection neurons (PNs) within HVC, a sensorimotor region important for song perception and production. These experiments show that neighboring HVC PNs can respond at markedly different times to song playback and that different syllables activate spatially intermingled PNs within a local (~100 μm) region of HVC. Moreover, noise correlations were stronger between PNs that responded most strongly to the same syllable and were spatially graded within and between classes of PNs. These findings support a model in which syllabic and temporal features of song are represented by spatially intermingled PNs functionally organized into cell- and syllable-type networks within local spatial scales in HVC. Copyright © 2015 the authors 0270-6474/15/355589-17$15.00/0.
Hallsworth-Pepin, Kymberlie; Martin, John; Mitreva, Makedonka
2017-01-01
Preventive chemotherapy has long been practiced against nematode parasites of livestock, leading to widespread drug resistance, and is increasingly being adopted for eradication of human parasitic nematodes even though it is similarly likely to lead to drug resistance. Given that the genetic architecture of resistance is poorly understood for any nematode, we have analyzed multidrug resistant Teladorsagia circumcincta, a major parasite of sheep, as a model for analysis of resistance selection. We introgressed a field-derived multiresistant genotype into a partially inbred susceptible genetic background (through repeated backcrossing and drug selection) and performed genome-wide scans in the backcross progeny and drug-selected F2 populations to identify the major genes responsible for the multidrug resistance. We identified variation linking candidate resistance genes to each drug class. Putative mechanisms included target site polymorphism, changes in likely regulatory regions and copy number variation in efflux transporters. This work elucidates the genetic architecture of multiple anthelmintic resistance in a parasitic nematode for the first time and establishes a framework for future studies of anthelmintic resistance in nematode parasites of humans. PMID:28644839
Stability Depends on Positive Autoregulation in Boolean Gene Regulatory Networks
Pinho, Ricardo; Garcia, Victor; Irimia, Manuel; Feldman, Marcus W.
2014-01-01
Network motifs have been identified as building blocks of regulatory networks, including gene regulatory networks (GRNs). The most basic motif, autoregulation, has been associated with bistability (when positive) and with homeostasis and robustness to noise (when negative), but its general importance in network behavior is poorly understood. Moreover, how specific autoregulatory motifs are selected during evolution and how this relates to robustness is largely unknown. Here, we used a class of GRN models, Boolean networks, to investigate the relationship between autoregulation and network stability and robustness under various conditions. We ran evolutionary simulation experiments for different models of selection, including mutation and recombination. Each generation simulated the development of a population of organisms modeled by GRNs. We found that stability and robustness positively correlate with autoregulation; in all investigated scenarios, stable networks had mostly positive autoregulation. Assuming biological networks correspond to stable networks, these results suggest that biological networks should often be dominated by positive autoregulatory loops. This seems to be the case for most studied eukaryotic transcription factor networks, including those in yeast, flies and mammals. PMID:25375153
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Weihua; Tran, William; Taatjes, Craig A.
Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs)more » derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS. Lastly, out of the 26 TPS’s profiled, 12 TPS’s were functional, with the majority of them exhibiting both monoterpene and sesquiterpene synthase activity.« less
MacAlpine, Heather K.; Lubelsky, Yoav; Hartemink, Alexander J.
2015-01-01
Start sites of DNA replication are marked by the origin recognition complex (ORC), which coordinates Mcm2–7 helicase loading to form the prereplicative complex (pre-RC). Although pre-RC assembly is well characterized in vitro, the process is poorly understood within the local chromatin environment surrounding replication origins. To reveal how the chromatin architecture modulates origin selection and activation, we “footprinted” nucleosomes, transcription factors, and replication proteins at multiple points during the Saccharomyces cerevisiae cell cycle. Our nucleotide-resolution protein occupancy profiles resolved a precise ORC-dependent footprint at 269 origins in G2. A separate class of inefficient origins exhibited protein occupancy only in G1, suggesting that stable ORC chromatin association in G2 is a determinant of origin efficiency. G1 nucleosome remodeling concomitant with pre-RC assembly expanded the origin nucleosome-free region and enhanced activation efficiency. Finally, the local chromatin environment restricts the loading of the Mcm2–7 double hexamer either upstream of or downstream from the ARS consensus sequence (ACS). PMID:25593310
Li, Yubing; Liu, Dianyi; López-Paz, Cristina; Olson, Bradley JSC; Umen, James G
2016-01-01
Proliferating cells actively control their size by mechanisms that are poorly understood. The unicellular green alga Chlamydomonas reinhardtii divides by multiple fission, wherein a ‘counting’ mechanism couples mother cell-size to cell division number allowing production of uniform-sized daughters. We identified a sizer protein, CDKG1, that acts through the retinoblastoma (RB) tumor suppressor pathway as a D-cyclin-dependent RB kinase to regulate mitotic counting. Loss of CDKG1 leads to fewer mitotic divisions and large daughters, while mis-expression of CDKG1 causes supernumerous mitotic divisions and small daughters. The concentration of nuclear-localized CDKG1 in pre-mitotic cells is set by mother cell size, and its progressive dilution and degradation with each round of cell division may provide a link between mother cell-size and mitotic division number. Cell-size-dependent accumulation of limiting cell cycle regulators such as CDKG1 is a potentially general mechanism for size control. DOI: http://dx.doi.org/10.7554/eLife.10767.001 PMID:27015111
Enforcement authority and vegetation change at Kumbhalgarh wildlife sanctuary, Rajasthan, India.
Robbins, Paul F; Chhangani, Anil K; Rice, Jennifer; Trigosa, Erika; Mohnot, S M
2007-09-01
Land cover change in protected areas is often associated with human use, especially illicit extraction, but the direction and spatial distribution of such effects and their drivers are poorly understood. We analyze and explain the spatial distribution of vegetation change at the Kumbhalgarh Wildlife Sanctuary in the Aravalli range of Rajasthan, India using remotely sensed data and observation of conservation institutions. Two satellite images are examined in time series over the 13 years following the founding of the sanctuary through a cross-tabulation technique of dominant classes of vegetation density. The resulting change trajectories are compared for their relative distance to high-traffic forest entrance points for local users. The results show 28% of the study area undergoing change, though in multiple trajectories, with both increasing and decreasing density of vegetation in discrete patches. Areas of change are shown to be closer to entrance points than areas experiencing no change. The patchiness of change results from complex issues in local enforcement authority for middle and lower-level officials in Forest Department bureaucracy, leading to further questions about the efficacy and impact of use restrictions in Protected Areas.
Harb, Kawssar; Magrinelli, Elia; Nicolas, Céline S; Lukianets, Nikita; Frangeul, Laura; Pietri, Mariel; Sun, Tao; Sandoz, Guillaume; Grammont, Franck; Jabaudon, Denis; Studer, Michèle; Alfano, Christian
2016-01-01
During cortical development, the identity of major classes of long-distance projection neurons is established by the expression of molecular determinants, which become gradually restricted and mutually exclusive. However, the mechanisms by which projection neurons acquire their final properties during postnatal stages are still poorly understood. In this study, we show that the number of neurons co-expressing Ctip2 and Satb2, respectively involved in the early specification of subcerebral and callosal projection neurons, progressively increases after birth in the somatosensory cortex. Ctip2/Satb2 postnatal co-localization defines two distinct neuronal subclasses projecting either to the contralateral cortex or to the brainstem suggesting that Ctip2/Satb2 co-expression may refine their properties rather than determine their identity. Gain- and loss-of-function approaches reveal that the transcriptional adaptor Lmo4 drives this maturation program through modulation of epigenetic mechanisms in a time- and area-specific manner, thereby indicating that a previously unknown genetic program postnatally promotes the acquisition of final subtype-specific features. DOI: http://dx.doi.org/10.7554/eLife.09531.001 PMID:26814051
Murine craniofacial development requires Hdac3-mediated repression of Msx gene expression
Singh, Nikhil; Gupta, Mudit; Trivedi, Chinmay M.; Singh, Manvendra K.; Li, Li; Epstein, Jonathan A.
2013-01-01
Craniofacial development is characterized by reciprocal interactions between neural crest cells and neighboring cell populations of ectodermal, endodermal and mesodermal origin. Various genetic pathways play critical roles in coordinating the development of cranial structures by modulating the growth, survival and differentiation of neural crest cells. However, the regulation of these pathways, particularly at the epigenomic level, remains poorly understood. Using murine genetics, we show that neural crest cells exhibit a requirement for the class I histone deacetylase Hdac3 during craniofacial development. Mice in which Hdac3 has been conditionally deleted in neural crest demonstrate fully penetrant craniofacial abnormalities, including microcephaly, cleft secondary palate and dental hypoplasia. Consistent with these abnormalities, we observe dysregulation of cell cycle genes and increased apoptosis in neural crest structures in mutant embryos. Known regulators of cell cycle progression and apoptosis in neural crest, including Msx1, Msx2 and Bmp4, are upregulated in Hdac3-deficient cranial mesenchyme. These results suggest that Hdac3 serves as a critical regulator of craniofacial morphogenesis, in part by repressing core apoptotic pathways in cranial neural crest cells. PMID:23506836
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nelson, Thomas; Chomiuk, Laura; Roy, Nirupam
2014-04-10
Despite being the prototype of its class, T Pyx is arguably the most unusual and poorly understood recurrent nova. Here, we use radio observations from the Karl G. Jansky Very Large Array to trace the evolution of the ejecta over the course of the 2011 outburst of T Pyx. The radio emission is broadly consistent with thermal emission from the nova ejecta. However, the radio flux began rising surprisingly late in the outburst, indicating that the bulk of the radio-emitting material was either very cold, or expanding very slowly, for the first ∼50 days of the outburst. Considering a plausiblemore » range of volume filling factors and geometries for the ejecta, we find that the high peak flux densities of the radio emission require a massive ejection of (1-30) × 10{sup –5} M {sub ☉}. This ejecta mass is much higher than the values normally associated with recurrent novae, and is more consistent with a nova on a white dwarf well below the Chandrasekhar limit.« less
Turnover of Glycerolipid Metabolite Pool and Seed Viability
Hu, Xiao-Long; Yu, Xiao-Mei; Chen, Hong-Ying
2018-01-01
Hydration–dehydration cycles can frequently cause stress to seeds, but can also be used to improve germination. However, the molecular basis of the stress caused is poorly understood. Herein, we examine the effects of hydration–dehydration cycles on seed viability and profile the membrane glycerolipid molecular species. We find that seed viability was not affected during the first two cycles, but significantly decreased as further cycles were applied, until all viability was lost. The abundances of seven glycerolipid classes increased and decreased through hydration and dehydration, respectively, but the phosphatidic acid and diacylglycerol abundances changed in the opposite sense, while total glycerolipid contents remained constant. This suggests that during hydration–dehydration cycles, turnover of glycerolipid metabolite pools take place, while no significant lipid synthesis or degradation is involved. As further hydration–dehydration cycles occurred, lipid unsaturation increased, plastidic lipids decreased, and phosphatidylserine acyl chains lengthened. The latter two could be lethal for seeds. Our findings reveal a novel model of membrane lipid changes, and provide new insights into the responses of seeds to hydration–dehydration cycles. PMID:29747431
Wang, Ye; Liu, Jie; Liu, Zheng; Chen, Jing; Hu, Xuemei; Hu, Yimeng; Yuan, Yin; Wu, Guijun; Dai, Zhe; Xu, Yancheng
2018-05-18
Spalt-like (Sall) proteins are a class of transcription factors. The role of Sall2 in beta cells remain poorly understood. Here, we aimed to explore whether Sall2 involved in lipotoxicity-mediated dysfunction and apoptosis in pancreatic NIT-1 beta cells. Our results showed that high concentrations of palmitic acid (PA) led to impaired cell viability and decreased Sall2 expression in NIT-1 cells. Knocking down of Sall2 in NIT-1 cells resulted in increased sensitivity to lipotoxicity and caused higher rates of cell apoptosis following PA treatment. Additionally, Sall2 Knockdown impaired insulin synthesis and secretion in response to glucose. Further research indicated Sall2 knockdown attenuate antioxidant capacity and decreased expression level of Peroxiredoxin 2 in NIT-1 cells. These finding implicate that Sall2 may play a significant role in NIT-1 cell function and cell apoptosis under lipotoxic conditions. Therefore, the study of Sall2 in NIT-1 cells provided a new perspective for molecular mechanism of lipotoxicity mediating dysfunction and apoptosis of beta cells. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Kapur, Rick; Kim, Michael; Aslam, Rukhsana; McVey, Mark J.; Tabuchi, Arata; Luo, Alice; Liu, Jonathan; Li, Yuan; Shanmugabhavananthan, Shanjeevan; Speck, Edwin R.; Zufferey, Anne; Yousef, George; Zhang, Haibo; Rondina, Matthew T.; Weyrich, Andrew S.; Porcelijn, Leendert; Kuebler, Wolfgang M.; Slutsky, Arthur S.
2017-01-01
Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti–major histocompatibility complex class I antibodies, we found CD4+CD25+FoxP3+ T regulatory cells (Tregs) and CD11c+ dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion. PMID:28202460
Polymorphism complexity and handedness inversion in serum albumin amyloid fibrils.
Usov, Ivan; Adamcik, Jozef; Mezzenga, Raffaele
2013-12-23
Protein-based amyloid fibrils can show a great variety of polymorphic structures within the same protein precursor, although the origins of these structural homologues remain poorly understood. In this work we investigate the fibrillation of bovine serum albumin--a model globular protein--and we follow the polymorphic evolution by a statistical analysis of high-resolution atomic force microscopy images, complemented, at larger length scales, by concepts based on polymer physics formalism. We identify six distinct classes of coexisting amyloid fibrils, including flexible left-handed twisted ribbons, rigid right-handed helical ribbons and nanotubes. We show that the rigid fibrils originate from flexible fibrils through two diverse polymorphic transitions, first, via a single-fibril transformation when the flexible left-handed twisted ribbons turn into the helical left-handed ribbons, to finally evolve into nanotube-like structures, and second, via a double-fibril transformation when two flexible left-handed twisted ribbons wind together resulting in a right-handed twisted ribbon, followed by a rigid right-handed helical ribbon polymorphic conformation. Hence, the change in handedness occurs with an increase in the level of the fibril's structural organization.
Impact of socioeconomic factors on nutritional status in primary school children.
Babar, Nabeela Fazal; Muzaffar, Rizwana; Khan, Muhammad Athar; Imdad, Seema
2010-01-01
Child malnutrition is a major public health and development concern in most of the poor communities leading to high morbidity and mortality. Various studies have highlighted the factors involved. The present study focuses on socioeconomic inequality resulting in malnutrition. Objectives of the Study were to find the Impact of socio-economic factors on nutritional status in primary school children. It was a cross sectional survey conducted at Lahore from February to August 2005 among primary schools from public and private sectors to assess the nutritional status of primary school going children age 5-11 years belonging to different socio economic classes of the society. Systematic random sampling technique was applied to collect the sample. Body Mass Index in relation to NHANES reference population was used for assessing nutritional status. The nutritional status of children from lower socio economic class was poor as compared to their counter parts in upper socio economic class. Children with BMI < 5th percentile were 41% in lower class while in upper class it was 19.28%. Prevalence of malnutrition was 42.3% among children of illiterate mothers as compare to 20% in those of literate mothers. Poverty, low literacy rate, large families, food insecurity, food safety, women's education appears to be the important underlying factors responsible for poor health status of children from low socioeconomic class. It requires economic, political and social changes as well as changes for personal advancement mainly through educational opportunities to improve the nutritional status of the children.
76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-04
... 200, Austin, TX (512-490-0057 ext. 223). FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, at the above... poorly understood, recovery is also dependant on incorporating research findings into adaptive management...
Kierepka, E M; Latch, E K
2016-01-01
Landscape genetics is a powerful tool for conservation because it identifies landscape features that are important for maintaining genetic connectivity between populations within heterogeneous landscapes. However, using landscape genetics in poorly understood species presents a number of challenges, namely, limited life history information for the focal population and spatially biased sampling. Both obstacles can reduce power in statistics, particularly in individual-based studies. In this study, we genotyped 233 American badgers in Wisconsin at 12 microsatellite loci to identify alternative statistical approaches that can be applied to poorly understood species in an individual-based framework. Badgers are protected in Wisconsin owing to an overall lack in life history information, so our study utilized partial redundancy analysis (RDA) and spatially lagged regressions to quantify how three landscape factors (Wisconsin River, Ecoregions and land cover) impacted gene flow. We also performed simulations to quantify errors created by spatially biased sampling. Statistical analyses first found that geographic distance was an important influence on gene flow, mainly driven by fine-scale positive spatial autocorrelations. After controlling for geographic distance, both RDA and regressions found that Wisconsin River and Agriculture were correlated with genetic differentiation. However, only Agriculture had an acceptable type I error rate (3–5%) to be considered biologically relevant. Collectively, this study highlights the benefits of combining robust statistics and error assessment via simulations and provides a method for hypothesis testing in individual-based landscape genetics. PMID:26243136
Li, Ji; Larregieu, Caroline A; Benet, Leslie Z
2016-12-01
Natural products (NPs) are compounds that are derived from natural sources such as plants, animals, and micro-organisms. Therapeutics has benefited from numerous drug classes derived from natural product sources. The Biopharmaceutics Drug Disposition Classification System (BDDCS) was proposed to serve as a basis for predicting the importance of transporters and enzymes in determining drug bioavailability and disposition. It categorizes drugs into one of four biopharmaceutical classes according to their water solubility and extent of metabolism. The present paper reviews 109 drugs from natural product sources: 29% belong to class 1 (high solubility, extensive metabolism), 22% to class 2 (low solubility, extensive metabolism), 40% to class 3 (high solubility, poor metabolism), and 9% to class 4 (low solubility, poor metabolism). Herein we evaluated the characteristics of NPs in terms of BDDCS class for all 109 drugs as wells as for subsets of NPs drugs derived from plant sources as antibiotics. In the 109 NPs drugs, we compiled 32 drugs from plants, 50% (16) of total in class 1, 22% (7) in class 2 and 28% (9) in class 3, none found in class 4; Meantime, the antibiotics were found 5 (16%) in class 2, 22 (71%) in class 3, and 4 (13%) in class 4; no drug was found in class 1. Based on this classification, we anticipate BDDCS to serve as a useful adjunct in evaluating the potential characteristics of new natural products. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.
Kong, Kyoung Ae; Khang, Young-Ho; Cho, Hong-Jun; Jang, Sung-Mi; Jung-Choi, Kyunghee
2017-04-20
The aim of this study was to examine the pattern of social inequality in self-rated health among the employed using the Wright's social class location indicator, and to assess the roles of material, behavioral, psychosocial, and workplace environmental factors as mediating factors in explaining the social class inequality in self-rated health in South Korea. This study used data from the 4th Korea National Health and Nutrition Examination Survey from 2007 to 2009. Study subjects included the employed population of 4392 men and 3309 women aged 19-64 years. Subjects were classified into twelve social class positions based on the Wright's social class map. The health outcome was self-rated health. Material, psychosocial, behavioral, and workplace environmental factors were considered as potential mediators in explaining social class health inequality. We calculated prevalence ratios of poor self-rated health according to social class, adjusted for age and mediating factors using Poisson regression models. Nonskilled workers and petty bourgeoisie reported worse self-rated health than other social classes among men. The age-adjusted prevalence of petty bourgeoisie and nonskilled workers were about four-fold greater than that of managers. Expert supervisors in the contradictory class location had a greater prevalence of poor self-rated health than experts in men. In women, the prevalence of poor self-rated health was greater in most social classes than their male counterparts, while the differences among social classes within women were not statistically significant. Workplace environmental factors explained the social class inequality by from 24 to 31% in nonskilled and skilled workers and nonskilled supervisors, respectively, and material factors showed an explanatory ability of about 8% for both nonskilled workers and petty bourgeoisie in men. We showed the inequality in self-rated health according to the Wright's social class in an industrialized Asian country. Policy efforts to improve workplace environments in nonskilled and skilled workers and nonskilled supervisors would have a moderate effect on reducing the magnitude of social class inequality in self-rated health. Furthermore, the means to improve power relations in the workplace should be devised to further reduce the social class inequalities in health.
Jonathan P. Benstead; James G. March; Catherine M. Pringle; Katherine C. Ewel; John W. Short
2009-01-01
Pacific island stream communities are species-poor because of the effects of extreme geographic isolation on colonization rates of taxa common to continental regions. The effects of such low species richness on stream ecosystem function are not well understood. Here, we provide data on community structure and leaf litter breakdown rate in a virtually pristine stream on...
The evolvability of programmable hardware.
Raman, Karthik; Wagner, Andreas
2011-02-06
In biological systems, individual phenotypes are typically adopted by multiple genotypes. Examples include protein structure phenotypes, where each structure can be adopted by a myriad individual amino acid sequence genotypes. These genotypes form vast connected 'neutral networks' in genotype space. The size of such neutral networks endows biological systems not only with robustness to genetic change, but also with the ability to evolve a vast number of novel phenotypes that occur near any one neutral network. Whether technological systems can be designed to have similar properties is poorly understood. Here we ask this question for a class of programmable electronic circuits that compute digital logic functions. The functional flexibility of such circuits is important in many applications, including applications of evolutionary principles to circuit design. The functions they compute are at the heart of all digital computation. We explore a vast space of 10(45) logic circuits ('genotypes') and 10(19) logic functions ('phenotypes'). We demonstrate that circuits that compute the same logic function are connected in large neutral networks that span circuit space. Their robustness or fault-tolerance varies very widely. The vicinity of each neutral network contains circuits with a broad range of novel functions. Two circuits computing different functions can usually be converted into one another via few changes in their architecture. These observations show that properties important for the evolvability of biological systems exist in a commercially important class of electronic circuitry. They also point to generic ways to generate fault-tolerant, adaptable and evolvable electronic circuitry.
Genetic dissection of MHC-associated susceptibility to Lepeophtheirus salmonis in Atlantic salmon
Gharbi, Karim; Glover, Kevin A; Stone, Louise C; MacDonald, Elizabeth S; Matthews, Louise; Grimholt, Unni; Stear, Michael J
2009-01-01
Background Genetic variation has been shown to play a significant role in determining susceptibility to the salmon louse, Lepeophtheirus salmonis. However, the mechanisms involved in differential response to infection remain poorly understood. Recent findings in Atlantic salmon (Salmo salar) have provided evidence for a potential link between marker variation at the major histocompatibility complex (MHC) and differences in lice abundance among infected siblings, suggesting that MHC genes can modulate susceptibility to the parasite. In this study, we used quantitative trait locus (QTL) analysis to test the effect of genomic regions linked to MHC class I and II on linkage groups (LG) 15 and 6, respectively. Results Significant QTL effects were detected on both LG 6 and LG 15 in sire-based analysis but the QTL regions remained unresolved due to a lack of recombination between markers. In dam-based analysis, a significant QTL was identified on LG 6, which accounted for 12.9% of within-family variance in lice abundance. However, the QTL was located at the opposite end of DAA, with no significant overlap with the MHC class II region. Interestingly, QTL modelling also revealed evidence of sex-linked differences in lice abundance, indicating that males and females may have different susceptibility to infection. Conclusion Overall, QTL analysis provided relatively weak support for a proximal effect of classical MHC regions on lice abundance, which can partly be explained by linkage to other genes controlling susceptibility to L. salmonis on the same chromosome. PMID:19397823
The Evolution of Tyrosine-Recombinase Elements in Nematoda
Szitenberg, Amir; Koutsovoulos, Georgios; Blaxter, Mark L.; Lunt, David H.
2014-01-01
Transposable elements can be categorised into DNA and RNA elements based on their mechanism of transposition. Tyrosine recombinase elements (YREs) are relatively rare and poorly understood, despite sharing characteristics with both DNA and RNA elements. Previously, the Nematoda have been reported to have a substantially different diversity of YREs compared to other animal phyla: the Dirs1-like YRE retrotransposon was encountered in most animal phyla but not in Nematoda, and a unique Pat1-like YRE retrotransposon has only been recorded from Nematoda. We explored the diversity of YREs in Nematoda by sampling broadly across the phylum and including 34 genomes representing the three classes within Nematoda. We developed a method to isolate and classify YREs based on both feature organization and phylogenetic relationships in an open and reproducible workflow. We also ensured that our phylogenetic approach to YRE classification identified truncated and degenerate elements, informatively increasing the number of elements sampled. We identified Dirs1-like elements (thought to be absent from Nematoda) in the nematode classes Enoplia and Dorylaimia indicating that nematode model species do not adequately represent the diversity of transposable elements in the phylum. Nematode Pat1-like elements were found to be a derived form of another Pat1-like element that is present more widely in animals. Several sequence features used widely for the classification of YREs were found to be homoplasious, highlighting the need for a phylogenetically-based classification scheme. Nematode model species do not represent the diversity of transposable elements in the phylum. PMID:25197791
The evolvability of programmable hardware
Raman, Karthik; Wagner, Andreas
2011-01-01
In biological systems, individual phenotypes are typically adopted by multiple genotypes. Examples include protein structure phenotypes, where each structure can be adopted by a myriad individual amino acid sequence genotypes. These genotypes form vast connected ‘neutral networks’ in genotype space. The size of such neutral networks endows biological systems not only with robustness to genetic change, but also with the ability to evolve a vast number of novel phenotypes that occur near any one neutral network. Whether technological systems can be designed to have similar properties is poorly understood. Here we ask this question for a class of programmable electronic circuits that compute digital logic functions. The functional flexibility of such circuits is important in many applications, including applications of evolutionary principles to circuit design. The functions they compute are at the heart of all digital computation. We explore a vast space of 1045 logic circuits (‘genotypes’) and 1019 logic functions (‘phenotypes’). We demonstrate that circuits that compute the same logic function are connected in large neutral networks that span circuit space. Their robustness or fault-tolerance varies very widely. The vicinity of each neutral network contains circuits with a broad range of novel functions. Two circuits computing different functions can usually be converted into one another via few changes in their architecture. These observations show that properties important for the evolvability of biological systems exist in a commercially important class of electronic circuitry. They also point to generic ways to generate fault-tolerant, adaptable and evolvable electronic circuitry. PMID:20534598
The evolution of tyrosine-recombinase elements in Nematoda.
Szitenberg, Amir; Koutsovoulos, Georgios; Blaxter, Mark L; Lunt, David H
2014-01-01
Transposable elements can be categorised into DNA and RNA elements based on their mechanism of transposition. Tyrosine recombinase elements (YREs) are relatively rare and poorly understood, despite sharing characteristics with both DNA and RNA elements. Previously, the Nematoda have been reported to have a substantially different diversity of YREs compared to other animal phyla: the Dirs1-like YRE retrotransposon was encountered in most animal phyla but not in Nematoda, and a unique Pat1-like YRE retrotransposon has only been recorded from Nematoda. We explored the diversity of YREs in Nematoda by sampling broadly across the phylum and including 34 genomes representing the three classes within Nematoda. We developed a method to isolate and classify YREs based on both feature organization and phylogenetic relationships in an open and reproducible workflow. We also ensured that our phylogenetic approach to YRE classification identified truncated and degenerate elements, informatively increasing the number of elements sampled. We identified Dirs1-like elements (thought to be absent from Nematoda) in the nematode classes Enoplia and Dorylaimia indicating that nematode model species do not adequately represent the diversity of transposable elements in the phylum. Nematode Pat1-like elements were found to be a derived form of another Pat1-like element that is present more widely in animals. Several sequence features used widely for the classification of YREs were found to be homoplasious, highlighting the need for a phylogenetically-based classification scheme. Nematode model species do not represent the diversity of transposable elements in the phylum.
Elementary School Children's Reasoning about Social Class: A Mixed-Methods Study
ERIC Educational Resources Information Center
Mistry, Rashmita S.; Brown, Christia S.; White, Elizabeth S.; Chow, Kirby A.; Gillen-O'Neel, Cari
2015-01-01
The current study examined children's identification and reasoning about their subjective social status (SSS), their beliefs about social class groups (i.e., the poor, middle class, and rich), and the associations between the two. Study participants were 117 10- to 12-year-old children of diverse racial, ethnic, and socioeconomic backgrounds…
USDA-ARS?s Scientific Manuscript database
The binding of peptides to classical major histocompatibility complex (MHC) class-I proteins is the single most selective step in antigen presentation. However, the peptide binding specificity of cattle MHC (bovine leucocyte antigen, BoLA) class I (BoLA-I) molecules remains poorly characterized. Her...
NASA Technical Reports Server (NTRS)
Benavides J. A.; Huchard, E.; Pettorelli, N.; King, A. J.; Brown, M. E.; Archer, C. E.; Appleton, C. C.; Raymond, M.; Cowlishaw, G.
2011-01-01
Host parasite diversity plays a fundamental role in ecological and evolutionary processes, yet the factors that drive it are still poorly understood. A variety of processes, operating across a range of spatial scales, are likely to influence both the probability of parasite encounter and subsequent infection. Here, we explored eight possible determinants of parasite richness, comprising rainfall and temperature at the population level, ranging behavior and home range productivity at the group level, and age, sex, body condition, and social rank at the individual level. We used a unique dataset describing gastrointestinal parasites in a terrestrial subtropical vertebrate (chacma baboons, Papio ursinus), comprising 662 faecal samples from 86 individuals representing all age-sex classes across two groups over two dry seasons in a desert population. Three mixed models were used to identify the most important factor at each of the three spatial scales (population, group, individual); these were then standardised and combined in a single, global, mixed model. Individual age had the strongest influence on parasite richness, in a convex relationship. Parasite richness was also higher in females and animals in poor condition, albeit at a lower order of magnitude than age. Finally, with a further halving of effect size, parasite richness was positively correlated to day range and temperature. These findings indicate that a range of factors influence host parasite richness through both encounter and infection probabilities, but that individual-level processes may be more important than those at the group or population level.
ERIC Educational Resources Information Center
Small, Mario Luis; McDermott, Monica
2006-01-01
Wilson (1987) and others argue that poor neighborhoods lack important organizational resources the middle class takes for granted, such as childcare centers, grocery stores and pharmacies. However, this approach does not distinguish poor neighborhoods from segregated neighborhoods, ignores immigration and neglects city differences. Using…
Global Digital Revolution and Africa: Transforming Nigerian Universities to World Class Institutions
ERIC Educational Resources Information Center
Isah, Emmanuel Aileonokhuoya; Ayeni, A. O.
2010-01-01
This study examined the global digital revolution and the transformation of Nigerian universities. The study overviewed university developments world wide in line with what obtains in Nigeria. The study highlighted the several challenges that face Nigerian universities inclusive of poor funding, poor personnel and the poor exposure to global…
Iltis, Ana S
2011-01-01
This essay examines conceptual difficulties with one of the ways in which justice has been understood and applied the ethical and regulatory review of human research. Justice requires the fair distribution of the benefits and burdens of research. Class membership is seen as justifying inclusion in higher hazard-no benefit research from which members of potentially vulnerable classes, such as children, typically would be excluded. I argue that class membership does not do the justificatory work it is thought to do and that the use of class membership to justify inclusion in higher hazard-no benefit research leads to unjustified discrimination of sick children and offers special protections to healthy children. © 2011 American Society of Law, Medicine & Ethics, Inc.
Espelt, Albert; Borrell, Carme; Rodríguez-Sanz, Maica; Muntaner, Carles; Pasarín, M Isabel; Benach, Joan; Schaap, Maartje; Kunst, Anton E; Navarro, Vicente
2008-10-01
To compare inequalities in self-perceived health in the population older than 50 years, in 2004, using Wright's social class dimensions, in nine European countries grouped in three political traditions (Social democracy, Christian democracy and Late democracies). Cross-sectional design, including data of the Survey of Health, Ageing and Retirement in Europe (Sweden, Denmark, Austria, France, Germany, The Netherlands, Spain, Italy and Greece). The population aged from 50 to 74 years was included. Absolute and relative social class dimension inequalities in poor self-reported health and long-term illness were determined for each sex and political tradition. Relative inequalities were assessed by fitting Poisson regression models with robust variance estimators. Absolute and relative health inequalities by social class dimensions are found in the three political traditions, but these differences are more marked in Late democracies and mainly among women. For example the prevalence ratio of poor self-perceived health comparing poorly educated women with highly educated women, was 1.75 (95% CI: 1.39-2.21) in Late democracies and 1.36 (95% CI: 1.21-1.52) in Social democracies. The prevalence differences were 24.2 and 13.7%, respectively. This study is one of the first to show the impact of different political traditions on social class inequalities in health. These results emphasize the need to evaluate the impact of the implementation of public policies.
The public's belief about biology.
Wolpert, L
2007-02-01
This short review is concerned with a topic that has been neglected and is still very poorly understood: what the general public think and believe about biology (including health and medicine, and bioethics), and, in particular, about biotechnology.
A Production Function Approach to Regional Environmental-Economic Assessments
Numerous difficulties await those creating regional-scale environmental assessments, from data having inconsistent spatial or temporal scales to poorly understood environmental processes and indicators. Including socioeconomic variables further complicates the situation. In place...
Blaming the helpers: the marginalization of teachers and parents of the urban poor.
Farber, B A; Azar, S T
1999-10-01
The nature and origins of the current tendency toward disparaging parents and teachers of the urban poor are examined. It is suggested that the influence of parents and teachers must be understood in the context of multiple intervening variables. Several explanations are offered for the phenomenon of blame, including the fact that women constitute the great majority of teachers and are often the primary agents of parenting.
ERIC Educational Resources Information Center
Jones, Stephanie
2007-01-01
This article draws from a three-year ethnographic study of girls and their mothers in a high-poverty, predominantly white community. Informed by critical and feminist theories of social class, I present four cases that highlight psychosocial tensions within the mother-daughter-teacher-researcher triangle and argue that white, middle-class female…
Squyres, S. W.; Arvidson, R. E.; Blaney, D.L.; Clark, B. C.; Crumpler, L.; Farrand, W. H.; Gorevan, S.; Herkenhoff, K. E.; Hurowitz, J.; Kusack, A.; McSween, H.Y.; Ming, D. W.; Morris, R.V.; Ruff, S.W.; Wang, A.; Yen, A.
2006-01-01
The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly sorted clastic rock that has a distinctive chemical composition that is high in Ti and P and low in Cr. Wishstone Class rock may be pyroclastic or impact in origin. Peace Class rock is a sedimentary material composed of ultramafic sand grains cemented by significant quantities of Mg- and Ca-sulfates. Peace Class rock may have formed when water briefly saturated the ultramafic sands and evaporated to allow precipitation of the sulfates. Watchtower Class rocks are similar chemically to Wishstone Class rocks and have undergone widely varying degrees of near-isochemical aqueous alteration. They may also be ejecta deposits, formed by impacts into Wishstone-rich materials and altered by small amounts of water. Backstay Class rocks are basalt/trachybasalt lavas that were emplaced in the Columbia Hills after the other rock classes were, either as impact ejecta or by localized volcanic activity. The geologic record preserved in the rocks of the Columbia Hills reveals a period very early in Martian history in which volcanic materials were widespread, impact was a dominant process, and water was commonly present. Copyright 2006 by the American Geophysical Union.
The Rocks of the Columbia Hills
NASA Technical Reports Server (NTRS)
Squyres, Steven W.; Arvidson, Raymond E.; Blaney, Diana L.; Clark, Benton C.; Crumpler, Larry; Farrand, William H.; Gorevan, Stephen; Herkenhoff, Kenneth; Hurowitz, Joel; Kusack, Alastair;
2006-01-01
The Mars Exploration Rover Spirit has identified five distinct rock types in the Columbia Hills of Gusev crater. Clovis Class rock is a poorly-sorted clastic rock that has undergone substantial aqueous alteration. We interpret it to be aqueously-altered ejecta deposits formed by impacts into basaltic materials. Wishstone Class rock is also a poorly-sorted clastic rock that has a distinctive chemical composition that is high in Ti and P and low in Cr. Wishstone Class rock may be pyroclastic in origin. Peace Class rock is a sedimentary material composed of ultramafic sand grains cemented by significant quantities of Mg- and Ca-sulfates. Peace Class rock may have formed when water briefly saturated the ultramafic sands, and evaporated to allow precipitation of the sulfates. Watchtower Class rocks are similar chemically to Wishstone Class rocks, and have undergone widely varying degrees of near-isochemical aqueous alteration. They may also be ejecta deposits, formed by impacts into Wishstone-rich materials and altered by small amounts of water. Backstay Class rocks are basalt/trachybasalt lavas that were emplaced in the Columbia Hills after the other rock classes were, either as impact ejecta or by localized volcanic activity. The geologic record preserved in the rocks of the Columbia Hills reveals a period very early in martian history in which volcanic materials were widespread, impact was a dominant process, and water was commonly present.
PHYTOASSESSMENT OF ESTUARINE SEDIMENTS
Most sediment quality assessments and quality guidelines are based on the laboratory response of single animal species and benthic animal community composition. The role of plants in this hazard assessment process is poorly understood despite the fact that plant-dominated habitat...
FACTORS INFLUENCING LIGHT-INDUCED MORTALITY OF ENTEROCOCCI IN SEDIMENT SUSPENSIONS
Contamination of recreational waters by pathogenic microorganisms occurs through complex, poorly understood interactions involving variable microbial sources, hydrodynamic transport, arid microbial fate processes. Fecal indicator bacteria such as enterococci have been used to ass...
K. J. McFarlane; S. H. Schoenholtz; R. F. Powers
2009-01-01
Belowground C and N storage is important in maintaining forestproductivity and to CO2 sequestration. How these pools respondto management is poorly understood. We investigated effectsof repeated applications of complete fertilizer and competing...
Predictive Models of Liver Cancer
Predictive models of chemical-induced liver cancer face the challenge of bridging causative molecular mechanisms to adverse clinical outcomes. The latent sequence of intervening events from chemical insult to toxicity are poorly understood because they span multiple levels of bio...
What Can Plasticity Contribute to Insect Responses to Climate Change?
Sgrò, Carla M; Terblanche, John S; Hoffmann, Ary A
2016-01-01
Plastic responses figure prominently in discussions on insect adaptation to climate change. Here we review the different types of plastic responses and whether they contribute much to adaptation. Under climate change, plastic responses involving diapause are often critical for population persistence, but key diapause responses under dry and hot conditions remain poorly understood. Climate variability can impose large fitness costs on insects showing diapause and other life cycle responses, threatening population persistence. In response to stressful climatic conditions, insects also undergo ontogenetic changes including hardening and acclimation. Environmental conditions experienced across developmental stages or by prior generations can influence hardening and acclimation, although evidence for the latter remains weak. Costs and constraints influence patterns of plasticity across insect clades, but they are poorly understood within field contexts. Plastic responses and their evolution should be considered when predicting vulnerability to climate change-but meaningful empirical data lag behind theory.
Activity-Induced Remodeling of Olfactory Bulb Microcircuits Revealed by Monosynaptic Tracing
Arenkiel, Benjamin R.; Hasegawa, Hiroshi; Yi, Jason J.; Larsen, Rylan S.; Wallace, Michael L.; Philpot, Benjamin D.; Wang, Fan; Ehlers, Michael D.
2011-01-01
The continued addition of new neurons to mature olfactory circuits represents a remarkable mode of cellular and structural brain plasticity. However, the anatomical configuration of newly established circuits, the types and numbers of neurons that form new synaptic connections, and the effect of sensory experience on synaptic connectivity in the olfactory bulb remain poorly understood. Using in vivo electroporation and monosynaptic tracing, we show that postnatal-born granule cells form synaptic connections with centrifugal inputs and mitral/tufted cells in the mouse olfactory bulb. In addition, newly born granule cells receive extensive input from local inhibitory short axon cells, a poorly understood cell population. The connectivity of short axon cells shows clustered organization, and their synaptic input onto newborn granule cells dramatically and selectively expands with odor stimulation. Our findings suggest that sensory experience promotes the synaptic integration of new neurons into cell type-specific olfactory circuits. PMID:22216277
The Multifactorial Epidemiology of Blackwater Fever.
Shanks, G Dennis
2017-12-01
Blackwater fever is a massive hemolytic event usually occurring in the context of repeated falciparum malaria infections and intermittent quinine use. Its etiology is poorly understood, and it is rarely seen today. Historical epidemiological observations from the 20th century demonstrated variable patterns in prisoners in Andaman Islands, refugees in Macedonia, canal workers in Panama, expatriates in Rhodesia, and Second World War soldiers. Rates of blackwater fever per 1,000 malaria cases varied over two orders of magnitude. Islands, such as the Andaman Islands and New Guinea, had lower blackwater fever rates than continental areas. During the Second World War, blackwater fever rates in British soldiers in West Africa and Australian soldiers in New Guinea differed by a factor of 40 despite similar treatment regimens and falciparum malaria transmission risks. Blackwater fever is a complex interaction between host erythrocyte, falciparum malaria, and antimalarial drugs which remains poorly understood.
Making Poor Choices? Demand Rationalities and School Choice in a Chilean Local Education Market
ERIC Educational Resources Information Center
Bonal, Xavier; Verger, Antoni; Zancajo, Adrián
2017-01-01
Although the literature on school choice rationalities is extensive, different authors interpret the processes of school choice for poor families in different ways. Positions vary between those that consider that poor families have the same capacity to choose as middle class families and those that value structural factors as constraints for…
Vouchers, Class Size Reduction, and Student Achievement: Considering the Evidence.
ERIC Educational Resources Information Center
Molnar, Alex
Proponents of private school vouchers argue that vouchers empower poor families and raise the academic achievement of poor children. They also argue that vouchers may improve achievement by forcing the public schools to compete in an education marketplace in which poor parents hold the power of the purse. Juxtaposed against this issue of vouchers…
Perceived sexism as a health determinant in Spain.
Borrell, Carme; Artazcoz, Lucia; Gil-González, Diana; Pérez, Glòria; Rohlfs, Izabella; Pérez, Katherine
2010-04-01
The goals of the present study are to explore the association between perceived sexism and self-perceived health, health-related behaviors, and unmet medical care needs among women in Spain; to analyze whether higher levels of discrimination are associated with higher prevalence of poor health indicators and to examine whether these relationships are modified by country of origin and social class. The study is based on a cross-sectional design using data from the 2006 Spanish Health Interview Survey. We included women aged 20-64 years (n = 10,927). Six dependent variables were examined: four of health (self-perceived health, mental health, hypertension, and having had an injury during the previous year), one health behavior (smoking), and another related to the use of the health services (unmet need for medical care). Perceived sexism was the main independent variable. Social class and country of origin were considered as effect modifiers. We obtained the prevalence of perceived sexism. Logistic regression models, adjusted for potential confounders, were fitted to study the association between sexism and poor health outcomes. The prevalence of perceived sexism was 3.4%. Perceived sexism showed positive and consistent associations with four poor health outcomes (poor self-perceived health, poor mental health, injuries in the last 12 months, and smoking). The strength of these associations increased with increased scores for perceived sexism, and the patterns were found to be modified by country of origin and social class. This study shows a consistent association between perceived sexism and poor health outcomes in a country of southern Europe with a strong patriarchal tradition.
Tracking contaminant flux from aquatic to terrestrial food webs
Aquatic insects provide a critical energy subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated aquatic resource utilization and contaminant exposure among riparian invertivores (spiders and herpt...
Asthma and Respiratory Allergic Disease
The pathogenesis of non-communicable diseases such as allergy is complex and poorly understood. The causes of chronic allergic diseases including asthma involve to a large extent, immunomodulation of the adaptive and particularly the innate immune systems and are markedly influen...
A Production Function Approach to Regional Environmental Economic Assessments
Regional-scale environmental assessments require integrating many available types of data having inconsistent spatial or temporal scales. Moreover, the relationships among the environmental variables in the assessment tend to be poorly understood, a situation made even more compl...
AtCHX13 is a plasma membrane K(+) transporter
USDA-ARS?s Scientific Manuscript database
Potassium (K+) homeostasis is essential for diverse cellular processes, although how various cation transporters collaborate to maintain a suitable K(+) required for growth and development is poorly understood. The Arabidopsis ("Arabidopsis thaliana") genome contains numerous cation:proton antiporte...
AtCHX13 is a plasma membrane K+ transporter
USDA-ARS?s Scientific Manuscript database
Potassium (K+) homeostasis is essential for diverse cellular processes, although how various cation transporters collaborate to maintain a suitable K+ required for growth and development is poorly understood. The Arabidopsis (Arabidopsis thaliana) genome contains numerous cation:proton antiporters (...
The 2011 National Wetland Condition Assessment
The ecological condition of wetland resources across the conterminous United States is poorly understood. To address this issue, the U.S. Environmental Protection Agency (USEPA), in collaboration with states, tribes, and other federal partners, is conducting the first-ever Natio...
Impacts of Human Activity on the Microbial Communities of Devon Island, Canadian High Arctic
NASA Astrophysics Data System (ADS)
Bywaters, K. B.; Burton, A. S.; Wallace, S. L.; Glass, B. J.
2016-09-01
The impacts of human activities on microbial communities in arctic environments are poorly understood. This project compares the distribution of microbes at the HMP Mars analog site prior to and after human settlement.
AN IMPROVED METHOD FOR DETECTING VIRUSES IN WATER
Enteroviruses are important etiological agents of waterborne disease and are responsible for outbreaks of gastroenteritis. However, the prevalence and occurrence of these pathogens in raw drinking water sources is poorly understood. This is primarily due to the limited methods ...
The mechanisms of intrarenal hemodynamic changes following acute arterial occlusion.
DOT National Transportation Integrated Search
1963-10-01
The hemodynamic response of the kidney to acute arterial occlusion is poorly understood. The purpose of the present study was to determine intrarenal hemodynamic changes in intact and isolated kidneys following arterial occlusion. : The relative role...
Prediction of Membership in Rehabilitation Counseling Professional Associations
ERIC Educational Resources Information Center
Phillips, Brian N.; Leahy, Michael J.
2012-01-01
Declining membership is a concerning yet poorly understood issue affecting professional associations across disciplines (Bauman, 2008). Rehabilitation counseling association membership is in decline even while number of certified rehabilitation counselors continues to increase (Leahy, 2009). Factors influencing rehabilitation counseling…
The prevalence and causes of autistic spectrum disorders.
Hainsworth, Terry
Autism and autistic spectrum disorders are still relatively poorly understood. This article outlines the results of new research into the prevalence of autism and into the causes of the condition and highlights implications for nurses from the findings.
Physical Activity among Men and Women in Midlife: Variations by Class and Employment Status.
ERIC Educational Resources Information Center
Phillips, Mark; Arber, Sarah; Ginn, Jay
2001-01-01
Analysis of data on British midlife adults indicated that being out of the work force between age 50 and state pension age has a different impact on participation in physical activity according to class and gender. Highest levels of inactivity are found among the unemployed working class and relate to low levels of education, poor health, and…
A Way Forward: Nurturing the Imagination at the Intersection of Race, Class, Gender, and Age
ERIC Educational Resources Information Center
Lockhart-Gilroy, Annie A.
2016-01-01
Those who are oppressed often find themselves internalizing voices that limit their ability. This article focuses on a population that falls on the non-hegemonic side of the intersection of race, class, gender, and age: Black girls from poor and working-class backgrounds. From my work with youth, I have noticed that internalizing these limiting…
NASA Astrophysics Data System (ADS)
Litjens, G. J. S.; Elliott, R.; Shih, N.; Feldman, M.; Barentsz, J. O.; Hulsbergen-van de Kaa, C. A.; Kovacs, I.; Huisman, H. J.; Madabhushi, A.
2014-03-01
Learning how to separate benign confounders from prostate cancer is important because the imaging characteristics of these confounders are poorly understood. Furthermore, the typical representations of the MRI parameters might not be enough to allow discrimination. The diagnostic uncertainty this causes leads to a lower diagnostic accuracy. In this paper a new cascaded classifier is introduced to separate prostate cancer and benign confounders on MRI in conjunction with specific computer-extracted features to distinguish each of the benign classes (benign prostatic hyperplasia (BPH), inflammation, atrophy or prostatic intra-epithelial neoplasia (PIN). In this study we tried to (1) calculate different mathematical representations of the MRI parameters which more clearly express subtle differences between different classes, (2) learn which of the MRI image features will allow to distinguish specific benign confounders from prostate cancer, and (2) find the combination of computer-extracted MRI features to best discriminate cancer from the confounding classes using a cascaded classifier. One of the most important requirements for identifying MRI signatures for adenocarcinoma, BPH, atrophy, inflammation, and PIN is accurate mapping of the location and spatial extent of the confounder and cancer categories from ex vivo histopathology to MRI. Towards this end we employed an annotated prostatectomy data set of 31 patients, all of whom underwent a multi-parametric 3 Tesla MRI prior to radical prostatectomy. The prostatectomy slides were carefully co-registered to the corresponding MRI slices using an elastic registration technique. We extracted texture features from the T2-weighted imaging, pharmacokinetic features from the dynamic contrast enhanced imaging and diffusion features from the diffusion-weighted imaging for each of the confounder classes and prostate cancer. These features were selected because they form the mainstay of clinical diagnosis. Relevant features for each of the classes were selected using maximum relevance minimum redundancy feature selection, allowing us to perform classifier independent feature selection. The selected features were then incorporated in a cascading classifier, which can focus on easier sub-tasks at each stage, leaving the more difficult classification tasks for later stages. Results show that distinct features are relevant for each of the benign classes, for example the fraction of extra-vascular, extra-cellular space in a voxel is a clear discriminator for inflammation. Furthermore, the cascaded classifier outperforms both multi-class and one-shot classifiers in overall accuracy for discriminating confounders from cancer: 0.76 versus 0.71 and 0.62.
Familiarity and Aptness in Metaphor Comprehension.
Damerall, Alison Whiteford; Kellogg, Ronald T
2016-01-01
The career of metaphor hypothesis suggests that novel metaphors are understood through a search for shared features between the topic and vehicle, but with repeated exposure, the figurative meaning is understood directly as a new category is established. The categorization hypothesis argues that instead good or apt metaphors are understood through a categorization process, whether or not they are familiar. Only poor metaphors ever invoke a literal comparison. In Experiment 1, with aptness equated, we found that high familiarity speeded comprehension time over low-familiarity metaphors. In Experiment 2a, providing a literal prime failed to facilitate interpretation of low-familiarity metaphors, contrary to the career of metaphor hypothesis. In Experiment 2b, with familiarity equated, high- and low-aptness metaphors did not differ, contrary to the categorization hypothesis.
Loneliness in psychosis: a systematic review.
Lim, Michelle H; Gleeson, John F M; Alvarez-Jimenez, Mario; Penn, David L
2018-03-01
The aim of the review is to understand the relationships between loneliness and related psychological and social factors in individuals with psychosis. Loneliness is poorly understood in people with psychosis. Given the myriad of social challenges facing individuals with psychosis, these findings can inform psychosocial interventions that specifically target loneliness in this vulnerable group. We adhered to the PRISMA guidelines and systematically reviewed empirical studies that measured loneliness either as a main outcome or as an associated variable in individuals with psychosis. A total of ten studies examining loneliness in people diagnosed with a psychotic disorder were examined. Heterogeneity in the assessment of loneliness was found, and there were contradictory findings on the relationship between loneliness and psychotic symptomatology. In individuals with psychosis, loneliness may be influenced by psychological and social factors such as increased depression, psychosis, and anxiety, poor social support, poor quality of life, more severe internalised stigma and perceived discrimination, and low self-esteem. The relationship between loneliness and psychosis remains poorly understood due to a lack of rigorous studies. Although having strong social relationships is crucial to facilitate recovery from serious mental illness, psychosocial interventions that specifically target loneliness in individuals with psychosis are lacking and sorely needed. Interventions targeting loneliness in those with psychosis will also need to account for additional barriers associated with psychosis (e.g., social skill deficits, impoverished social networks, and negative symptoms).
Continuous-variable quantum key distribution protocols over noisy channels.
García-Patrón, Raúl; Cerf, Nicolas J
2009-04-03
A continuous-variable quantum key distribution protocol based on squeezed states and heterodyne detection is introduced and shown to attain higher secret key rates over a noisy line than any other one-way Gaussian protocol. This increased resistance to channel noise can be understood as resulting from purposely adding noise to the signal that is converted into the secret key. This notion of noise-enhanced tolerance to noise also provides a better physical insight into the poorly understood discrepancies between the previously defined families of Gaussian protocols.
ERIC Educational Resources Information Center
Apple, Michael W.
1983-01-01
The connections between class and gender must be recognized if attempts to rationalize and proletarianize teaching are to be understood. Behaviorally-specified curriculum, prepackaged programs, and repeated testing and accountability measures represent attempts by state governments and by male administrators to wrest control of instruction from a…
Understanding the linkage between the physicochemical (PC) properties of nanoparticles (NP) and their activation of biological systems is poorly understood, yet fundamental to predicting nanotoxicity, idenitifying mode of actions and developing appropriate and effective regul...
Physiological benefits of nectar-feeding by a predatory beetle
USDA-ARS?s Scientific Manuscript database
Extrafloral nectar is an important food source for many animals, including predatory lady beetles (Coleoptera: Coccinellidae), although the physiological benefits of nectar consumption are poorly understood for most consumers. Under laboratory conditions, we confined new females of Coleomegilla macu...
Fructose, high fructose corn syrup, sucrose, and non-alcoholic liver disease
USDA-ARS?s Scientific Manuscript database
Nonalcoholic fatty liver disease (NAFLD), formerly called nonalcoholic steatohepatitis, is characterized by hepatic steatosis and abnormal triglyceride accumulation in liver cells. Its etiology, pathophysiology, and pathogenesis are still poorly understood. Some have suggested that the increased in...
Salary, Performance, and Superintendent Turnover
ERIC Educational Resources Information Center
Grissom, Jason A.; Mitani, Hajime
2016-01-01
Purpose: Superintendent retention is an important goal for many school districts, yet the factors contributing to superintendent turnover are poorly understood. Most prior quantitative studies of superintendent turnover have relied on small, cross-sectional samples, limiting the evidence base. Utilizing longitudinal administrative records from…
New perspectives on microbial community distortion after whole-genome amplification
Whole-genome amplification (WGA) has become an important tool to explore the genomic information of microorganisms in an environmental sample with limited biomass, however potential selective biases during the amplification processes are poorly understood. Here, we describe the e...
Abbassian, Ali; Thomas, Rhidian
2008-06-01
Ankle ligament injuries in the presence or in the absence of fractures are common. They often present a diagnostic challenge, and their management is poorly understood and subject to debate. This article reviews and discusses the current literature on the management and diagnosis of these injuries.
Latent Class Analysis of Lifestyle Characteristics and Health Risk Behaviors among College Youth
Pasch, Keryn E.; Lust, Katherine; Story, Mary; Ehlinger, Ed
2010-01-01
Few studies have examined the context of a wide range of risk behaviors among emerging adults (ages 18–25 years), approximately half of whom in the USA enroll in post-secondary educational institutions. The objective of this research was to examine behavioral patterning in weight behaviors (diet and physical activity), substance use, sexual behavior, stress, and sleep among undergraduate students. Health survey data were collected among undergraduates attending a large, public US university (n=2,026). Latent class analysis was used to identify homogeneous, mutually exclusive “classes” (patterns) of ten leading risk behaviors. Resulting classes differed for males and females. Female classes were defined as: (1) poor lifestyle (diet, physical activity, sleep), yet low-risk behaviors (e.g., smoking, binge drinking, sexual risk, drunk driving; 40.0% of females), (2) high risk (high substance use, intoxicated sex, drunk driving, poor diet, inadequate sleep) (24.3%), (3) moderate lifestyle, few risk behaviors (20.4%), (4) “health conscious” (favorable diet/physical activity with some unhealthy weight control; 15.4%). Male classes were: (1) poor lifestyle, low risk (with notably high stress, insufficient sleep, 9.2% of males), (2) high risk (33.6% of males, similar to class 2 in females), (3) moderate lifestyle, low risk (51.0%), and (4) “classic jocks” (high physical activity, binge drinking, 6.2%). To our knowledge, this is among the first research to examine complex lifestyle patterning among college youth, particularly with emphasis on the role of weight-related behaviors. These findings have important implications for targeting much needed health promotion strategies among emerging adults and college youth. PMID:19499339
NASA Technical Reports Server (NTRS)
Murphy, Kyle R.; Mann, Ian R.; Rae, I. Jonathan; Sibeck, David G.; Watt, Clare E. J.
2016-01-01
Wave-particle interactions play a crucial role in energetic particle dynamics in the Earths radiation belts. However, the relative importance of different wave modes in these dynamics is poorly understood. Typically, this is assessed during geomagnetic storms using statistically averaged empirical wave models as a function of geomagnetic activity in advanced radiation belt simulations. However, statistical averages poorly characterize extreme events such as geomagnetic storms in that storm-time ultralow frequency wave power is typically larger than that derived over a solar cycle and Kp is a poor proxy for storm-time wave power.
ERIC Educational Resources Information Center
Larsson, Esbjörn
2016-01-01
This article investigates the monitorial system of education in Sweden between 1820 and 1843. In contrast to previous research, which has emphasised monitorial education as a method for disciplining poor children, this article compares the use of the method in schools for the working classes and in academic schools. Using concepts such as…
Review of "Incomplete: How Middle Class Schools Aren't Making the Grade". Think Tank Review
ERIC Educational Resources Information Center
Baker, Bruce D.
2011-01-01
"Incomplete: How Middle Class Schools Aren't Making the Grade" is a new report from Third Way, a Washington, D.C.-based policy think tank. The report aims to convince parents, taxpayers and policymakers that they should be as concerned about middle-class schools not making the grade as they are about the failures of the nation's large, poor, urban…
Brand, Serge; Kirov, Roumen; Kalak, Nadeem; Gerber, Markus; Pühse, Uwe; Lemola, Sakari; Correll, Christoph U; Cortese, Samuele; Meyer, Till; Holsboer-Trachsler, Edith
2015-01-01
Perfectionism is understood as a set of personality traits such as unrealistically high and rigid standards for performance, fear of failure, and excessive self-criticism. Previous studies showed a direct association between increased perfectionism and poor sleep, though without taking into account possible mediating factors. Here, we tested the hypothesis that perfectionism was directly associated with poor sleep, and that this association collapsed, if mediating factors such as stress and poor emotion regulation were taken into account. Three hundred and forty six young adult students (M=23.87 years) completed questionnaires relating to perfectionism traits, sleep, and psychological functioning such as stress perception, coping with stress, emotion regulation, and mental toughness. Perfectionism was directly associated with poor sleep and poor psychological functioning. When stress, poor coping, and poor emotion regulation were entered in the equation, perfectionism traits no longer contributed substantively to the explanation of poor sleep. Though perfectionism traits seem associated with poor sleep, the direct role of such traits seemed small, when mediating factors such as stress perception and emotion regulation were taken into account.
Brand, Serge; Kirov, Roumen; Kalak, Nadeem; Gerber, Markus; Pühse, Uwe; Lemola, Sakari; Correll, Christoph U; Cortese, Samuele; Meyer, Till; Holsboer-Trachsler, Edith
2015-01-01
Background Perfectionism is understood as a set of personality traits such as unrealistically high and rigid standards for performance, fear of failure, and excessive self-criticism. Previous studies showed a direct association between increased perfectionism and poor sleep, though without taking into account possible mediating factors. Here, we tested the hypothesis that perfectionism was directly associated with poor sleep, and that this association collapsed, if mediating factors such as stress and poor emotion regulation were taken into account. Methods Three hundred and forty six young adult students (M=23.87 years) completed questionnaires relating to perfectionism traits, sleep, and psychological functioning such as stress perception, coping with stress, emotion regulation, and mental toughness. Results Perfectionism was directly associated with poor sleep and poor psychological functioning. When stress, poor coping, and poor emotion regulation were entered in the equation, perfectionism traits no longer contributed substantively to the explanation of poor sleep. Conclusion Though perfectionism traits seem associated with poor sleep, the direct role of such traits seemed small, when mediating factors such as stress perception and emotion regulation were taken into account. PMID:25678791
Causal explanations for class inequality in health--an empirical analysis.
Lundberg, O
1991-01-01
One of the most important issues for research on social class inequalities in health are the causes behind such differences. So far, the debate on class inequalities in health has mainly been centred around hypotheses on artefactual and selectional processes. Although most contributors to this branch of research have argued in favour of causal explanations, these have gained very little systematic scrutiny. In this article, several possible causal factors are singled out for empirical testing. The effect of these factors on class differences in physical and mental illness is studied by means of logit regressions. On the basis of these analyses, it is shown that physical working conditions are the prime source of class inequality in physical illness, although economic hardship during upbringing and health related behaviours also contribute. For class inequality in mental illness these three factors plus weak social network are important. In sum, a large part of the class differences in physical as well as mental illness can be understood as a result of systematic differences between classes in living conditions, primarily differences in working conditions.
Class, Social Suffering, and Health Consumerism.
Merrild, Camilla Hoffmann; Risør, Mette Bech; Vedsted, Peter; Andersen, Rikke Sand
2016-01-01
In recent years an extensive social gradient in cancer outcome has attracted much attention, with late diagnosis proposed as one important reason for this. Whereas earlier research has investigated health care seeking among cancer patients, these social differences may be better understood by looking at health care seeking practices among people who are not diagnosed with cancer. Drawing on long-term ethnographic fieldwork among two different social classes in Denmark, our aim in this article is to explore the relevance of class to health care seeking practices and illness concerns. In the higher middle class, we predominantly encountered health care seeking resembling notions of health consumerism, practices sanctioned and encouraged by the health care system. However, among people in the lower working class, health care seeking was often shaped by the inseparability of physical, political, and social dimensions of discomfort, making these practices difficult for the health care system to accommodate.
Timsit, E; Dendukuri, N; Schiller, I; Buczinski, S
2016-12-01
Diagnosis of bovine respiratory disease (BRD) in beef cattle placed in feedlots is typically based on clinical illness (CI) detected by pen-checkers. Unfortunately, the accuracy of this diagnostic approach (namely, sensitivity [Se] and specificity [Sp]) remains poorly understood, in part due to the absence of a reference test for ante-mortem diagnosis of BRD. Our objective was to pool available estimates of CI's diagnostic accuracy for BRD diagnosis in feedlot beef cattle while adjusting for the inaccuracy in the reference test. The presence of lung lesions (LU) at slaughter was used as the reference test. A systematic review of the literature was conducted to identify research articles comparing CI detected by pen-checkers during the feeding period to LU at slaughter. A hierarchical Bayesian latent-class meta-analysis was used to model test accuracy. This approach accounted for imperfections of both tests as well as the within and between study variability in the accuracy of CI. Furthermore, it also predicted the Se CI and Sp CI for future studies. Conditional independence between CI and LU was assumed, as these two tests are not based on similar biological principles. Seven studies were included in the meta-analysis. Estimated pooled Se CI and Sp CI were 0.27 (95% Bayesian credible interval: 0.12-0.65) and 0.92 (0.72-0.98), respectively, whereas estimated pooled Se LU and Sp LU were 0.91 (0.82-0.99) and 0.67 (0.64-0.79). Predicted Se CI and Sp CI for future studies were 0.27 (0.01-0.96) and 0.92 (0.14-1.00), respectively. The wide credible intervals around predicted Se CI and Sp CI estimates indicated considerable heterogeneity among studies, which suggests that pooled Se CI and Sp CI are not generalizable to individual studies. In conclusion, CI appeared to have poor Se but high Sp for BRD diagnosis in feedlots. Furthermore, considerable heterogeneity among studies highlighted an urgent need to standardize BRD diagnosis in feedlots. Copyright © 2016 Elsevier B.V. All rights reserved.
Vågerö, Denny; Aronsson, Vanda; Modin, Bitte
2018-04-01
Transgenerational determinants of longevity are poorly understood. We used data from four linked generations (G0, G1, G2 and G3) of the Uppsala Birth Cohort Multigeneration Study to address this issue. Mortality in G1 (N = 9565) was followed from 1961-2015 and analysed in relation to tertiles of their parents' (G0) age-at-death using Cox regression. Parental social class and marital status were adjusted for in the analyses, as was G1's birth order and adult social class. For an almost entirely deceased segment of G1 (n = 1149), born 1915-1917, we compared exact age-at-death with G0 parents' age-at-death. Finally, we explored 'resilience' as a potentially important mechanism for intergenerational transmission of longevity, using conscript information from psychological interviews of G2 and G3 men. G0 men's and women's ages-at-death were independently associated with G1 midlife and old age mortality. This association was robust and minimally reduced when G0 and G1 social class were adjusted for. We observed an increased lifespan in all social groups. Median difference in age-at-death for sons compared to fathers was + 3.9 years, and + 6.9 years for daughters compared to mothers.Parents' and maternal grandmother's longevity were associated with resilience in subsequent generations. Resilience scores of G2 men were also associated with those of their G3 sons and with their own mortality in midlife. The chance of reaching a high age is transmitted from parents to children in a modest, but robust way. Longevity inheritance is paralleled by the inheritance of individual resilience. Individual resilience, we propose, develops in the first part of life as a response to adversity and early experience in general. This gives rise to a transgenerational pathway, distinct from social class trajectories. A theory of longevity inheritance should bring together previous thinking around general susceptibility, frailty and resilience with new insights from epigenetics and social epidemiology.
A novel role of HLA class I in the pathology of medulloblastoma.
Smith, Courtney; Santi, Mariarita; Rajan, Bhargavi; Rushing, Elisabeth J; Choi, Mi Rim; Rood, Brian R; Cornelison, Robert; MacDonald, Tobey J; Vukmanovic, Stanislav
2009-07-12
MHC class I expression by cancer cells enables specific antigen recognition by the immune system and protection of the host. However, in some cancer types MHC class I expression is associated with an unfavorable outcome. We explored the basis of MHC class I association with unfavorable prognostic marker expression in the case of medulloblastoma. We investigated expression of four essential components of MHC class I (heavy chain, beta2m, TAP1 and TAP2) in 10 medulloblastoma mRNA samples, a tissue microarray containing 139 medulloblastoma tissues and 3 medulloblastoma cell lines. Further, in medulloblastoma cell lines we evaluated the effects of HLA class I engagement on activation of ERK1/2 and migration in vitro. The majority of specimens displayed undetectable or low levels of the heavy chains. Medulloblastomas expressing high levels of HLA class I displayed significantly higher levels of anaplasia and c-myc expression, markers of poor prognosis. Binding of beta2m or a specific antibody to open forms of HLA class I promoted phosphorylation of ERK1/2 in medulloblastoma cell line with high levels, but not in the cell line with low levels of HLA heavy chain. This treatment also promoted ERK1/2 activation dependent migration of medulloblastoma cells. MHC class I expression in medulloblastoma is associated with anaplasia and c-myc expression, markers of poor prognosis. Peptide- and/or beta2m-free forms of MHC class I may contribute to a more malignant phenotype of medulloblastoma by modulating activation of signaling molecules such as ERK1/2 that stimulates cell mobility.
A novel role of HLA class I in the pathology of medulloblastoma
Smith, Courtney; Santi, Mariarita; Rajan, Bhargavi; Rushing, Elisabeth J; Choi, Mi Rim; Rood, Brian R; Cornelison, Robert; MacDonald, Tobey J; Vukmanovic, Stanislav
2009-01-01
Background MHC class I expression by cancer cells enables specific antigen recognition by the immune system and protection of the host. However, in some cancer types MHC class I expression is associated with an unfavorable outcome. We explored the basis of MHC class I association with unfavorable prognostic marker expression in the case of medulloblastoma. Methods We investigated expression of four essential components of MHC class I (heavy chain, β2m, TAP1 and TAP2) in 10 medulloblastoma mRNA samples, a tissue microarray containing 139 medulloblastoma tissues and 3 medulloblastoma cell lines. Further, in medulloblastoma cell lines we evaluated the effects of HLA class I engagement on activation of ERK1/2 and migration in vitro. Results The majority of specimens displayed undetectable or low levels of the heavy chains. Medulloblastomas expressing high levels of HLA class I displayed significantly higher levels of anaplasia and c-myc expression, markers of poor prognosis. Binding of β2m or a specific antibody to open forms of HLA class I promoted phosphorylation of ERK1/2 in medulloblastoma cell line with high levels, but not in the cell line with low levels of HLA heavy chain. This treatment also promoted ERK1/2 activation dependent migration of medulloblastoma cells. Conclusion MHC class I expression in medulloblastoma is associated with anaplasia and c-myc expression, markers of poor prognosis. Peptide- and/or β2m-free forms of MHC class I may contribute to a more malignant phenotype of medulloblastoma by modulating activation of signaling molecules such as ERK1/2 that stimulates cell mobility. PMID:19594892
Taylor, Cliff D.; Giles, Stuart A.
2015-01-01
USGS review of PRISM-I data suggests that there is abundant documentation of the Bou Naga alkaline complex and to a lesser degree, the Guelb er Richat carbonatite complex, but that all other occurrences of U, Th, REE, and associated elements are poorly described, and poorly understood (Taylor, 2007)
Atherosclerosis associated with pericardial effusion in a central bearded dragon (Pogona vitticeps).
Schilliger, Lionel; Lemberger, Karin; Chai, Norin; Bourgeois, Aude; Charpentier, Maud
2010-09-01
Atherosclerosis is a common disease in pet birds, particularly in psittacines, and is frequently found when performing postmortem examinations on adult and old dogs, in which it is mainly associated with endocrine diseases, such as hypothyroidism and diabetes mellitus. However, atherosclerosis is poorly documented in reptiles and consequently poorly understood. In the current case report, atherosclerosis and pericardial effusion were diagnosed in a 2-year-old male central bearded dragon (Pogona vitticeps) based on ultrasound visualization, necropsy, and histologic examination.
Peterson, Sarah H.; McHuron, Elizabeth A.; Kennedy, Stephanie N.; Ackerman, Joshua T.; Rea, Lorrie D.; Castellini, J. Margaret; O'Hara, Todd M.; Costa, Daniel P.
2016-01-01
Mercury (Hg) biomonitoring of pinnipeds increasingly utilizes nonlethally collected tissues such as hair and blood. The relationship between total Hg concentrations ([THg]) in these tissues is not well understood for marine mammals, but it can be important for interpretation of tissue concentrations with respect to ecotoxicology and biomonitoring. We examined [THg] in blood and hair in multiple age classes of four pinniped species. For each species, we used paired blood and hair samples to quantify the ability of [THg] in hair to predict [THg] in blood at the time of sampling and examined the influence of varying ontogenetic phases and life history of the sampled animals. Overall, we found that the relationship between [THg] in hair and blood was affected by factors including age class, weaning status, growth, and the time difference between hair growth and sample collection. Hair [THg] was moderately to strongly predictive of current blood [THg] for adult female Steller sea lions (Eumetopias jubatus), adult female California sea lions (Zalophus californianus), and adult harbor seals (Phoca vitulina), whereas hair [THg] was poorly predictive or not predictive (different times of year) of blood [THg] for adult northern elephant seals (Mirounga angustirostris). Within species, except for very young pups, hair [THg] was a weaker predictor of blood [THg] for prereproductive animals than for adults likely due to growth, variability in foraging behavior, and transitions between ontogenetic phases. Our results indicate that the relationship between hair [THg] and blood [THg] in pinnipeds is variable and that ontogenetic phase and life history should be considered when interpreting [THg] in these tissues.
Knopf, Daniel A.; Alpert, P. A.; Wang, B.; ...
2014-08-11
The effect of anthropogenic and biogenic organic particles on atmospheric glaciation processes is poorly understood. We use an optical microscopy setup to identify the ice nuclei (IN) active in immersion freezing (IMF) and deposition ice nucleation within a large population of particles collected on a substrate from an ambient environment in central California dominated by urban and marine aerosols. Multimodal microspectroscopy methods are applied to characterize the physicochemical properties and mixing state of the individual IN and particle populations to identify particle-type classes. The temperature onsets of water uptake occurred between 235 and 257 K at subsaturated conditions, and themore » onsets of IMF proceeded at subsaturated and saturated conditions for 235–247 K, relevant for ice nucleation in mixed-phase clouds. Particles also took up water and nucleated ice between 226 and 235 K and acted as deposition IN with onset temperatures below 226 K, a temperature range relevant to cirrus cloud formation. The identified IN belong to the most common particle-type classes observed in the field samples: organic coated sea salt and Na-rich, secondary, and refractory carbonaceous particles. Based on these observations, we suggest that the IN are not always particles with unique chemical composition and exceptional ice nucleation propensity; rather, they are common particles in the ambient particle population. Lastly, the results suggest that particle-type abundance and total particle surface area are also crucial factors, in addition to particle-type ice nucleation efficiency, in determining ice formation within the particle population.« less
Reviews and new metallogenic models of mineral deposits in South China: An introduction
NASA Astrophysics Data System (ADS)
Hu, Rui-Zhong; Chen, Wei Terry; Xu, De-Ru; Zhou, Mei-Fu
2017-04-01
In South China, the Yangtze and Cathaysia blocks were welded together along the Jiangnan Fold Belt during Neoproterozoic time (∼830 Ma). Large-scale mineralization in these two blocks occurred from Proterozoic to Cenozoic, making the region one of the most important polymetallic metallogenic provinces in the world. Of particular importance are world-class deposits of iron-oxide copper gold (IOCG), sediment-hosted Mn-P-Al-(Ni, Mo, PGE), syenite-carbonatite-related REE, felsic intrusion-related Sn-W-Mo-Cu-Fe-Pb-Zn, mafic intrusion-related V-Ti-Fe and Cu-Ni-PGE and low-temperature hydrothermal Pb, Zn, Au, and Sb (Fig. 1). In addition, the Ta-Nb, Hg, As, Tl and U deposits in South China are among the world largest of these kinds. Because of these deposits, South China has been a focus of researches for many years. Publications before 2005 were mostly restricted in Chinese. In the past decade, some case studies on some world-class deposits in South China are available in international journals. These recent studies have advanced our understanding of their mode of formation. However, some important issues regarding the timing, tectonic setting and mechanisms of metal concentration still remain poorly understood. This special issue brings together some of the latest information on these topics, including major review papers on specific types of mineralization and several papers dealing with some specific deposits in the region. We anticipate that this issue will generate more interests in the studies of mineral deposits in South China. In this introduction, we outline the tectonic framework and associated deposits.
Barrionuevo, Paula; Cassataro, Juliana; Delpino, M. Victoria; Zwerdling, Astrid; Pasquevich, Karina A.; Samartino, Clara García; Wallach, Jorge C.; Fossati, Carlos A.; Giambartolomei, Guillermo H.
2008-01-01
The strategies that allow Brucella abortus to survive inside macrophages for prolonged periods and to avoid the immunological surveillance of major histocompatibility complex class II (MHC-II)-restricted gamma interferon (IFN-γ)-producing CD4+ T lymphocytes are poorly understood. We report here that infection of THP-1 cells with B. abortus inhibited expression of MHC-II molecules and antigen (Ag) processing. Heat-killed B. abortus (HKBA) also induced both these phenomena, indicating the independence of bacterial viability and involvement of a structural component of the bacterium. Accordingly, outer membrane protein 19 (Omp19), a prototypical B. abortus lipoprotein, inhibited both MHC-II expression and Ag processing to the same extent as HKBA. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited MHC-II expression, indicating that any Brucella lipoprotein could down-modulate MHC-II expression and Ag processing. Inhibition of MHC-II expression and Ag processing by either HKBA or lipidated Omp19 (L-Omp19) depended on Toll-like receptor 2 and was mediated by interleukin-6. HKBA or L-Omp19 also inhibited MHC-II expression and Ag processing of human monocytes. In addition, exposure to the synthetic lipohexapeptide inhibited Ag-specific T-cell proliferation and IFN-γ production of peripheral blood mononuclear cells from Brucella-infected patients. Together, these results indicate that there is a mechanism by which B. abortus may prevent recognition by T cells to evade host immunity and establish a chronic infection. PMID:17984211
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sedighi, Sina; Kirk, Donald Walter; Singh, Chandra Veer, E-mail: chandraveer.singh@utoronto.ca
2015-09-21
Bulk metallic glasses are a relatively new class of amorphous metal alloy which possess unique mechanical and magnetic properties. The specific concentrations and combinations of alloy elements needed to prevent crystallization during melt quenching remains poorly understood. A correlation between atomic properties that can explain some of the previously identified glass forming ability (GFA) anomalies of the NiAl and CuZr systems has been identified, with these findings likely extensible to other transition metal–transition metal and transition metal–metalloid (TM–M) alloy classes as a whole. In this work, molecular dynamics simulation methods are utilized to study thermodynamic, kinetic, and structural properties ofmore » equiatomic CuZr and NiAl metallic glasses in an attempt to further understand the underlying connections between glass forming ability, nature of atomic level bonding, short and medium range ordering, and the evolution of structure and relaxation properties in the disordered phase. The anomalous breakdown of the fragility parameter as a useful GFA indicator in TM–M alloy systems is addressed through an in-depth investigation of bulk stiffness properties and the evolution of (pseudo)Gruneisen parameters over the quench domain, with the efficacy of other common glass forming ability indicators similarly being analyzed through direct computation in respective CuZr and NiAl systems. Comparison of fractional liquid-crystal density differences in the two systems revealed 2-3 times higher values for the NiAl system, providing further support for its efficacy as a general purpose GFA indicator.« less
USING MOLECULAR PROBES TO STUDY INTERFACIAL REDOX REACTION AT FE-BEARING SMECTITES
The interfacial electron transfer of clay-water systems has a wide range of significance in geochemical and biogeochernical environments. However the mechanism of interfacial electron transport is poorly understood. The electron transfer mechanism at the solid-water interfaces of...
Larval fish distribution in the St. Louis River estuary
Our objective was to determine what study design, environmental, and habitat variables contribute to the distribution and abundance of larval fish in the St. Louis River estuary. Larval fish habitat associations are poorly understood in Great Lakes coastal wetlands, yet critical ...
Post-traumatic unilateral plantar hyperhidrosis.
Eren, Y; Yavasoglu, N G; Comoglu, S S
2016-02-01
Localized unilateral hyperhidrosis is rare and poorly understood, sometimes stemming from trauma. Feet, quite vulnerable to trauma are affected by disease-mediated plantar hyperhidrosis, usually bilaterally. This report describes partial hyperhidrosis developing post-traumatically on the left plantar region of a 52-year-old male.
Predator-prey interaction reveals local effects of high-altitude insect migration
USDA-ARS?s Scientific Manuscript database
High-altitude nocturnal insect migrations represent significant pulses of resources, yet are difficult to study and poorly understood. Predator-prey interactions, specifically migratory moth consumption by high-flying bats, potentially reveal flows of migratory insects across a landscape. In North...
Assessing Effects of Pesticides on the Bee Immune System
Populations of some managed and wild pollinators are in decline as a result of multiple interacting factors including parasites, disease, poor nutrition and pesticides. The role that diminished immunity plays in these declines is not understood. The U.S. Environmental Protection ...
USDA-ARS?s Scientific Manuscript database
Colony development, which includes hyphal extension, branching, anastomosis and asexual sporulation are fundamental aspects of the lifecycle of filamentous fungi; genetic mechanisms underlying these phenomena are poorly understood. We conducted transcriptional profiling during colony development of...
USEPA RESEARCH ON FISH - HABITAT RELATIONSHIPS IN GREAT LAKES COASTAL MARSHES
Despite numerous studies documenting fish use of particular habitat elements, the role of habitat mosaics in supporting wetland fishes is poorly understood. USEPA's Mid-Continent Ecology Division has initiated research to identify relationships of fish and habitat in coastal mars...
A Cellular Game of Telephone: Trans Tissue Reprogramming of Responses to Toxic Stimuli
Exposure to air pollution is a leading cause of cardiopulmonary morbidity and mortality; however, while these effects outside the lung have been associated with aberrant oxidative stress and inflammation, the underlying molecular mechanisms are poorly understood. We hypothesized ...
Cellular Plasticity in the Diabetic Myocardium
2017-09-01
demonstrated that obese diabetic db/db mice in a C57Bl6J background exhibit cardiac remodeling, associated with modest ventricular dilation...HFpEF, the cellular basis for fibrotic remodeling of the ventricle is poorly understood. Metabolic diseases (such as obesity and diabetes) are
Reduce Confusion about Diffusion.
ERIC Educational Resources Information Center
Hebrank, Mary R.
1997-01-01
Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…
INTERNATIONAL CHILDHOOD CANCER COHORT CONSORTIUM (Journal Article)
Childhood cancers are rare conditions whose etiology is poorly understood. There is evidence that for some, the causal pathway may commence in utero or during peri-conception. One traditional epidemiologic approach to the study of rare diseases is the use of a retrospective cas...
A Multilevel Investigation of Neighborhood Effects on Parental Warmth
ERIC Educational Resources Information Center
Tendulkar, Shalini A.; Buka, Stephen; Dunn, Erin C.; Subramanian, S. V.; Koenen, Karestan C.
2010-01-01
Although researchers recognize that social contexts shape parenting behaviors, the relationship between neighborhood environment and parenting remains poorly understood. To address this gap, we investigated the associations between compositional and contextual (structural, social, and safety) characteristics of neighborhoods and parental warmth.…
Origins of Brain Tumor Macrophages.
De Palma, Michele
2016-12-12
The ontogeny of brain-tumor-associated macrophages is poorly understood. New findings indicate that both resident microglia and blood-derived monocytes generate the pool of macrophages that infiltrate brain tumors of either primary or metastatic origin. Copyright © 2016 Elsevier Inc. All rights reserved.
Pollinator guilds respond differently to urban habitat fragmentation in a oak-savannah ecosystem
USDA-ARS?s Scientific Manuscript database
Habitat fragmentation is widely thought to threaten biodiversity. However, response of pollinators to habitat fragmentation is still poorly understood, as pollinator communities are notoriously spatially variable. We investigated pollinator community structure in a highly fragmented oak-savannah ec...
Wetland creation, enhancement, and restoration activities are commonly implemented to compensate for wetland loss or degradation. However, functional equivalence in restored and created wetland habitats is often poorly understood. In estuarine habitats, changes in habitat qualit...
Ozone-Induced Metabolic Impairment is Attenuated in Adrenalectomized Wistar Kyoto Rats
Rationale: Air pollutants have been linked to increased incidence of metabolic syndrome however the mechanisms are poorly understood. We have recently shown that ozone exposure induces significant hyperglycemia together with elevated serum leptin and epinephrine in the Wistar Ky...
THE INTERACTION OF VAPOUR PHASE ORGANIC COMPOUNDS WITH INDOOR SINKS
The interaction of indoor air pollutants with interior surfaces (i.e., sinks) is a well known, but poorly understood, phenomenon. Studies have shown that re-emissions of adsorbed organic vapours can contribute to elevated concentrations of organics in indoor environments. Researc...
Preschool Executive Functioning Abilities Predict Early Mathematics Achievement
ERIC Educational Resources Information Center
Clark, Caron A. C.; Pritchard, Verena E.; Woodward, Lianne J.
2010-01-01
Impairments in executive function have been documented in school-age children with mathematical learning difficulties. However, the utility and specificity of preschool executive function abilities in predicting later mathematical achievement are poorly understood. This study examined linkages between children's developing executive function…
HYDRAULIC REDISTRIBUTION IN THE PACIFIC NORTHWEST: TWEAKING THE SYSTEM
Hydraulic redistribution (HR) has recently been documented in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the soil-root system to tease apart ...
REVIEW OF QUANTITATIVE STANDARDS AND GUIDELINES FOR FUNGI IN INDOOR AIR
Exposure to fungal aerosols clearly causes human disease. However, methods for assessing exposure remain poorly understood, and guidelines for interpreting data are often contradictory. The purposes of this paper are to review and compare existing guidelines for indoor airborne...
NASA Astrophysics Data System (ADS)
Tu, Shiqi; Yuan, Guo-Cheng; Shao, Zhen
2017-01-01
Recently, long non-coding RNAs (lncRNAs) have emerged as an important class of molecules involved in many cellular processes. One of their primary functions is to shape epigenetic landscape through interactions with chromatin modifying proteins. However, mechanisms contributing to the specificity of such interactions remain poorly understood. Here we took the human and mouse lncRNAs that were experimentally determined to have physical interactions with Polycomb repressive complex 2 (PRC2), and systematically investigated the sequence features of these lncRNAs by developing a new computational pipeline for sequences composition analysis, in which each sequence is considered as a series of transitions between adjacent nucleotides. Through that, PRC2-binding lncRNAs were found to be associated with a set of distinctive and evolutionarily conserved sequence features, which can be utilized to distinguish them from the others with considerable accuracy. We further identified fragments of PRC2-binding lncRNAs that are enriched with these sequence features, and found they show strong PRC2-binding signals and are more highly conserved across species than the other parts, implying their functional importance.
Spellmon, Nicholas; Sun, Xiaonan; Sirinupong, Nualpun; Edwards, Brian; Li, Chunying; Yang, Zhe
2015-01-01
SMYD proteins are an exciting field of study as they are linked to many types of cancer-related pathways. Cardiac and skeletal muscle development and function also depend on SMYD proteins opening a possible avenue for cardiac-related treatment. Previous crystal structure studies have revealed that this special class of protein lysine methyltransferases have a bilobal structure, and an open-closed motion may regulate substrate specificity. Here we use the molecular dynamics simulation to investigate the still-poorly-understood SMYD2 dynamics. Cross-correlation analysis reveals that SMYD2 exhibits a negative correlated inter-lobe motion. Principle component analysis suggests that this correlated dynamic is contributed to by a twisting motion of the C-lobe with respect to the N-lobe and a clamshell-like motion between the lobes. Dynamical network analysis defines possible allosteric paths for the correlated dynamics. There are nine communities in the dynamical network with six in the N-lobe and three in the C-lobe, and the communication between the lobes is mediated by a lobe-bridging β hairpin. This study provides insight into the dynamical nature of SMYD2 and could facilitate better understanding of SMYD2 substrate specificity.
Role of selenium-containing proteins in T cell and macrophage function
Carlson, Bradley A.; Yoo, Min-Hyuk; Shrimali, Rajeev K.; Irons, Robert; Gladyshev, Vadim N.; Hatfield, Dolph L.; Park, Jin Mo
2011-01-01
Synopsis Selenium has been known for many years to have a role in boosting immune function, but the manner in which this element acts at the molecular level in host defense and inflammatory diseases is poorly understood. To elucidate the role of selenium-containing proteins in immune function, we knocked out the expression of this protein class in T cells or macrophages of mice by targeting the removal of the selenocysteine tRNA gene using loxP-Cre technology. Mice with selenoprotein-less T cells manifested reduced pools of mature and functional T cells in lymphoid tissues and an impairment in T cell-dependent antibody responses. Furthermore, selenoprotein deficiency in T cells led to an inability of these cells to suppress reactive oxygen species (ROS) production, which in turn affected their ability to proliferate in response to T cell receptor stimulation. Selenoprotein-less macrophages, on the other hand, manifested mostly normal inflammatory responses, but this deficiency resulted in an altered regulation in extracellular matrix-related gene expression and a diminished migration of macrophages in a protein gel matrix. These observations provided novel insights into the role of selenoproteins in immune function and tissue homeostasis. PMID:20576203
First evidences of interaction between pyranoanthocyanins and salivary proline-rich proteins.
García-Estévez, Ignacio; Cruz, Luís; Oliveira, Joana; Mateus, Nuno; de Freitas, Victor; Soares, Susana
2017-08-01
The contribution of other classes of polyphenol compounds besides tannins to the overall perception of astringency is still poorly understood. So, this work aimed to study the interaction between a family of salivary proline-rich proteins (aPRPs) and representative pyranoanthocyanins in red wines [pyranomalvidin-3-glucoside (vitisin B), pyranomalvidin-3-glucoside-catechol, and pyranomalvidin-3-glucoside-epicatechin] using saturation transfer difference-NMR and MALDI-TOF. For vitisin B K D was of 1.74mM; for pyranomalvidin-3-glucoside-catechol was 1.17mM and for pyranomalvidin-3-glucoside-epicatechin it was 0.87mM. The presence of the flavanol structural unit in the pyranoanthocyanins led to an increase in their interaction with aPRPs. Further, it is also interesting that the values obtained were in the range of K D obtained previously reported for the interaction between the human saliva proline-rich peptides (IB7 14 and IB9 37 ) and procyanidins. Overall, the results obtained suggest that, along with tannins, other polyphenols present in red wine, namely pyranoanthocyanins, could actively contribute to red wine global astringency. Copyright © 2017 Elsevier Ltd. All rights reserved.
Involvement of the Calcium-sensing Receptor in Human Taste Perception
Ohsu, Takeaki; Amino, Yusuke; Nagasaki, Hiroaki; Yamanaka, Tomohiko; Takeshita, Sen; Hatanaka, Toshihiro; Maruyama, Yutaka; Miyamura, Naohiro; Eto, Yuzuru
2010-01-01
By human sensory analyses, we found that various extracellular calcium-sensing receptor (CaSR) agonists enhance sweet, salty, and umami tastes, although they have no taste themselves. These characteristics are known as “kokumi taste” and often appear in traditional Japanese cuisine. Although GSH is a typical kokumi taste substance (taste enhancer), its mode of action is poorly understood. Here, we demonstrate how the kokumi taste is enhanced by the CaSR, a close relative of the class C G-protein-coupled receptors T1R1, T1R2, and T1R3 (sweet and umami receptors). We identified a large number of CaSR agonist γ-glutamyl peptides, including GSH (γ-Glu-Cys-Gly) and γ-Glu-Val-Gly, and showed that these peptides elicit the kokumi taste. Further analyses revealed that some known CaSR agonists such as Ca2+, protamine, polylysine, l-histidine, and cinacalcet (a calcium-mimetic drug) also elicit the kokumi taste and that the CaSR-specific antagonist, NPS-2143, significantly suppresses the kokumi taste. This is the first report indicating a distinct function of the CaSR in human taste perception. PMID:19892707
Gidda, Satinder K; Watt, Samantha C; Collins-Silva, Jillian; Kilaru, Aruna; Arondel, Vincent; Yurchenko, Olga; Horn, Patrick J; James, Christopher N; Shintani, David; Ohlrogge, John B; Chapman, Kent D; Mullen, Robert T; Dyer, John M
2013-01-01
While lipid droplets have traditionally been considered as inert sites for the storage of triacylglycerols and sterol esters, they are now recognized as dynamic and functionally diverse organelles involved in energy homeostasis, lipid signaling, and stress responses. Unlike most other organelles, lipid droplets are delineated by a half-unit membrane whose protein constituents are poorly understood, except in the specialized case of oleosins, which are associated with seed lipid droplets. Recently, we identified a new class of lipid-droplet associated proteins called LDAPs that localize specifically to the lipid droplet surface within plant cells and share extensive sequence similarity with the small rubber particle proteins (SRPPs) found in rubber-accumulating plants. Here, we provide additional evidence for a role of LDAPs in lipid accumulation in oil-rich fruit tissues, and further explore the functional relationships between LDAPs and SRPPs. In addition, we propose that the larger LDAP/SRPP protein family plays important roles in the compartmentalization of lipophilic compounds, including triacylglycerols and polyisoprenoids, into lipid droplets within plant cells. Potential roles in lipid droplet biogenesis and function of these proteins also are discussed. PMID:24305619
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sathiyamoorthy, Karthik; Hu, Yao Xiong; Möhl, Britta S.
Herpesvirus entry into host cells is mediated by multiple virally encoded receptor binding and membrane fusion glycoproteins. Despite their importance in host cell tropism and associated disease pathology, the underlying and essential interactions between these viral glycoproteins remain poorly understood. For Epstein–Barr virus (EBV), gHgL/gp42 complexes bind HLA class II to activate membrane fusion with B cells, but gp42 inhibits fusion and entry into epithelial cells. To clarify the mechanism by which gp42 controls the cell specificity of EBV infection, in this paper we determined the structure of gHgL/gp42 complex bound to an anti-gHgL antibody (E1D1). The critical regulator ofmore » EBV tropism is the gp42 N-terminal domain, which tethers the HLA-binding domain to gHgL by wrapping around the exterior of three gH domains. Both the gp42 N-terminal domain and E1D1 selectively inhibit epithelial-cell fusion; however, they engage distinct surfaces of gHgL. Finally, these observations clarify key determinants of EBV host cell tropism.« less
Taxonomic bias in biodiversity data and societal preferences.
Troudet, Julien; Grandcolas, Philippe; Blin, Amandine; Vignes-Lebbe, Régine; Legendre, Frédéric
2017-08-22
Studying and protecting each and every living species on Earth is a major challenge of the 21 st century. Yet, most species remain unknown or unstudied, while others attract most of the public, scientific and government attention. Although known to be detrimental, this taxonomic bias continues to be pervasive in the scientific literature, but is still poorly studied and understood. Here, we used 626 million occurrences from the Global Biodiversity Information Facility (GBIF), the biggest biodiversity data portal, to characterize the taxonomic bias in biodiversity data. We also investigated how societal preferences and taxonomic research relate to biodiversity data gathering. For each species belonging to 24 taxonomic classes, we used the number of publications from Web of Science and the number of web pages from Bing searches to approximate research activity and societal preferences. Our results show that societal preferences, rather than research activity, strongly correlate with taxonomic bias, which lead us to assert that scientists should advertise less charismatic species and develop societal initiatives (e.g. citizen science) that specifically target neglected organisms. Ensuring that biodiversity is representatively sampled while this is still possible is an urgent prerequisite for achieving efficient conservation plans and a global understanding of our surrounding environment.
Shu, G; Tang, Y; Zhou, Y; Wang, C; Song, J-G
2011-12-01
Histone deacetylase (HDAC) inhibitors are a class of promising anticancer reagents. They are able to induce apoptosis in embryonic carcinoma (EC) cells. However, the underlying mechanism remains poorly understood. Here we show that increased expression of zinc-finger protein regulator of apoptosis and cell-cycle arrest (Zac1) is implicated in HDAC inhibitor-induced apoptosis in F9 and P19 EC cells. By chromatin immunoprecipitation analysis we identified that increased Zac1 expression is mediated by histone acetylation of the Zac1 promoter region. Knockdown of Zac1 inhibited HDAC inhibitor-induced cell apoptosis. Moreover, HDAC inhibitors repressed nuclear factor-κB (NF-κB) activity, and this effect is abrogated by Zac1 knockdown. Consistently, Zac1 overexpression suppressed cellular NF-κB activity. Further investigation showed that Zac1 inhibits NF-κB activity by interacting with the C-terminus of the p65 subunit, which suppresses the phosphorylation of p65 at Ser468 and Ser536 residues. These results indicate that Zac1 is a histone acetylation-regulated suppressor of NF-κB, which is induced and implicated in HDAC inhibitor-mediated EC cell apoptosis.
Hur, Junho K.; Luo, Yicheng; Moon, Sungjin; Ninova, Maria; Marinov, Georgi K.; Chung, Yun D.; Aravin, Alexei A.
2016-01-01
The conserved THO/TREX (transcription/export) complex is critical for pre-mRNA processing and mRNA nuclear export. In metazoa, TREX is loaded on nascent RNA transcribed by RNA polymerase II in a splicing-dependent fashion; however, how TREX functions is poorly understood. Here we show that Thoc5 and other TREX components are essential for the biogenesis of piRNA, a distinct class of small noncoding RNAs that control expression of transposable elements (TEs) in the Drosophila germline. Mutations in TREX lead to defects in piRNA biogenesis, resulting in derepression of multiple TE families, gametogenesis defects, and sterility. TREX components are enriched on piRNA precursors transcribed from dual-strand piRNA clusters and colocalize in distinct nuclear foci that overlap with sites of piRNA transcription. The localization of TREX in nuclear foci and its loading on piRNA precursor transcripts depend on Cutoff, a protein associated with chromatin of piRNA clusters. Finally, we show that TREX is required for accumulation of nascent piRNA precursors. Our study reveals a novel splicing-independent mechanism for TREX loading on nascent RNA and its importance in piRNA biogenesis. PMID:27036967
Sathiyamoorthy, Karthik; Hu, Yao Xiong; Möhl, Britta S.; ...
2016-12-08
Herpesvirus entry into host cells is mediated by multiple virally encoded receptor binding and membrane fusion glycoproteins. Despite their importance in host cell tropism and associated disease pathology, the underlying and essential interactions between these viral glycoproteins remain poorly understood. For Epstein–Barr virus (EBV), gHgL/gp42 complexes bind HLA class II to activate membrane fusion with B cells, but gp42 inhibits fusion and entry into epithelial cells. To clarify the mechanism by which gp42 controls the cell specificity of EBV infection, in this paper we determined the structure of gHgL/gp42 complex bound to an anti-gHgL antibody (E1D1). The critical regulator ofmore » EBV tropism is the gp42 N-terminal domain, which tethers the HLA-binding domain to gHgL by wrapping around the exterior of three gH domains. Both the gp42 N-terminal domain and E1D1 selectively inhibit epithelial-cell fusion; however, they engage distinct surfaces of gHgL. Finally, these observations clarify key determinants of EBV host cell tropism.« less
The genomic landscape of acute lymphoblastic leukemia in children and young adults.
Mullighan, Charles G
2014-12-05
Our understanding of the genetic basis of childhood acute lymphoblastic leukemia (ALL) has been greatly advanced by genomic profiling and sequencing studies. These efforts have characterized the genetic basis of recently described and poorly understood subtypes of ALL, including early T-cell precursor ALL, Philadelphia chromosome-like (Ph-like) ALL, and ALL with intrachromosomal amplification of chromosome 21, and have identified several rational therapeutic targets in high-risk ALL, notably ABL1-class and JAK-STAT inhibitors in Ph-like ALL. Deep sequencing studies are also refining our understanding of the genetic basis of clonal heterogeneity and relapse. These studies have elucidated the nature of clonal evolution during disease progression and identified genetic changes that confer resistance to specific therapeutic agents, including CREBBP and NT5C2. Genomic profiling has also identified common and rare inherited genetic variants that influence the risk of developing leukemia. These efforts are now being extended to ALL in adolescents and adults with the goal of fully defining the genetic landscape of ALL to further improve treatment outcomes in high-risk populations. © 2014 by The American Society of Hematology. All rights reserved.
Inositol phosphates in the environment.
Turner, Benjamin L; Papházy, Michael J; Haygarth, Philip M; McKelvie, Ian D
2002-01-01
The inositol phosphates are a group of organic phosphorus compounds found widely in the natural environment, but that represent the greatest gap in our understanding of the global phosphorus cycle. They exist as inositols in various states of phosphorylation (bound to between one and six phosphate groups) and isomeric forms (e.g. myo, D-chiro, scyllo, neo), although myo-inositol hexakisphosphate is by far the most prevalent form in nature. In terrestrial environments, inositol phosphates are principally derived from plants and accumulate in soils to become the dominant class of organic phosphorus compounds. Inositol phosphates are also present in large amounts in aquatic environments, where they may contribute to eutrophication. Despite the prevalence of inositol phosphates in the environment, their cycling, mobility and bioavailability are poorly understood. This is largely related to analytical difficulties associated with the extraction, separation and detection of inositol phosphates in environmental samples. This review summarizes the current knowledge of inositol phosphates in the environment and the analytical techniques currently available for their detection in environmental samples. Recent advances in technology, such as the development of suitable chromatographic and capillary electrophoresis separation techniques, should help to elucidate some of the more pertinent questions regarding inositol phosphates in the natural environment. PMID:12028785
Real-Time Observation of Human LINE-1 Retrotransposon Activity in Bacteria
NASA Astrophysics Data System (ADS)
Kaur, Davneet; Kuhlman, Thomas; Kuhlman Team; Nigel Goldenfeld Collaboration
Transposable elements (TEs) are fundamental building blocks of all genomes. Retrotransposable elements (RTEs) are one of the two primary classes of TEs that are ubiquitous in eukaryotes. They propagate through a copy-and-paste mechanism utilizing reverse-transcribed mRNA intermediates. This leads to disruption and dispersal of coding and control elements throughout the genome, and consequently TEs are thought to be a major driving force behind diversification. However, RTEs are absent in most prokaryotes including E. coli. and the reason for this remains an open question. Despite their prevalence, there still remain many unanswered questions about how `hot' or active L1 RTEs (L1Hs) function. In particular, their rates of activity and their effects upon their host are currently poorly understood and only roughly estimated within the limitations of available technology. To address these unanswered questions, we have constructed and released an L1H element in E. coli to quantify its rates of activity and physiological effects on its host. To overcome the technical limitations, we've designed fluorescent visualization and quantification techniques that make real time high resolution observations of retrotransposition events as they occur in living cells.
Allosteric regulation of rhomboid intramembrane proteolysis.
Arutyunova, Elena; Panwar, Pankaj; Skiba, Pauline M; Gale, Nicola; Mak, Michelle W; Lemieux, M Joanne
2014-09-01
Proteolysis within the lipid bilayer is poorly understood, in particular the regulation of substrate cleavage. Rhomboids are a family of ubiquitous intramembrane serine proteases that harbour a buried active site and are known to cleave transmembrane substrates with broad specificity. In vitro gel and Förster resonance energy transfer (FRET)-based kinetic assays were developed to analyse cleavage of the transmembrane substrate psTatA (TatA from Providencia stuartii). We demonstrate significant differences in catalytic efficiency (kcat/K0.5) values for transmembrane substrate psTatA (TatA from Providencia stuartii) cleavage for three rhomboids: AarA from P. stuartii, ecGlpG from Escherichia coli and hiGlpG from Haemophilus influenzae demonstrating that rhomboids specifically recognize this substrate. Furthermore, binding of psTatA occurs with positive cooperativity. Competitive binding studies reveal an exosite-mediated mode of substrate binding, indicating allostery plays a role in substrate catalysis. We reveal that exosite formation is dependent on the oligomeric state of rhomboids, and when dimers are dissociated, allosteric substrate activation is not observed. We present a novel mechanism for specific substrate cleavage involving several dynamic processes including positive cooperativity and homotropic allostery for this interesting class of intramembrane proteases. © 2014 The Authors.
Allosteric regulation of rhomboid intramembrane proteolysis
Arutyunova, Elena; Panwar, Pankaj; Skiba, Pauline M; Gale, Nicola; Mak, Michelle W; Lemieux, M Joanne
2014-01-01
Proteolysis within the lipid bilayer is poorly understood, in particular the regulation of substrate cleavage. Rhomboids are a family of ubiquitous intramembrane serine proteases that harbour a buried active site and are known to cleave transmembrane substrates with broad specificity. In vitro gel and Förster resonance energy transfer (FRET)-based kinetic assays were developed to analyse cleavage of the transmembrane substrate psTatA (TatA from Providencia stuartii). We demonstrate significant differences in catalytic efficiency (kcat/K0.5) values for transmembrane substrate psTatA (TatA from Providencia stuartii) cleavage for three rhomboids: AarA from P. stuartii, ecGlpG from Escherichia coli and hiGlpG from Haemophilus influenzae demonstrating that rhomboids specifically recognize this substrate. Furthermore, binding of psTatA occurs with positive cooperativity. Competitive binding studies reveal an exosite-mediated mode of substrate binding, indicating allostery plays a role in substrate catalysis. We reveal that exosite formation is dependent on the oligomeric state of rhomboids, and when dimers are dissociated, allosteric substrate activation is not observed. We present a novel mechanism for specific substrate cleavage involving several dynamic processes including positive cooperativity and homotropic allostery for this interesting class of intramembrane proteases. PMID:25009246
NASA Technical Reports Server (NTRS)
Cucinotta, Francis; Badhwar, Gautam; Saganti, Premkumar; Schimmerling, Walter; Wilson, John; Peterson, Leif; Dicello, John
2002-01-01
In this paper we discuss expected lifetime excess cancer risks for astronauts returning from exploration class missions. For the first time we make a quantitative assessment of uncertainties in cancer risk projections for space radiation exposures. Late effects from the high charge and energy (HZE) ions present in the galactic cosmic rays including cancer and the poorly understood risks to the central nervous system constitute the major risks. Methods used to project risk in low Earth orbit are seen as highly uncertain for projecting risks on exploration missions because of the limited radiobiology data available for estimating HZE ion risks. Cancer risk projections are described as a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Monte-Carlo sampling from subjective error distributions represents the lack of knowledge in each factor to quantify risk projection overall uncertainty. Cancer risk analysis is applied to several exploration mission scenarios. At solar minimum, the number of days in space where career risk of less than the limiting 3% excess cancer mortality can be assured at a 95% confidence level is found to be only of the order of 100 days.
Huang, Yunlong; Li, Yuju; Zhang, Hainan; Zhao, Runze; Jing, Ran; Xu, Yinghua; He, Miao; Peer, Justin; Kim, Yeong C; Luo, Jiangtao; Tong, Zenghan; Zheng, Jialin
2018-01-01
Zika virus (ZIKV) is a neurotrophic flavivirus that is capable of infecting humans, leading to brain abnormalities during fetal development. The ZIKV infectivity in neural target cells remains poorly understood. Here, we found that ZIKV specifically infected glial fibrillary acidic protein- and S100B-positive primary human astrocytes derived from fetal brains. In contrast, neuron-specific Class III β-tubulin (TuJ1)-positive neurons in the astrocyte cultures and SOX2-positive neural progenitor cells derived from the fetal brains were less susceptible to ZIKV infection compared with astrocytes. The infected astrocytes released competent viral particles and manifested programmed cell death with a progressive cytopathic effect. Interestingly, ZIKV infection in human fetal astrocytes induced a significant increase of extracellular vesicles (EVs). Treatment with GW4869, a specific inhibitor of neutral sphingomyelinase-2, decreased EV levels, suppressed ZIKV propagation, and reduced the release of infectious virions in astrocytes. Therefore, ZIKV infects primary human fetal astrocytes and the infection can be suppressed by neutral sphingomyelinase-2 inhibitor GW4869. Further investigation into sphingomyelin metabolism and EVs may provide insights to the therapeutic treatment of ZIKV infection.
Classification of communication signals of the little brown bat
NASA Astrophysics Data System (ADS)
Melendez, Karla V.; Jones, Douglas L.; Feng, Albert S.
2005-09-01
Little brown bats, Myotis lucifugus, are known for their ability to echolocate and utilize their echolocation system to navigate, locate, and identify prey. Their echolocation signals have been characterized in detail, but their communication signals are poorly understood despite their widespread use during the social interactions. The goal of this study was to characterize the communication signals of little brown bats. Sound recordings were made overnight on five individual bats (housed separately from a large group of captive bats) for 7 nights, using a Pettersson ultrasound detector D240x bat detector and Nagra ARES-BB digital recorder. The spectral and temporal characteristics of recorded sounds were first analyzed using BATSOUND software from Pettersson. Sounds were first classified by visual observation of calls' temporal pattern and spectral composition, and later using an automatic classification scheme based on multivariate statistical parameters in MATLAB. Human- and machine-based analysis revealed five discrete classes of bat's communication signals: downward frequency-modulated calls, constant frequency calls, broadband noise bursts, broadband chirps, and broadband click trains. Future studies will focus on analysis of calls' spectrotemporal modulations to discriminate any subclasses that may exist. [Research supported by Grant R01-DC-04998 from the National Institute for Deafness and Communication Disorders.
Scleroderma Related Lung Disease: Is There a Pathogenic Role for Adipokines?
Haley, Shannon; Shah, Dilip; Romero, Freddy; Summer, Ross
2013-01-01
Scleroderma is a systemic autoimmune disease of unknown etiology whose hallmark features include endothelial cell dysfunction, fibroblast proliferation and immune dysregulation. Although virtually any organ can be pathologically involved in scleroderma, lung complications including interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are the leading cause of death in patients with this condition. Currently, the molecular mechanisms leading to development of scleroderma-related lung disease are poorly understood; however, the systemic nature of this condition has led many to implicate circulating factors in the pathogenesis of some of its organ impairment. In this article, we focus on a new class of circulating factors derived from adipose-tissue called adipokines, which are known to be altered in scleroderma. Recently, the adipokines adiponectin and leptin have been found to regulate biological activities in endothelial, fibroblast and immune cell types in lung and in many other tissues. The pleiotropic nature of these circulating factors and their functional activity on many cell types implicated in the pathogenesis of ILD and PAH suggest these hormones may play a mechanistic role in the onset and/or progression of scleroderma-related lung diseases. PMID:24173692
Heino, Jani; Grönroos, Mira
2014-01-01
The regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small-grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position (NP), but it showed a weaker relationship with niche breadth (NB). Abundance was at best weakly related to these explanatory niche-based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites. PMID:24963387
NASA Astrophysics Data System (ADS)
Choi, D. H.; Noh, J. H.; Selph, K. E.; Lee, C. M.
2016-02-01
Photosynthetic picoeukaryotes (PPEs) are major oceanic primary producers. However, the diversity of such communities remains poorly understood, especially in the northwestern (NW) Pacific. We investigated the abundance and diversity of PPEs, and recorded environmental variables, along a transect from the coast to the open Pacific Ocean. High-throughput tag sequencing (using the MiSeq system) revealed the diversity of plastid 16S rRNA genes. The dominant PPEs changed at the class level along the transect. Prymnesiophyceae were the only dominant PPEs in the warm pool of the NW Pacific, but Mamiellophyceae dominated in coastal waters of the East China Sea. Phylogenetically, most Prymnesiophyceae sequences could not be resolved at lower taxonomic levels because no close relatives have been cultured. Within the Mamiellophyceae, the genera Micromonas and Ostreococcus dominated in marginal coastal areas affected by open water, whereas Bathycoccus dominated in the lower euphotic depths of open oligotrophic waters. Cryptophyceae and Phaeocystis (of the Prymnesiophyceae) dominated in areas affected principally by coastal water. We also defined the biogeographical distributions of Chrysophyceae, Prasinophyceae, Bacillariophyceaea, and Pelagophyceae. These distributions were influenced by temperature, salinity, and chlorophyll a and nutrient concentrations.
Size of age-0 crappies (Pomoxis spp.) relative to reservoir habitats and water levels
Kaczka, Levi J.; Miranda, Leandro E.
2014-01-01
Variable year-class strength is common in crappie Pomoxis spp. populations in many reservoirs, yet the mechanisms behind this variability are poorly understood. Size-dependent mortality of age-0 fishes has long been recognized in the population ecology literature; however, investigations about the effects of environmental factors on age-0 crappie size are lacking. The objective of this study was to determine if differences existed in total length of age-0 crappies between embayment and floodplain habitats in reservoirs, while accounting for potential confounding effects of water level and crappie species. To this end, we examined size of age-0 crappies in four flood-control reservoirs in northwest Mississippi over 4years. Age-0 crappies inhabiting uplake floodplain habitats grew to a larger size than fish in downlake embayments, but this trend depended on species, length of time a reservoir was dewatered in the months preceding spawning, and reservoir water level in the months following spawning. The results from our study indicate that water-level management may focus not only on allowing access to quality nursery habitat, but that alternating water levels on a multiyear schedule could increase the quality of degraded littoral habitats.
Murine craniofacial development requires Hdac3-mediated repression of Msx gene expression.
Singh, Nikhil; Gupta, Mudit; Trivedi, Chinmay M; Singh, Manvendra K; Li, Li; Epstein, Jonathan A
2013-05-15
Craniofacial development is characterized by reciprocal interactions between neural crest cells and neighboring cell populations of ectodermal, endodermal and mesodermal origin. Various genetic pathways play critical roles in coordinating the development of cranial structures by modulating the growth, survival and differentiation of neural crest cells. However, the regulation of these pathways, particularly at the epigenomic level, remains poorly understood. Using murine genetics, we show that neural crest cells exhibit a requirement for the class I histone deacetylase Hdac3 during craniofacial development. Mice in which Hdac3 has been conditionally deleted in neural crest demonstrate fully penetrant craniofacial abnormalities, including microcephaly, cleft secondary palate and dental hypoplasia. Consistent with these abnormalities, we observe dysregulation of cell cycle genes and increased apoptosis in neural crest structures in mutant embryos. Known regulators of cell cycle progression and apoptosis in neural crest, including Msx1, Msx2 and Bmp4, are upregulated in Hdac3-deficient cranial mesenchyme. These results suggest that Hdac3 serves as a critical regulator of craniofacial morphogenesis, in part by repressing core apoptotic pathways in cranial neural crest cells. Copyright © 2013 Elsevier Inc. All rights reserved.
Temperature-driven regime shifts in the dynamics of size-structured populations.
Ohlberger, Jan; Edeline, Eric; Vøllestad, Leif Asbjørn; Stenseth, Nils C; Claessen, David
2011-02-01
Global warming impacts virtually all biota and ecosystems. Many of these impacts are mediated through direct effects of temperature on individual vital rates. Yet how this translates from the individual to the population level is still poorly understood, hampering the assessment of global warming impacts on population structure and dynamics. Here, we study the effects of temperature on intraspecific competition and cannibalism and the population dynamical consequences in a size-structured fish population. We use a physiologically structured consumer-resource model in which we explicitly model the temperature dependencies of the consumer vital rates and the resource population growth rate. Our model predicts that increased temperature decreases resource density despite higher resource growth rates, reflecting stronger intraspecific competition among consumers. At a critical temperature, the consumer population dynamics destabilize and shift from a stable equilibrium to competition-driven generation cycles that are dominated by recruits. As a consequence, maximum age decreases and the proportion of younger and smaller-sized fish increases. These model predictions support the hypothesis of decreasing mean body sizes due to increased temperatures. We conclude that in size-structured fish populations, global warming may increase competition, favor smaller size classes, and induce regime shifts that destabilize population and community dynamics.
Purohit, Sharad; Sharma, Ashok; She, Jin-Xiong
2015-01-01
Complex interactions between a series of environmental factors and genes result in progression to clinical type 1 diabetes in genetically susceptible individuals. Despite several decades of research in the area, these interactions remain poorly understood. Several studies have yielded associations of certain foods, infections, and immunizations with the onset and progression of diabetes autoimmunity, but most findings are still inconclusive. Environmental triggers are difficult to identify mainly due to (i) large number and complex nature of environmental exposures, including bacteria, viruses, dietary factors, and environmental pollutants, (ii) reliance on low throughput technology, (iii) less efforts in quantifying host response, (iv) long silent period between the exposure and clinical onset of T1D which may lead to loss of the exposure fingerprints, and (v) limited sample sets. Recent development in multiplex technologies has enabled systematic evaluation of different classes of molecules or macroparticles in a high throughput manner. However, the use of multiplex assays in type 1 diabetes research is limited to cytokine assays. In this review, we will discuss the potential use of multiplex high throughput technologies in identification of environmental triggers and host response in type 1 diabetes.
CUP-1 Is a Novel Protein Involved in Dietary Cholesterol Uptake in Caenorhabditis elegans
Valdes, Victor J.; Athie, Alejandro; Salinas, Laura S.; Navarro, Rosa E.; Vaca, Luis
2012-01-01
Sterols transport and distribution are essential processes in all multicellular organisms. Survival of the nematode Caenorhabditis elegans depends on dietary absorption of sterols present in the environment. However the general mechanisms associated to sterol uptake in nematodes are poorly understood. In the present work we provide evidence showing that a previously uncharacterized transmembrane protein, designated Cholesterol Uptake Protein-1 (CUP-1), is involved in dietary cholesterol uptake in C. elegans. Animals lacking CUP-1 showed hypersensitivity to cholesterol limitation and were unable to uptake cholesterol. A CUP-1-GFP fusion protein colocalized with cholesterol-rich vesicles, endosomes and lysosomes as well as the plasma membrane. Additionally, by FRET imaging, a direct interaction was found between the cholesterol analog DHE and the transmembrane “cholesterol recognition/interaction amino acid consensus” (CRAC) motif present in C. elegans CUP-1. In-silico analysis identified two mammalian homologues of CUP-1. Most interestingly, CRAC motifs are conserved in mammalian CUP-1 homologous. Our results suggest a role of CUP-1 in cholesterol uptake in C. elegans and open up the possibility for the existence of a new class of proteins involved in sterol absorption in mammals. PMID:22479487
MicroRNA-27a promotes myoblast proliferation by targeting myostatin
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Zhiqing; Chen, Xiaoling; Yu, Bing
2012-06-29
Highlights: Black-Right-Pointing-Pointer We identified a myogenic role for miR-27a and a new target, myostatin. Black-Right-Pointing-Pointer The miR-27a was confirmed to target myostatin 3 Prime UTR. Black-Right-Pointing-Pointer miR-27a is upregulated and myostatin is downregulated during myoblast proliferation. Black-Right-Pointing-Pointer miR-27a promotes myoblast proliferation by reducing the expression of myostatin. -- Abstract: MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs that play critical roles in skeletal muscle development as well as in regulation of muscle cell proliferation and differentiation. However, the role of miRNAs in myoblast proliferation remains poorly understood. Here we found that the expression of miR-27a was increased during proliferationmore » of C2C12 myoblasts. Moreover, overexpression of miR-27a in C2C12 cells promoted myoblast proliferation by reducing the expression of myostatin, a critical inhibitor of skeletal myogenesis. In addition, the miR-27a was confirmed to target myostatin 3 Prime UTR by a luciferase reporter analysis. Together, these results suggest that miR-27a promotes myoblast proliferation through targeting myostatin.« less
Mapping the exciton diffusion in semiconductor nanocrystal solids.
Kholmicheva, Natalia; Moroz, Pavel; Bastola, Ebin; Razgoniaeva, Natalia; Bocanegra, Jesus; Shaughnessy, Martin; Porach, Zack; Khon, Dmitriy; Zamkov, Mikhail
2015-03-24
Colloidal nanocrystal solids represent an emerging class of functional materials that hold strong promise for device applications. The macroscopic properties of these disordered assemblies are determined by complex trajectories of exciton diffusion processes, which are still poorly understood. Owing to the lack of theoretical insight, experimental strategies for probing the exciton dynamics in quantum dot solids are in great demand. Here, we develop an experimental technique for mapping the motion of excitons in semiconductor nanocrystal films with a subdiffraction spatial sensitivity and a picosecond temporal resolution. This was accomplished by doping PbS nanocrystal solids with metal nanoparticles that force the exciton dissociation at known distances from their birth. The optical signature of the exciton motion was then inferred from the changes in the emission lifetime, which was mapped to the location of exciton quenching sites. By correlating the metal-metal interparticle distance in the film with corresponding changes in the emission lifetime, we could obtain important transport characteristics, including the exciton diffusion length, the number of predissociation hops, the rate of interparticle energy transfer, and the exciton diffusivity. The benefits of this approach to device applications were demonstrated through the use of two representative film morphologies featuring weak and strong interparticle coupling.
Variability of the symbiotic X-ray binary GX 1+4. Enhanced activity near periastron passage
NASA Astrophysics Data System (ADS)
Iłkiewicz, Krystian; Mikołajewska, Joanna; Monard, Berto
2017-05-01
Context. GX 1+4 belongs to a rare class of X-ray binaries with red giant donors, symbiotic X-ray binaries. It has a history of complicated variability on multiple timescales in the optical light and X-rays. The nature of this variability remains poorly understood. Aims: We aim to study variability of GX 1+4 on long timescale in X-ray and optical bands. Methods: We took X-ray observations from the INTEGRAL Soft Gamma-Ray Imager and RXTE All Sky Monitor. Optical observations were made with the INTEGRAL Optical Monitoring Camera. Results: The variability of GX 1+4 both in optical light and hard X-ray emission (>17 keV) is dominated by 50-70 d quasi-periodic changes. The amplitude of this variability is highest during the periastron passage, while during the potential neutron star eclipse the system is always at minimum. This confirms the 1161 d orbital period that has had been proposed for the system based on radial velocity curve. Neither the quasi-periodic variability or the orbital period are detected in soft X-ray emission (1.3-12.2 keV), where the binary shows no apparent periodicity.
Miller-Fleming, Tyne W; Petersen, Sarah C; Manning, Laura; Matthewman, Cristina; Gornet, Megan; Beers, Allison; Hori, Sayaka; Mitani, Shohei; Bianchi, Laura; Richmond, Janet; Miller, David M
2016-01-01
Genetic programming and neural activity drive synaptic remodeling in developing neural circuits, but the molecular components that link these pathways are poorly understood. Here we show that the C. elegans Degenerin/Epithelial Sodium Channel (DEG/ENaC) protein, UNC-8, is transcriptionally controlled to function as a trigger in an activity-dependent mechanism that removes synapses in remodeling GABAergic neurons. UNC-8 cation channel activity promotes disassembly of presynaptic domains in DD type GABA neurons, but not in VD class GABA neurons where unc-8 expression is blocked by the COUP/TF transcription factor, UNC-55. We propose that the depolarizing effect of UNC-8-dependent sodium import elevates intracellular calcium in a positive feedback loop involving the voltage-gated calcium channel UNC-2 and the calcium-activated phosphatase TAX-6/calcineurin to initiate a caspase-dependent mechanism that disassembles the presynaptic apparatus. Thus, UNC-8 serves as a link between genetic and activity-dependent pathways that function together to promote the elimination of GABA synapses in remodeling neurons. DOI: http://dx.doi.org/10.7554/eLife.14599.001 PMID:27403890
Linkage disequilibrium between STRPs and SNPs across the human genome.
Payseur, Bret A; Place, Michael; Weber, James L
2008-05-01
Patterns of linkage disequilibrium (LD) reveal the action of evolutionary processes and provide crucial information for association mapping of disease genes. Although recent studies have described the landscape of LD among single nucleotide polymorphisms (SNPs) from across the human genome, associations involving other classes of molecular variation remain poorly understood. In addition to recombination and population history, mutation rate and process are expected to shape LD. To test this idea, we measured associations between short-tandem-repeat polymorphisms (STRPs), which can mutate rapidly and recurrently, and SNPs in 721 regions across the human genome. We directly compared STRP-SNP LD with SNP-SNP LD from the same genomic regions in the human HapMap populations. The intensity of STRP-SNP LD, measured by the average of D', was reduced, consistent with the action of recurrent mutation. Nevertheless, a higher fraction of STRP-SNP pairs than SNP-SNP pairs showed significant LD, on both short (up to 50 kb) and long (cM) scales. These results reveal the substantial effects of mutational processes on LD at STRPs and provide important measures of the potential of STRPs for association mapping of disease genes.
Convergent microRNA actions coordinate neocortical development.
Barca-Mayo, Olga; De Pietri Tonelli, Davide
2014-08-01
Neocortical development is a complex process that, at the cellular level, involves tight control of self-renewal, cell fate commitment, survival, differentiation and delamination/migration. These processes require, at the molecular level, the precise regulation of intrinsic signaling pathways and extrinsic factors with coordinated action in a spatially and temporally specific manner. Transcriptional regulation plays an important role during corticogenesis; however, microRNAs (miRNAs) are emerging as important post-transcriptional regulators of various aspects of central nervous system development. miRNAs are a class of small, single-stranded noncoding RNA molecules that control the expression of the majority of protein coding genes (i.e., targets). How do different miRNAs achieve precise control of gene networks during neocortical development? Here, we critically review all the miRNA-target interactions validated in vivo, with relevance to the generation and migration of pyramidal-projection glutamatergic neurons, and for the initial formation of cortical layers in the embryonic development of rodent neocortex. In particular, we focus on convergent miRNA actions, which are still a poorly understood layer of complexity in miRNA signaling, but potentially one of the keys to disclosing how miRNAs achieve the precise coordination of complex biological processes such as neocortical development.
Cipriano, Rocco C; Smith, McKenzie L; Vermeersch, Kathleen A; Dove, Alistair D M; Styczynski, Mark P
2015-03-01
Atlantic salmon Salmo salar undergo months-long inappetence during spawning, but it is not known whether this inappetence is a pathological state or one for which the fish are adapted. Recent work has shown that inappetent whale sharks can exhibit circulating metabolite profiles similar to ketosis known to occur in humans during starvation. In this work, metabolite profiling was used to explore differences in analyte profiles between a cohort of inappetent spawning run Atlantic salmon and captively reared animals that were fed up to and through the time of sampling. The two classes of animals were easily distinguished by their metabolite profiles. The sea-run fish had elevated ɷ-9 fatty acids relative to the domestic feeding animals, while other fatty acid concentrations were reduced. Sugar alcohols were generally elevated in inappetent animals, suggesting potentially novel metabolic responses or pathways in fish that feature these compounds. Compounds expected to indicate a pathological catabolic state were not more abundant in the sea-run fish, suggesting that the animals, while inappetent, were not stressed in an unnatural way. These findings demonstrate the power of discovery-based metabolomics for exploring biochemistry in poorly understood animal models. Copyright © 2015 Elsevier Inc. All rights reserved.
The Inescapable Influence of Noncoding RNAs in Cancer
Adams, Brian D.; Anastasiadou, Eleni; Esteller, Manel; He, Lin; Slack, Frank J.
2015-01-01
This report summarizes information presented at the 2015 Keystone Symposium on “MicroRNAs and Noncoding RNAs in Cancer”. Nearly two decades after the discovery of the first microRNA (miRNA), the role of noncoding RNAs in developmental processes and the mechanisms behind their dysregulation in cancer has been steadily elucidated. Excitingly, miRNAs have begun making their way into the clinic to combat disease such a hepatitis C, and various forms of cancer. Therefore, at this Keystone meeting novel findings were presented that enhance our view on how small and long noncoding RNAs control developmental timing and oncogenic processes. Recurring themes included, 1) how miRNAs can be differentially processed, degraded, and regulated by ribonucleoprotein (RNP) complexes, 2) how particular miRNA genetic networks that control developmental process, when disrupted, can result in cancer disease, 3) the technologies available to therapeutically deliver RNA to combat diseases such as cancer, and 4) the elucidation of the mechanism of actions for long noncoding RNAs, currently a poorly understood class of noncoding RNA. During the meeting there was an emphasis on presenting unpublished findings, and the breadth of topics covered reflected how inescapable the influence of noncoding RNAs are in development and cancer. PMID:26567137
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schmandt, Nicolaus; Velisetty, Phanindra; Chalamalasetti, Sreevatsa V.
Recent high resolution structures of several pentameric ligand–gated ion channels have provided unprecedented details of their molecular architecture. However, the conformational dynamics and structural rearrangements that underlie gating and allosteric modulation remain poorly understood. We used a combination of electrophysiology, double electron–electron resonance (DEER) spectroscopy, and x-ray crystallography to investigate activation mechanisms in a novel functional chimera with the extracellular domain (ECD) of amine-gated Erwinia chrysanthemi ligand–gated ion channel, which is activated by primary amines, and the transmembrane domain of Gloeobacter violaceus ligand–gated ion channel, which is activated by protons. We found that the chimera was independently gated by primarymore » amines and by protons. The crystal structure of the chimera in its resting state, at pH 7.0 and in the absence of primary amines, revealed a closed-pore conformation and an ECD that is twisted with respect to the transmembrane region. Amine- and pH-induced conformational changes measured by DEER spectroscopy showed that the chimera exhibits a dual mode of gating that preserves the distinct conformational changes of the parent channels. Collectively, our findings shed light on both conserved and divergent features of gating mechanisms in this class of channels, and will facilitate the design of better allosteric modulators.« less
Scientific rationale for Uranus and Neptune in situ explorations
NASA Astrophysics Data System (ADS)
Mousis, O.; Atkinson, D. H.; Cavalié, T.; Fletcher, L. N.; Amato, M. J.; Aslam, S.; Ferri, F.; Renard, J.-B.; Spilker, T.; Venkatapathy, E.; Wurz, P.; Aplin, K.; Coustenis, A.; Deleuil, M.; Dobrijevic, M.; Fouchet, T.; Guillot, T.; Hartogh, P.; Hewagama, T.; Hofstadter, M. D.; Hue, V.; Hueso, R.; Lebreton, J.-P.; Lellouch, E.; Moses, J.; Orton, G. S.; Pearl, J. C.; Sánchez-Lavega, A.; Simon, A.; Venot, O.; Waite, J. H.; Achterberg, R. K.; Atreya, S.; Billebaud, F.; Blanc, M.; Borget, F.; Brugger, B.; Charnoz, S.; Chiavassa, T.; Cottini, V.; d'Hendecourt, L.; Danger, G.; Encrenaz, T.; Gorius, N. J. P.; Jorda, L.; Marty, B.; Moreno, R.; Morse, A.; Nixon, C.; Reh, K.; Ronnet, T.; Schmider, F.-X.; Sheridan, S.; Sotin, C.; Vernazza, P.; Villanueva, G. L.
2018-06-01
The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission.
Chung, Hsiao-Hang; Schwinn, Kathy E.; Ngo, Hanh M.; Lewis, David H.; Massey, Baxter; Calcott, Kate E.; Crowhurst, Ross; Joyce, Daryl C.; Gould, Kevin S.; Davies, Kevin M.; Harrison, Dion K.
2015-01-01
Plant betalain pigments are intriguing because they are restricted to the Caryophyllales and are mutually exclusive with the more common anthocyanins. However, betalain biosynthesis is poorly understood compared to that of anthocyanins. In this study, betalain production and betalain-related genes were characterized in Parakeelya mirabilis (Montiaceae). RT-PCR and transcriptomics identified three sequences related to the key biosynthetic enzyme Dopa 4,5-dioxgenase (DOD). In addition to a LigB gene similar to that of non-Caryophyllales species (Class I genes), two other P. mirabilis LigB genes were found (DOD and DOD-like, termed Class II). PmDOD and PmDOD-like had 70% amino acid identity. Only PmDOD was implicated in betalain synthesis based on transient assays of enzyme activity and correlation of transcript abundance to spatio-temporal betalain accumulation. The role of PmDOD-like remains unknown. The striking pigment patterning of the flowers was due to distinct zones of red betacyanin and yellow betaxanthin production. The major betacyanin was the unglycosylated betanidin rather than the commonly found glycosides, an occurrence for which there are a few previous reports. The white petal zones lacked pigment but had DOD activity suggesting alternate regulation of the pathway in this tissue. DOD and DOD-like sequences were also identified in other betalain-producing species but not in examples of anthocyanin-producing Caryophyllales or non-Caryophyllales species. A Class I LigB sequence from the anthocyanin-producing Caryophyllaceae species Dianthus superbus and two DOD-like sequences from the Amaranthaceae species Beta vulgaris and Ptilotus spp. did not show DOD activity in the transient assay. The additional sequences suggests that DOD is part of a larger LigB gene family in betalain-producing Caryophyllales taxa, and the tandem genomic arrangement of two of the three B. vulgaris LigB genes suggests the involvement of duplication in the gene family evolution. PMID:26217353
Ombrello, Michael J; Remmers, Elaine F; Tachmazidou, Ioanna; Grom, Alexei; Foell, Dirk; Haas, Johannes-Peter; Martini, Alberto; Gattorno, Marco; Özen, Seza; Prahalad, Sampath; Zeft, Andrew S; Bohnsack, John F; Mellins, Elizabeth D; Ilowite, Norman T; Russo, Ricardo; Len, Claudio; Hilario, Maria Odete E; Oliveira, Sheila; Yeung, Rae S M; Rosenberg, Alan; Wedderburn, Lucy R; Anton, Jordi; Schwarz, Tobias; Hinks, Anne; Bilginer, Yelda; Park, Jane; Cobb, Joanna; Satorius, Colleen L; Han, Buhm; Baskin, Elizabeth; Signa, Sara; Duerr, Richard H; Achkar, J P; Kamboh, M Ilyas; Kaufman, Kenneth M; Kottyan, Leah C; Pinto, Dalila; Scherer, Stephen W; Alarcón-Riquelme, Marta E; Docampo, Elisa; Estivill, Xavier; Gül, Ahmet; de Bakker, Paul I W; Raychaudhuri, Soumya; Langefeld, Carl D; Thompson, Susan; Zeggini, Eleftheria; Thomson, Wendy; Kastner, Daniel L; Woo, Patricia
2015-12-29
Systemic juvenile idiopathic arthritis (sJIA) is an often severe, potentially life-threatening childhood inflammatory disease, the pathophysiology of which is poorly understood. To determine whether genetic variation within the MHC locus on chromosome 6 influences sJIA susceptibility, we performed an association study of 982 children with sJIA and 8,010 healthy control subjects from nine countries. Using meta-analysis of directly observed and imputed SNP genotypes and imputed classic HLA types, we identified the MHC locus as a bona fide susceptibility locus with effects on sJIA risk that transcended geographically defined strata. The strongest sJIA-associated SNP, rs151043342 [P = 2.8 × 10(-17), odds ratio (OR) 2.6 (2.1, 3.3)], was part of a cluster of 482 sJIA-associated SNPs that spanned a 400-kb region and included the class II HLA region. Conditional analysis controlling for the effect of rs151043342 found that rs12722051 independently influenced sJIA risk [P = 1.0 × 10(-5), OR 0.7 (0.6, 0.8)]. Meta-analysis of imputed classic HLA-type associations in six study populations of Western European ancestry revealed that HLA-DRB1*11 and its defining amino acid residue, glutamate 58, were strongly associated with sJIA [P = 2.7 × 10(-16), OR 2.3 (1.9, 2.8)], as was the HLA-DRB1*11-HLA-DQA1*05-HLA-DQB1*03 haplotype [6.4 × 10(-17), OR 2.3 (1.9, 2.9)]. By examining the MHC locus in the largest collection of sJIA patients assembled to date, this study solidifies the relationship between the class II HLA region and sJIA, implicating adaptive immune molecules in the pathogenesis of sJIA.
Health and the 2008 Economic Recession: Evidence from the United Kingdom
Astell-Burt, Thomas; Feng, Xiaoqi
2013-01-01
Introduction The economic recession which began in 2008 has resulted in a substantial increase in unemployment across many countries, including the United Kingdom. Strong association between unemployment and poor health status among individuals is widely recognised. We investigated whether the prevalence of poor health at a population level increased concurrent to the rise in unemployment during the economic recession, and whether the impact on health varied by geographical and socioeconomic circumstances. Method Health, demographic and socioeconomic measures on 1.36 million survey responses aged 16–64 were extracted from the Quarterly Labour Force Survey of the United Kingdom, collected every three months, from January 2006 to December 2010. The likelihood of self-reporting poor health status and specific types of health problems (depression, mental illness, cardiovascular and respiratory) across time were estimated separately using logistic regression. Explanatory variables included economic status (International Labour Organization definition), occupational class, age, gender, country of birth, ethnicity, educational qualifications, couple status, household tenure, number of dependents, and geographical region. Results Unemployment (age-gender adjusted) rose from 4.5% in January 2008 to 7.1% by September 2009. The reporting of poor health status increased from 25.7% in July 2009 to 29.5% by December 2010. Similar increases were found for cardiovascular and respiratory health problems; not depression or mental illness. The prevalence of poor health status among the unemployed decreased from 28.8% in July 2008, to 24.9% by March 2009; but this was followed by an increase in poor health experienced across all regions and by all socioeconomic groups, including those who remained employed, regardless of their occupational class. Interpretation Although our study found no exacerbation of pre-recession health inequalities, the rise in poor health status not only for the unemployed, but also among people who remained employed, regardless of their occupational class, justifies concern voiced among many public health commentators. PMID:23437208
Soy Saponins: Current Research and Future Goals
USDA-ARS?s Scientific Manuscript database
Saponins are a biologically active class of triterpenoid phytochemicals found in soybeans at concentrations similar to those of the isoflavones, and the role they may play in nutrition and health is not well understood. Research the functionality of these compounds in animals and humans has been ha...
The influence of spatial processes on population dynamics within river-stream networks is poorly understood. Utilizing spatially explicit analyses of temporal genetic variance, we examined whether persistence of Central Stonerollers (Campostoma anomalum) reflects differences in h...
Worldwide patterns of ancestry, divergence, and admixture in domesticated cattle
USDA-ARS?s Scientific Manuscript database
The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 anima...
ERIC Educational Resources Information Center
Blystone, Robert V.; Blodgett, Kevin
2006-01-01
The scientific method is the principal methodology by which biological knowledge is gained and disseminated. As fundamental as the scientific method may be, its historical development is poorly understood, its definition is variable, and its deployment is uneven. Scientific progress may occur without the strictures imposed by the formal…
From Movements to Actions: Two Mechanisms for Learning Action Sequences
ERIC Educational Resources Information Center
Endress, Ansgar D.; Wood, Justin N.
2011-01-01
When other individuals move, we interpret their movements as discrete, hierarchically-organized, goal-directed actions. However, the mechanisms that integrate visible movement features into actions are poorly understood. Here, we consider two sequence learning mechanisms--transitional probability-based (TP) and position-based encoding…
Accumulation of the Antibiotic Phenazine-1-Carboxylic Acid in the Rhizosphere of Dryland Cereals
USDA-ARS?s Scientific Manuscript database
Natural antibiotics are thought to function in the defense, fitness, competitiveness, biocontrol activity, communication and gene regulation of microorganisms. However, the scale and quantitative aspects of antibiotic production in natural settings are poorly understood. We addressed these fundament...
Background/Questions/Methods Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because ...
Olfactory disruption: towards controlling important insect vectors of disease
USDA-ARS?s Scientific Manuscript database
Chemical repellents are used to decrease contacts between insect disease vectors and their hosts, thus reducing the probability of disease transmission. The molecular mechanisms by which repellents have their effects are poorly understood and remain a controversial topic. Here we present recent re...
USDA-ARS?s Scientific Manuscript database
Environmental enteric dysfunction (EED), a condition characterized by small intestine inflammation and abnormal gut permeability, is widespread in children in developing countries and a major cause of growth failure. The pathophysiology of EED remains poorly understood. We measured serum metabolite...
LOCAL VS. REGIONAL EFFECTS ON FISH DIVERSITY AS MEDIATED BY STREAMFLOW DISTURBANCE REGIME
abstract
The interplay of local and regional processes on fish diversity is poorly understood, especially related to patterns of streamflow disturbance regime. Articulation of the relationship between flow disturbance patterns and river fishes across local to regional scal...
USDA-ARS?s Scientific Manuscript database
Virtually every mammalian cell, including cardiomyocytes, possesses an intrinsic circadian clock. The role of this transcriptionally based molecular mechanism in cardiovascular biology is poorly understood. We hypothesized that the circadian clock within the cardiomyocyte influences diurnal variatio...
The role of methionine metabolism in inflammatory bowel disease
USDA-ARS?s Scientific Manuscript database
Methionine (Met) cycle activity is critical for normal cell functions. Met metabolites S-adenosylmethionine (SAM) and methylthioadenosine (MTA) are anti-inflammatory, yet their role in inflammatory bowel disease (IBD) is poorly understood. We hypothesize that active IBD leads to changes in Met metab...
Molecular basis for the thermostability of Newcastle disease virus
USDA-ARS?s Scientific Manuscript database
Thermostable Newcastle disease virus (NDV) vaccines have been used widely to protect village chickens against Newcastle disease, due to their decreased dependence on cold chain for transport and storage. However, the genetic basis underlying the NDV thermostability is poorly understood. In this stud...
Development and preliminary validation of the Parenting around SNAcking Questionnaire (P-SNAQ)
USDA-ARS?s Scientific Manuscript database
Snacking makes significant contributions to children's dietary intake but is poorly understood from a parenting perspective. This research was designed to develop and evaluate the psychometrics of a theoretically grounded, empirically-informed measure of snack parenting. The Parenting around SNAckin...
Do boll weevils really diapause?
USDA-ARS?s Scientific Manuscript database
Boll weevil, Anthonomus grandis grandis Boheman, diapause has been poorly understood since the term was first used 50 yrs ago to describe the pest’s winter dormancy in temperate regions. This literature-based study found that low temperature and changes in photoperiod are the boll weevil diapause-i...
Effects of exurban development on trophic interactions in a desert landscape
USDA-ARS?s Scientific Manuscript database
Context Mechanisms of ecosystem change in urbanizing landscapes are poorly understood, especially in exurban areas featuring residential or commercial development set in a matrix of modified and natural vegetation. We asked how development altered trophic interactions and ecosystem processes in the ...
Secondary organic aerosol (SOA) might affect the atmospheric radiation balance through absorbing light at shorter visible and UV wavelengths. However, the composition and optical properties of light-absorbing SOA is poorly understood. In this work, SOA filter samples were collect...
Reproductive responses of northern goshawks to variable prey populations
Susan R. Salafsky; Richard T. Reynolds; Barry R. Noon; John A. Wiens
2007-01-01
Developing comprehensive conservation strategies requires knowledge of factors influencing population growth and persistence. Although variable prey resources are often associated with fluctuations in raptor demographic parameters, the mechanisms of food limitation are poorly understood, especially for a generalist predator like the northern goshawk (Accipiter...
Aquatic insects provide a critical nutrient subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated relationships between aquatic (resource utilization) and contaminant exposure for a riparian invert...
The geography of spatial synchrony
Jonathan A. Walter; Lawrence W. Sheppard; Thomas L. Anderson; Jude H. Kastens; Ottar N. Bjørnstad; Andrew M. Liebhold; Daniel C. Reuman; Bernd Blasius
2017-01-01
Spatial synchrony, defined as correlated temporal fluctuations among populations, is a fundamental feature of population dynamics, but many aspects of synchrony remain poorly understood. Few studies have examined detailed geographical patterns of synchrony; instead most focus on how synchrony declines with increasing linear distance between locations, making the...
Relations between Alcohol, Violence and Victimization in Adolescence
ERIC Educational Resources Information Center
Shepherd, J. P.; Sutherland, I.; Newcombe, R. G.
2006-01-01
Background: Compared to links between alcohol and aggression, links between alcohol and vulnerability are poorly understood. Objectives: To determine whether there is a significant relationship between vulnerability to physical violence and alcohol consumption in adolescence independent of a relationship between alcohol consumption and violent…
Heredity Factors in Spatial Visualization.
ERIC Educational Resources Information Center
Vandenberg, S. G.
Spatial visualization is not yet clearly understood. Some researchers have concluded that two factors or abilities are involved, spatial orientation and spatial visualization. Different definitions and different tests have been proposed for these two abilities. Several studies indicate that women generally perform more poorly on spatial tests than…
Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...
ERIC Educational Resources Information Center
Brock, David
2009-01-01
Despite student interest, the heart is often a poorly understood topic in biology. To help students understand this vital organ's physiology, the author created this investigation activity involving the mammalian heart and its role in the circulatory system. Students design, build, and demonstrate working artificial "hearts" to exhibit what they…
ERIC Educational Resources Information Center
Harrow, Chris; Chin, Lillian
2014-01-01
Exploration, innovation, proof: For students, teachers, and others who are curious, keeping an open mind and being ready to investigate unusual or unexpected properties will always lead to learning something new. Technology can further this process, allowing various behaviors to be analyzed that were previously memorized or poorly understood. This…
Multi-scale assessment of human-induced changes to Amazonian instream habitats
Context: Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon.Objectives: Determine the degree to which ph...
Child stunting is associated with low circulating essential amino acids
USDA-ARS?s Scientific Manuscript database
Stunting affects about one-quarter of children under five worldwide. The pathogenesis of stunting is poorly understood. Nutritional interventions have had only modest effects in reducing stunting. We hypothesized that insufficiency in essential amino acids may be limiting the linear growth of childr...
Introduction to the Thematic Minireview Series: Brain glycogen metabolism.
Carlson, Gerald M; Dienel, Gerald A; Colbran, Roger J
2018-05-11
The synthesis of glycogen allows for efficient intracellular storage of glucose molecules in a soluble form that can be rapidly released to enter glycolysis in response to energy demand. Intensive studies of glucose and glycogen metabolism, predominantly in skeletal muscle and liver, have produced innumerable insights into the mechanisms of hormone action, resulting in the award of several Nobel Prizes over the last one hundred years. Glycogen is actually present in all cells and tissues, albeit at much lower levels than found in muscle or liver. However, metabolic and physiological roles of glycogen in other tissues are poorly understood. This series of Minireviews summarizes what is known about the enzymes involved in brain glycogen metabolism and studies that have linked glycogen metabolism to multiple brain functions involving metabolic communication between astrocytes and neurons. Recent studies unexpectedly linking some forms of epilepsy to mutations in two poorly understood proteins involved in glycogen metabolism are also reviewed. © 2018 Carlson et al.
Immigrant dairy workers' perceptions of health and safety on the farm in America's Heartland.
Liebman, Amy King; Juarez-Carrillo, Patricia Margarita; Reyes, Iris Anne Cruz; Keifer, Matthew Charles
2016-03-01
Dairy farming is dangerous. Yearly, farms grow fewer and larger by employing immigrant workers, who have limited industrial agriculture experience and safety and health training. We examined results of five focus groups with 37 Hispanic, immigrant dairy workers. Analysis followed a grounded theory approach and employed ATLAS.ti. Reported injury experience affirmed the hazardous nature of dairy. Some workers received appropriate worker compensation benefits, whereas others were instructed to deny work-relatedness. Some employers covered medical injury costs out-of-pocket, whereas others did not. Cows were a major injury source. Pressure to work and weather were noted as injury risk factors. Worker compensation was poorly understood, and immigration status and fear of deportation influenced injury and hazard reporting. Injury management practices range from benevolent to threatening. Workers compensation is poorly understood and undocumented status is an occupational hazard. We underscore the need for further research and immigration policy change. © 2015 Wiley Periodicals, Inc.
Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere.
Fear, R C; Milan, S E; Maggiolo, R; Fazakerley, A N; Dandouras, I; Mende, S B
2014-12-19
The structure of Earth's magnetosphere is poorly understood when the interplanetary magnetic field is northward. Under this condition, uncharacteristically energetic plasma is observed in the magnetotail lobes, which is not expected in the textbook model of the magnetosphere. Using satellite observations, we show that these lobe plasma signatures occur on high-latitude magnetic field lines that have been closed by the fundamental plasma process of magnetic reconnection. Previously, it has been suggested that closed flux can become trapped in the lobe and that this plasma-trapping process could explain another poorly understood phenomenon: the presence of auroras at extremely high latitudes, called transpolar arcs. Observations of the aurora at the same time as the lobe plasma signatures reveal the presence of a transpolar arc. The excellent correspondence between the transpolar arc and the trapped closed flux at high altitudes provides very strong evidence of the trapping mechanism as the cause of transpolar arcs. Copyright © 2014, American Association for the Advancement of Science.
Sea-level-induced seismicity and submarine landslide occurrence
Brothers, Daniel S.; Luttrell, Karen M.; Chaytor, Jason D.
2013-01-01
The temporal coincidence between rapid late Pleistocene sea-level rise and large-scale slope failures is widely documented. Nevertheless, the physical mechanisms that link these phenomena are poorly understood, particularly along nonglaciated margins. Here we investigate the causal relationships between rapid sea-level rise, flexural stress loading, and increased seismicity rates along passive margins. We find that Coulomb failure stress across fault systems of passive continental margins may have increased more than 1 MPa during rapid late Pleistocene–early Holocene sea-level rise, an amount sufficient to trigger fault reactivation and rupture. These results suggest that sea-level–modulated seismicity may have contributed to a number of poorly understood but widely observed phenomena, including (1) increased frequency of large-scale submarine landslides during rapid, late Pleistocene sea-level rise; (2) emplacement of coarse-grained mass transport deposits on deep-sea fans during the early stages of marine transgression; and (3) the unroofing and release of methane gas sequestered in continental slope sediments.
Wang, Yong Xin; Mandal, Deendayal; Wang, Suizhau; Hughes, Dennis; Pollock, Raphael E; Lev, Dina; Kleinerman, Eugenie; Hayes-Jordan, Andrea
2009-01-01
Despite aggressive therapy, Ewing's sarcoma (ES) patients have a poor five-year overall survival of only 20-40%. Pulmonary metastasis is the most common form of demise in these patients. The pathogenesis of pulmonary metastasis is poorly understood and few orthotopic models exist that allow study of spontaneous pulmonary metastasis in ES. We have developed a novel orthotopic xenograft model in which spontaneous pulmonary metastases develop. While the underlying biology of ES is incompletely understood, in addition to the EWS-FLI-1 mutation, it is known that platelet-derived growth factor receptor beta (PDGFR-beta) is highly expressed in ES. Hypothesizing that PDGFR-beta expression is indicative of a specific role for this receptor protein in ES progression, the effect of PDGFR-beta inhibition on ES growth and metastasis was assessed in this novel orthotopic ES model. Silencing PDGFR-beta reduced spontaneous growth and metastasis in ES. Preclinical therapeutically relevant findings such as these may ultimately lead to new treatment initiatives in ES.
Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents.
Seibt, Julie; Richard, Clément J; Sigl-Glöckner, Johanna; Takahashi, Naoya; Kaplan, David I; Doron, Guy; de Limoges, Denis; Bocklisch, Christina; Larkum, Matthew E
2017-09-25
How sleep influences brain plasticity is not known. In particular, why certain electroencephalographic (EEG) rhythms are linked to memory consolidation is poorly understood. Calcium activity in dendrites is known to be necessary for structural plasticity changes, but this has never been carefully examined during sleep. Here, we report that calcium activity in populations of neocortical dendrites is increased and synchronised during oscillations in the spindle range in naturally sleeping rodents. Remarkably, the same relationship is not found in cell bodies of the same neurons and throughout the cortical column. Spindles during sleep have been suggested to be important for brain development and plasticity. Our results provide evidence for a physiological link of spindles in the cortex specific to dendrites, the main site of synaptic plasticity.Different stages of sleep, marked by particular electroencephalographic (EEG) signatures, have been linked to memory consolidation, but underlying mechanisms are poorly understood. Here, the authors show that dendritic calcium synchronisation correlates with spindle-rich sleep phases.
Poor, Rural Neighborhoods and Early School Achievement.
ERIC Educational Resources Information Center
Bickel, Robert; Smith, Cynthia; Eagle, Teresa Hardman
A study sought to identify the existence of neighborhood effects on school achievement that are independent of social class and family background among students from poor, rural neighborhoods. Ethnographic material yielded a concept of rural West Virginia neighborhoods in which residents expect their encounters to be friendly, informal, almost…
Two decades of Neo-Marxist class analysis and health inequalities: A critical reconstruction
Muntaner, Carles; Ng, Edwin; Chung, Haejoo; Prins, Seth J
2015-01-01
Most population health researchers conceptualize social class as a set of attributes and material conditions of life of individuals. The empiricist tradition of ‘class as an individual attribute' equates class to an ‘observation', precluding the investigation of unobservable social mechanisms. Another consequence of this view of social class is that it cannot be conceptualized, measured, or intervened upon at the meso- or macro levels, being reduced to a personal attribute. Thus, population health disciplines marginalize rich traditions in Marxist theory whereby ‘class' is understood as a ‘hidden' social mechanism such as exploitation. Yet Neo-Marxist social class has been used over the last two decades in population health research as a way of understanding how health inequalities are produced. The Neo-Marxist approach views social class in terms of class relations that give persons control over productive assets and the labour power of others (property and managerial relations). We critically appraise the contribution of the Neo-Marxist approach during the last two decades and suggest realist amendments to understand class effects on the social determinants of health and health outcomes. We argue that when social class is viewed as a social causal mechanism it can inform social change to reduce health inequalities. PMID:26345311
Neuner, Stephanie
2016-01-01
This contribution focuses on the medical practice of the policlinics in Würzburg and Göttingen in the first half of the nineteenth century. In these institutions patients were treated free of charge by medical students and assistant physicians who, in turn, were able to gain further experience and develop their skills. The policlinics were therefore an important part of poor-healthcare in both these cities. The essay tries in particular to illustrate healthcare for poor patients against the background of their everyday lives and working environment. Based on the situation of individual poor patients, the concepts of 'sickness' and 'poverty' are discussed as mutually dependent determinants of the 'reality of life' among the urban lower classes. This contribution combines the evaluation of medical practice journals and patient histories with the analysis of source materials on urban poor relief and healthcare. It looks particularly at the children and elderly people who attended the policlinics. The encounters between physicians and poor patients documented in the sources not only provide valuable insights into historical patient behaviours, they also open up new perspectives of the physician-patient relationship during the nineteenth century transition from the 'sickbed-society' to hospital medicine.
A missed Fe-S cluster handoff causes a metabolic shakeup.
Berteau, Olivier
2018-05-25
The general framework of pathways by which iron-sulfur (Fe-S) clusters are assembled in cells is well-known, but the cellular consequences of disruptions to that framework are not fully understood. Crooks et al. report a novel cellular system that creates an acute Fe-S cluster deficiency, using mutants of ISCU, the main scaffold protein for Fe-S cluster assembly. Surprisingly, the resultant metabolic reprogramming leads to the accumulation of lipid droplets, a situation encountered in many poorly understood pathological conditions, highlighting unanticipated links between Fe-S assembly machinery and human disease. © 2018 Berteau.
Sulfate resistance of high calcium fly ash concrete
NASA Astrophysics Data System (ADS)
Dhole, Rajaram
Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime-fly ash pastes confirmed that fly ash mortar or concrete mixes forming more monosulfate than ettringite before exposure to sulfates would offer poor sulfate resistance and vice versa. During quantitative Rietveld analysis carried out for determining ettringite, monosulfate and gypsum formed in the fly ash pastes, it was observed that fly ash mixtures showing more ettringite after exposures to sulfates, give poor sulfate resistance. A good relationship between the amounts of ettringite formed and expansions of mortar specimens in the ASTM C 1012 test was found.
Economic development: the middle class and international migration in the Dominican Republic.
Bray, D
1984-01-01
"The Dominican Republic is classified as one of a group of Latin American and Caribbean countries whose international migratory flows appear to be primarily composed of the urban middle class, rather than the rural poor. It is argued that Dominican middle class international migration has emerged as a partial solution to a political economic crisis that was dramatized by the April Revolution of 1965 and deepened through the 1970s with the failure of industrialization strategies to generate significant changes in the class structure." excerpt
Imbalanced Learning for Functional State Assessment
NASA Technical Reports Server (NTRS)
Li, Feng; McKenzie, Frederick; Li, Jiang; Zhang, Guangfan; Xu, Roger; Richey, Carl; Schnell, Tom
2011-01-01
This paper presents results of several imbalanced learning techniques applied to operator functional state assessment where the data is highly imbalanced, i.e., some function states (majority classes) have much more training samples than other states (minority classes). Conventional machine learning techniques usually tend to classify all data samples into majority classes and perform poorly for minority classes. In this study, we implemented five imbalanced learning techniques, including random undersampling, random over-sampling, synthetic minority over-sampling technique (SMOTE), borderline-SMOTE and adaptive synthetic sampling (ADASYN) to solve this problem. Experimental results on a benchmark driving lest dataset show thai accuracies for minority classes could be improved dramatically with a cost of slight performance degradations for majority classes,
Connecting Depth and Balance in Class
ERIC Educational Resources Information Center
Kuhn, Matthew S.
2008-01-01
Tremendous growth in educational technology tools, applications, and Web 2.0 resources have created a plethora of new methods to meet the learning needs of all students. Unfortunately, the potential of these methods is hardly understood before a new technological breakthrough makes its way into the classroom, through either teachers or, more…
ERIC Educational Resources Information Center
Malikow, Max
2006-01-01
Masochism, the irrational self-infliction of pain, is more easily defined than understood. Once, a teacher used the word "cutting" only reference to a student skipping class. But, in recent years, it has taken on additional meaning. Cutting, or self-injury, is a deliberate self-harming behavior but without conscious suicidal ideation. To define…
Sequences for Student Investigation
ERIC Educational Resources Information Center
Barton, Jeffrey; Feil, David; Lartigue, David; Mullins, Bernadette
2004-01-01
We describe two classes of sequences that give rise to accessible problems for undergraduate research. These problems may be understood with virtually no prerequisites and are well suited for computer-aided investigation. The first sequence is a variation of one introduced by Stephen Wolfram in connection with his study of cellular automata. The…
"Boyz to Men": Masculinities, Schooling and Labour Transitions in De-Industrial Times.
ERIC Educational Resources Information Center
Nayak, Anoop
2003-01-01
In postindustrial society, masculinities at school must be understood in the context of family, history, locality, and global change. An ethnography of white working-class male school subculture shows how they resist globalization by asserting traditional masculinity, providing the illusion of stability. (Contains 40 references.) (SK)
Targeting Efficient Studying--First-Semester Psychology Students' Experiences
ERIC Educational Resources Information Center
Öhrstedt, Maria; Scheja, Max
2018-01-01
Background: How students go about studying, including the learning activities that students engage in both during and between classes, is not easily understood. Previous research indicates that critical student features, such as approaches to learning and decisions of how to organise studying activities, develop in bidirectional interactions…
Social Representations of High School Students about Mathematics Assessment
ERIC Educational Resources Information Center
Martínez-Sierra, Gustavo; Valle-Zequeida, María E.; Miranda-Tirado, Marisa; Dolores-Flores, Crisólogo
2016-01-01
The perceptions of students about assessment in mathematics classes have been sparsely investigated. In order to fill this gap, this qualitative study aims to identify the social "representations" (understood as the system of values, ideas, and practices about a social object) of high school students regarding "assessment in…
Enabling Student Nurses to Use the Information Superhighway.
ERIC Educational Resources Information Center
Bachman, Jean A.; Panzarine, Susan
1998-01-01
Twenty nursing graduate students in an Internet-based course were compared with 23 who did not take the course. The former were more likely to be connected to nursing networks, used Internet-based health information in practice, used computer skills for other classes, and understood the relevance of telemedicine. (SK)
An ethylene-induced regulatory module delays rose flower senescence by regulating cytokinin content
USDA-ARS?s Scientific Manuscript database
In many plant species, including rose (Rosa hybrida), flower senescence is promoted by the gaseous hormone, ethylene, and inhibited by cytokinin (CTK) class of hormones. However, the molecular mechanisms underlying these antagonistic effects are not well understood. In this current study, we charact...
Exposure to mixtures is frequent, but biologic pathways such as metabolic inhibition, are poorly understood. CHCl3 and TCE are model volatiles frequently co-occurring; combined exposure results in less than additive hepatotoxicity. Here, we explore the underlying metabolic inte...
DOT National Transportation Integrated Search
1998-03-01
The contribution of a cement-stabilized base course to the strength of the rigid pavement structure is poorly understood. The objective of this research was to obtain data on the response of the rigid pavement slab-joint-foundation system by conducti...
Childhood asthma is a multifactorial disease with a disturbingly high incidence in urbanized areas. The pathogenesis of asthma is poorly understood due to the complex relationship between genetic susceptibility and modulating environmental factors. The Mechanistic Indicators of C...
NITROGEN OUTPUTS FROM FECAL AND URINE DEPOSITION OF SMALL MAMMALS: IMPLICATIONS FOR NITROGEN CYCLING
The contribution of small mammals to nitrogen cycling is poorly understood, but it could have reverberations back to the producer community by maintaining or perhaps magnifying nitrogen availability. Our objective was to model nitrogen outputs (deposition of feces and urine) of ...
Accumulation of the antibiotic phenazine-1-carboxylic acid in the rhizosphere of dryland cereals
USDA-ARS?s Scientific Manuscript database
Natural antibiotics are thought to function in microbial defense, fitness, competitiveness, biocontrol, communication and gene regulation. However, the frequency and amount of antibiotics produced in nature are poorly understood. In this study, we assessed the geographic distribution of indigenous p...
Genomic medicine and ethnic differences in cardiovascular disease risk
USDA-ARS?s Scientific Manuscript database
The origins of health disparities are a poorly understood public health problem. The effects of culture, environmental hazards, and social marginalization differ between ethnicities and have strong effects on health differences. The role of the genome in health is well established and we present a s...
BACKGROUND: Influenza peaks during the wintertime in temperate regions and during the annual rainy season in tropical regions – however reasons for the observed differences in disease ecology are poorly understood. We hypothesize that episodes of extreme precipitation also result...
USDA-ARS?s Scientific Manuscript database
During polarized growth of pollen tubes, endomembrane trafficking and actin polymerization are two critical processes that establish membrane/wall homeostasis and maintain growth polarity. Fine-tuned interactions between these two processes are therefore necessary but poorly understood. To better un...
DOT National Transportation Integrated Search
2016-02-01
Rural intersections account for 30% of crashes in rural areas and 6% of all fatal crashes, representing a significant but poorly : understood safety problem. Transportation agencies have traditionally implemented countermeasures to address rural inte...
Flavonoids, alkali earth and rare earth elements affect germination of pecan pollen
USDA-ARS?s Scientific Manuscript database
The factors regulating pecan [Carya illinoinensis (Wangenh.) K. Koch] pollen grain germination on receptive stigmatic flower surfaces in vivo or in vitro in pollen viability assays are poorly understood. While there are many potential regulating factors, there is evidence for involvement of flavonol...
Neural Correlates of Socioeconomic Status in the Developing Human Brain
ERIC Educational Resources Information Center
Noble, Kimberly G.; Houston, Suzanne M.; Kan, Eric; Sowell, Elizabeth R.
2012-01-01
Socioeconomic disparities in childhood are associated with remarkable differences in cognitive and socio-emotional development during a time when dramatic changes are occurring in the brain. Yet, the neurobiological pathways through which socioeconomic status (SES) shapes development remain poorly understood. Behavioral evidence suggests that…
USDA-ARS?s Scientific Manuscript database
Liver toxicity is frequently seen in relation to allogeneic hematopoietic stem cell transplantation (HSCT), but pathogenesis and the risk factors are poorly understood. The purpose of this study was to investigate associations between liver toxicity, gastrointestinal toxicity, and levels of immune-r...
NITROGEN OUTPUTS OF SMALL MAMMALS FROM FECAL AND URINE DEPOSITION: IMPLICATIONS FOR NITROGEN CYCLING
The contribution of small mammals in nitrogen cycling is poorly understood and could have reverberations back to the producer community by maintaining or even magnifying increased nitrogen availability. Our objective was to model nitrogen outputs (deposition of feces and urine) ...
Feeding behavior and injury caused by Lygus hesperus
USDA-ARS?s Scientific Manuscript database
Despite the importance of Lygus hesperus as a crop pest in the western United States, key aspects of its feeding behavior and consequent injury to cotton are poorly understood. Previous studies of Lygus stage-dependent injury to cotton produced conflicting results. We sought to clarify these relat...
Structural Equations and Causal Explanations: Some Challenges for Causal SEM
ERIC Educational Resources Information Center
Markus, Keith A.
2010-01-01
One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…
USDA-ARS?s Scientific Manuscript database
Contamination of aquatic habitats with anthropogenic nutrients has been associated with an increase in mosquito larval populations but the underlying mechanisms remain poorly understood. We examined the individual and combined effects of two synthetic fertilizers (ammonium sulfate and potassium chlo...
Verbal Understanding and Pavlovian Processes
ERIC Educational Resources Information Center
Tonneau, François
2004-01-01
The behavioral processes through which people react appropriately to verbal descriptions remain poorly understood. I argue here that these processes are Pavlovian. Common objections to a Pavlovian account of symbolic behavior evidence a lack of familiarity with the relevant data or misunderstandings of operant theory. Although much remains to be…
Redefining the Longitude/Latitude Experience with a Scaffolded Geocache
ERIC Educational Resources Information Center
Hammond, Thomas; Bozdin, Alec M.; Stanlick, Sarah E.
2014-01-01
Latitude and longitude are foundational concepts for geography education, yet they are typically poorly understood by students and receive indifferent attention from instructors and publishers' materials. Social studies teachers can take advantage of increasingly ubiquitous geolocating devices such as Global Positions Systems (GPS) to provide…
Wheat streak mosaic virus coat protein is a host-specific long-distance transport determinant in oat
USDA-ARS?s Scientific Manuscript database
Viral determinants involved in systemic infection of hosts by monocot-infecting plant viruses are poorly understood. Wheat streak mosaic virus (WSMV, genus Tritimovirus, family Potyviridae) exclusively infects monocotyledonous crops such as wheat, oat, barley, maize, triticale, and rye. Previously, ...
Genotype-specific responses of apple roots to pathogenic infection by Pythium ultimum
USDA-ARS?s Scientific Manuscript database
Resistance mechanisms employed to defend against soilborne necrotrophic pathogens are poorly understood, particularly with respect to perennial tree fruit crops such as apple. Pythium ultimum is a component of the pathogen complex that incites apple replant disease (ARD). Different levels of tolera...
The Structure of Integral Dimensions: Contrasting Topological and Cartesian Representations
ERIC Educational Resources Information Center
Jones, Matt; Goldstone, Robert L.
2013-01-01
Diverse evidence shows that perceptually integral dimensions, such as those composing color, are represented holistically. However, the nature of these holistic representations is poorly understood. Extant theories, such as those founded on multidimensional scaling or general recognition theory, model integral stimulus spaces using a Cartesian…
Speleothems as Examples of Chemical Equilibrium Processes.
ERIC Educational Resources Information Center
Wilson, James R.
1984-01-01
The chemical formation of speleothems such as stalactites and stalagmites is poorly understood by introductory geology instructors and misrepresented in most textbooks. Although evaporation may be a controlling factor in some caves, it is necessary to consider chemical precipitation as more important in controlling the diagenesis of calcium…
Aboveground and belowground net primary production
Hal O. Liechty; Mark H. Eisenbies
2000-01-01
The relationship among net primary productivity (NPP), hydroperiod, and fertility in forested wetlands is poorly understood (Burke and others 1999), particularly with respect to belowground NPP (Megonigal and others 1997). Although some researchers have studied aboveground and belowground primary production in depressional, forested wetland systems, e.g., Day and...
Remote Sensing and Underwater Glider Observations of a Springtime Plume in Western Lake Superior
Plumes are commonly observed in satellite imagery of western Lake Superior following storm events, and represent a significant cross-shelf pathway for sediment and other constituents. However, their subsurface extent is poorly understood. This study reports results from plume ob...
Effects of Rhododendron maximum L. on Acer rubrum L. Seedling Establishment
Barton D. Clinton; James M. Vose
1996-01-01
Rhododendron maximum L. restricts regeneration of overstory species; however, the mechanisms are poorly understood. Three treatments were used to examine the effects of R. maximum germination success and survival of Acer rubrum L. under a closed overstory canopy: (1) R. maximum understory, (2)...
The effects of anthropogenic contaminants on Gulf of Mexico plant communities are poorly understood despite the threatened condition of a number of seagrass communities and wetland habitats. In this study, we focused particular attention on the concern that elevated nutrient
l...
The Psychophysiological Mechanisms of Alexithymia in Autism Spectrum Disorder
ERIC Educational Resources Information Center
Gaigg, Sebastian B.; Cornell, Anna S. F.; Bird, Geoffrey
2018-01-01
Accumulating evidence indicates that co-occurring alexithymia underlies several facets of the social-emotional difficulties common in individuals with autism spectrum disorder. The mechanisms involved, however, remain poorly understood because measuring alexithymia relies heavily on self-report. To address this issue, carefully matched groups of…
Sugary beverage intake and preclinical Alzheimer's disease in the community
USDA-ARS?s Scientific Manuscript database
IMPORTANCE: Sugary beverages are a key component of the Western diet, yet the long-term effects of these beverages on the brain are poorly understood. OBJECTIVE: To determine whether habitual sugary beverage consumption is associated with markers of preclinical Alzheimers disease (AD) and/or vascu...
Spread and development of Phytophthora ramorum in a California christmas tree farm
Gary A. Chastagner; Kathy Riley; Norm Dart
2008-01-01
The risk of conifers being infected by Phytophthora ramorum under natural conditions is poorly understood. In California, infected conifers commonly occur as understory plants beneath or adjacent to heavily infected plants like California bay laurel (Umbellularia californica). During wet periods, P. ramorum is...
Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf
Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical process...
HYDRAULIC REDISTRIBUTION IN A DOUGLAS-FIR FOREST: LESSONS FROM SYSTEM MANIPULATIONS
Hydraulic redistribution (HR) has been shown to slow drying of surface soils during drought in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the...
Perfluoro compounds are ubiquitous contaminants in human blood. The pathways which result in near universal exposure to humans in modern societies are not clearly understood. Sources to environmental compartments and transport between compartments are only poorly studies, and thi...
Glucose supplementation has minimal effects on blood neutrophil functionand gene expression in vitro
USDA-ARS?s Scientific Manuscript database
During early lactation, glucose availability is low and the effect of glucose supply on bovine polymorphonuclear leukocyte (PMNL) function is poorly understood. The objective of this study was to determine the effect of glucose supplementation on the function and transcriptomic inflammatory respons...
The water balance components of undisturbed tropical woodlands in the Brazilian cerrado
USDA-ARS?s Scientific Manuscript database
Deforestation of the Brazilian cerrado region has caused major changes in hydrological processes. These changes in water balance components are still poorly understood but are important for making land management decisions in this region. To better understand pre-deforestation conditions, we determi...
Soil type and species diversity influence selection on physiology in Panicum virgatum
USDA-ARS?s Scientific Manuscript database
Species diversity influences the productivity and stability of plant communities, but its effect on the evolution of species within those communities is poorly understood. In this study, we tested whether species diversity and soil type influence selection on physiology in switchgrass (Panicum virga...
Mechanisms of increased lifespan in hypoxia in the alfalfa leafcutting bee, Megachile rotundata
USDA-ARS?s Scientific Manuscript database
Genetic variation accounts for a small amount of variation in lifespan, while environmental stressors are strong predictors. Hypoxia is an environmental stress that increases longevity in some contexts, but the mechanisms remain poorly understood. In the bee Megachile rotundata, lifespan doubles upo...
Evidence synthesis and its role in evidence-based health care.
Pearson, Alan
2014-12-01
The central role of evidence synthesis (or the systematic review of evidence) in evidence-based health care is often poorly understood. There are numerous examples in the literature of poorly conceived and/or executed systematic reviews and of a lack of awareness of the international standards developed by the international leaders in systematic reviews. The Cochrane Collaboration has played a critical global role in developing and refining systematic review methods in relation to evidence of effects and of diagnostic accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.
Thinking Strategically to Record Notes in Content Classes
ERIC Educational Resources Information Center
Boyle, Joseph R.
2011-01-01
Although teachers today use a variety of teaching methods in content-area classrooms, lecture learning and note-taking still comprise a considerable portion of time in these classes. Unfortunately, most students are poor note-takers, typically recording only about one quarter of lecture notes. Strategic note-taking was developed to assist students…
Unintended Consequences: How Science Professors Discourage Women of Color
ERIC Educational Resources Information Center
Johnson, Angela C.
2007-01-01
This study examined how 16 Black, Latina, and American Indian women science students reacted to their undergraduate science classes. I focused on the meanings they made of the common features of university science documented by Seymour and Hewitt (1997), including large, competitive, fast-paced classes, poor teaching, and an unsupportive culture.…
Domestic Violence among the Black Poor: Intersectionality and Social Justice
ERIC Educational Resources Information Center
Conwill, William Louis
2010-01-01
There are striking gender, race, and class variations in rates of domestic violence. Some leading family theorists called for an intersectional analysis of how gender, race and class systems interact to improve domestic violence theory. This article improves domestic violence theory by: 1) using the discourse, or language, of intersectionality; 2)…
Parental Engagement in a Reggio Emilia-Inspired Head Start Program
ERIC Educational Resources Information Center
Smith, Stephanie C.
2014-01-01
In the United States, progressive education programs have historically failed to take hold among low-income families, even when that population has been their initial focus. Instead, these programs tend to become popular among middle-class or affluent families. Some research suggests that working-class/poor families' expectations of education may…
Methods to improve routine bioassay monitoring for freshly separated, poorly transported plutonium
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bihl, D.E.; Lynch, T.P.; Carbaugh, E.H.
1988-09-01
Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than the 500-day half-time recommended for class Y plutonium in Publication 30 of the International Commission on Radiological Protection(ICRP). The more tenaciously retained material is referred to as super class Y plutonium. The ability to detect super class Y plutonium by current routine bioassay measurements is shown to be poor. Pacific Northwest Laboratory staff involved in the Hanford Internal Dosimetry Program investigated four methods to se if improvements in routine monitoring of workers for fresh super class Y plutoniummore » are feasible. The methods were lung counting, urine sampling, fecal sampling, and use of diethylenetriaminepentaacetate (DTPA) to enhance urinary excretion. Use of DTPA was determined to be not feasible. Routine fecal sampling was found to be feasible but not recommended. Recommendations were made to improve the detection level for routine annual urinalysis and routine annual lung counting. 12 refs., 9 figs., 7 tabs.« less
Findlay, Eileen J
2009-01-01
This article examines the life histories of women return migrants to Puerto Rico. It emphasizes the cultural aspects of return migration, especially how the narrators understood and expressed their collective identity as distinctive from Puerto Ricans born and raised on the island. These informants turned their life histories into morality fables of class mobility, gender role restriction, and social rejection on the island. These tales asserted their radical differences from both middle class-islanders, whom they had joined, and the working-class diaspora in New York City, from which they had come. The narrators also built an organization which reinforced their "Latin New Yorker" identity, invented on the island.
Miyamoto, Takamichi; Obayashi, Tohru; Hattori, Eijirou; Yamauchi, Yasuteru; Niwa, Akihiro; Isobe, Mitsuaki
2010-03-01
The clinical course of elderly patients with acute myocardial infarction (AMI) can sometimes unexpectedly result in an adverse outcome even when therapy appears to be successful. We suspect that specific factors may characterize this worsening of status during hospitalization. This study examines whether the pre-hospital physical activity status of the elderly treated with percutaneous coronary intervention (PCI) for AMI affects their in-hospital course. We studied 110 consecutive patients, aged 80 or older, who had undergone emergent PCI for AMI. Patients were divided into two groups based on clinical presentation: Better Killip class (Killip classes I and II) and Worse Killip class (Killip classes III and IV). Patients were also divided into two groups based on pre-hospital physical activity status, determined retrospectively by review of medical records: Good physical activity (n=57) comprising those able to go out alone independently and Poor physical activity comprising those mainly confined to home (n=53). The overall in-hospital mortality rate was 9.1% for the study population. The Worse Killip class group had a higher in-hospital mortality rate than the Better Killip class group (27.8% vs 5.4%, respectively; p=0.0102). In addition, the Poor physical activity group had a higher in-hospital mortality rate than the Good physical activity group (15.1% vs. 3.5%, respectively; p=0.047). These data suggest that pre-hospital physical activity status in elderly patients with AMI may affect in-hospital mortality as well as Killip class.
ERIC Educational Resources Information Center
Dreyer, Lorna M.; Singh, Suzanne A. M.
2016-01-01
This article examines the subjective life experiences of racial minority Xhosa speakers and the factors that contribute to their continued poor academic performance in a previously Whites-only school in South Africa. Vygotskian sociocultural perspective in relation to creating a democratic educational system and Bronfenbrenner's biosystemic theory…
ERIC Educational Resources Information Center
González-Rivera, Christian
2014-01-01
New York's community colleges have a key role to play in elevating poor and working poor New Yorkers into the ranks of the middle class. The economy is producing few decent-paying jobs for people with only a high school diploma, and community colleges offer the most accessible path for people to obtain a post-secondary credential. However, tens of…
Teixeira, M C; Carbone, C; Souto, E B
2017-10-01
Solid lipid nanoparticle (SLN), nanostructured lipid carriers (NLC) and hybrid nanoparticles, have gained increasing interest as drug delivery systems because of their potential to load and release drugs from the Biopharmaceutical classification system (BCS) of class II (low solubility and high permeability) and of class IV (low solubility and low permeability). Lipid properties (e.g. high solubilizing potential, biocompatibility, biotolerability, biodegradability and distinct route of absorption) contribute for the improvement of the bioavailability of these drugs for a set of administration routes. Their interest continues to grow, as translated by the number of patents being field worldwide. This paper discusses the recent advances on the use of SLN, NLC and lipid-polymer hybrid nanoparticles for the loading of lipophilic, poorly water-soluble and poorly permeable drugs, being developed for oral, topical, parenteral and ocular administration, also discussing the industrial applications of these systems. A review of the patents filled between 2014 and 2017, concerning the original inventions of lipid nanocarriers, is also provided. Copyright © 2017 Elsevier Ltd. All rights reserved.
Mehdipanah, Roshanak; Rodríguez-Sanz, Maica; Malmusi, Davide; Muntaner, Carles; Díez, Elia; Bartoll, Xavier; Borrell, Carme
2014-09-01
In the last decade, the Neighbourhoods Law in Catalonia (Spain) funded municipalities that presented urban renewal projects within disadvantaged neighbourhoods focusing on physical, social and economic improvements. The objective of the study was to evaluate the effects of this law on the health and health inequalities of residents in the intervened neighbourhoods in the city of Barcelona. A quasi-experimental predesign and postdesign was used to compare adult residents in five intervened neighbourhoods with eight non-intervened comparison neighbourhoods with similar socioeconomic characteristics. The Barcelona Health Survey was used for studying self-rated and mental health in pre (2001, 2006) and post (2011) years. Poisson regression models stratified by sex were used to compute prevalence ratios comparing 2011 with 2006, and later stratified by social class, to study health inequalities. The intervened neighbourhoods had a significant decrease in poor self-rated health in both sexes while no significant changes occurred in the comparison group. When stratified by social class, a significant improvement was observed in poor self-rated health in the manual group of the intervened neighbourhoods in both sexes, resulting in a decrease in self-rated health inequalities. Similar results were observed in poor mental health of women, while in men, poor mental health worsens in both neighbourhood groups but mostly in the comparison group. The Neighbourhoods Law had a positive effect on self-rated health and seems to prevent poor mental health increases in both sexes and especially among manual social classes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Modelling income distribution impacts of water sector projects in Bangladesh.
Ahmed, C S; Jones, S
1991-09-01
Dynamic analysis was conducted to assess the long-term impacts of water sector projects on agricultural income distribution, and sensitivity analysis was conducted to check the robustness of the 5 assumptions in this study of income distribution and water sector projects in Bangladesh. 7 transitions are analyzed for mutually exclusive irrigation and flooding projects: Nonirrigation to 1) LLP irrigation, 2) STW irrigation, 3) DTW irrigation, 4) major gravity irrigation, and manually operated shallow tubewell irrigation (MOSTI) and Flood Control Projects (FCD) of 6) medium flooded to shallow flooded, and 7) deeply flooded to shallow flooded. 5 analytical stages are involved: 1) farm budgets are derived with and without project cropping patterns for each transition. 2) Estimates are generated for value added/hectare from each transition. 3) Assumptions are made about the number of social classes, distribution of land ownership between classes, extent of tenancy for each social class, term of tenancy contracts, and extent of hiring of labor for each social class. 4) Annual value added/hectare is distributed among social classes. 5) Using Gini coefficients and simple ratios, the distribution of income between classes is estimated for with and without transition. Assumption I is that there are 4 social classes defined by land acreage: large farmers (5 acres), medium farmers (1.5-5.0), small farmers, (.01-1.49), and landless. Assumption II is that land distribution follows the 1978 Land Occupancy Survey (LOS). Biases, if any, are indicated. Assumption III is that large farmers sharecrop out 15% of land to small farmers. Assumption IV is that landlords provide nonirrigated crop land and take 50% of the crop, and, under irrigation, provide 50% of the fertilizer, pesticide, and irrigation costs and take 50% of the crop. Assumption V is that hired and family labor is assumed to be 40% for small farmers, 60% for medium farmers, and 80% for large farmers. It is understood that the analysis is partially complete, since there if no Assessment of the impact on nonagricultural income and employment, or secondary impacts such as demand for irrigation equipment, services for processing, manufacture and transport services, or investment of new agricultural surpluses. Few empirical studies have been done and the estimates apply only to individual project areas. The results show that inequality is greatest with major (gravity) irrigation, followed by STW, DTW and LLP, FCD (medium to shallow), FCD (deep to shallow), and the most equitable MOSTI. Changes in the absolute income accruing to the rural poor would lead to the rank of major gravity irrigation as raising more above the poverty line, followed by MOSTI, minor irritation (STW, DTW, and LLP), and FCD schemes.
USDA-ARS?s Scientific Manuscript database
In lower vertebrates, the contribution of the spleen to anti-bacterial immunity is poorly understood. Researchers have previously reported a phenotypic and genetic correlation between resistance to Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD) and spleen so...
A sprinkling experiment to quantify celerity-velocity differences at the hillslope scale
The difference between celerity and velocity of hillslope water flow is poorly understood. We assessed these differences by combining a 24-day hillslope sprinkling experiment with a spatially explicit hydrologic model analysis. We focused our work at Watershed 10 at the H.J. And...
Impaired Associative Taste Learning and Abnormal Brain Activation in Kinase-Defective eEF2K Mice
ERIC Educational Resources Information Center
Gildish, Iness; Manor, David; David, Orit; Sharma, Vijendra; Williams, David; Agarwala, Usha; Wang, Xuemin; Kenney, Justin W.; Proud, Chris G.; Rosenblum, Kobi
2012-01-01
Memory consolidation is defined temporally based on pharmacological interventions such as inhibitors of mRNA translation (molecular consolidation) or post-acquisition deactivation of specific brain regions (systems level consolidation). However, the relationship between molecular and systems consolidation are poorly understood. Molecular…
ERIC Educational Resources Information Center
Sashittal, Hemant C.; Jassawalla, Avan R.; Markulis, Peter
2012-01-01
Apathy and social disconnectedness among undergraduate business students remain poorly understood and under-researched--despite evidence that they produce an adverse impact on learning-related outcomes. Qualitative research was initially conducted among a sample of undergraduate business students to identify the antecedents and learning-related…
Heredia-Langner, Alejandro; Cort, John; Bailey, Vanessa
2018-01-16
The Fishing for Features Signature Discovery project developed a framework for discovering signature features in challenging environments involving large and complex data sets or where phenomena may be poorly characterized or understood. Researchers at PNNL have applied the framework to the optimization of biofuels blending and to discover signatures of climate change on microbial soil communities.
This project examined a common, but poorly understood, problem associated with land development, namely the modifications made to soil structure and the associated reduced rainfall infiltration and increased runoff. The project was divided into two separate major tasks: 1) to tes...
Engineering Education as a Complex System
ERIC Educational Resources Information Center
Gattie, David K.; Kellam, Nadia N.; Schramski, John R.; Walther, Joachim
2011-01-01
This paper presents a theoretical basis for cultivating engineering education as a complex system that will prepare students to think critically and make decisions with regard to poorly understood, ill-structured issues. Integral to this theoretical basis is a solution space construct developed and presented as a benchmark for evaluating…
Can Near-Peer Teaching Improve Academic Performance?
ERIC Educational Resources Information Center
Williams, Brett; Fowler, James
2014-01-01
Near peer teaching is becoming increasingly popular within healthcare education. The experiences and effects of near-peer teaching upon the near-peer teachers' academic performance are poorly understood. In order to address this, the objective of this study was to examine whether a near-peer teaching program improved the overall clinical unit…
Stages and Spatial Scales of Recruitment Limitation in Southern Appalachain Forests
James S. Clark; Eric Macklin; Leslie Wood
1998-01-01
Recruitment limitation of tree population dynamics is poorly understood, because fecundity and dispersal are difficult to characterize in closed stands. We present an approach that estimates seed production and dispersal under closed canopies and four limitations on recruitment: tree density and location, fecundity, seed dispersal, and establishment. Consistent...
Genetic structure and domestication of carrot (Daucus carota subsp. sativus L.) (Apiaceae)
USDA-ARS?s Scientific Manuscript database
Analyses of genetic structure and phylogenetic relationships illuminate the origin and domestication of modern crops. Despite being an important world-wide vegetable, the genetic structure and domestication of carrot (Daucus carota L.) is poorly understood. We provide the first such study using a la...
Emotional climate and feeding styles: observational analysis of dinner in low-income families
USDA-ARS?s Scientific Manuscript database
Indulgent feeding styles have been associated with a higher risk for childhood overweight. The processes through which feeding styles impact child weight are poorly understood. The aim of this study was to observe differences in the emotional climate created by parents (affect, tone of voice, gest...
USDA-ARS?s Scientific Manuscript database
The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate pathogen capable of causing explosive disease epidemics that drastically reduce the yield of soybean (Glycine max). Currently, the molecular mechanisms by which P. pachyrhizi and other rust fungi cause disease are poorly understood...
Developing Research Relationships toward a Learning Partnership
ERIC Educational Resources Information Center
Kaasila, Raimo; Lutovac, Sonja
2015-01-01
Research relationships are often poorly understood. Why are some collaborations between research partners more productive than others? This question was a starting point of this paper. By describing their own experiences over a period of three years, the authors evaluated research relationships through collaborative self-study. At the beginning,…
Reciprocal Peer Coaching: A Critical Contributor to Implementing Individual Leadership Plans
ERIC Educational Resources Information Center
Goldman, Ellen; Wesner, Marilyn; Karnchanomai, Ornpawee
2013-01-01
Billions of dollars are spent annually on programs to develop organizational leaders, yet the effectiveness of these programs is poorly understood. Scholars advise that value is enhanced by the development of individual leadership plans at program completion, followed by implementation experience with subsequent coaching and reflection. The…
BEL1-LIKE HOMEODOMAIN 11 regulated chloroplast development and chlorophyll synthesis in tomato fruit
USDA-ARS?s Scientific Manuscript database
Chloroplast development and chlorophyll content and metabolism in unripe tomato contribute to the growth and development of the fruit, and also the ripe fruit quality, but the mechanism is poorly understood. In this work, seven homeobox-containing transcription factors (TFs) with specific ripening-a...
Geographic variation in mycangial communities of Xyleborus glabratus
USDA-ARS?s Scientific Manuscript database
Abstract Factors that influence fungal communities in ambrosia beetle mycangia are poorly understood. The beetle that is responsible for spreading laurel wilt in the SE USA, Xyleborus glabratus, was examined at three sites along a 500 km N-S transect in Florida, each populated by host trees in the ...
Effects of Post-Encoding Stress on Performance in the DRM False Memory Paradigm
ERIC Educational Resources Information Center
Pardilla-Delgado, Enmanuelle; Alger, Sara E.; Cunningham, Tony J.; Kinealy, Brian; Payne, Jessica D.
2016-01-01
Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false…
ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA
The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...
Critical role for CCAAT/Enhancer-binding protein beta in immune complex-induced acute lung injury
USDA-ARS?s Scientific Manuscript database
Although inflammation plays a central role in the pathogenesis of acute lung injury (ALI), the molecular mechanisms underlying inflammatory responses in ALI are poorly understood, and therapeutic options remain limited. The CCAAT/enhancer-binding protein (C/EBP) gamma and -gamma have been implicated...
Starvation Promotes Odor/Feeding-Time Associations in Flies
ERIC Educational Resources Information Center
Chouhan, Nitin Singh; Wolf, Reinard; Heisenberg, Martin
2017-01-01
Starvation causes a motivational state that facilitates diverse behaviors such as feeding, walking, and search. Starved "Drosophila" can form odor/feeding-time associations but the role of starvation in encoding of "time" is poorly understood. Here we show that the extent of starvation is correlated with the fly's ability to…
Cobalt Distribution and Speciation: Effect of Aging, Intermittent Submergence, In situ Rice Roots
The speciation and distribution of cobalt (Co) in soils is poorly understood. This study was conducted using X-ray absorption spectroscopy (XAS) techniques to examine the influence of soluble Co(II) aging, submergence-dried cycling, and the presence of in vivo rice roots on the...
What makes Great Basin sagebrush ecosystems invasible by Bromus tectorum?
Jeanne C. Chambers; Bruce A. Roundy; Robert R. Blank; Susan E. Meyer; A. Whittaker
2007-01-01
Ecosystem susceptibility to invasion by nonnative species is poorly understood, but evidence is increasing that spatial and temporal variability in resources has large-scale effects. We conducted a study in Artemisia tridentata ecosystems at two Great Basin locations examining differences in resource availability and invasibility of Bromus...
RATIONALE: Exposure to ambient particulate matter (PM) and ozone has been associated with cardiovascular disease (CVD). However, the mechanisms linking PM and ozone exposure to CVD remain poorly understood .OBJECTIVE: This study explored associations between short-term exposures ...
Accessing and Selecting Word Meaning in Autism Spectrum Disorder
ERIC Educational Resources Information Center
Henderson, L. M.; Clarke, P. J.; Snowling, M. J.
2011-01-01
Background: Comprehension difficulties are commonly reported in autism spectrum disorder (ASD) but the causes of these difficulties are poorly understood. This study investigates how children with ASD access and select meanings of ambiguous words to test four hypotheses regarding the nature of their comprehension difficulties: semantic deficit,…
USDA-ARS?s Scientific Manuscript database
Next generation fungal amplicon sequencing is being used with increasing frequency to study fungal diversity in various ecosystems; however, the influence of sample preparation on the characterization of fungal community is poorly understood. We investigated the effects of four procedural modificati...
Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because they are difficult to sample and...
Coping Mediates the Association between Gender and Depressive Symptomatology in Adolescence
ERIC Educational Resources Information Center
Malooly, Ashley M.; Flannery, Kaitlin M.; Ohannessian, Christine McCauley
2017-01-01
Previous studies have found evidence for gender and racial/ethnic differences in depressive symptoms in adolescence; however, the mechanisms driving this relationship are poorly understood. The goal of this study was to examine the role of individual differences in dispositional coping in the relationships between gender and depressive…
USDA-ARS?s Scientific Manuscript database
The optimal defense theory (ODT) predicts that plants allocate defense compounds to their tissues depending on its value and the likelihood of herbivore attack. Whereas ODT has been confirmed for static damage levels it remains poorly understood if ODT holds true for defense organization of inducibl...
Drought and leaf herbivory influence floral volatiles and pollinator attraction
Laura A. Burkle; Justin B. Runyon
2016-01-01
The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...
Ozone exposure decreases belowground carbon allocation and root growth of plants;however,the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood.To evaluate the potential for plant compensation,we followed the prog...
Rationale: Exposure to particulate matter is a risk factor for cardiopulmonary disease but the related molecular mechanisms are poorly understood. Previously we studied cardiovascular responses in healthy WKY rats following inhalation exposure to ultrafine carbon particles (UfCPs...
Relationship of neuropeptide FF receptors with pubertal maturation of gilts
USDA-ARS?s Scientific Manuscript database
Mechanisms governing the timing of puberty in pigs are poorly understood. A genome-wide association study for age at first estrus in pigs identified candidate genes including NPFFR2, which is a putative receptor for RFamide-related peptides (RFRP). RFRP has been shown to negatively regulate secret...
Development of Sensitivity to Audiovisual Temporal Asynchrony during Midchildhood
ERIC Educational Resources Information Center
Kaganovich, Natalya
2016-01-01
Temporal proximity is one of the key factors determining whether events in different modalities are integrated into a unified percept. Sensitivity to audiovisual temporal asynchrony has been studied in adults in great detail. However, how such sensitivity matures during childhood is poorly understood. We examined perception of audiovisual temporal…
Understanding Authority in Classrooms: A Review of Theory, Ideology, and Research
ERIC Educational Resources Information Center
Pace, Judith L.; Hemmings, Annette
2007-01-01
Authority is a fundamental, problematic, and poorly understood component of classroom life. A better understanding of classroom authority can be achieved by reviewing writings on social theory, educational ideology, and qualitative research in schools. Social theories provide important analytical tools for examining the constitutive elements of…
Impacts of feral horse use on riparian vegetation within the sagebrush steppe
USDA-ARS?s Scientific Manuscript database
Feral horses inhabit rangeland ecosystems around the world, but their impacts on riparian ecosystems are poorly understood. We characterized impacts of a free-ranging horse population on the structure and composition of riparian plant communities in the sagebrush steppe ecosystem in the western US....
The industrial solvent perchloroethylene (PERC) is listed as a hazardous air pollutant in the 1990 Ammendments to Clean Air Act and is a known neurotoxicant. However, the mechanisms by which PERC alters nervous system function are poorly understood. In recent years, it has been d...
USDA-ARS?s Scientific Manuscript database
The fungus Slafractonia leguminicola, the causal agent of blackpatch disease of legumes produces two mycotoxins slaframine and swainsonine, causing slobbers’ symptoms and locoism of grazing animals, respectively. The genetics of this important fungus is poorly understood. This work aimed to develop ...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heredia-Langner, Alejandro; Cort, John; Bailey, Vanessa
2016-07-21
The Fishing for Features Signature Discovery project developed a framework for discovering signature features in challenging environments involving large and complex data sets or where phenomena may be poorly characterized or understood. Researchers at PNNL have applied the framework to the optimization of biofuels blending and to discover signatures of climate change on microbial soil communities.