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Sample records for abundance increased dramatically

  1. Dramatic increase in the relative abundance of large male dungeness crabs Cancer magister following closure of commercial fishing in Glacier Bay, Alaska

    USGS Publications Warehouse

    Taggart, S.J.; Shirley, T.C.; O'Clair, C. E.; Mondragon, J.

    2004-01-01

    The size structure of the population of the Dungeness crab Cancer magister was studied at six sites in or near Glacier Bay, Alaska, before and after the closure of commercial fishing. Seven years of preclosure and 4 years of postclosure data are presented. After the closure of Glacier Bay to commercial fishing, the number and size of legal-sized male Dungeness crabs increased dramatically at the experimental sites. Female and sublegal-sized male crabs, the portions of the population not directly targeted by commercial fishing, did not increase in size or abundance following the closure. There was not a large shift in the size-abundance distribution of male crabs at the control site that is still open to commercial fishing. Marine protected areas are being widely promoted as effective tools for managing fisheries while simultaneously meeting marine conservation goals and maintaining marine biodiversity. Our data demonstrate that the size of male Dungeness crabs can markedly increase in a marine reserve, which supports the concept that marine reserves could help maintain genetic diversity in Dungeness crabs and other crab species subjected to size-limit fisheries and possibly increase the fertility of females. ?? 2004 by the American Fisheries Society.

  2. Dramatic increase in fatigue life in hierarchical graphene composites.

    PubMed

    Yavari, F; Rafiee, M A; Rafiee, J; Yu, Z-Z; Koratkar, N

    2010-10-01

    We report the synthesis and fatigue characterization of fiberglass/epoxy composites with various weight fractions of graphene platelets infiltrated into the epoxy resin as well as directly spray-coated on to the glass microfibers. Remarkably only ∼0.2% (with respect to the epoxy resin weight and ∼0.02% with respect to the entire laminate weight) of graphene additives enhanced the fatigue life of the composite in the flexural bending mode by up to 1200-fold. By contrast, under uniaxial tensile fatigue conditions, the graphene fillers resulted in ∼3-5-fold increase in fatigue life. The fatigue life increase (in the flexural bending mode) with graphene additives was ∼1-2 orders of magnitude superior to those obtained using carbon nanotubes. In situ ultrasound analysis of the nanocomposite during the cyclic fatigue test suggests that the graphene network toughens the fiberglass/epoxy-matrix interface and prevents the delamination/buckling of the glass microfibers under compressive stress. Such fatigue-resistant hierarchical materials show potential to improve the safety, reliability, and cost effectiveness of fiber-reinforced composites that are increasingly the material of choice in the aerospace, automotive, marine, sports, biomedical, and wind energy industries.

  3. Publications on Peripheral Nerve Injuries during World War I: A Dramatic Increase in Knowledge.

    PubMed

    Koehler, Peter J

    2016-01-01

    Publications from French (Jules Tinel and Chiriachitza Athanassio-Bénisty), English (James Purves-Stewart, Arthur Henry Evans and Hartley Sidney Carter), German (Otfrid Foerster and Hermann Oppenheim) and American (Charles Harrison Frazier and Byron Stookey) physicians from both sides of the front during World War I (WWI) contributed to a dramatic increase in knowledge about peripheral nerve injuries. Silas Weir Mitchell's original experience with respect to these injuries, and particularly causalgia, during the American Civil War was further expanded in Europe during WWI. Following the translation of one of his books, he was referred to mainly by French physicians. During WWI, several French books were in turn translated into English, which influenced American physicians, as was observed in the case of Byron Stookey. The establishment of neurological centres played an important role in the concentration of experience and knowledge. Several eponyms originated during this period (including the Hoffmann-Tinel sign and the Froment sign). Electrodiagnostic tools were increasingly used.

  4. Dramatic Increases of Soil Microbial Functional Gene Diversity at the Treeline Ecotone of Changbai Mountain

    PubMed Central

    Shen, Congcong; Shi, Yu; Ni, Yingying; Deng, Ye; Van Nostrand, Joy D.; He, Zhili; Zhou, Jizhong; Chu, Haiyan

    2016-01-01

    The elevational and latitudinal diversity patterns of microbial taxa have attracted great attention in the past decade. Recently, the distribution of functional attributes has been in the spotlight. Here, we report a study profiling soil microbial communities along an elevation gradient (500–2200 m) on Changbai Mountain. Using a comprehensive functional gene microarray (GeoChip 5.0), we found that microbial functional gene richness exhibited a dramatic increase at the treeline ecotone, but the bacterial taxonomic and phylogenetic diversity based on 16S rRNA gene sequencing did not exhibit such a similar trend. However, the β-diversity (compositional dissimilarity among sites) pattern for both bacterial taxa and functional genes was similar, showing significant elevational distance-decay patterns which presented increased dissimilarity with elevation. The bacterial taxonomic diversity/structure was strongly influenced by soil pH, while the functional gene diversity/structure was significantly correlated with soil dissolved organic carbon (DOC). This finding highlights that soil DOC may be a good predictor in determining the elevational distribution of microbial functional genes. The finding of significant shifts in functional gene diversity at the treeline ecotone could also provide valuable information for predicting the responses of microbial functions to climate change. PMID:27524983

  5. Dramatic Increases of Soil Microbial Functional Gene Diversity at the Treeline Ecotone of Changbai Mountain.

    PubMed

    Shen, Congcong; Shi, Yu; Ni, Yingying; Deng, Ye; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Chu, Haiyan

    2016-01-01

    The elevational and latitudinal diversity patterns of microbial taxa have attracted great attention in the past decade. Recently, the distribution of functional attributes has been in the spotlight. Here, we report a study profiling soil microbial communities along an elevation gradient (500-2200 m) on Changbai Mountain. Using a comprehensive functional gene microarray (GeoChip 5.0), we found that microbial functional gene richness exhibited a dramatic increase at the treeline ecotone, but the bacterial taxonomic and phylogenetic diversity based on 16S rRNA gene sequencing did not exhibit such a similar trend. However, the β-diversity (compositional dissimilarity among sites) pattern for both bacterial taxa and functional genes was similar, showing significant elevational distance-decay patterns which presented increased dissimilarity with elevation. The bacterial taxonomic diversity/structure was strongly influenced by soil pH, while the functional gene diversity/structure was significantly correlated with soil dissolved organic carbon (DOC). This finding highlights that soil DOC may be a good predictor in determining the elevational distribution of microbial functional genes. The finding of significant shifts in functional gene diversity at the treeline ecotone could also provide valuable information for predicting the responses of microbial functions to climate change. PMID:27524983

  6. Publications on Peripheral Nerve Injuries during World War I: A Dramatic Increase in Knowledge.

    PubMed

    Koehler, Peter J

    2016-01-01

    Publications from French (Jules Tinel and Chiriachitza Athanassio-Bénisty), English (James Purves-Stewart, Arthur Henry Evans and Hartley Sidney Carter), German (Otfrid Foerster and Hermann Oppenheim) and American (Charles Harrison Frazier and Byron Stookey) physicians from both sides of the front during World War I (WWI) contributed to a dramatic increase in knowledge about peripheral nerve injuries. Silas Weir Mitchell's original experience with respect to these injuries, and particularly causalgia, during the American Civil War was further expanded in Europe during WWI. Following the translation of one of his books, he was referred to mainly by French physicians. During WWI, several French books were in turn translated into English, which influenced American physicians, as was observed in the case of Byron Stookey. The establishment of neurological centres played an important role in the concentration of experience and knowledge. Several eponyms originated during this period (including the Hoffmann-Tinel sign and the Froment sign). Electrodiagnostic tools were increasingly used. PMID:27035152

  7. Dramatic increase in sea otter mortality from white sharks in California

    USGS Publications Warehouse

    Tinker, M. Tim; Hatfield, Brian B.; Harris, Michael D.; Ames, Jack A.

    2016-01-01

    Although southern sea otters (Enhydra lutris nereis) are not considered prey for white sharks (Carcharodon carcharias), sharks do nonetheless bite sea otters. We analyzed spatial and temporal trends in shark bites on sea otters in California, assessing the frequency of shark bite wounds in 1,870 carcasses collected since 1985. The proportion of stranded sea otters having shark bites has increased sharply since 2003, and white shark bites now account for >50% of recovered carcasses. The trend was most pronounced in the southern part of the range, from Estero Bay to Point Conception, where shark bite frequency has increased eightfold. Seasonal trends were also evident: most shark-bitten carcasses are recovered in late summer and fall; however, the period of elevated shark bite frequency has lengthened. The causes of these trends are unclear, but possible contributing factors include increased white shark abundance and/or changes in white shark behavior and distribution. In particular, the spatiotemporal patterns of shark-bitten sea otters match increases in pinniped populations, and the increased availability of marine mammal prey for white sharks may have led to more sharks spending more time in nearshore waters utilized by both sea otters and pinnipeds.

  8. Mammalian Brain Development is Accompanied by a Dramatic Increase in Bipolar DNA Methylation

    PubMed Central

    Sun, Ming-an; Sun, Zhixiong; Wu, Xiaowei; Rajaram, Veena; Keimig, David; Lim, Jessica; Zhu, Hongxiao; Xie, Hehuang

    2016-01-01

    DNA methylation is an epigenetic mechanism critical for tissue development and cell specification. Mammalian brains consist of many different types of cells with assumedly distinct DNA methylation profiles, and thus some genomic loci may demonstrate bipolar DNA methylation pattern, i.e. hypermethylated in one cell subset but hypomethylated in others. Currently, how extensive methylation patterns vary among brain cells is unknown and bipolar methylated genomic loci remain largely unexplored. In this study, we implemented a procedure to infer cell-subset specific methylated (CSM) loci from the methylomes of human and mouse frontal cortices at different developmental stages. With the genome-scale hairpin bisulfite sequencing approach, we demonstrated that the majority of CSM loci predicted likely resulted from the methylation differences among brain cells rather than from asymmetric DNA methylation between DNA double strands. Correlated with enhancer-associated histone modifications, putative CSM loci increased dramatically during early stages of brain development and were enriched for GWAS variants associated with neurological disorder-related diseases/traits. Altogether, this study provides a procedure to identify genomic regions showing methylation differences in a mixed cell population and our results suggest that a set of cis-regulatory elements are primed in early postnatal life whose functions may be compromised in human neurological disorders. PMID:27585862

  9. Mammalian Brain Development is Accompanied by a Dramatic Increase in Bipolar DNA Methylation.

    PubMed

    Sun, Ming-An; Sun, Zhixiong; Wu, Xiaowei; Rajaram, Veena; Keimig, David; Lim, Jessica; Zhu, Hongxiao; Xie, Hehuang

    2016-01-01

    DNA methylation is an epigenetic mechanism critical for tissue development and cell specification. Mammalian brains consist of many different types of cells with assumedly distinct DNA methylation profiles, and thus some genomic loci may demonstrate bipolar DNA methylation pattern, i.e. hypermethylated in one cell subset but hypomethylated in others. Currently, how extensive methylation patterns vary among brain cells is unknown and bipolar methylated genomic loci remain largely unexplored. In this study, we implemented a procedure to infer cell-subset specific methylated (CSM) loci from the methylomes of human and mouse frontal cortices at different developmental stages. With the genome-scale hairpin bisulfite sequencing approach, we demonstrated that the majority of CSM loci predicted likely resulted from the methylation differences among brain cells rather than from asymmetric DNA methylation between DNA double strands. Correlated with enhancer-associated histone modifications, putative CSM loci increased dramatically during early stages of brain development and were enriched for GWAS variants associated with neurological disorder-related diseases/traits. Altogether, this study provides a procedure to identify genomic regions showing methylation differences in a mixed cell population and our results suggest that a set of cis-regulatory elements are primed in early postnatal life whose functions may be compromised in human neurological disorders. PMID:27585862

  10. Constitutive Expression of GATA4 Dramatically Increases the Cardiogenic Potential of D3 Mouse Embryonic Stem Cells

    PubMed Central

    Laemmle, Lillian L.; Cohen, Justus B.; Glorioso, Joseph C.

    2016-01-01

    The transcription factor GATA binding protein 4 (GATA4) is a vital regulator of cardiac programming that acts by inducing the expression of many different genes involved in cardiomyogenesis. Here we generated a D3 mouse embryonic stem cell line that constitutively expresses high levels of GATA4 and show that these cells have dramatically increased cardiogenic potential compared to an eGFP-expressing control cell line. Embryoid bodies (EB) derived from the D3-GATA4 line displayed increased levels of cardiac gene expression and showed more abundant cardiomyocyte differentiation than control eGFP EB. These cells and two additional lines expressing lower levels of GATA4 provide a platform to screen previously untested cardiac genes and gene combinations for their ability to further increase the efficiency of cardiomyocyte differentiation beyond that achieved by transgenic GATA4 alone. Non-integrative delivery of identified gene combinations will aid in the production of differentiated cells for the treatment of ischemic cardiomyopathy. PMID:27441042

  11. Permeability enhancers dramatically increase zanamivir absolute bioavailability in rats: implications for an orally bioavailable influenza treatment.

    PubMed

    Holmes, Eric H; Devalapally, Harikrishna; Li, Libin; Perdue, Michael L; Ostrander, Gary K

    2013-01-01

    We have demonstrated that simple formulations composed of the parent drug in combination with generally regarded as safe (GRAS) permeability enhancers are capable of dramatically increasing the absolute bioavailability of zanamivir. This has the advantage of not requiring modification of the drug structure to promote absorption, thus reducing the regulatory challenges involved in conversion of an inhaled to oral route of administration of an approved drug. Absolute bioavailability increases of up to 24-fold were observed when Capmul MCM L8 (composed of mono- and diglycerides of caprylic/capric acids in glycerol) was mixed with 1.5 mg of zanamivir and administered intraduodenally to rats. Rapid uptake (t(max) of 5 min) and a C(max) of over 7200 ng/mL was achieved. Variation of the drug load or amount of enhancer demonstrated a generally linear variation in absorption, indicating an ability to optimize a formulation for a desired outcome such as a targeted C(max) for enzyme saturation. No absorption enhancement was observed when the enhancer was given 2 hr prior to drug administration, indicating, in combination with the observed tmax, that absorption enhancement is temporary. This property is significant and aligns well with therapeutic applications to limit undesirable drug-drug interactions, potentially due to the presence of other poorly absorbed polar drugs. These results suggest that optimal human oral dosage forms of zanamivir should be enteric-coated gelcaps or softgels for intraduodenal release. There continues to be a strong need and market for multiple neuraminidase inhibitors for influenza treatment. Creation of orally available formulations of inhibitor drugs that are currently administered intravenously or by inhalation would provide a significant improvement in treatment of influenza. The very simple GRAS formulation components and anticipated dosage forms would require low manufacturing costs and yield enhanced convenience. These results are being

  12. Permeability enhancers dramatically increase zanamivir absolute bioavailability in rats: implications for an orally bioavailable influenza treatment.

    PubMed

    Holmes, Eric H; Devalapally, Harikrishna; Li, Libin; Perdue, Michael L; Ostrander, Gary K

    2013-01-01

    We have demonstrated that simple formulations composed of the parent drug in combination with generally regarded as safe (GRAS) permeability enhancers are capable of dramatically increasing the absolute bioavailability of zanamivir. This has the advantage of not requiring modification of the drug structure to promote absorption, thus reducing the regulatory challenges involved in conversion of an inhaled to oral route of administration of an approved drug. Absolute bioavailability increases of up to 24-fold were observed when Capmul MCM L8 (composed of mono- and diglycerides of caprylic/capric acids in glycerol) was mixed with 1.5 mg of zanamivir and administered intraduodenally to rats. Rapid uptake (t(max) of 5 min) and a C(max) of over 7200 ng/mL was achieved. Variation of the drug load or amount of enhancer demonstrated a generally linear variation in absorption, indicating an ability to optimize a formulation for a desired outcome such as a targeted C(max) for enzyme saturation. No absorption enhancement was observed when the enhancer was given 2 hr prior to drug administration, indicating, in combination with the observed tmax, that absorption enhancement is temporary. This property is significant and aligns well with therapeutic applications to limit undesirable drug-drug interactions, potentially due to the presence of other poorly absorbed polar drugs. These results suggest that optimal human oral dosage forms of zanamivir should be enteric-coated gelcaps or softgels for intraduodenal release. There continues to be a strong need and market for multiple neuraminidase inhibitors for influenza treatment. Creation of orally available formulations of inhibitor drugs that are currently administered intravenously or by inhalation would provide a significant improvement in treatment of influenza. The very simple GRAS formulation components and anticipated dosage forms would require low manufacturing costs and yield enhanced convenience. These results are being

  13. Dramatic declines in Euphausia pacifica abundance in the East China Sea: response to recent regional climate change.

    PubMed

    Xu, Zhao-Li; Zhang, Dong

    2014-03-01

    As with other marine ecosystems around the world, water temperature has been anomalously warm in recent years in the East China Sea. We analyzed historical data to explore the effects of climatic change on the abundance and distribution variation of Euphausia pacifica in the East China Sea (the Changjiang River estuary and adjacent areas). In 1959, the highest abundance occurred in the spring and autumn, and this krill species was still abundant in May 1974; however, its abundance was significantly reduced in 2002, markedly in spring. Euphausia pacifica was the numerically dominant euphausiid in the East China Sea in 1959. Its mean abundance was up to 1.91 ind m(-3) and 1.64 ind/m(3) in 1959 and 1974, respectively; however, this figure decreased to 0.36 ind m(-3) in 2002. Since 2003, the abundances have been near zero in the most years. Both inter-annual (between November 1959 and 2002) and inter-monthly (between May and June 1959) comparisons suggest that E. pacifica has had a temperature-driven northward movement in response to rising sea surface temperature, especially the positive anomalies since 1997. However, E. pacifica did not come back to the previous habitat when temperature became relative cold. Hence additional factors affecting the E. pacifica distribution and abundance need to be investigated in the future study.

  14. Increased natural mortality at low abundance can generate an Allee effect in a marine fish.

    PubMed

    Kuparinen, Anna; Hutchings, Jeffrey A

    2014-10-01

    Negative density-dependent regulation of population dynamics promotes population growth at low abundance and is therefore vital for recovery following depletion. Inversely, any process that reduces the compensatory density-dependence of population growth can negatively affect recovery. Here, we show that increased adult mortality at low abundance can reverse compensatory population dynamics into its opposite-a demographic Allee effect. Northwest Atlantic cod (Gadus morhua) stocks collapsed dramatically in the early 1990s and have since shown little sign of recovery. Many experienced dramatic increases in natural mortality, ostensibly attributable in some populations to increased predation by seals. Our findings show that increased natural mortality of a magnitude observed for overfished cod stocks has been more than sufficient to fundamentally alter the dynamics of density-dependent population regulation. The demographic Allee effect generated by these changes can slow down or even impede the recovery of depleted populations even in the absence of fishing. PMID:26064531

  15. Increased natural mortality at low abundance can generate an Allee effect in a marine fish.

    PubMed

    Kuparinen, Anna; Hutchings, Jeffrey A

    2014-10-01

    Negative density-dependent regulation of population dynamics promotes population growth at low abundance and is therefore vital for recovery following depletion. Inversely, any process that reduces the compensatory density-dependence of population growth can negatively affect recovery. Here, we show that increased adult mortality at low abundance can reverse compensatory population dynamics into its opposite-a demographic Allee effect. Northwest Atlantic cod (Gadus morhua) stocks collapsed dramatically in the early 1990s and have since shown little sign of recovery. Many experienced dramatic increases in natural mortality, ostensibly attributable in some populations to increased predation by seals. Our findings show that increased natural mortality of a magnitude observed for overfished cod stocks has been more than sufficient to fundamentally alter the dynamics of density-dependent population regulation. The demographic Allee effect generated by these changes can slow down or even impede the recovery of depleted populations even in the absence of fishing.

  16. Dam removal increases American eel abundance in distant headwater streams

    USGS Publications Warehouse

    Hitt, Nathaniel P.; Eyler, Sheila; Wofford, John E.B.

    2012-01-01

    American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with decreasing minimum eel lengths in headwater streams, suggesting that the dam previously impeded migration of many small-bodied individuals (<300 mm TL). We hypothesize that restoring connectivity to headwater streams could increase eel population growth rates by increasing female eel numbers and fecundity. This study demonstrated that dams may influence eel abundances in headwater streams up to 150 river kilometers distant, and that dam removal may provide benefits for eel management and conservation at the landscape scale.

  17. The Mixmasters: A Smart Marketing Mix Helps a Small College Dramatically Increase Student Enrollments.

    ERIC Educational Resources Information Center

    Paul, R. Dana; Stark, Ken

    1983-01-01

    Adrian College's steady increase and confidence in enrollment projections stem from a research-based, thoughtfully planned, carefully implemented, highly controlled marketing programs. Four major elements of a successful marketing mix are identified: product, price, place, promotion. (MLW)

  18. Germination dramatically increases isoflavonoid content and diversity in chickpea (Cicer arietinum L.) seeds.

    PubMed

    Wu, Ziyun; Song, Lixia; Feng, Shengbao; Liu, Yuancai; He, Guangyuan; Yioe, Yoecelyn; Liu, Shao Quan; Huang, Dejian

    2012-09-01

    The effect of germination on bioactive components in legume seeds was investigated in terms of the antioxidant capacity and total phenolic contents. Germination increased the total phenolic content and antioxidant capacity of most seeds. Particularly in chickpea seeds, the isoflavone contents increased by over 100 fold, mainly due to the increase of formononetin and biochanin A level. As a result, these two compounds were conveniently isolated from the germinated seeds in preparative scale and structurally confirmed by UV-vis, ESI-MS, and (1)H NMR spectroscopies. Isoflavonoid fingerprints analyzed by HPLC-PDA and LC-ESI-MS demonstrated that germination could significantly increase isoflavonoids diversity. Twenty-five isoflavonoids were detected and identified tentatively. These include 20 isoflavones, 2 isoflavanones, and 3 pterocarpan phytoalexins. Total isoflavonoid content of germinated chickpea was approximately 5-fold of that of germinated soybean. Our findings suggest that the germinated chickpea seeds could serve as a promising functional food rich in isoflavonoids.

  19. Dramatic Increase in Oxidative Stress in Carbon-Irradiated Normal Human Skin Fibroblasts

    PubMed Central

    Laurent, Carine; Leduc, Alexandre; Pottier, Ivannah; Prévost, Virginie; Sichel, François; Lefaix, Jean-Louis

    2013-01-01

    Skin complications were recently reported after carbon-ion (C-ion) radiation therapy. Oxidative stress is considered an important pathway in the appearance of late skin reactions. We evaluated oxidative stress in normal human skin fibroblasts after carbon-ion vs. X-ray irradiation. Survival curves and radiobiological parameters were calculated. DNA damage was quantified, as were lipid peroxidation (LPO), protein carbonylation and antioxidant enzyme activities. Reduced and oxidized glutathione ratios (GSH/GSSG) were determined. Proinflammatory cytokine secretion in culture supernatants was evaluated. The relative biological effectiveness (RBE) of C-ions vs. X-rays was 4.8 at D0 (irradiation dose corresponding to a surviving fraction of 37%). Surviving fraction at 2 Gy (SF2) was 71.8% and 7.6% for X-rays and C-ions, respectively. Compared with X-rays, immediate DNA damage was increased less after C-ions, but a late increase was observed at D10% (irradiation dose corresponding to a surviving fraction of 10%). LPO products and protein carbonyls were only increased 24 hours after C-ions. After X-rays, superoxide dismutase (SOD) activity was strongly increased immediately and on day 14 at D0% (irradiation dose corresponding to a surviving fraction of around 0%), catalase activity was unchanged and glutathione peroxidase (GPx) activity was increased only on day 14. These activities were decreased after C-ions compared with X-rays. GSH/GSSG was unchanged after X-rays but was decreased immediately after C-ion irradiation before an increase from day 7. Secretion of IL-6 was increased at late times after X-ray irradiation. After C-ion irradiation, IL-6 concentration was increased on day 7 but was lower compared with X-rays at later times. C-ion effects on normal human skin fibroblasts seemed to be harmful in comparison with X-rays as they produce late DNA damage, LPO products and protein carbonyls, and as they decrease antioxidant defences. Mechanisms leading to this

  20. Scavenging ROS dramatically increase NMDA receptor whole-cell currents in painted turtle cortical neurons.

    PubMed

    Dukoff, David James; Hogg, David William; Hawrysh, Peter John; Buck, Leslie Thomas

    2014-09-15

    Oxygen deprivation triggers excitotoxic cell death in mammal neurons through excessive calcium loading via over-activation of N-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. This does not occur in the western painted turtle, which overwinters for months without oxygen. Neurological damage is avoided through anoxia-mediated decreases in NMDA and AMPA receptor currents that are dependent upon a modest rise in intracellular Ca(2+) concentrations ([Ca(2+)]i) originating from mitochondria. Anoxia also blocks mitochondrial reactive oxygen species (ROS) generation, which is another potential signaling mechanism to regulate glutamate receptors. To assess the effects of decreased intracellular [ROS] on NMDA and AMPA receptor currents, we scavenged ROS with N-2-mercaptopropionylglycine (MPG) or N-acetylcysteine (NAC). Unlike anoxia, ROS scavengers increased NMDA receptor whole-cell currents by 100%, while hydrogen peroxide decreased currents. AMPA receptor currents and [Ca(2+)]i concentrations were unaffected by ROS manipulation. Because decreases in [ROS] increased NMDA receptor currents, we next asked whether mitochondrial Ca(2+) release prevents receptor potentiation during anoxia. Normoxic activation of mitochondrial ATP-sensitive potassium (mKATP) channels with diazoxide decreased NMDA receptor currents and was unaffected by subsequent ROS scavenging. Diazoxide application following ROS scavenging did not rescue scavenger-mediated increases in NMDA receptor currents. Fluorescent measurement of [Ca(2+)]i and ROS levels demonstrated that [Ca(2+)]i increases before ROS decreases. We conclude that decreases in ROS concentration are not linked to anoxia-mediated decreases in NMDA/AMPA receptor currents but are rather associated with an increase in NMDA receptor currents that is prevented during anoxia by mitochondrial Ca(2+) release.

  1. An intertidal snail shows a dramatic size increase over the past century.

    PubMed

    Fisher, Jonathan A D; Rhile, Erika C; Liu, Harrison; Petraitis, Peter S

    2009-03-31

    Changes in the shell architecture of marine snails enhance defenses and greatly improve survival against predators. In the northwest Atlantic Ocean, shorter and thicker shells have been reported for several species following the introduction of predatory Carcinus maenas crabs early in the 20th century. But we report that the shell lengths of Nucella lapillus actually increased by an average of 22.6% over the past century, with no evidence of shell thickening after correcting for shell length. The increases in shell length were greatest on sheltered shores, highlighting the interaction between wave exposure and the sampling period. Comparisons were based on archived shells collected in 1915-1922 from sites that were resampled in 2007. N. lapillus is an important member of North Atlantic marine ecosystems, and our results suggest that the impacts of historical changes in species' key morphological traits on marine ecosystems remain underappreciated. PMID:19307561

  2. An intertidal snail shows a dramatic size increase over the past century.

    PubMed

    Fisher, Jonathan A D; Rhile, Erika C; Liu, Harrison; Petraitis, Peter S

    2009-03-31

    Changes in the shell architecture of marine snails enhance defenses and greatly improve survival against predators. In the northwest Atlantic Ocean, shorter and thicker shells have been reported for several species following the introduction of predatory Carcinus maenas crabs early in the 20th century. But we report that the shell lengths of Nucella lapillus actually increased by an average of 22.6% over the past century, with no evidence of shell thickening after correcting for shell length. The increases in shell length were greatest on sheltered shores, highlighting the interaction between wave exposure and the sampling period. Comparisons were based on archived shells collected in 1915-1922 from sites that were resampled in 2007. N. lapillus is an important member of North Atlantic marine ecosystems, and our results suggest that the impacts of historical changes in species' key morphological traits on marine ecosystems remain underappreciated.

  3. An intertidal snail shows a dramatic size increase over the past century

    PubMed Central

    Fisher, Jonathan A. D.; Rhile, Erika C.; Liu, Harrison; Petraitis, Peter S.

    2009-01-01

    Changes in the shell architecture of marine snails enhance defenses and greatly improve survival against predators. In the northwest Atlantic Ocean, shorter and thicker shells have been reported for several species following the introduction of predatory Carcinus maenas crabs early in the 20th century. But we report that the shell lengths of Nucella lapillus actually increased by an average of 22.6% over the past century, with no evidence of shell thickening after correcting for shell length. The increases in shell length were greatest on sheltered shores, highlighting the interaction between wave exposure and the sampling period. Comparisons were based on archived shells collected in 1915–1922 from sites that were resampled in 2007. N. lapillus is an important member of North Atlantic marine ecosystems, and our results suggest that the impacts of historical changes in species' key morphological traits on marine ecosystems remain underappreciated. PMID:19307561

  4. Dramatic increase of the near-IR flux of the young source V2492 Cyg

    NASA Astrophysics Data System (ADS)

    Arkharov, A. A.; Lorenzetti, D.; Giannini, T.; Antoniucci, S.; Di Paola, A.; Vitali, F.; Larionov, V. M.

    2015-04-01

    In the framework of our EXor monitoring program dubbed EXORCISM (EXOR OptiCal and Infrared Systematic Monitoring - Antoniucci et al. 2013 PPVI, Lorenzetti et al. 2007 ApJ 665, 1182; Lorenzetti et al. 2009 ApJ 693, 1056), we are now observing a new increase of the near-IR brightness of the protostar V2492 Cyg, based on data taken at the AZT24 1m IR telescope (Campo Imperatore, Italy).

  5. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

    NASA Astrophysics Data System (ADS)

    Tippett, Michael K.; Cohen, Joel E.

    2016-02-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from `outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related.

  6. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity.

    PubMed

    Tippett, Michael K; Cohen, Joel E

    2016-02-29

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related.

  7. Boronophenylalanine uptake in C6 glioma model is dramatically increased by L-DOPA preloading.

    PubMed

    Capuani, S; Gili, T; Bozzali, M; Russo, S; Porcari, P; Cametti, C; Muolo, M; D'Amore, E; Maraviglia, B; Lazzarino, G; Pastore, F S

    2009-07-01

    One of the main limitations for BNCT effectiveness is the insufficient intake of (10)B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT. PMID:19375337

  8. Adaptation of Lactococcus lactis to high growth temperature leads to a dramatic increase in acidification rate.

    PubMed

    Chen, Jun; Shen, Jing; Ingvar Hellgren, Lars; Ruhdal Jensen, Peter; Solem, Christian

    2015-09-21

    Lactococcus lactis is essential for most cheese making, and this mesophilic bacterium has its growth optimum around 30 °C. We have, through adaptive evolution, isolated a mutant TM29 that grows well up to 39 °C, and continuous growth at 40 °C is possible if pre-incubated at a slightly lower temperature. At the maximal permissive temperature for the wild-type, 38 °C, TM29 grows 33% faster and has a 12% higher specific lactate production rate than its parent MG1363, which results in fast lactate accumulation. Genome sequencing was used to reveal the mutations accumulated, most of which were shown to affect thermal tolerance. Of the mutations with more pronounced effects, two affected expression of single proteins (chaperone; riboflavin transporter), two had pleiotropic effects (RNA polymerase) which changed the gene expression profile, and one resulted in a change in the coding sequence of CDP-diglyceride synthase. A large deletion containing 10 genes was also found to affect thermal tolerance significantly. With this study we demonstrate a simple approach to obtain non-GMO derivatives of the important L. lactis that possess properties desirable by the industry, e.g. thermal robustness and increased rate of acidification. The mutations we have identified provide a genetic basis for further investigation of thermal tolerance.

  9. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

    PubMed Central

    Tippett, Michael K.; Cohen, Joel E.

    2016-01-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from ‘outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954–2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related. PMID:26923210

  10. Dramatic early event in chronic allograft nephropathy: increased but not decreased expression of MMP-9 gene

    PubMed Central

    2013-01-01

    Objective The infiltration of mononuclear cells and replication and migration of smooth muscle cells (SMCs) from media into the intima in the vascular wall are the cardinal pathological changes in the early stage of chronic allograft nephropathy (CAN). But the mechanism is unclear. Therefore we investigated the role of matrix metalloproteinase 9 (MMP-9) and its interaction with TGF-beta1, tubulointerstitial mononuclear cells infiltration and migration of SMCs in the early stage of CAN. Methods Kidneys of Fisher (F334) rats were orthotopically transplanted into bilaterally nephrectomized Lewis (LEW) recipients. To suppress an initial episode of acute rejection, rats were briefly treated with cyclosporine A (1.5 mg/kg/day) for the first 10 days. Animals were harvested at 12 weeks after transplantation for histological, immunohistochemistry and molecular biological analysis. Results The expression of MMP-9 was up-regulated in interstitium and vascular wall in the early stage of CAN, where there were interstitial mononuclear cells infiltration and SMCs migration and proliferation. Moreover the expression of MMP-9 were positively correlated with the degree of interstitial mononuclear cells infiltration, the quantity of SMCs in arteriolar wall, and also the increased TFG-beta1 expression in the tubulointerstitium and arteriolar wall. Conclusions MMP-9 may play an important role in the mechanism of pathological changes during the earlier period of CAN. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1582313332832700. PMID:23351884

  11. Adaptation of Lactococcus lactis to high growth temperature leads to a dramatic increase in acidification rate.

    PubMed

    Chen, Jun; Shen, Jing; Ingvar Hellgren, Lars; Ruhdal Jensen, Peter; Solem, Christian

    2015-01-01

    Lactococcus lactis is essential for most cheese making, and this mesophilic bacterium has its growth optimum around 30 °C. We have, through adaptive evolution, isolated a mutant TM29 that grows well up to 39 °C, and continuous growth at 40 °C is possible if pre-incubated at a slightly lower temperature. At the maximal permissive temperature for the wild-type, 38 °C, TM29 grows 33% faster and has a 12% higher specific lactate production rate than its parent MG1363, which results in fast lactate accumulation. Genome sequencing was used to reveal the mutations accumulated, most of which were shown to affect thermal tolerance. Of the mutations with more pronounced effects, two affected expression of single proteins (chaperone; riboflavin transporter), two had pleiotropic effects (RNA polymerase) which changed the gene expression profile, and one resulted in a change in the coding sequence of CDP-diglyceride synthase. A large deletion containing 10 genes was also found to affect thermal tolerance significantly. With this study we demonstrate a simple approach to obtain non-GMO derivatives of the important L. lactis that possess properties desirable by the industry, e.g. thermal robustness and increased rate of acidification. The mutations we have identified provide a genetic basis for further investigation of thermal tolerance. PMID:26388459

  12. Adaptation of Lactococcus lactis to high growth temperature leads to a dramatic increase in acidification rate

    PubMed Central

    Chen, Jun; Shen, Jing; Ingvar Hellgren, Lars; Ruhdal Jensen, Peter; Solem, Christian

    2015-01-01

    Lactococcus lactis is essential for most cheese making, and this mesophilic bacterium has its growth optimum around 30 °C. We have, through adaptive evolution, isolated a mutant TM29 that grows well up to 39 °C, and continuous growth at 40 °C is possible if pre-incubated at a slightly lower temperature. At the maximal permissive temperature for the wild-type, 38 °C, TM29 grows 33% faster and has a 12% higher specific lactate production rate than its parent MG1363, which results in fast lactate accumulation. Genome sequencing was used to reveal the mutations accumulated, most of which were shown to affect thermal tolerance. Of the mutations with more pronounced effects, two affected expression of single proteins (chaperone; riboflavin transporter), two had pleiotropic effects (RNA polymerase) which changed the gene expression profile, and one resulted in a change in the coding sequence of CDP-diglyceride synthase. A large deletion containing 10 genes was also found to affect thermal tolerance significantly. With this study we demonstrate a simple approach to obtain non-GMO derivatives of the important L. lactis that possess properties desirable by the industry, e.g. thermal robustness and increased rate of acidification. The mutations we have identified provide a genetic basis for further investigation of thermal tolerance. PMID:26388459

  13. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity.

    PubMed

    Tippett, Michael K; Cohen, Joel E

    2016-01-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related. PMID:26923210

  14. Interleukin-7 and immune reconstitution in cancer patients: a new paradigm for dramatically increasing overall survival.

    PubMed

    Morre, Michel; Beq, Stéphanie

    2012-03-01

    Although great effort is being expended in the development of cancer immunotherapies, it is surprising that global lymphopenia and its various dimensions are not being systematically assessed in cancer patients. The incident pathologies associated with various immunosuppressed conditions such as those found in HIV infection have taught us that measuring various T cell populations including CD4 provides the clinician with a reliable measure for gauging the risk of cancer and opportunistic infections. Importantly, recent data emphasize the key link between lymphocyte T cell counts and overall survival in cancer patients receiving chemotherapy. Treatment of immunocompromised patients with interleukin-7 (IL-7), a critical growth and homeostatic factor for T cells, has been shown to produce a compelling profile of T cell reconstitution. The clinical results of this investigational therapy confirm data obtained from numerous preclinical studies and demonstrate the long-term stability of this immune reconstitution, not only on CD4 but also on CD8 T cells, involving recent thymic emigrants as well as naive, memory, and central memory T cells. Furthermore, IL-7 therapy also contributes to restoration of a broadened diversity of the T cell repertoire as well as to migration of these cells to lymph nodes and tissues. All these properties support the initiation of new clinical studies aimed at reconstituting the immune system of cancer patients before or immediately after chemotherapy in order to demonstrate a potentially profound increase in overall survival.

  15. New Technologies Promise Dramatic Increase In Capabilities of the Very Large Array

    NASA Astrophysics Data System (ADS)

    1996-06-01

    The National Science Foundation's Very Large Array (VLA) radio telescope in New Mexico is an exceedingly powerful scientific instrument, and has transformed many areas of astronomy in its more than 15 years of operation. It has been used by more astronomers and has produced more scientific papers than any other radio telescope. Though its position as one of the world's premier radio telescopes will remain unchallenged for a long time, new technologies could increase its scientific capabilities greater than tenfold. Details were presented today to the American Astronomical Society's meeting in Madison, Wisconsin. An enhanced VLA, incorporating state-of-the-art technologies, would provide scientists with a number of important, new capabilities, including detailed investigations of the physics of solar radio bursts; improved radar probes of planets, asteroids and comets; the ability to image protoplanetary disks around young stars; more rapid response and effective observations of transient events such as supernovae; new types of information about gas both within our own Galaxy and in other galaxies; and greatly improved ability to study clusters of galaxies and extremely distant objects in the Universe. In addition, the enhanced VLA will serve as an improved partner with the Very Long Baseline Array (VLBA), a continent-wide radio telescope, also part of the National Radio Astronomy Observatory (NRAO). "The VLA upgrade proposes an essentially new instrument, created from two existing instruments, with power and capability far exceeding that of either one alone," said Rick Perley, NRAO Project Scientist for the VLA Upgrade Project. "It builds on the existing staff and infrastructure and would hardly affect operations costs. In today's fiscal climate, this provides the benefit of a `new' instrument with outstanding scientific capability at the least cost," Perley added. The VLA was built in the 1970s and dedicated in 1980. At the time of its completion, it was a state

  16. Increased seawater temperature increases the abundance and alters the structure of natural Vibrio populations associated with the coral Pocillopora damicornis

    PubMed Central

    Tout, Jessica; Siboni, Nachshon; Messer, Lauren F.; Garren, Melissa; Stocker, Roman; Webster, Nicole S.; Ralph, Peter J.; Seymour, Justin R.

    2015-01-01

    Rising seawater temperature associated with global climate change is a significant threat to coral health and is linked to increasing coral disease and pathogen-related bleaching events. We performed heat stress experiments with the coral Pocillopora damicornis, where temperature was increased to 31°C, consistent with the 2–3°C predicted increase in summer sea surface maxima. 16S rRNA amplicon sequencing revealed a large shift in the composition of the bacterial community at 31°C, with a notable increase in Vibrio, including known coral pathogens. To investigate the dynamics of the naturally occurring Vibrio community, we performed quantitative PCR targeting (i) the whole Vibrio community and (ii) the coral pathogen Vibrio coralliilyticus. At 31°C, Vibrio abundance increased by 2–3 orders of magnitude and V. coralliilyticus abundance increased by four orders of magnitude. Using a Vibrio-specific amplicon sequencing assay, we further demonstrated that the community composition shifted dramatically as a consequence of heat stress, with significant increases in the relative abundance of known coral pathogens. Our findings provide quantitative evidence that the abundance of potential coral pathogens increases within natural communities of coral-associated microbes as a consequence of rising seawater temperature and highlight the potential negative impacts of anthropogenic climate change on coral reef ecosystems. PMID:26042096

  17. Climate change: Increasing shrub abundance in the Arctic

    NASA Astrophysics Data System (ADS)

    Sturm, Matthew; Racine, Charles; Tape, Kenneth

    2001-05-01

    The warming of the Alaskan Arctic during the past 150 years has accelerated over the last three decades and is expected to increase vegetation productivity in tundra if shrubs become more abundant; indeed, this transition may already be under way according to local plot studies and remote sensing. Here we present evidence for a widespread increase in shrub abundance over more than 320 km of Arctic landscape during the past 50 years, based on a comparison of historic and modern aerial photographs. This expansion will alter the partitioning of energy in summer and the trapping and distribution of snow in winter, as well as increasing the amount of carbon stored in a region that is believed to be a net source of carbon dioxide.

  18. Severe plant invasions can increase mycorrhizal fungal abundance and diversity.

    PubMed

    Lekberg, Ylva; Gibbons, Sean M; Rosendahl, Søren; Ramsey, Philip W

    2013-07-01

    Invasions by non-native plants can alter ecosystem functions and reduce native plant diversity, but relatively little is known about their effect on belowground microbial communities. We show that invasions by knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula, hereafter spurge)--but not cheatgrass (Bromus tectorum)--support a higher abundance and diversity of symbiotic arbuscular mycorrhizal fungi (AMF) than multi-species native plant communities. The higher AMF richness associated with knapweed and spurge is unlikely due to a co-invasion by AMF, because a separate sampling showed that individual native forbs hosted a similar AMF abundance and richness as exotic forbs. Native grasses associated with fewer AMF taxa, which could explain the reduced AMF richness in native, grass-dominated communities. The three invasive plant species harbored distinct AMF communities, and analyses of co-occurring native and invasive plants indicate that differences were partly driven by the invasive plants and were not the result of pre-invasion conditions. Our results suggest that invasions by mycotrophic plants that replace poorer hosts can increase AMF abundance and richness. The high AMF richness in monodominant plant invasions also indicates that the proposed positive relationship between above and belowground diversity is not always strong. Finally, the disparate responses among exotic plants and consistent results between grasses and forbs suggest that AMF respond more to plant functional group than plant provenance.

  19. Dramatic Science

    ERIC Educational Resources Information Center

    McGregor, Debbie; Precious, Wendy

    2010-01-01

    The setting: the science classroom. The characters: you and your students. The scene: Your students acting out scientific discoveries, modeling a frog's life cycle, mimicking the transition from liquid to solid. This is "dramatic science", a teaching approach that uses acting techniques to explore and develop young children's ideas about science.…

  20. Dramatic increase in late Cenozoic alpine erosion rates recorded by cave sediment in the southern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Refsnider, Kurt A.

    2010-09-01

    Apparent increases in sedimentation rates during the past 5 Ma have been inferred at sites around the globe to document increased terrestrial erosion rates, but direct erosion rate records spanning this period are sparse. Modern and paleo-erosion rates for a small alpine catchment (3108 m above sea level) in the Southern Rocky Mountains are measured using the cosmogenic radionuclides (CRNs) 10Be and 26Al in cave sediment, bedrock on the overlying landscape surface, and coarse bedload in a modern fluvial drainage. The unique setting of the Marble Mountain cave system allows the inherited erosion rates to be interpreted as basin-averaged erosion rates, resulting in the first CRN-based erosion rate record from the Rocky Mountains spanning 5 Myr. Pliocene erosion rates, derived from the oldest cave sample (4.9 ± 0.4 Ma), for the landscape above the cave are 4.9 ± 1.1 m Myr - 1 . Mid Pleistocene erosion rates are nearly an order of magnitude higher (33.1 ± 2.7 to 41.3 ± 3.9 m Myr - 1 ), and modern erosion rates are similar; due to the effects of snow shielding, these erosion rate estimates are likely higher than actual rates by 10-15%. The most likely explanation for this dramatic increase in erosion rates, which likely occurred shortly before 1.2 Ma, is an increase in the effectiveness of periglacial weathering processes at high elevations related to a cooler and wetter climate during the Pleistocene, providing support for the hypothesis that changes in late Cenozoic climate are responsible for increased continental erosion.

  1. Dramatic Teaching for Dramatic Learning

    ERIC Educational Resources Information Center

    Graves, Julie

    2010-01-01

    Ressler's "Dramatic Changes" is a powerful guide for anyone brave enough to create a space for young people to discuss sexual orientation and gender identity. Her accessible style and tangible suggestions describe a creative and educationally sound approach to supporting youth in thoughtfully wrestling with one of the most controversial social…

  2. Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

    PubMed

    Moran, Matthew D

    2014-10-01

    How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity.

  3. Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

    PubMed

    Moran, Matthew D

    2014-10-01

    How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity. PMID:25198902

  4. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    PubMed Central

    Genung, Mark A.; Lessard, Jean-Philippe; Brown, Claire B.; Bunn, Windy A.; Cregger, Melissa A.; Reynolds, Wm. Nicholas; Felker-Quinn, Emmi; Stevenson, Mary L.; Hartley, Amanda S.; Crutsinger, Gregory M.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    Background In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. Methodology/Principal Findings Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot) of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1) plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2) plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. Conclusions/Significance These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems. PMID:20090850

  5. Honokiol nanosuspensions: preparation, increased oral bioavailability and dramatically enhanced biodistribution in the cardio-cerebro-vascular system.

    PubMed

    Han, Meihua; Yu, Xin; Guo, Yifei; Wang, Yanhong; Kuang, Haixue; Wang, Xiangtao

    2014-04-01

    Honokiol is a phytochemical component with multiple pharmacological activities, but Honokiol's wider use has been restricted by its poor solubility. Using bovine serum albumin and polyvinylpyrrolidone as stabilisers in a solvent precipitation-ultrasonication method, Honokiol nanosuspensions were prepared with a mean particle size of 116.2 nm (±2 nm), a zeta potential of -44.7 mV (±1.7 mV) and a high drug payload of 50.4 ± 0.6% (w/w). X-ray powder diffraction and differential scanning calorimetry indicated that Honokiol was in an amorphous state in the nanosuspensions, in contrast with bulk Honokiol powder. Honokiol was released faster in vitro from nanosuspensions with no burst release, and the highest 98% cumulative release was after 60 h. Honokiol nanosuspensions improved the oral bioavailability of Honokiol in in vivo studies in rats with a 3.94-fold Cmax and a 2.2-fold AUC(0-t). Remarkably, in contrast to oral administration, intraperitoneal administration of Honokiol nanosuspensions could dramatically alter the biodistribution of Honokiol, resulting in a much higher drug level and tissue bioavailability in the blood, heart and brain, benefitting the treatment of cardio-cerebro-vascular diseases.

  6. Pathbreaking CBO Study Shows Dramatic Increases in Income Disparities in 1980s and 1990s: An Analysis of the CBO Data. Revised.

    ERIC Educational Resources Information Center

    Shapiro, Isaac; Greenstein, Robert; Primus, Wendell

    A study by the Congressional Budget Office of income and tax trends since 1979 showed dramatic increases in income disparities, especially between the wealthiest one percent of Americans and the rest of society, in the 1980s and 1990s. The percentage of income Americans paid in federal taxes declined for every income group between 1979-97. The…

  7. Climate warming increases biodiversity of small rodents by favoring rare or less abundant species in a grassland ecosystem.

    PubMed

    Jiang, Guangshun; Liu, Jun; Xu, Lei; Yu, Guirui; He, Honglin; Zhang, Zhibin

    2013-06-01

    Our Earth is facing the challenge of accelerating climate change, which imposes a great threat to biodiversity. Many published studies suggest that climate warming may cause a dramatic decline in biodiversity, especially in colder and drier regions. In this study, we investigated the effects of temperature, precipitation and a normalized difference vegetation index on biodiversity indices of rodent communities in the current or previous year for both detrended and nondetrended data in semi-arid grassland of Inner Mongolia during 1982-2006. Our results demonstrate that temperature showed predominantly positive effects on the biodiversity of small rodents; precipitation showed both positive and negative effects; a normalized difference vegetation index showed positive effects; and cross-correlation function values between rodent abundance and temperature were negatively correlated with rodent abundance. Our results suggest that recent climate warming increased the biodiversity of small rodents by providing more benefits to population growth of rare or less abundant species than that of more abundant species in Inner Mongolia grassland, which does not support the popular view that global warming would decrease biodiversity in colder and drier regions. We hypothesized that higher temperatures might benefit rare or less abundant species (with smaller populations and more folivorous diets) by reducing the probability of local extinction and/or by increasing herbaceous food resources.

  8. Dietary phytoestrogens present in soy dramatically increase cardiotoxicity in male mice receiving a chemotherapeutic tyrosine kinase inhibitor.

    PubMed

    Harvey, Pamela Ann; Leinwand, Leslie Anne

    2015-01-01

    Use of soy supplements to inhibit cancer cell growth is increasing among patients due to the perception that phytoestrogens in soy inhibit carcinogenesis via induction of apoptosis. Genistein, the most prevalent phytoestrogen in soy, is a potent endocrine disruptor and tyrosine kinase inhibitor (TKI) that causes apoptosis in many cells types. Chemotherapeutic TKIs limit cancer cell growth via the same mechanisms. However, TKIs such as Sunitinib cause cardiotoxicity in a significant number of patients. Molecular interactions between Sunitinib and dietary TKIs like genistein have not been examined in cardiomyocytes. Significant lethality occurred in mice treated with Sunitinib and fed a phytoestrogen-supplemented diet. Isolated cardiomyocytes co-treated with genistein and Sunitinib exhibited additive inhibition of signaling molecules important for normal cardiac function and increased apoptosis compared with Sunitinib alone. Thus, dietary soy supplementation should be avoided during administration of Sunitinib due to exacerbated cardiotoxicity, despite evidence for positive effects in cancer.

  9. Temephos resistance and esterase activity in the mosquito Aedes aegypti in Havana, Cuba increased dramatically between 2006 and 2008.

    PubMed

    Bisset, J A; Rodríguez, M M; Ricardo, Y; Ranson, H; Pérez, O; Moya, M; Vázquez, A

    2011-09-01

    Aedes aegypti (L.) (Diptera: Culicidae) control programmes in Cuba rely on the application of the organophosphate temephos for larval control. Hence, the monitoring of resistance to this insecticide is an essential component of such programmes. Here, 15 field populations from different municipalities of Havana City were assayed for resistance to temephos. High levels of resistance were detected in all strains and resistance ratios were highly correlated with esterase activity (P = 0.00001). Populations from three municipalities were tested in both 2006 and 2008; resistance and esterase activities both significantly increased during this 2-year period. Synergist studies demonstrated that neither glutathione transferases nor monooxygenases were associated with the increase in resistance to temephos in this period. The duration of the efficacy of commercial formulations of temephos in controlling Ae. aegypti populations in Havana City was reduced by the high level of temephos resistance observed; hence these data are of clear operational significance for the dengue control programme in Cuba. New integrated strategies to avoid further increases in temephos resistance in Cuba are necessary.

  10. Calcium isotope evidence for dramatic increase of continental weathering during the Toarcian oceanic anoxic event (Early Jurassic)

    NASA Astrophysics Data System (ADS)

    Brazier, Jean-Michel; Suan, Guillaume; Tacail, Théo; Simon, Laurent; Martin, Jeremy E.; Mattioli, Emanuela; Balter, Vincent

    2015-02-01

    The early Toarcian was punctuated by pulses of massive carbon injection that are thought to have triggered, through increased greenhouse conditions, elevated continental discharge and nutrient input, marine anoxia, seawater acidification and species extinctions. Nevertheless, the mode and tempo of changes in continental weathering across this interval remains highly debated, leading to considerable uncertainty about the main causes of these perturbations. In this study we present calcium isotope measurements (δ44/40Ca) of well-preserved brachiopods and bulk rock samples from the hemipelagic strata of Pliensbachian-Toarcian age of Peniche in Portugal in order to constrain changes in the calcium cycle and hence changes in continental weathering during the early Toarcian. The data reveal a similar trend as carbon isotope data from the same section and show negative excursions of about 0.5‰ at the Pliensbachian-Toarcian transition (Pl-To) and at the base of the Toarcian Oceanic Anoxic Event (T-OAE) interval. The comparison of δ44/40Ca ratios recorded in brachiopods and bulk rock corrected for variable dolomite contribution indicates that these excursions reflect changes in the global isotopic composition of seawater rather than changes in the dominant mineralogy of calcifying organisms or in hydrological budget of the considered basin. Box modeling results suggest that the Pl-To and T-OAE δ44/40Ca excursions can be explained by a transient 90% decrease of carbonate accumulation due to seawater acidification followed by a 500% increase in continental weathering rates. The sharp increases in continental weathering inferred from the δ44/40Ca ratios seem overall consistent with lower Toarcian sedimentological and biotic records that document rapid crises in carbonate production followed by episodes of increased calcium carbonate burial. Nevertheless, the maximum of carbonate burial recorded by most NW European basinal successions occurs several hundreds of kyrs after

  11. Geographical distribution and dramatic increases in incidences of malaria: consequences of the resettlement scheme in Gambela, SW Ethiopia.

    PubMed

    Woube, M

    1997-09-01

    The spatial distribution of malaria results from the interaction between vector, parasite, host, physical and human environments. This basic geographical approach provides an illustration of the geographical distribution of malaria in the world, particularly in the tropical regions. Due to the global climate change and population movements, it is predicted that malaria could have a greater impact on the non-immune or unprepared populations in the Northern Hemisphere in the coming decades. Presently, Sub-Saharan Africa (SSA) is the most adversely affected region in the world. Like any other SSA country, Ethiopia suffers from both epidemic (unstable) and endemic (stable) malaria in the high and lowland regions, respectively. Gambela is one of the areas with stable malaria in the humid tropical region of the country. This study is based on observations, unpublished data, interviews and discussions with settlers and officials in Gambela. It is found that a degree of diverse malaria prevalence is associated with altitudinal, temperature and rainfall variations. Owing to the settlement and land-use changes, unexpected rainfall patterns, temperature increase, unstable political system and poverty, malaria has gone beyond its geographical limits. As a result, the number of malaria affected people has increased in the last 12 years. It is suggested that proper physical and social planning, understanding the geography, entomology, epidemiology, behaviour and life-cycle of malaria parasite, cooperation between the policy-makers, malaria specialists, neighbouring countries and international communities are urgent, if malaria has to be controlled and eradicated.

  12. Dramatic increase in negative superhelicity of plasmid DNA in the forespore compartment of sporulating cells of Bacillus subtilis.

    PubMed Central

    Nicholson, W L; Setlow, P

    1990-01-01

    Plasmid pUB110, isolated from vegetative cells of Bacillus subtilis, has an average of 34 negative supertwists (tau av = -34). This value falls to -30 early in sporulation, and the plasmid in the mother cell compartment maintains a tau av of -30. However, the plasmid within the developing forespore becomes much more negatively supercoiled, reaching a tau av of -47 in the dormant spore. This increased negative supercoiling in the forespore plasmid takes place in parallel with the synthesis of small, acid-soluble spore proteins, alpha and beta; and the plasmid from spores lacking small, acid-soluble proteins alpha and beta has a tau av of -40. The large increase in negative supercoiling of spore plasmid was also observed with Bacillus megaterium and in B. subtilis containing a plasmid with an origin different from that of pUB110. During spore germination plasmid pUB110 rapidly relaxed back to the tau av value characteristic of vegetative cells. It is possible that the observed changes in forespore plasmid topology are involved in modulating gene expression, DNA photochemistry, or both of these parameters in this compartment. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 PMID:2104613

  13. Dramatic Enhancement of Graphene Oxide/Silk Nanocomposite Membranes: Increasing Toughness, Strength, and Young's modulus via Annealing of Interfacial Structures.

    PubMed

    Wang, Yaxian; Ma, Ruilong; Hu, Kesong; Kim, Sunghan; Fang, Guangqiang; Shao, Zhengzhong; Tsukruk, Vladimir V

    2016-09-21

    We demonstrate that stronger and more robust nacre-like laminated GO (graphene oxide)/SF (silk fibroin) nanocomposite membranes can be obtained by selectively tailoring the interfacial interactions between "bricks"-GO sheets and "mortar"-silk interlayers via controlled water vapor annealing. This facial annealing process relaxes the secondary structure of silk backbones confined between flexible GO sheets. The increased mobility leads to a significant increase in ultimate strength (by up to 41%), Young's modulus (up to 75%) and toughness (up to 45%). We suggest that local silk recrystallization is initiated in the proximity to GO surface by the hydrophobic surface regions serving as nucleation sites for β-sheet domains formation and followed by SF assembly into nanofibrils. Strong hydrophobic-hydrophobic interactions between GO layers with SF nanofibrils result in enhanced shear strength of layered packing. This work presented here not only gives a better understanding of SF and GO interfacial interactions, but also provides insight on how to enhance the mechanical properties for the nacre-mimic nanocomposites by focusing on adjusting the delicate interactions between heterogeneous "brick" and adaptive "mortar" components with water/temperature annealing routines. PMID:27580039

  14. Elevated atmospheric [CO2 ] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves.

    PubMed

    Fitzgerald, Glenn J; Tausz, Michael; O'Leary, Garry; Mollah, Mahabubur R; Tausz-Posch, Sabine; Seneweera, Saman; Mock, Ivan; Löw, Markus; Partington, Debra L; McNeil, David; Norton, Robert M

    2016-06-01

    Wheat production will be impacted by increasing concentration of atmospheric CO2 [CO2 ], which is expected to rise from about 400 μmol mol(-1) in 2015 to 550 μmol mol(-1) by 2050. Changes to plant physiology and crop responses from elevated [CO2 ] (e[CO2 ]) are well documented for some environments, but field-level responses in dryland Mediterranean environments with terminal drought and heat waves are scarce. The Australian Grains Free Air CO2 Enrichment facility was established to compare wheat (Triticum aestivum) growth and yield under ambient (~370 μmol(-1) in 2007) and e[CO2 ] (550 μmol(-1) ) in semi-arid environments. Experiments were undertaken at two dryland sites (Horsham and Walpeup) across three years with two cultivars, two sowing times and two irrigation treatments. Mean yield stimulation due to e[CO2 ] was 24% at Horsham and 53% at Walpeup, with some treatment responses greater than 70%, depending on environment. Under supplemental irrigation, e[CO2 ] stimulated yields at Horsham by 37% compared to 13% under rainfed conditions, showing that water limited growth and yield response to e[CO2 ]. Heat wave effects were ameliorated under e[CO2 ] as shown by reductions of 31% and 54% in screenings and 10% and 12% larger kernels (Horsham and Walpeup). Greatest yield stimulations occurred in the e[CO2 ] late sowing and heat stressed treatments, when supplied with more water. There were no clear differences in cultivar response due to e[CO2 ]. Multiple regression showed that yield response to e[CO2 ] depended on temperatures and water availability before and after anthesis. Thus, timing of temperature and water and the crop's ability to translocate carbohydrates to the grain postanthesis were all important in determining the e[CO2 ] response. The large responses to e[CO2 ] under dryland conditions have not been previously reported and underscore the need for field level research to provide mechanistic understanding for adapting crops to a changing

  15. Elevated atmospheric [CO2 ] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves.

    PubMed

    Fitzgerald, Glenn J; Tausz, Michael; O'Leary, Garry; Mollah, Mahabubur R; Tausz-Posch, Sabine; Seneweera, Saman; Mock, Ivan; Löw, Markus; Partington, Debra L; McNeil, David; Norton, Robert M

    2016-06-01

    Wheat production will be impacted by increasing concentration of atmospheric CO2 [CO2 ], which is expected to rise from about 400 μmol mol(-1) in 2015 to 550 μmol mol(-1) by 2050. Changes to plant physiology and crop responses from elevated [CO2 ] (e[CO2 ]) are well documented for some environments, but field-level responses in dryland Mediterranean environments with terminal drought and heat waves are scarce. The Australian Grains Free Air CO2 Enrichment facility was established to compare wheat (Triticum aestivum) growth and yield under ambient (~370 μmol(-1) in 2007) and e[CO2 ] (550 μmol(-1) ) in semi-arid environments. Experiments were undertaken at two dryland sites (Horsham and Walpeup) across three years with two cultivars, two sowing times and two irrigation treatments. Mean yield stimulation due to e[CO2 ] was 24% at Horsham and 53% at Walpeup, with some treatment responses greater than 70%, depending on environment. Under supplemental irrigation, e[CO2 ] stimulated yields at Horsham by 37% compared to 13% under rainfed conditions, showing that water limited growth and yield response to e[CO2 ]. Heat wave effects were ameliorated under e[CO2 ] as shown by reductions of 31% and 54% in screenings and 10% and 12% larger kernels (Horsham and Walpeup). Greatest yield stimulations occurred in the e[CO2 ] late sowing and heat stressed treatments, when supplied with more water. There were no clear differences in cultivar response due to e[CO2 ]. Multiple regression showed that yield response to e[CO2 ] depended on temperatures and water availability before and after anthesis. Thus, timing of temperature and water and the crop's ability to translocate carbohydrates to the grain postanthesis were all important in determining the e[CO2 ] response. The large responses to e[CO2 ] under dryland conditions have not been previously reported and underscore the need for field level research to provide mechanistic understanding for adapting crops to a changing

  16. Teaching Dramatic Literature.

    ERIC Educational Resources Information Center

    McCloskey, Susan

    1984-01-01

    Describes the use of scene work, informal presentations of dramatic passages, to explore aspects of plays that readers are likely to overlook. Finds that this scene work increases the pertinence of students' comments in class and the ambitiousness of their written work. (MM)

  17. On the Dramatic Increase ofDitrupa arietina O.F. Müller (Annelida: Polychaeta) Along Both the French and the Spanish Catalan Coasts

    NASA Astrophysics Data System (ADS)

    Grémare, A.; Sardá, R.; Medernach, L.; Jordana, E.; Pinedo, S.; Amouroux, J. M.; Martin, D.; Nozais, C.; Charles, F.

    1998-10-01

    The distribution and population structure of the serpulid polychaete Ditrupa arietinawere assessed along the section of the Mediterranean coast between Barcelona and Montpellier. The study combined: (1) the analysis of the existing historical data referring to the period before the 1970s; (2) the results of impact assessment surveys carried out in the late 1980s and the 1990s; and (3) the results of two surveys carried out in the Bay of Blanes and along the coast between Cape Cerbère and Port-la-Nouvelle during 1996. The results of the surveys carried out in the 1990s show the occurrence of high densities (i.e. >1000 ind m -2) of Ditrupa arietinaat all the sites sampled. These results can be compared with the few reports of this species before 1970, leading to the conclusion that D. arietinahas recently increased all along the Catalan coast. Ditrupa arietinais preferentially found between 20 and 30 m depth, which mostly corresponds to well-sorted fine sands and muddy sands. Both the results of population monitoring and the heterogeneity of population structure at small spatial scale show that the dynamics of this species is unstable. The observed distribution pattern is therefore interpreted as resulting from a response to both wide-scale environmental parameters (accounting for the dramatic increase of the species at a wide geographical scale), and to local environmental factors (accounting for small-scale heterogeneity in population structure). Analysis of the relationship between sedimentary data and densities of D. arietinasuggests that this species is highly sensitive to the presence of fine sediments. However, because of the regional importance of the phenomenon, it is concluded that the dramatic increase of D. arietinaalong both the Spanish and the French Catalan coast does not result from sediment instability.

  18. Long-term increase in Karenia brevis abundance along the Southwest Florida Coast

    PubMed Central

    Brand, Larry E.; Compton, Angela

    2008-01-01

    Data collected along the southwest coast of Florida between Tampa Bay and Sanibel Island on the abundance of the toxic dinoflagellate Karenia brevis from 1954 to 2002 were examined for spatial and temporal patterns. K. brevis was found to be approximately 20-fold more abundant within 5 km of the shoreline than 20-30 km offshore. Overall, K. brevis was approximately 13-18-fold more abundant in 1994-2002 than in 1954-1963. In 1954-1963, K. brevis occurred primarily in the fall months. In 1994-2002, it was more abundant not only in the fall, but also in the winter and spring months. It is hypothesized that greater nutrient availability in the ecosystem is the most likely cause of this increase in K. brevis biomass, and the large increase in the human population and its activities in South Florida over the past half century is a major factor. PMID:18437245

  19. Streptomycin use in apple orchards did not increase abundance of mobile resistance genes.

    PubMed

    Duffy, Brion; Holliger, Eduard; Walsh, Fiona

    2014-01-01

    Streptomycin is used as a first-line defense and tetracycline as a second-line defense, in the fight against fire blight disease in apple and pear orchards. We have performed the first study to quantitatively analyze the influence of streptomycin use in agriculture on the abundance of streptomycin and tetracycline resistance genes in apple orchards. Flowers, leaves, and soil were collected from three orchard sites in 2010, 2011, and 2012. Gene abundance distribution was analyzed using two-way anova and principal component analysis to investigate relationships between gene abundance data over time and treatment. The mobile antibiotic resistance genes, strA, strB, tetB, tetM, tetW, and the insertion sequence IS1133, were detected prior to streptomycin treatment in almost all samples, indicating the natural presence of these resistance genes in nature. Statistically significant increases in the resistance gene abundances were occasional, inconsistent, and not reproducible from one year to the next. We conclude that the application of streptomycin in these orchards was not associated with sustained increases in streptomycin or tetracycline resistance gene abundances.

  20. Soil nutrient additions increase invertebrate herbivore abundances, but not herbivory, across three grassland systems.

    PubMed

    La Pierre, Kimberly J; Smith, Melinda D

    2016-02-01

    Resource availability may influence invertebrate communities, with important consequences for ecosystem function, such as biomass production. We assessed: (1) the effects of experimental soil nutrient additions on invertebrate abundances and feeding rates and (2) the resultant changes in the effects of invertebrates on aboveground plant biomass at three grassland sites spanning the North American Central Plains, across which plant tissue chemistry and biomass vary. Invertebrate communities and rates of herbivory were sampled within a long-term nutrient-addition experiment established at each site along the broad Central Plains precipitation gradient. Additionally, the effects of invertebrates on aboveground plant biomass were determined under ambient and elevated nutrient conditions. At the more mesic sites, invertebrate herbivore abundances increased and their per capita rate of herbivory decreased with nutrient additions. In contrast, at the semi-arid site where plant biomass is low and plant nutrient concentrations are high, invertebrate herbivore abundances did not vary and per capita rates of herbivory increased with nutrient additions. No change in the effect of invertebrate herbivores on aboveground plant biomass was observed at any of the sites. In sum, nutrient additions induced shifts in both plant biomass and leaf nutrient content, which altered invertebrate abundances and feeding rate. However, due to the inverse relationship between changes in herbivore abundance and per capita rates of herbivory, nutrient additions did not alter the effect of invertebrates on aboveground biomass. Overall, we suggest that this inverse response of herbivore abundance and per capita feeding rate may buffer ecosystems against changes in invertebrate damage in response to fluctuations in nutrient levels.

  1. Decreasing Abundance, Increasing Diversity and Changing Structure of the Wild Bee Community (Hymenoptera: Anthophila) along an Urbanization Gradient

    PubMed Central

    Fortel, Laura; Henry, Mickaël; Guilbaud, Laurent; Guirao, Anne Laure; Kuhlmann, Michael; Mouret, Hugues; Rollin, Orianne; Vaissière, Bernard E.

    2014-01-01

    Background Wild bees are important pollinators that have declined in diversity and abundance during the last decades. Habitat destruction and fragmentation associated with urbanization are reported as part of the main causes of this decline. Urbanization involves dramatic changes of the landscape, increasing the proportion of impervious surface while decreasing that of green areas. Few studies have investigated the effects of urbanization on bee communities. We assessed changes in the abundance, species richness, and composition of wild bee community along an urbanization gradient. Methodology/Principal Findings Over two years and on a monthly basis, bees were sampled with colored pan traps and insect nets at 24 sites located along an urbanization gradient. Landscape structure within three different radii was measured at each study site. We captured 291 wild bee species. The abundance of wild bees was negatively correlated with the proportion of impervious surface, while species richness reached a maximum at an intermediate (50%) proportion of impervious surface. The structure of the community changed along the urbanization gradient with more parasitic species in sites with an intermediate proportion of impervious surface. There were also greater numbers of cavity-nesting species and long-tongued species in sites with intermediate or higher proportion of impervious surface. However, urbanization had no effect on the occurrence of species depending on their social behavior or body size. Conclusions/Significance We found nearly a third of the wild bee fauna known from France in our study sites. Indeed, urban areas supported a diverse bee community, but sites with an intermediate level of urbanization were the most speciose ones, including greater proportion of parasitic species. The presence of a diverse array of bee species even in the most urbanized area makes these pollinators worthy of being a flagship group to raise the awareness of urban citizens about

  2. Increased energy expenditure by a seabird in response to higher food abundance

    USGS Publications Warehouse

    Jodice, P.G.R.; Roby, D.D.; Suryan, R.M.; Irons, D.B.; Turco, K.R.; Brown, E.D.; Thedinga, J.F.; Visser, G.H.

    2006-01-01

    Variability in forage fish abundance strongly affects seabird behavior and reproductive success, although details of this relationship are unclear. During 1997 and 1998, we measured (1) daily energy expenditure (DEE) of 80 parent black-legged kittiwakes Rissa tridactyla at 2 colonies in Prince William Sound, Alaska (North Icy Bay and Shoup Bay), (2) abundance of surface-schooling forage fishes within the foraging range of each colony, and (3) diet composition, energy delivery rates to nestlings, and reproductive success of kittiwakes at these same colonies. Female DEE was highest at North Icy Bay in 1998, while male DEE did not differ by colony year. Abundances of Pacific herring Clupea pallasi and sand lance Ammodytes hexapterus were highest near North Icy Bay in 1998 and nearly egual in density, although Age 1+ herring comprised the majority of the diet there. Energy delivery rates to nestlings, nestling growth rates, and productivity were also highest at North Icy Bay in 1998. We suggest that female kittiwakes responded to the increased abundance of Age 1+ herring near North Icy Bay in 1998 by increasing their DEE, which in turn positively affected reproductive success. Given that adult kittiwakes have been shown to suffer decreased survival as a response to increased energy expenditure during brood rearing, the positive correlation we observed between increased abundance of a high quality food source, parental effort, and productivity is consistent with maximizing lifetime reproductive success. The lack of a response in male DEE suggests that brood-rearing roles in kittiwakes differ between genders. ?? Inter-Research 2006.

  3. Targeted disruption of BMP signaling through type IA receptor (BMPR1A) in osteocyte suppresses SOST and RANKL, leading to dramatic increase in bone mass, bone mineral density and mechanical strength.

    PubMed

    Kamiya, Nobuhiro; Shuxian, Lin; Yamaguchi, Ryosuke; Phipps, Matthew; Aruwajoye, Olumide; Adapala, Naga Suresh; Yuan, Hui; Kim, Harry K W; Feng, Jian Q

    2016-10-01

    Recent studies suggest a critical role of osteocytes in controlling skeletal development and bone remodeling although the molecular mechanism is largely unknown. This study investigated BMP signaling in osteocytes by disrupting Bmpr1a under the Dmp1-promoter. The conditional knockout (cKO) mice displayed a striking osteosclerotic phenotype with increased trabecular bone volume, thickness, number, and mineral density as assessed by X-ray and micro-CT. The bone histomorphometry, H&E, and TRAP staining revealed a dramatic increase in trabecular and cortical bone masses but a sharp reduction in osteoclast number. Moreover, there was an increase in BrdU positive osteocytes (2-5-fold) and osteoid volume (~4-fold) but a decrease in the bone formation rate (~85%) in the cKO bones, indicating a defective mineralization. The SEM analysis revealed poorly formed osteocytes: a sharp increase in cell numbers, a great reduction in cell dendrites, and a remarkable change in the cell distribution pattern. Molecular studies demonstrated a significant decrease in the Sost mRNA levels in bone (>95%), and the SOST protein levels in serum (~85%) and bone matrices. There was a significant increase in the β-catenin (>3-fold) mRNA levels as well as its target genes Tcf1 (>6-fold) and Tcf3 (~2-fold) in the cKO bones. We also showed a significant decrease in the RANKL levels of serum proteins (~65%) and bone mRNA (~57%), and a significant increase in the Opg mRNA levels (>20-fold) together with a significant reduction in the Rankl/Opg ratio (>95%), which are responsible for a sharp reduction in the cKO osteoclasts. The values of mechanical strength were higher in cKO femora (i.e. max force, displacement, and work failure). These results suggest that loss of BMP signaling specifically in osteocytes dramatically increases bone mass presumably through simultaneous inhibition of RANKL and SOST, leading to osteoclast inhibition and Wnt activation together. Finally, a working hypothesis is

  4. Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake.

    PubMed

    Sweet, Shannan K; Griffin, Kevin L; Steltzer, Heidi; Gough, Laura; Boelman, Natalie T

    2015-06-01

    Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake.

  5. Increasing aridity reduces soil microbial diversity and abundance in global drylands.

    PubMed

    Maestre, Fernando T; Delgado-Baquerizo, Manuel; Jeffries, Thomas C; Eldridge, David J; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana; Gaitán, Juan; Gutiérrez, Julio R; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L; Miriti, Maria; Naseri, Kamal; Ospina, Abelardo; Stavi, Ilan; Wang, Deli; Woods, Natasha N; Yuan, Xia; Zaady, Eli; Singh, Brajesh K

    2015-12-22

    Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands.

  6. Increasing aridity reduces soil microbial diversity and abundance in global drylands.

    PubMed

    Maestre, Fernando T; Delgado-Baquerizo, Manuel; Jeffries, Thomas C; Eldridge, David J; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana; Gaitán, Juan; Gutiérrez, Julio R; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L; Miriti, Maria; Naseri, Kamal; Ospina, Abelardo; Stavi, Ilan; Wang, Deli; Woods, Natasha N; Yuan, Xia; Zaady, Eli; Singh, Brajesh K

    2015-12-22

    Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands. PMID:26647180

  7. Increasing aridity reduces soil microbial diversity and abundance in global drylands

    PubMed Central

    Delgado-Baquerizo, Manuel; Jeffries, Thomas C.; Eldridge, David J.; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A.; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana; Gaitán, Juan; Gutiérrez, Julio R.; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L.; Miriti, Maria; Naseri, Kamal; Ospina, Abelardo; Stavi, Ilan; Wang, Deli; Woods, Natasha N.; Yuan, Xia; Zaady, Eli; Singh, Brajesh K.

    2015-01-01

    Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands. PMID:26647180

  8. Creative Dramatics. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Gabriel, Julia; Sidlovskaya, Olga; Stotter, Ruth; Haugen, Kirsten; Leithold, Naomi

    2000-01-01

    Presents five articles on using creative dramatics in early childhood education: (1) "Drama: A Rehearsal for Life" (Julia Gabriel); (2) "Fairy Tales Enhance Imagination and Creative Thinking" (Olga Sidlovskaya); (3) "Starting with a Story" (Ruth Stotter); (4) "Using Creative Dramatics to Include All Children" (Kirsten Haugen); and (5) "Helping…

  9. Creative Dramatics Handbook.

    ERIC Educational Resources Information Center

    Philadelphia School District, PA. Office of Early Childhood Programs.

    This handbook on creative dramatics at the elementary school level is primarily intended to assist the teacher who already has some training in creative dramatics. The handbook contains sections on (1) the philosophy and objectives of the program, including a discussion of an affective curriculum; (2) definitions of key concepts, including general…

  10. Apparent increase in coccolithophore abundance in the subtropical North Atlantic from 1990 to 2014

    NASA Astrophysics Data System (ADS)

    Krumhardt, Kristen M.; Lovenduski, Nicole S.; Freeman, Natalie M.; Bates, Nicholas R.

    2016-02-01

    As environmental conditions evolve with rapidly increasing atmospheric CO2, biological communities will change as species reorient their distributions, adapt, or alter their abundance. In the surface ocean, dissolved inorganic carbon (DIC) has been increasing over the past several decades as anthropogenic CO2 dissolves into seawater, causing acidification (decreases in pH and carbonate ion concentration). Calcifying phytoplankton, such as coccolithophores, are thought to be especially vulnerable to ocean acidification. How coccolithophores will respond to increasing carbon input has been a subject of much speculation and inspired numerous laboratory and mesocosm experiments, but how they are currently responding in situ is less well documented. In this study, we use coccolithophore (haptophyte) pigment data collected at the Bermuda Atlantic Time-series Study (BATS) site together with satellite estimates (1998-2014) of surface chlorophyll and particulate inorganic carbon (PIC) as a proxy for coccolithophore abundance to show that coccolithophore populations in the North Atlantic subtropical gyre have been increasing significantly over the past 2 decades. Over 1990-2012, we observe a 37 % increase in euphotic zone-integrated coccolithophore pigment abundance at BATS, though we note that this is sensitive to the period being analyzed. We further demonstrate that variability in coccolithophore chlorophyll a here is positively correlated with variability in nitrate and DIC (and especially the bicarbonate ion) in the upper 30 m of the water column. Previous studies have suggested that coccolithophore photosynthesis may benefit from increasing CO2, but calcification may eventually be hindered by low pHT (< 7.7). Given that DIC has been increasing at BATS by ˜ 1.4 µmol kg-1 yr-1 over the period of 1991-2012, we speculate that coccolithophore photosynthesis and perhaps calcification may have increased in response to anthropogenic CO2 input.

  11. Inherited microbial symbionts increase herbivore abundances and alter arthropod diversity on a native grass.

    PubMed

    Faeth, Stanley H; Shochat, Eyal

    2010-05-01

    Some microbial symbionts of plants are maternally inherited and thus functionally increase genetic and phenotypic variation within plant populations. This variation, coupled with that of the host plant and environment, may alter abundances, diversity, and trophic structure of associated plant and animal communities. Fungal endophytes in the genus Neotyphodium are vertically transmitted, asexual microbial symbionts of grasses that remain asymptomatic and rely upon their hosts for resources and transmission via seeds, often providing benefits to their hosts, including protection against herbivores. Endophyte infections may influence associated arthropod communities in agronomic grasses, but the long-term effects of endophytes and variation in host genotype and resource availability on arthropod communities in native grass populations are unknown. We conducted a long-term field experiment with four maternal genotypes of an infected (E+) native grass (Festuca arizonica) from whence the endophyte was experimentally removed (E-) and water availability was controlled, to test the effects of infection, plant genotype, and resources on abundances, biomass, diversity (richness and evenness), and trophic structure of the arthropod community. Generally, E+ grasses harbored more arthropods, including more herbivores, predators, and detritivores, suggesting that the effects of endophytes cascaded upward through trophic levels in terms of abundances, at least in early ontogeny of the host. That E+ plants harbored more herbivorous insects than E- plants suggests that infection does not increase but instead decreases resistance to herbivores, contrary to prevailing concepts of endophytes as defensive mutualists. Infection did not alter overall species richness of the arthropod community or richness of herbivores but reduced natural enemy richness, especially that of parasites, and increased richness of detritivores. Reduced richness and shifts in evenness of natural enemies on E

  12. Ninespine Stickleback Abundance in Lake Michigan Increases After Dreissenid Mussel Invasion

    USGS Publications Warehouse

    Madenjian, Charles P.; Bunnell, David B.; Gorman, Owen T.

    2010-01-01

    Based on data from our annual lakewide bottom trawl survey of Lake Michigan, we determined that density of ninespine sticklebacks Pungitius pungitius increased from an average of 0.234 kg/ha during 1973–1995 to an average of 1.318 kg/ha during 1996–2007. This greater-than-fivefold increase in density coincided with the dreissenid mussel invasion of Lake Michigan. Intervention analysis revealed that ninespine stickleback density in Lake Michigan significantly increased between the two time periods. In contrast, based on data from our annual bottom trawl survey of U.S. waters of Lake Superior, ninespine stickleback density decreased from an average of 0.133 kg/ha during 1978–1999 to an average of only 0.026 kg/ha during 2000–2007. This greater-than-fivefold density decrease, which was found to be significant via intervention analysis, coincided with population recovery for both lean and fat morphotypes of lake trout Salvelinus namaycush in Lake Superior. In contrast to Lake Michigan, dreissenid mussels have not invaded Lake Superior on a lakewide basis. Thus, a comparison of these two lakes indicated that the increase in ninespine stickleback abundance in Lake Michigan was most likely attributable to the dreissenid mussel invasion. In addition, based on our correlation analysis, alewives Alosa pseudoharengus did not have an adverse effect on ninespine stickleback abundance in Lake Michigan. Perhaps the recent increase in biomass of green algae Cladophora spp. associated with the dreissenid mussel invasion improved spawning habitat quality for ninespine sticklebacks and led to their stepwise abundance increase in Lake Michigan beginning in 1996

  13. Increasing N abundance in the northwestern Pacific Ocean due to atmospheric nitrogen deposition.

    PubMed

    Kim, Tae-Wook; Lee, Kitack; Najjar, Raymond G; Jeong, Hee-Dong; Jeong, Hae Jin

    2011-10-28

    The relative abundance of nitrate (N) over phosphorus (P) has increased over the period since 1980 in the marginal seas bordering the northwestern Pacific Ocean, located downstream of the populated and industrialized Asian continent. The increase in N availability within the study area was mainly driven by increasing N concentrations and was most likely due to deposition of pollutant nitrogen from atmospheric sources. Atmospheric nitrogen deposition had a high temporal correlation with N availability in the study area (r = 0.74 to 0.88), except in selected areas wherein riverine nitrogen load may be of equal importance. The increase in N availability caused by atmospheric deposition and riverine input has switched extensive parts of the study area from being N-limited to P-limited. PMID:21940860

  14. Habitat alteration increases invasive fire ant abundance to the detriment of amphibians and reptiles

    USGS Publications Warehouse

    Todd, B.D.; Rothermel, B.B.; Reed, R.N.; Luhring, T.M.; Schlatter, K.; Trenkamp, L.; Gibbons, J.W.

    2008-01-01

    Altered habitats have been suggested to facilitate red imported fire ant (Solenopsis invicta) colonization and dispersal, possibly compounding effects of habitat alteration on native wildlife. In this study, we compared colonization intensity of wood cover boards by S. invicta among four forest management treatments in South Carolina, USA: an unharvested control (>30 years old); a partially thinned stand; a clearcut with coarse woody debris retained; and a clearcut with coarse woody debris removed. Additionally, we compared dehydration rates and survival of recently metamorphosed salamanders (marbled salamanders, Ambystoma opacum, and mole salamanders, A. talpoideum) among treatments. We found that the number of wood cover boards colonized by S. invicta differed significantly among treatments, being lowest in the unharvested forest treatments and increasing with the degree of habitat alteration. Salamanders that were maintained in experimental field enclosures to study water loss were unexpectedly subjected to high levels of S. invicta predation that differed among forest treatments. All known predation by S. invicta was restricted to salamanders in clearcuts. The amount of vegetative ground cover was inversely related to the likelihood of S. invicta predation of salamanders. Our results show that S. invicta abundance increases with habitat disturbance and that this increased abundance has negative consequences for amphibians that remain in altered habitats. Our findings also suggest that the presence of invasive S. invicta may compromise the utility of cover boards and other techniques commonly used in herpetological studies in the Southeast. ?? 2007 Springer Science+Business Media B.V.

  15. Pepino (Solanum muricatum) planting increased diversity and abundance of bacterial communities in karst area

    PubMed Central

    Hu, Jinxiang; Yang, Hui; Long, Xiaohua; Liu, Zhaopu; Rengel, Zed

    2016-01-01

    Soil nutrients and microbial communities are the two key factors in revegetation of barren environments. Ecological stoichiometry plays an important role in ecosystem function and limitation, but the relationships between above- and belowground stoichiometry and the bacterial communities in a typical karst region are poorly understood. We used pepino (Solanum muricatum) to examine the stoichiometric traits between soil and foliage, and determine diversity and abundance of bacteria in the karst soil. The soil had a relatively high pH, low fertility, and coarse texture. Foliar N:P ratio and the correlations with soil nitrogen and phosphorus suggested nitrogen limitation. The planting of pepino increased soil urease activity and decreased catalase activity. Higher diversity of bacteria was determined in the pepino rhizosphere than bulk soil using a next-generation, Illumina-based sequencing approach. Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the dominant phyla in all samples, accounting for more than 80% of the reads. On a genus level, all 625 detected genera were found in all rhizosphere and bulk soils, and 63 genera showed significant differences among samples. Higher Shannon and Chao 1 indices in the rhizosphere than bulk soil indicated that planting of pepino increased diversity and abundance of bacterial communities in karst area. PMID:26902649

  16. Pepino (Solanum muricatum) planting increased diversity and abundance of bacterial communities in karst area.

    PubMed

    Hu, Jinxiang; Yang, Hui; Long, Xiaohua; Liu, Zhaopu; Rengel, Zed

    2016-02-23

    Soil nutrients and microbial communities are the two key factors in revegetation of barren environments. Ecological stoichiometry plays an important role in ecosystem function and limitation, but the relationships between above- and belowground stoichiometry and the bacterial communities in a typical karst region are poorly understood. We used pepino (Solanum muricatum) to examine the stoichiometric traits between soil and foliage, and determine diversity and abundance of bacteria in the karst soil. The soil had a relatively high pH, low fertility, and coarse texture. Foliar N:P ratio and the correlations with soil nitrogen and phosphorus suggested nitrogen limitation. The planting of pepino increased soil urease activity and decreased catalase activity. Higher diversity of bacteria was determined in the pepino rhizosphere than bulk soil using a next-generation, Illumina-based sequencing approach. Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the dominant phyla in all samples, accounting for more than 80% of the reads. On a genus level, all 625 detected genera were found in all rhizosphere and bulk soils, and 63 genera showed significant differences among samples. Higher Shannon and Chao 1 indices in the rhizosphere than bulk soil indicated that planting of pepino increased diversity and abundance of bacterial communities in karst area.

  17. Projections of climate conditions that increase coral disease susceptibility and pathogen abundance and virulence

    NASA Astrophysics Data System (ADS)

    Maynard, Jeffrey; van Hooidonk, Ruben; Eakin, C. Mark; Puotinen, Marjetta; Garren, Melissa; Williams, Gareth; Heron, Scott F.; Lamb, Joleah; Weil, Ernesto; Willis, Bette; Harvell, C. Drew

    2015-07-01

    Rising sea temperatures are likely to increase the frequency of disease outbreaks affecting reef-building corals through impacts on coral hosts and pathogens. We present and compare climate model projections of temperature conditions that will increase coral susceptibility to disease, pathogen abundance and pathogen virulence. Both moderate (RCP 4.5) and fossil fuel aggressive (RCP 8.5) emissions scenarios are examined. We also compare projections for the onset of disease-conducive conditions and severe annual coral bleaching, and produce a disease risk summary that combines climate stress with stress caused by local human activities. There is great spatial variation in the projections, both among and within the major ocean basins, in conditions favouring disease development. Our results indicate that disease is as likely to cause coral mortality as bleaching in the coming decades. These projections identify priority locations to reduce stress caused by local human activities and test management interventions to reduce disease impacts.

  18. Increased abundance of distal sodium transporters in rat kidney during vasopressin escape.

    PubMed

    Ecelbarger, C A; Knepper, M A; Verbalis, J G

    2001-02-01

    Hyponatremia is associated with inappropriately elevated vasopressin levels. A brisk natriuresis precedes the escape from this antidiuresis. Thus, the hypothesis was that the abundance of one or more of the sodium transporters of the distal tubule (a site for fine tuning of sodium balance) would be altered during vasopressin escape. Semiquantitative immunoblotting was used to examine the regulation of abundance of several sodium transporters/channels of the thick ascending limb through the collecting duct in the rat model. Osmotic minipumps to infuse dDAVP, the V2-selective vasopressin agonist (5 ng/h) for the entire experiment, were implanted in Male Sprague-Dawley rats. After 4 d, rats were divided into a control (dry AIN-76 diet/ad libitum water) or a water-loaded (gelled-agar-AIN-76 diet/ad libitum water) group. Rats were killed after 1, 2, 3, or 7 additional days. The water-loaded rats were hyponatremic (plasma Na+, 98 to 122 mmol/L) and manifested the expected early natriuresis and diuresis of vasopressin escape. Water loading (with dDAVP infusion) resulted in increased whole-kidney abundances of the thiazide-sensitive Na-Cl co-transporter, the alpha-subunit of the epithelial sodium channel (ENaC), and the 70-kD dimer of the gamma-subunit of ENaC. No changes were observed for the ss-subunit of ENaC. Similar protein changes have recently been associated with elevated aldosterone levels in rats. However, plasma aldosterone levels were significantly suppressed in this model. These data suggest that several distal sodium reabsorptive mechanisms are upregulated during vasopressin escape; this may help to attenuate the developing hyponatremia resulting from water loading when vasopressin levels are inappropriately elevated. PMID:11158210

  19. Wastewater Irrigation Increases the Abundance of Potentially Harmful Gammaproteobacteria in Soils in Mezquital Valley, Mexico

    PubMed Central

    Broszat, Melanie; Nacke, Heiko; Blasi, Ronja; Siebe, Christina; Huebner, Johannes; Daniel, Rolf

    2014-01-01

    Wastewater contains large amounts of pharmaceuticals, pathogens, and antimicrobial resistance determinants. Only a little is known about the dissemination of resistance determinants and changes in soil microbial communities affected by wastewater irrigation. Community DNAs from Mezquital Valley soils under irrigation with untreated wastewater for 0 to 100 years were analyzed by quantitative real-time PCR for the presence of sul genes, encoding resistance to sulfonamides. Amplicon sequencing of bacterial 16S rRNA genes from community DNAs from soils irrigated for 0, 8, 10, 85, and 100 years was performed and revealed a 14% increase of the relative abundance of Proteobacteria in rainy season soils and a 26.7% increase in dry season soils for soils irrigated for 100 years with wastewater. In particular, Gammaproteobacteria, including potential pathogens, such as Pseudomonas, Stenotrophomonas, and Acinetobacter spp., were found in wastewater-irrigated fields. 16S rRNA gene sequencing of 96 isolates from soils irrigated with wastewater for 100 years (48 from dry and 48 from rainy season soils) revealed that 46% were affiliated with the Gammaproteobacteria (mainly potentially pathogenic Stenotrophomonas strains) and 50% with the Bacilli, whereas all 96 isolates from rain-fed soils (48 from dry and 48 from rainy season soils) were affiliated with the Bacilli. Up to six types of antibiotic resistance were found in isolates from wastewater-irrigated soils; sulfamethoxazole resistance was the most abundant (33.3% of the isolates), followed by oxacillin resistance (21.9% of the isolates). In summary, we detected an increase of potentially harmful bacteria and a larger incidence of resistance determinants in wastewater-irrigated soils, which might result in health risks for farm workers and consumers of wastewater-irrigated crops. PMID:24951788

  20. Dietary fucoidan modulates the gut microbiota in mice by increasing the abundance of Lactobacillus and Ruminococcaceae.

    PubMed

    Shang, Qingsen; Shan, Xindi; Cai, Chao; Hao, Jiejie; Li, Guoyun; Yu, Guangli

    2016-07-13

    Recently, fucoidan has been proposed as a potential prebiotic agent for functional food and pharmaceutical development. However, while previous studies illustrated favorable modulations of gut microbiota by fucoidan, changes in the overall microbial structure remain elusive. In the present study, modulations of gut microbiota by different fucoidans were studied using high throughput sequencing and bioinformatics analysis. We found that at the expense of opportunistic pathogenic bacteria such as Peptococcus, the abundance of beneficial bacteria including Lactobacillus and Ruminococcaceae was significantly increased in response to fucoidan treatment. Besides, by maintaining a more balanced composition of gut microbiota, dietary fucoidan also significantly reduced the antigen load and the inflammatory response in the host as evidenced by the decreased serum lipopolysaccharide-binding protein levels. Collectively, our results indicate that fucoidan can be used as a gut microbiota modulator for health promotion and treatment of intestinal dysbiosis.

  1. Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli.

    PubMed

    Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia; Ramayo-Caldas, Yuliaxis; Estellé, Jordi; Ma, Tao; Madsen, Lise; Kristiansen, Karsten; Svensson-Frej, Marcus

    2015-01-01

    The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance of the immune system. In line with this, the prevalence of persistent worm infections is inversely correlated with the incidence of immune-associated diseases, prompting the use of controlled parasite infections for therapeutic purposes. Despite this, the impact of parasite infection on the intestinal microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences the intestinal microbiota and the adaptive immune system. Our results illustrate the complex interactions between these factors in the intestinal tract, and contribute to furthering the understanding of this interplay, which is of crucial importance considering that 500 million people globally are suffering from these infections and their potential use for therapeutic purposes. PMID:25942314

  2. Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli.

    PubMed

    Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia; Ramayo-Caldas, Yuliaxis; Estellé, Jordi; Ma, Tao; Madsen, Lise; Kristiansen, Karsten; Svensson-Frej, Marcus

    2015-01-01

    The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance of the immune system. In line with this, the prevalence of persistent worm infections is inversely correlated with the incidence of immune-associated diseases, prompting the use of controlled parasite infections for therapeutic purposes. Despite this, the impact of parasite infection on the intestinal microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences the intestinal microbiota and the adaptive immune system. Our results illustrate the complex interactions between these factors in the intestinal tract, and contribute to furthering the understanding of this interplay, which is of crucial importance considering that 500 million people globally are suffering from these infections and their potential use for therapeutic purposes.

  3. Topoisomerase I deficiency causes RNA polymerase II accumulation and increases AID abundance in immunoglobulin variable genes.

    PubMed

    Maul, Robert W; Saribasak, Huseyin; Cao, Zheng; Gearhart, Patricia J

    2015-06-01

    Activation-induced deaminase (AID) is a DNA cytosine deaminase that diversifies immunoglobulin genes in B cells. Recent work has shown that RNA polymerase II (Pol II) accumulation correlates with AID recruitment. However, a direct link between Pol II and AID abundance has not been tested. We used the DT40 B-cell line to manipulate levels of Pol II by decreasing topoisomerase I (Top1), which relaxes DNA supercoiling in front of the transcription complex. Top1 was decreased by stable transfection of a short hairpin RNA against Top1, which produced an accumulation of Pol II in transcribed genes, compared to cells transfected with sh-control RNA. The increased Pol II density enhanced AID recruitment to variable genes in the λ light chain locus, and resulted in higher levels of somatic hypermutation and gene conversion. It has been proposed by another lab that AID itself might directly suppress Top1 to increase somatic hypermutation. However, we found that in both AID(+/+) and AID(-/-) B cells from DT40 and mice, Top1 protein levels were identical, indicating that the presence or absence of AID did not decrease Top1 expression. Rather, our results suggest that the mechanism for increased diversity when Top1 is reduced is that Pol II accumulates and recruits AID to variable genes.

  4. Altered rainfall patterns increase forb abundance and richness in native tallgrass prairie

    PubMed Central

    Jones, Sydney K.; Collins, Scott L.; Blair, John M.; Smith, Melinda D.; Knapp, Alan K.

    2016-01-01

    Models predict that precipitation variability will increase with climate change. We used a 15-year precipitation manipulation experiment to determine if altering the timing and amount of growing season rainfall will impact plant community structure in annually burned, native tallgrass prairie. The altered precipitation treatment maintained the same total growing season precipitation as the ambient precipitation treatment, but received a rainfall regime of fewer, larger rain events, and longer intervals between events each growing season. Although this change in precipitation regime significantly lowered mean soil water content, overall this plant community was remarkably resistant to altered precipitation with species composition relatively stable over time. However, we found significantly higher forb cover and richness and slightly lower grass cover on average with altered precipitation, but the forb responses were manifest only after a ten-year lag period. Thus, although community structure in this grassland is relatively resistant to this type of altered precipitation regime, forb abundance in native tallgrass prairie may increase in a future characterized by increased growing season precipitation variability. PMID:26830847

  5. Is consolidation drainage an indirect mechanism for increased abundance of cattail in northern prairie wetlands?

    USGS Publications Warehouse

    Wiltermuth, Mark T.; Anteau, Michael J.

    2016-01-01

    In the Prairie Pothole Region of North America, disturbances to wetlands that disrupt water-level fluctuations in response to wet–dry climatic conditions have the potential to alter natural vegetative communities in favor of species that proliferate in stable environments, such as cattail (Typha spp.). We evaluated the effect of water-level dynamics during a recent fluctuation in wet–dry conditions on cattail coverage within semipermanently and permanently ponded wetlands situated in watersheds with different land use and amounts of wetland drainage. We found that ponded water depth increase was significantly greater in wetlands where water levels were not near the spill point of the topographic basin, where banks were steeper, and in larger wetlands where past dry conditions had less influence on change in pond area. Proportion of the wetland covered by cattail was negatively correlated with increased water depth, bank slope and pond area. Our observations provide evidence that cattail coverage in prairie wetlands is regulated by water-level fluctuations and that land use surrounding the wetland might have an indirect effect on cattail coverage by altering water-level response to wet–dry climate conditions. For example, drainage of smaller wetlands into larger wetlands that are characterized by more permanent hydroperiods, leads to stabilized water levels near their spill point and is therefore a potential mechanism for increased cattail abundance in the northern prairie region.

  6. Dietary flavonoid fisetin increases abundance of high-molecular-mass hyaluronan conferring resistance to prostate oncogenesis.

    PubMed

    Lall, Rahul K; Syed, Deeba N; Khan, Mohammad Imran; Adhami, Vaqar M; Gong, Yuansheng; Lucey, John A; Mukhtar, Hasan

    2016-09-01

    We and others have shown previously that fisetin, a plant flavonoid, has therapeutic potential against many cancer types. Here, we examined the probable mechanism of its action in prostate cancer (PCa) using a global metabolomics approach. HPLC-ESI-MS analysis of tumor xenografts from fisetin-treated animals identified several metabolic targets with hyaluronan (HA) as the most affected. Efficacy of fisetin on HA was then evaluated in vitro and also in vivo in the transgenic TRAMP mouse model of PCa. Size exclusion chromatography-multiangle laser light scattering (SEC-MALS) was performed to analyze the molar mass (Mw) distribution of HA. Fisetin treatment downregulated intracellular and secreted HA levels both in vitro and in vivo Fisetin inhibited HA synthesis and degradation enzymes, which led to cessation of HA synthesis and also repressed the degradation of the available high-molecular-mass (HMM)-HA. SEC-MALS analysis of intact HA fragment size revealed that cells and animals have more abundance of HMM-HA and less of low-molecular-mass (LMM)-HA upon fisetin treatment. Elevated HA levels have been shown to be associated with disease progression in certain cancer types. Biological responses triggered by HA mainly depend on the HA polymer length where HMM-HA represses mitogenic signaling and has anti-inflammatory properties whereas LMM-HA promotes proliferation and inflammation. Similarly, Mw analysis of secreted HA fragment size revealed less HMM-HA is secreted that allowed more HMM-HA to be retained within the cells and tissues. Our findings establish that fisetin is an effective, non-toxic, potent HA synthesis inhibitor, which increases abundance of antiangiogenic HMM-HA and could be used for the management of PCa.

  7. Dietary flavonoid fisetin increases abundance of high-molecular-mass hyaluronan conferring resistance to prostate oncogenesis.

    PubMed

    Lall, Rahul K; Syed, Deeba N; Khan, Mohammad Imran; Adhami, Vaqar M; Gong, Yuansheng; Lucey, John A; Mukhtar, Hasan

    2016-09-01

    We and others have shown previously that fisetin, a plant flavonoid, has therapeutic potential against many cancer types. Here, we examined the probable mechanism of its action in prostate cancer (PCa) using a global metabolomics approach. HPLC-ESI-MS analysis of tumor xenografts from fisetin-treated animals identified several metabolic targets with hyaluronan (HA) as the most affected. Efficacy of fisetin on HA was then evaluated in vitro and also in vivo in the transgenic TRAMP mouse model of PCa. Size exclusion chromatography-multiangle laser light scattering (SEC-MALS) was performed to analyze the molar mass (Mw) distribution of HA. Fisetin treatment downregulated intracellular and secreted HA levels both in vitro and in vivo Fisetin inhibited HA synthesis and degradation enzymes, which led to cessation of HA synthesis and also repressed the degradation of the available high-molecular-mass (HMM)-HA. SEC-MALS analysis of intact HA fragment size revealed that cells and animals have more abundance of HMM-HA and less of low-molecular-mass (LMM)-HA upon fisetin treatment. Elevated HA levels have been shown to be associated with disease progression in certain cancer types. Biological responses triggered by HA mainly depend on the HA polymer length where HMM-HA represses mitogenic signaling and has anti-inflammatory properties whereas LMM-HA promotes proliferation and inflammation. Similarly, Mw analysis of secreted HA fragment size revealed less HMM-HA is secreted that allowed more HMM-HA to be retained within the cells and tissues. Our findings establish that fisetin is an effective, non-toxic, potent HA synthesis inhibitor, which increases abundance of antiangiogenic HMM-HA and could be used for the management of PCa. PMID:27335141

  8. Dramatic Increases in Obesity and Overweight Prevalence and Body Mass Index Among Ethnic-Immigrant and Social Class Groups in the United States, 1976–2008

    PubMed Central

    Siahpush, Mohammad; Hiatt, Robert A.; Timsina, Lava R.

    2010-01-01

    This study examined trends in US obesity and overweight prevalence and body mass index (BMI) among 30 immigrant groups, stratified by race/ethnicity and length of immigration, and among detailed education, occupation, and income/poverty groups from 1976 to 2008. Using 1976–2008 National Health Interview Surveys, differentials in obesity, overweight, and BMI, based on self-reported height and weight, were analyzed by using disparity indices, logistic, and linear regression. The obesity prevalence for the US population aged ≥18 tripled from 8.7% in 1976 to 27.4% in 2008. Overweight prevalence increased from 36.9% in 1976 to 62.0% in 2008. During 1991–2008, obesity prevalence for US-born adults increased from 13.9 to 28.7%, while prevalence for immigrants increased from 9.5 to 20.7%. While immigrants in each ethnic group and time period had lower obesity and overweight prevalence and BMI than the US-born, immigrants’ risk of obesity and overweight increased with increasing duration of residence. In 2003–2008, obesity prevalence ranged from 2.3% for recent Chinese immigrants to 31–39% for American Indians, US-born blacks, Mexicans, and Puerto Ricans, and long-term Mexican and Puerto Rican immigrants. Between 1976 and 2008, the obesity prevalence more than quadrupled for those with a college education or sales occupation. Although higher prevalence was observed for lower education, income, and occupation levels in each period, socioeconomic gradients in obesity and overweight decreased over time because of more rapid increases in prevalence among higher socioeconomic groups. Continued immigrant and socioeconomic disparities in prevalence will likely have substantial impacts on future obesity trends in the US. PMID:20549318

  9. Developmental expression of chicken antithrombin III is regulated by increased RNA abundance and intracellular processing.

    PubMed

    Amrani, D L; Rosenberg, J; Samad, F; Bergtrom, G; Banfield, D K

    1993-01-23

    We isolated and sequenced a 432 bp cDNA to cAT-III, that encoded 115 nucleotides of 5' untranslated sequence, a 17 amino acid long signal peptide and residues 1-88 of the mature protein, and used it to prepare a probe for measuring and correlating the developmental changes of steady-state cAT-III mRNA levels with known changes in antigen levels. Densitometric analysis of nuclease protection (n = 2), Northern blot (n = 4), and slot blots (n = 3) of total RNA from chick livers of 16-day-old embryos to 6-day-old chicks showed a 2.6 +/- 0.5-fold increase in steady-state cAT-III mRNA levels. Assay of functional mRNA levels by in vitro translation of poly(A)+ RNA and specific immunoprecipitation of 35S-Met-labelled cAT-III was comparable to RNA analysis (16-day-old embryos vs. 10-day-old hatchlings). We evaluated whether there were developmental differences in post-translational secretion which may also contribute to the regulation of the circulating level of this protein. Pulse-chase studies of freshly-isolated hepatocytes from 16-day-old embryos and 10-day-old hatchlings maintained in suspension demonstrated a approx. 5.0-5.5-fold increase in cAT-III levels at steady-state secretion. The above findings indicate that changes in circulating cAT-III levels during late embryonic development are primarily due to increased abundance of cAT-III mRNA. In addition, we postulate that post-translational intracellular processing may account for further differences in circulating protein levels. PMID:8424948

  10. Metabolic engineering of hydroxy fatty acid production in plants: RcDGAT2 drives dramatic increases in ricinoleate levels in seed oil

    PubMed Central

    Burgal, Julie; Shockey, Jay; Lu, Chaofu; Dyer, John; Larson, Tony; Graham, Ian; Browse, John

    2010-01-01

    Summary A central goal of green chemistry is to produce industrially useful fatty acids in oilseed crops. Although genes encoding suitable fatty acid-modifying enzymes are available from many wild species, progress has been limited because the expression of these genes in transgenic plants produces low yields of the desired products. For example, Ricinus communis fatty acid hydroxylase 12 (FAH12) produces a maximum of only 17% hydroxy fatty acids (HFAs) when expressed in Arabidopsis. cDNA clones encoding R. communis enzymes for additional steps in the seed oil biosynthetic pathway were identified. Expression of these cDNAs in FAH12 transgenic plants revealed that the R. communis type-2 acyl-coenzyme A:diacylglycerol acyltransferase (RcDGAT2) could increase HFAs from 17% to nearly 30%. Detailed comparisons of seed neutral lipids from the single- and double-transgenic lines indicated that RcDGAT2 substantially modified the triacylglycerol (TAG) pool, with significant increases in most of the major TAG species observed in native castor bean oil. These data suggest that RcDGAT2 prefers acyl-coenzyme A and diacylglycerol substrates containing HFAs, and biochemical analyses of RcDGAT2 expressed in yeast cells confirmed a strong preference for HFA-containing diacylglycerol substrates. Our results demonstrate that pathway engineering approaches can be used successfully to increase the yields of industrial feedstocks in plants, and that members of the DGAT2 gene family probably play a key role in this process. PMID:18643899

  11. Intake of Meat Proteins Substantially Increased the Relative Abundance of Genus Lactobacillus in Rat Feces

    PubMed Central

    Zhu, Yingying; Lin, Xisha; Li, He; Li, Yingqiu; Shi, Xuebin; Zhao, Fan; Xu, Xinglian; Li, Chunbao; Zhou, Guanghong

    2016-01-01

    Diet has been shown to have a critical influence on gut bacteria and host health, and high levels of red meat in diet have been shown to increase colonic DNA damage and thus be harmful to gut health. However, previous studies focused more on the effects of meat than of meat proteins. In order to investigate whether intake of meat proteins affects the composition and metabolic activities of gut microbiota, feces were collected from growing rats that were fed with either meat proteins (from beef, pork or fish) or non-meat proteins (casein or soy) for 14 days. The resulting composition of gut microbiota was profiled by sequencing the V4-V5 region of the 16S ribosomal RNA genes and the short chain fatty acids (SCFAs) were analyzed using gas chromatography. The composition of gut microbiota and SCFA levels were significantly different between the five diet groups. At a recommended dose of 20% protein in the diet, meat protein-fed rats had a higher relative abundance of the beneficial genus Lactobacillus, but lower levels of SCFAs and SCFA-producing bacteria including Fusobacterium, Bacteroides and Prevotella, compared with the soy protein-fed group. Further work is needed on the regulatory pathways linking dietary protein intake to gut microbiota. PMID:27042829

  12. Intake of Meat Proteins Substantially Increased the Relative Abundance of Genus Lactobacillus in Rat Feces.

    PubMed

    Zhu, Yingying; Lin, Xisha; Li, He; Li, Yingqiu; Shi, Xuebin; Zhao, Fan; Xu, Xinglian; Li, Chunbao; Zhou, Guanghong

    2016-01-01

    Diet has been shown to have a critical influence on gut bacteria and host health, and high levels of red meat in diet have been shown to increase colonic DNA damage and thus be harmful to gut health. However, previous studies focused more on the effects of meat than of meat proteins. In order to investigate whether intake of meat proteins affects the composition and metabolic activities of gut microbiota, feces were collected from growing rats that were fed with either meat proteins (from beef, pork or fish) or non-meat proteins (casein or soy) for 14 days. The resulting composition of gut microbiota was profiled by sequencing the V4-V5 region of the 16S ribosomal RNA genes and the short chain fatty acids (SCFAs) were analyzed using gas chromatography. The composition of gut microbiota and SCFA levels were significantly different between the five diet groups. At a recommended dose of 20% protein in the diet, meat protein-fed rats had a higher relative abundance of the beneficial genus Lactobacillus, but lower levels of SCFAs and SCFA-producing bacteria including Fusobacterium, Bacteroides and Prevotella, compared with the soy protein-fed group. Further work is needed on the regulatory pathways linking dietary protein intake to gut microbiota. PMID:27042829

  13. Intake of Meat Proteins Substantially Increased the Relative Abundance of Genus Lactobacillus in Rat Feces.

    PubMed

    Zhu, Yingying; Lin, Xisha; Li, He; Li, Yingqiu; Shi, Xuebin; Zhao, Fan; Xu, Xinglian; Li, Chunbao; Zhou, Guanghong

    2016-01-01

    Diet has been shown to have a critical influence on gut bacteria and host health, and high levels of red meat in diet have been shown to increase colonic DNA damage and thus be harmful to gut health. However, previous studies focused more on the effects of meat than of meat proteins. In order to investigate whether intake of meat proteins affects the composition and metabolic activities of gut microbiota, feces were collected from growing rats that were fed with either meat proteins (from beef, pork or fish) or non-meat proteins (casein or soy) for 14 days. The resulting composition of gut microbiota was profiled by sequencing the V4-V5 region of the 16S ribosomal RNA genes and the short chain fatty acids (SCFAs) were analyzed using gas chromatography. The composition of gut microbiota and SCFA levels were significantly different between the five diet groups. At a recommended dose of 20% protein in the diet, meat protein-fed rats had a higher relative abundance of the beneficial genus Lactobacillus, but lower levels of SCFAs and SCFA-producing bacteria including Fusobacterium, Bacteroides and Prevotella, compared with the soy protein-fed group. Further work is needed on the regulatory pathways linking dietary protein intake to gut microbiota.

  14. Seed-specific heterologous expression of a nasturtium FAE gene in Arabidopsis results in a dramatic increase in the proportion of erucic acid.

    PubMed

    Mietkiewska, Elzbieta; Giblin, E Michael; Wang, Song; Barton, Dennis L; Dirpaul, Joan; Brost, Jennifer M; Katavic, Vesna; Taylor, David C

    2004-09-01

    The fatty acid elongase [often designated FAE or beta-(or 3-) ketoacyl-CoA synthase] is a condensing enzyme and is the first component of the elongation complex involved in synthesis of erucic acid (22:1) in seeds of garden nasturtium (Tropaeolum majus). Using a degenerate primers approach, a cDNA of a putative embryo FAE was obtained showing high homology to known plant elongases. This cDNA contains a 1,512-bp open reading frame that encodes a protein of 504 amino acids. A genomic clone of the nasturtium FAE was isolated and sequence analyses indicated the absence of introns. Northern hybridization showed the expression of this nasturtium FAE gene to be restricted to the embryo. Southern hybridization revealed the nasturtium beta-ketoacyl-CoA synthase to be encoded by a small multigene family. To establish the function of the elongase homolog, the cDNA was introduced into two different heterologous chromosomal backgrounds (Arabidopsis and tobacco [Nicotiana tabacum]) under the control of a seed-specific (napin) promoter and the tandem 35S promoter, respectively. Seed-specific expression resulted in up to an 8-fold increase in erucic acid proportions in Arabidopsis seed oil, while constitutive expression in transgenic tobacco tissue resulted in increased proportions of very long chain saturated fatty acids. These results indicate that the nasturtium FAE gene encodes a condensing enzyme involved in the biosynthesis of very long chain fatty acids, utilizing monounsaturated and saturated acyl substrates. Given its strong and unique preference for elongating 20:1-CoA, the utility of the FAE gene product for directing or engineering increased synthesis of erucic acid is discussed.

  15. Dramatic increase in SHP2 binding activity of Helicobacter pylori Western CagA by EPIYA-C duplication: its implications in gastric carcinogenesis

    PubMed Central

    Nagase, Lisa; Hayashi, Takeru; Senda, Toshiya; Hatakeyama, Masanori

    2015-01-01

    Infection with cagA-positive Helicobacter pylori is critically associated with the development of gastric cancer. The cagA-encoded CagA is delivered into gastric epithelial cells via type IV secretion, where it interacts with and thereby deregulates the pro-oncogenic phosphatase SHP2. East Asian CagA and Western CagA are two major CagA species produced by H. pylori circulating in East Asian countries and in the rest of the world, respectively. The SHP2 binding site of Western CagA, termed the EPIYA-C segment, variably duplicates and infection with H. pylori carrying Western CagA with multiple EPIYA-C segments is a distinct risk factor of gastric cancer. Here we show that duplication of EPIYA-C from one to two or more increases SHP2 binding of Western CagA by more than one hundredfold. Based on the decisive difference in SHP2 binding, Western CagA can be divided into two types: type I CagA carrying a single EPIYA-C segment and type II CagA carrying multiple EPIYA-C segments. Gastric epithelial cells expressing type II CagA acquire the ability to invade extracellular matrices, a malignant cellular trait associated with deregulated SHP2. A big leap in SHP2 binding activity may therefore provide molecular basis that makes type II Western CagA a distinct gastric cancer risk. PMID:26507409

  16. Viral prevalence increases with regional colony abundance in honey bee drones (Apis mellifera L).

    PubMed

    Forfert, Nadège; Natsopoulou, Myrsini E; Paxton, Robert J; Moritz, Robin F A

    2016-10-01

    Transmission among colonies is a central feature for the epidemiology of honey bee pathogens. High colony abundance may promote transmission among colonies independently of apiary layout, making colony abundance a potentially important parameter determining pathogen prevalence in populations of honey bees. To test this idea, we sampled male honey bees (drones) from seven distinct drone congregation areas (DCA), and used their genotypes to estimate colony abundance at each site. A multiplex ligation dependent probe amplification assay (MLPA) was used to assess the prevalence of ten viruses, using five common viral targets, in individual drones. There was a significant positive association between colony abundance and number of viral infections. This result highlights the potential importance of high colony abundance for pathogen prevalence, possibly because high population density facilitates pathogen transmission. Pathogen prevalence in drones collected from DCAs may be a useful means of estimating the disease status of a population of honey bees during the mating season, especially for localities with a large number of wild or feral colonies.

  17. Viral prevalence increases with regional colony abundance in honey bee drones (Apis mellifera L).

    PubMed

    Forfert, Nadège; Natsopoulou, Myrsini E; Paxton, Robert J; Moritz, Robin F A

    2016-10-01

    Transmission among colonies is a central feature for the epidemiology of honey bee pathogens. High colony abundance may promote transmission among colonies independently of apiary layout, making colony abundance a potentially important parameter determining pathogen prevalence in populations of honey bees. To test this idea, we sampled male honey bees (drones) from seven distinct drone congregation areas (DCA), and used their genotypes to estimate colony abundance at each site. A multiplex ligation dependent probe amplification assay (MLPA) was used to assess the prevalence of ten viruses, using five common viral targets, in individual drones. There was a significant positive association between colony abundance and number of viral infections. This result highlights the potential importance of high colony abundance for pathogen prevalence, possibly because high population density facilitates pathogen transmission. Pathogen prevalence in drones collected from DCAs may be a useful means of estimating the disease status of a population of honey bees during the mating season, especially for localities with a large number of wild or feral colonies. PMID:27444641

  18. Increases in Calmodulin Abundance and Stabilization of Activated iNOS Mediate Bacterial Killing in RAW 264.7 Macrophages

    SciTech Connect

    Smallwood, Heather S.; Shi, Liang; Squier, Thomas C.

    2006-08-01

    The rapid activation of macrophages in response to bacterial antigens is central to the innate immune system that permits the recognition and killing of pathogens to limit infection. To understand regulatory mechanisms underlying macrophage activation, we have investigated changes in the abundance of calmodulin (CaM) and iNOS in response to the bacterial cell wall component lipopolysaccharide (LPS) using RAW 264.7 macrophages. Critical to these measurements was the ability to differentiate free iNOS from the CaM-bound (active) form of iNOS associated with nitric oxide generation. We observe a rapid two-fold increase in CaM abundance during the first 30 minutes that is blocked by inhibition of NF?B nuclear translocation or protein synthesis. A similar two-fold increase in the abundance of the complex between CaM and iNOS is observed with the same time dependence. In contrast, there are no detectable increases in the CaM-free (i.e., inactive) form of iNOS within the first hour; it remains at a very low abundance during the initial phase of macrophage activation. Increasing cellular CaM levels in stably transfected cells results in a corresponding increase in the abundance of the CaM/iNOS complex that promotes effective bacterial killing following challenge by Salmonella typhimurium. Thus, LPS-dependent increases in CaM abundance function in the stabilization and activation of iNOS on the rapid time-scale associated with macrophage activation and bacterial killing. These results explain how CaM and iNOS coordinately function to form a stable complex that is part of a rapid host-response that functions within the first 30 minutes following bacterial infection to up-regulate the innate immune system involving macrophage activation.

  19. Increasing shrub abundance and N addition in Arctic tundra affect leaf and root litter decomposition differently

    NASA Astrophysics Data System (ADS)

    McLaren, J.; van de Weg, M. J.; Shaver, G. R.; Gough, L.

    2013-12-01

    Changes in global climate have resulted in a ';greening' of the Arctic as the abundance of deciduous shrub species increases. Consequently, not only the living plant community, but also the litter composition changes, which in turn can affect carbon turnover patterns in the Arctic. We examined effects of changing litter composition (both root and leaf litter) on decomposition rates with a litter bag study, and specifically focused on the impact of deciduous shrub Betula nana litter on litter decomposition from two evergreen shrubs (Ledum palustre, and Vaccinium vitis-idaea) and one graminoid (Eriophorum vaginatum) species. Additionally, we investigated how decomposition was affected by nutrient availability by placing the litterbags in an ambient and a fertilized moist acidic tundra environment. Measurements were carried out seasonally over 2 years (after snow melt, mid-growing season, end growing season). We measured litter mass loss over time, as well as the respiration rates (standardized for temperature and moisture) and temperature sensitivity of litter respiration at the time of harvesting the litter bags. For leaves, Betula litter decomposed faster than the other three species, with Eriophorum leaves decomposing the slowest. This pattern was observed for both mass loss and litter respiration rates, although the differences in respiration became smaller over time. Surprisingly, combining Betula with any other species resulted in slower overall weight loss rates than would be predicted based on monoculture weight loss rates. This contrasted with litter respiration at the time of sampling, which showed a positive mixing effect of adding Betula leaf liter to the other species. Apparently, during the first winter months (September - May) Betula litter decomposition is negatively affected by mixing the species and this legacy can still be observed in the total mass loss results later in the year. For root litter there were fewer effects of species identity on root

  20. Comet 67P/Churyumov-Gerasimenko’s Increasing Atomic Sulfur Abundance Observed by Rosetta Alice

    NASA Astrophysics Data System (ADS)

    Feaga, Lori M.; Feldman, Paul D.; A'Hearn, Michael F.; Bertaux, Jean-Loup; Keeney, Brian A.; Knight, Matthew M.; Noonan, John; Parker, Joel Wm.; Schindhelm, Eric; Steffl, Andrew J.; Stern, S. Alan; Vervack, Ronald J.; Weaver, Harold A.

    2015-11-01

    Alice, NASA’s lightweight and low-power far-ultraviolet (FUV) imaging spectrograph onboard ESA’s comet orbiting spacecraft Rosetta (Stern et al. 2007), is continuing its characterization of the nucleus and coma of the Jupiter family comet 67P/Churyumov-Gerasimenko (C-G) as it approaches and recedes from perihelion. With a spectral range from 700-2050 Å, Alice has the ability to detect the atomic sulfur multiplets at 1429 Å, 1479 Å and 1814 Å. Sulfur in C-G’s coma is most likely a dissociation product of CS2 and OCS, but could also be produced after a secondary dissociation from H2S and SO2, all molecular species measured in C-G’s coma by ROSINA, the Rosetta orbiter’s mass spectrometer.Due to low abundances, Alice did not detect sulfur atoms at C-G until May 2015 when the comet was at ~1.7 AU and still 3 months from perihelion. Now, sulfur is ubiquitous in Alice observations above the limb of the nucleus. There is evidence that there is not a strong dependence of the abundance of sulfur on the distance from the nucleus in the pre-perihelion radial profiles of the gas, which may be indicative of the parent molecule and its distribution. This will be investigated further. The evolution of the presence of the three sulfur multiplets, their relative abundances and excitation processes, and behavior pre- and post-perihelion will be presented.

  1. Urbanized landscapes favored by fig-eating birds increase invasive but not native juvenile strangler fig abundance.

    PubMed

    Caughlin, Trevor; Wheeler, Jessica H; Jankowski, Jill; Lichstein, Jeremy W

    2012-07-01

    Propagule pressure can determine the success or failure of invasive plant range expansion. Range expansion takes place at large spatial scales, often encompassing many types of land cover, yet the effect of landscape context on propagule pressure remains largely unknown. Many studies have reported a positive correlation between invasive plant abundance and human land use; increased propagule pressure in these landscapes may be responsible for this correlation. We tested the hypothesis that increased rates of seed dispersal by fig-eating birds, which are more common in urban habitats, result in an increase in invasive strangler fig abundance in landscapes dominated by human land use. We quantified abundance of an invasive species (Ficus microcarpa) and a native species (F. aurea) of strangler fig in plots spanning the entire range of human land use in South Florida, USA, from urban parking lots to native forest. We then compared models that predicted juvenile fig abundance based on distance to adult fig seed sources and fig-eating bird habitat quality with models that lacked one or both of these terms. The best model for juvenile invasive fig abundance included both distance to adult and fig-eating bird habitat terms, suggesting that landscape effects on invasive fig abundance are mediated by seed-dispersing birds. In contrast, the best model for juvenile native fig abundance included only presence/absence of adults, suggesting that distance from individual adult trees may have less effect on seed limitation for a native species compared to an invasive species undergoing range expansion. However, models for both species included significant effects of adult seed sources, implying that juvenile abundance is limited by seed arrival. This result was corroborated by a seed addition experiment that indicated that both native and invasive strangler figs were strongly seed limited. Understanding how landscape context affects the mechanisms of plant invasion may lead to

  2. Female offspring desertion and male-only care increase with natural and experimental increase in food abundance

    PubMed Central

    Eldegard, Katrine; Sonerud, Geir A.

    2009-01-01

    In species with biparental care, one parent may escape the costs of parental care by deserting and leaving the partner to care for the offspring alone. A number of theoretical papers have suggested a link between uniparental offspring desertion and ecological factors, but empirical evidence is scarce. We investigated the relationship between uniparental desertion and food abundance in a natural population of Tengmalm's owl Aegolius funereus, both by means of a 5-year observational study and a 1-year experimental study. Parents and offspring were fitted with radio-transmitters in order to reveal the parental care strategy (i.e. care or desert) of individual parents, and to keep track of the broods post-fledging. We found that 70 per cent of the females from non-experimental nests deserted, while their partner continued to care for their joint offspring alone. Desertion rate was positively related to natural prey population densities and body reserves of the male partner. In response to food supplementation, a larger proportion of the females deserted, and females deserted the offspring at an earlier age. Offspring survival during the post-fledging period tended to be lower in deserted than in non-deserted broods. We argue that the most important benefit of deserting may be remating (sequential polyandry). PMID:19324835

  3. Female offspring desertion and male-only care increase with natural and experimental increase in food abundance.

    PubMed

    Eldegard, Katrine; Sonerud, Geir A

    2009-05-01

    In species with biparental care, one parent may escape the costs of parental care by deserting and leaving the partner to care for the offspring alone. A number of theoretical papers have suggested a link between uniparental offspring desertion and ecological factors, but empirical evidence is scarce. We investigated the relationship between uniparental desertion and food abundance in a natural population of Tengmalm's owl Aegolius funereus, both by means of a 5-year observational study and a 1-year experimental study. Parents and offspring were fitted with radio-transmitters in order to reveal the parental care strategy (i.e. care or desert) of individual parents, and to keep track of the broods post-fledging. We found that 70 per cent of the females from non-experimental nests deserted, while their partner continued to care for their joint offspring alone. Desertion rate was positively related to natural prey population densities and body reserves of the male partner. In response to food supplementation, a larger proportion of the females deserted, and females deserted the offspring at an earlier age. Offspring survival during the post-fledging period tended to be lower in deserted than in non-deserted broods. We argue that the most important benefit of deserting may be remating (sequential polyandry). PMID:19324835

  4. Obesity-Dependent Increases in Oocyte mRNAs Are Associated With Increases in Proinflammatory Signaling and Gut Microbial Abundance of Lachnospiraceae in Female Mice.

    PubMed

    Xie, Fang; Anderson, Christopher L; Timme, Kelsey R; Kurz, Scott G; Fernando, Samodha C; Wood, Jennifer R

    2016-04-01

    RNAs stored in the metaphase II-arrested oocyte play important roles in successful embryonic development. Their abundance is defined by transcriptional activity during oocyte growth and selective degradation of transcripts during LH-induced oocyte maturation. Our previous studies demonstrated that mRNA abundance is increased in mature ovulated oocytes collected from obese humans and mice and therefore may contribute to reduced oocyte developmental competence associated with metabolic dysfunction. In the current study mouse models of diet-induced obesity were used to determine whether obesity-dependent increases in proinflammatory signaling regulate ovarian abundance of oocyte-specific mRNAs. The abundance of oocyte-specific Bnc1, Dppa3, and Pou5f1 mRNAs as well as markers of proinflammatory signaling were significantly increased in ovaries of obese compared with lean mice which were depleted of fully grown preovulatory follicles. Chromatin-immunoprecipitation analyses also demonstrated increased association of phosphorylated signal transducer and activator of transcription 3 with the Pou5f1 promoter in ovaries of obese mice suggesting that proinflammatory signaling regulates transcription of this gene in the oocyte. The cecum microbial content of lean and obese female mice was subsequently examined to identify potential relationships between microbial composition and proinflammatory signaling in the ovary. Multivariate Association with Linear Models identified significant positive correlations between cecum abundance of the bacterial family Lachnospiraceae and ovarian abundance of Tnfa as well as Dppa3, Bnc1, and Pou5f1 mRNAs. Together, these data suggest that diet-induced changes in gut microbial composition may be contributing to ovarian inflammation which in turn alters ovarian gene expression and ultimately contributes to obesity-dependent reduction in oocyte quality and development of infertility in obese patients.

  5. Obesity-Dependent Increases in Oocyte mRNAs Are Associated With Increases in Proinflammatory Signaling and Gut Microbial Abundance of Lachnospiraceae in Female Mice.

    PubMed

    Xie, Fang; Anderson, Christopher L; Timme, Kelsey R; Kurz, Scott G; Fernando, Samodha C; Wood, Jennifer R

    2016-04-01

    RNAs stored in the metaphase II-arrested oocyte play important roles in successful embryonic development. Their abundance is defined by transcriptional activity during oocyte growth and selective degradation of transcripts during LH-induced oocyte maturation. Our previous studies demonstrated that mRNA abundance is increased in mature ovulated oocytes collected from obese humans and mice and therefore may contribute to reduced oocyte developmental competence associated with metabolic dysfunction. In the current study mouse models of diet-induced obesity were used to determine whether obesity-dependent increases in proinflammatory signaling regulate ovarian abundance of oocyte-specific mRNAs. The abundance of oocyte-specific Bnc1, Dppa3, and Pou5f1 mRNAs as well as markers of proinflammatory signaling were significantly increased in ovaries of obese compared with lean mice which were depleted of fully grown preovulatory follicles. Chromatin-immunoprecipitation analyses also demonstrated increased association of phosphorylated signal transducer and activator of transcription 3 with the Pou5f1 promoter in ovaries of obese mice suggesting that proinflammatory signaling regulates transcription of this gene in the oocyte. The cecum microbial content of lean and obese female mice was subsequently examined to identify potential relationships between microbial composition and proinflammatory signaling in the ovary. Multivariate Association with Linear Models identified significant positive correlations between cecum abundance of the bacterial family Lachnospiraceae and ovarian abundance of Tnfa as well as Dppa3, Bnc1, and Pou5f1 mRNAs. Together, these data suggest that diet-induced changes in gut microbial composition may be contributing to ovarian inflammation which in turn alters ovarian gene expression and ultimately contributes to obesity-dependent reduction in oocyte quality and development of infertility in obese patients. PMID:26881311

  6. Increased abundance of terrestrial isopod populations in terrestrial ecosystems contaminated with petrochemical wastes.

    PubMed

    Faulkner, B C; Lochmiller, R L

    2000-07-01

    Arthropods are integral components of the food chain, and because many reside in close association to the soil and its contaminants, their communities may be sensitive indicators of ecotoxicity. We examined the influence of petrochemical contaminants on the abundance of several taxonomic groups of macroarthropods, with an emphasis on isopods, residing on two reference sites and three petrochemical-contaminated sites at an abandoned oil refinery site in southwestern Oklahoma. Relative densities of surface-dwelling macroarthropod assemblages were significantly greater on contaminated sites than reference sites. Differences in terrestrial isopod populations were particularly remarkable and consistent across study sites, with densities approaching 180-fold greater on contaminated than reference sites. Similarity comparisons indicated that abundances and composition of macroarthropod assemblages sampled on the contaminated sites were more similar to one another than to the communities residing on reference sites. Although preliminary, these initial results support the hypothesis that macroarthropod assemblages, in particular isopods, are sensitive to soil contaminants and could be a valuable approach to evaluating the effects of petrochemical contamination of soils on terrestrial ecosystems.

  7. Greater deciduous shrub abundance extends the annual period of maximum tundra greenness and increases modeled net CO2 uptake

    NASA Astrophysics Data System (ADS)

    Sweet, S. K.; Griffin, K. L.; Steltzer, H.; Gough, L.; Boelman, N.

    2014-12-01

    Satellite studies of the terrestrial Arctic report increased summer greening and longer green seasons over the past several decades, which may increase productivity and lengthen the period of carbon uptake. These trends have been attributed largely to increasing air temperatures and reduced snow cover duration. However, deciduous shrubs are concurrently becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim in this research was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) over the growing season in the northern foothills of the Brooks Range, Alaska (68º38' N, 149º34' W). We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology using the normalized difference vegetation index (NDVI) and piecewise linear regression modeling. We used a tundra plant-community specific leaf area index (LAI) model to estimate LAI throughout the season. We then used a tundra specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of maximum greenness significantly earlier than evergreen/graminoid canopies, but both communities reached the onset of senescence at similar times, resulting in a net extension of the peak green season in deciduous shrub communities compared to evergreen/graminoid communities. The combined effect of a longer peak green season and greater leaf area of deciduous shrub canopies increased the net carbon uptake in deciduous shrub communities compared to evergreen/graminoid communities. However, the longer peak season alone significantly increased carbon uptake in deciduous shrub communities, suggesting that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf

  8. Increased renal Na-K-ATPase, NCC, and beta-ENaC abundance in obese Zucker rats.

    PubMed

    Bickel, C A; Verbalis, J G; Knepper, M A; Ecelbarger, C A

    2001-10-01

    Renal sodium retention, as a result of increased abundance of sodium transporters, may play a role in the development and/or maintenance of the increased blood pressure in obesity. To address this hypothesis, we evaluated the relative abundances of renal sodium transporters in lean and obese Zucker rats at 2 and 4 mo of age by semiquantitative immunoblotting. Mean systolic blood pressure was higher in obese rats relative to lean at 3 mo, P < 0.02. Furthermore, circulating insulin levels were 6- or 13-fold higher in obese rats compared with lean at 2 or 4 mo of age, respectively. The abundances of the alpha(1)-subunit of Na-K-ATPase, the thiazide-sensitive Na-Cl cotransporter (NCC or TSC), and the beta-subunit of the epithelial sodium channel (ENaC) were all significantly increased in the obese rats' kidneys. There were no differences for the sodium hydrogen exchanger (NHE3), the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2 or BSC1), the type II sodium-phosphate cotransporter (NaPi-2), or the alpha-subunit of ENaC. These selective increases could possibly increase sodium retention by the kidney and therefore could play a role in obesity-related hypertension. PMID:11553510

  9. The rainy season increases the abundance and richness of the aquatic insect community in a Neotropical reservoir.

    PubMed

    Santana, H S; Silva, L C F; Pereira, C L; Simião-Ferreira, J; Angelini, R

    2015-01-01

    Alterations in aquatic systems and changes in water levels, whether due to rains or dam-mediated control can cause changes in community structure, forcing the community to readjust to the new environment. This study tested the hypothesis that there is an increase in the richness and abundance of aquatic insects during the rainy season in the Serra da Mesa Reservoir, with the premise that increasing the reservoir level provides greater external material input and habitat diversity, and, therefore, conditions that promote colonization by more species. We used the paired t test to test the differences in richness, beta diversity, and abundance, and a Non-metric Multidimensional Scaling (NMDS) was performed to identify patterns in the community under study. Additionally, Pearson correlations were analyzed between the richness, abundance, and beta diversity and the level of the reservoir. We collected 35,028 aquatic insect larvae (9,513 in dry period and 25,515 in the rainy season), predominantly of the Chironomidae family, followed by orders Ephemeroptera, Trichoptera, and Odonata. Among the 33 families collected, only 12 occurred in the dry season, while all occurred in the rainy season. These families are common in lentic environments, and the dominance of Chironomidae was associated with its fast colonization, their behavior of living at high densities and the great tolerance to low levels of oxygen in the environment. The hypothesis was confirmed, as the richness, beta diversity, and abundance were positively affected by the increase in water levels due to the rainy season, which most likely led to greater external material input, greater heterogeneity of habitat, and better conditions for colonization by several families. PMID:25945631

  10. The rainy season increases the abundance and richness of the aquatic insect community in a Neotropical reservoir.

    PubMed

    Santana, H S; Silva, L C F; Pereira, C L; Simião-Ferreira, J; Angelini, R

    2015-01-01

    Alterations in aquatic systems and changes in water levels, whether due to rains or dam-mediated control can cause changes in community structure, forcing the community to readjust to the new environment. This study tested the hypothesis that there is an increase in the richness and abundance of aquatic insects during the rainy season in the Serra da Mesa Reservoir, with the premise that increasing the reservoir level provides greater external material input and habitat diversity, and, therefore, conditions that promote colonization by more species. We used the paired t test to test the differences in richness, beta diversity, and abundance, and a Non-metric Multidimensional Scaling (NMDS) was performed to identify patterns in the community under study. Additionally, Pearson correlations were analyzed between the richness, abundance, and beta diversity and the level of the reservoir. We collected 35,028 aquatic insect larvae (9,513 in dry period and 25,515 in the rainy season), predominantly of the Chironomidae family, followed by orders Ephemeroptera, Trichoptera, and Odonata. Among the 33 families collected, only 12 occurred in the dry season, while all occurred in the rainy season. These families are common in lentic environments, and the dominance of Chironomidae was associated with its fast colonization, their behavior of living at high densities and the great tolerance to low levels of oxygen in the environment. The hypothesis was confirmed, as the richness, beta diversity, and abundance were positively affected by the increase in water levels due to the rainy season, which most likely led to greater external material input, greater heterogeneity of habitat, and better conditions for colonization by several families.

  11. Increasing thiamine concentrations in lake trout eggs from Lakes Huron and Michigan coincide with low alewife abundance

    USGS Publications Warehouse

    Riley, Stephen C.; Rinchard, Jacques; Honeyfield, Dale C.; Evans, Allison N.; Begnoche, Linda

    2011-01-01

    Lake trout Salvelinus namaycush in the Laurentian Great Lakes suffer from thiamine deficiency as a result of adult lake trout consuming prey containing thiaminase, a thiamine-degrading enzyme. Sufficiently low egg thiamine concentrations result in direct mortality of or sublethal effects on newly hatched lake trout fry. To determine the prevalence and severity of low thiamine in lake trout eggs, we monitored thiamine concentrations in lake trout eggs from 15 sites in Lakes Huron and Michigan from 2001 to 2009. Lake trout egg thiamine concentrations at most sites in both lakes were initially low and increased over time at 11 of 15 sites, and the proportion of females with egg thiamine concentrations lower than the recommended management objective of 4 nmol/g decreased over time at eight sites. Egg thiamine concentrations at five of six sites in Lakes Huron and Michigan were significantly inversely related to site-specific estimates of mean abundance of alewives Alosa pseudoharengus, and successful natural reproduction of lake trout has been observed in Lake Huron since the alewife population crashed. These results support the hypothesis that low egg thiamine in Great Lakes lake trout is associated with increased alewife abundance and that low alewife abundance may currently be a prerequisite for successful reproduction by lake trout in the Great Lakes.

  12. Whale, Whale, Everywhere: Increasing Abundance of Western South Atlantic Humpback Whales (Megaptera novaeangliae) in Their Wintering Grounds

    PubMed Central

    Danilewicz, Daniel; Andriolo, Artur; Secchi, Eduardo R.; Zerbini, Alexandre N.

    2016-01-01

    The western South Atlantic (WSA) humpback whale population inhabits the coast of Brazil during the breeding and calving season in winter and spring. This population was depleted to near extinction by whaling in the mid-twentieth century. Despite recent signs of recovery, increasing coastal and offshore development pose potential threats to these animals. Therefore, continuous monitoring is needed to assess population status and support conservation strategies. The aim of this work was to present ship-based line-transect estimates of abundance for humpback whales in their WSA breeding ground and to investigate potential changes in population size. Two cruises surveyed the coast of Brazil during August-September in 2008 and 2012. The area surveyed in 2008 corresponded to the currently recognized population breeding area; effort in 2012 was limited due to unfavorable weather conditions. WSA humpback whale population size in 2008 was estimated at 16,410 (CV = 0.228, 95% CI = 10,563–25,495) animals. In order to compare abundance between 2008 and 2012, estimates for the area between Salvador and Cabo Frio, which were consistently covered in the two years, were computed at 15,332 (CV = 0.243, 95% CI = 9,595–24,500) and 19,429 (CV = 0.101, 95% CI = 15,958–23,654) whales, respectively. The difference in the two estimates represents an increase of 26.7% in whale numbers in a 4-year period. The estimated abundance for 2008 is considered the most robust for the WSA humpback whale population because the ship survey conducted in that year minimized bias from various sources. Results presented here indicate that in 2008, the WSA humpback whale population was at least around 60% of its estimated pre-modern whaling abundance and that it may recover to its pre-exploitation size sooner than previously estimated. PMID:27736958

  13. Increased microRNA-34c abundance in Alzheimer's disease circulating blood plasma

    PubMed Central

    Bhatnagar, Shephali; Chertkow, Howard; Schipper, Hyman M.; Yuan, Zongfei; Shetty, Vikranth; Jenkins, Samantha; Jones, Timothy; Wang, Eugenia

    2014-01-01

    Circulating microRNAs, present either in the cellular component, peripheral blood mononuclear cells (PBMC), or in cell-free plasma, have emerged as biomarkers for age-dependent systemic, disease-associated changes in many organs. Previously, we have shown that microRNA (miR)-34a is increased in circulating PBMC of Alzheimer's disease (AD) patients. In the present study, we show that this microRNA's sister, miR-34c, exhibits even greater increase in both cellular and plasma components of AD circulating blood samples, compared to normal age-matched controls. Statistical analysis shows the accuracy of levels of miR-34c assayed by receiver operating characteristic (ROC) analysis: the area under the curve is 0.99 (p < 0.0001) and the 95% confidence level extends from 0.97 to 1. Pearson correlation between miR-34c levels and mild and moderate AD, as defined by the mini-mental state examination (MMSE), shows an r-value of −0.7, suggesting a relatively strong inverse relationship between the two parameters. These data show that plasma levels of microRNA 34c are much more prominent in AD than those of its sister, miR-34a, or than its own level in PBMC. Transfection studies show that miR-34c, as does its sister miR-34a, represses the expression of several selected genes involved in cell survival and oxidative defense pathways, such as Bcl2, SIRT1, and others, in cultured cells. Taken together, our results indicate that increased levels of miR-34c in both PBMC and plasma may reflect changes in circulating blood samples in AD patients, compared to age-matched normal controls. PMID:24550773

  14. Dramatizing Nonfiction with Emerging Readers.

    ERIC Educational Resources Information Center

    Putnam, Lynne

    1991-01-01

    Presents scenarios from a kindergarten classroom in which dramatization is used extensively in conjunction with nonfiction books. Shows how the children acted out topics that ranged from the Pilgrims' first Thanksgiving to the life of Dr. Martin Luther King, Jr., showing that they were able to develop rich representations of nonfiction materials.…

  15. Dramatic Techniques in ESL Instruction.

    ERIC Educational Resources Information Center

    Radin, Barbara

    Three techniques have been found to be helpful in using dramatic techniques to provide motivation, self-confidence, and self-esteem to students of English as a second language at Hostos Community College. Strategic interaction is a technique based on the open-ended scenario, in which students are free to respond to the problem presented in the…

  16. Long-term field application of sewage sludge increases the abundance of antibiotic resistance genes in soil.

    PubMed

    Chen, Qinglin; An, Xinli; Li, Hu; Su, Jianqiang; Ma, Yibing; Zhu, Yong-Guan

    2016-01-01

    Sewage sludge and manure are common soil amendments in crop production; however, their impact on the abundance and diversity of the antibiotic resistome in soil remains elusive. In this study, by using high-throughput sequencing and high-throughput quantitative PCR, the patterns of bacterial community and antibiotic resistance genes (ARGs) in a long-term field experiment were investigated to gain insights into these impacts. A total of 130 unique ARGs and 5 mobile genetic elements (MGEs) were detected and the long-term application of sewage sludge and chicken manure significantly increased the abundance and diversity of ARGs in the soil. Genes conferring resistance to beta-lactams, tetracyclines, and multiple drugs were dominant in the samples. Sewage sludge or chicken manure applications caused significant enrichment of 108 unique ARGs and MGEs with a maximum enrichment of up to 3845 folds for mexF. The enrichment of MGEs suggested that the application of sewage sludge or manure may accelerate the dissemination of ARGs in soil through horizontal gene transfer (HGT). Based on the co-occurrence pattern of ARGs subtypes revealed by network analysis, aacC, oprD and mphA-02, were proposed to be potential indicators for quantitative estimation of the co-occurring ARGs subtypes abundance by power functions. The application of sewage sludge and manure resulted in significant increase of bacterial diversity in soil, Proteobacteria, Acidobacteria, Actinobacteria and Chloroflexi were the dominant phyla (>10% in each sample). Five bacterial phyla (Chloroflexi, Planctomycetes, Firmicutes, Gemmatimonadetes and Bacteroidetes) were found to be significantly correlated with the ARGs in soil. Mantel test and variation partitioning analysis (VPA) suggested that bacterial community shifts, rather than MGEs, is the major driver shaping the antibiotic resistome. Additionally, the co-occurrence pattern between ARGs and microbial taxa revealed by network analysis indicated that four

  17. Long-term field application of sewage sludge increases the abundance of antibiotic resistance genes in soil.

    PubMed

    Chen, Qinglin; An, Xinli; Li, Hu; Su, Jianqiang; Ma, Yibing; Zhu, Yong-Guan

    2016-01-01

    Sewage sludge and manure are common soil amendments in crop production; however, their impact on the abundance and diversity of the antibiotic resistome in soil remains elusive. In this study, by using high-throughput sequencing and high-throughput quantitative PCR, the patterns of bacterial community and antibiotic resistance genes (ARGs) in a long-term field experiment were investigated to gain insights into these impacts. A total of 130 unique ARGs and 5 mobile genetic elements (MGEs) were detected and the long-term application of sewage sludge and chicken manure significantly increased the abundance and diversity of ARGs in the soil. Genes conferring resistance to beta-lactams, tetracyclines, and multiple drugs were dominant in the samples. Sewage sludge or chicken manure applications caused significant enrichment of 108 unique ARGs and MGEs with a maximum enrichment of up to 3845 folds for mexF. The enrichment of MGEs suggested that the application of sewage sludge or manure may accelerate the dissemination of ARGs in soil through horizontal gene transfer (HGT). Based on the co-occurrence pattern of ARGs subtypes revealed by network analysis, aacC, oprD and mphA-02, were proposed to be potential indicators for quantitative estimation of the co-occurring ARGs subtypes abundance by power functions. The application of sewage sludge and manure resulted in significant increase of bacterial diversity in soil, Proteobacteria, Acidobacteria, Actinobacteria and Chloroflexi were the dominant phyla (>10% in each sample). Five bacterial phyla (Chloroflexi, Planctomycetes, Firmicutes, Gemmatimonadetes and Bacteroidetes) were found to be significantly correlated with the ARGs in soil. Mantel test and variation partitioning analysis (VPA) suggested that bacterial community shifts, rather than MGEs, is the major driver shaping the antibiotic resistome. Additionally, the co-occurrence pattern between ARGs and microbial taxa revealed by network analysis indicated that four

  18. Increased waterborne blaNDM-1 resistance gene abundances associated with seasonal human pilgrimages to the upper ganges river.

    PubMed

    Ahammad, Z S; Sreekrishnan, T R; Hands, C L; Knapp, C W; Graham, D W

    2014-01-01

    Antibiotic resistance (AR) is often rooted in inappropriate antibiotic use, but poor water quality and inadequate sanitation exacerbate the problem, especially in emerging countries. An example is increasing multi-AR due to mobile carbapenemases, such as NDM-1 protein (coded by blaNDM-1 genes), which can produce extreme drug-resistant phenotypes. In 2010, NDM-1 positive isolates and blaNDM-1 genes were detected in surface waters across Delhi and have since been detected across the urban world. However, little is known about blaNDM-1 levels in more pristine locations, such as the headwaters of the Upper Ganges River. This area is of particular interest because it receives massive numbers of visitors during seasonal pilgrimages in May/June, including visitors from urban India. Here we quantified blaNDM-1 abundances, other AR genes (ARG), and coliform bacteria in sediments and water column samples from seven sites in the Rishikesh-Haridwar region of the Upper Ganges and five sites on the Yamuna River in Delhi to contrast blaNDM-1 levels and water quality conditions between season and region. Water quality in the Yamuna was very poor (e.g., anoxia at all sites), and blaNDM-1 abundances were high across sites in water (5.4 ± 0.4 log(blaNDM-1·mL(-1)); 95% confidence interval) and sediment (6.3 ± 0.7 log(blaNDM-1·mg(-1))) samples from both seasons. In contrast, water column blaNDM-1 abundances were very low across all sites in the Upper Ganges in February (2.1 ± 0.6 log(blaNDM-1·mL(-1))), and water quality was good (e.g., near saturation oxygen). However, per capita blaNDM-1 levels were 20 times greater in June in the Ganges water column relative to February, and blaNDM-1 levels significantly correlated with fecal coliform levels (r = 0.61; p = 0.007). Given that waste management infrastructure is limited in Rishikesh-Haridwar, data imply blaNDM-1 levels are higher in visitor's wastes than local residents, which results in seasonally higher blaNDM-1 levels in the

  19. Increased waterborne blaNDM-1 resistance gene abundances associated with seasonal human pilgrimages to the upper ganges river.

    PubMed

    Ahammad, Z S; Sreekrishnan, T R; Hands, C L; Knapp, C W; Graham, D W

    2014-01-01

    Antibiotic resistance (AR) is often rooted in inappropriate antibiotic use, but poor water quality and inadequate sanitation exacerbate the problem, especially in emerging countries. An example is increasing multi-AR due to mobile carbapenemases, such as NDM-1 protein (coded by blaNDM-1 genes), which can produce extreme drug-resistant phenotypes. In 2010, NDM-1 positive isolates and blaNDM-1 genes were detected in surface waters across Delhi and have since been detected across the urban world. However, little is known about blaNDM-1 levels in more pristine locations, such as the headwaters of the Upper Ganges River. This area is of particular interest because it receives massive numbers of visitors during seasonal pilgrimages in May/June, including visitors from urban India. Here we quantified blaNDM-1 abundances, other AR genes (ARG), and coliform bacteria in sediments and water column samples from seven sites in the Rishikesh-Haridwar region of the Upper Ganges and five sites on the Yamuna River in Delhi to contrast blaNDM-1 levels and water quality conditions between season and region. Water quality in the Yamuna was very poor (e.g., anoxia at all sites), and blaNDM-1 abundances were high across sites in water (5.4 ± 0.4 log(blaNDM-1·mL(-1)); 95% confidence interval) and sediment (6.3 ± 0.7 log(blaNDM-1·mg(-1))) samples from both seasons. In contrast, water column blaNDM-1 abundances were very low across all sites in the Upper Ganges in February (2.1 ± 0.6 log(blaNDM-1·mL(-1))), and water quality was good (e.g., near saturation oxygen). However, per capita blaNDM-1 levels were 20 times greater in June in the Ganges water column relative to February, and blaNDM-1 levels significantly correlated with fecal coliform levels (r = 0.61; p = 0.007). Given that waste management infrastructure is limited in Rishikesh-Haridwar, data imply blaNDM-1 levels are higher in visitor's wastes than local residents, which results in seasonally higher blaNDM-1 levels in the

  20. Increased Waterborne blaNDM-1 Resistance Gene Abundances Associated with Seasonal Human Pilgrimages to the Upper Ganges River

    PubMed Central

    2014-01-01

    Antibiotic resistance (AR) is often rooted in inappropriate antibiotic use, but poor water quality and inadequate sanitation exacerbate the problem, especially in emerging countries. An example is increasing multi-AR due to mobile carbapenemases, such as NDM-1 protein (coded by blaNDM-1 genes), which can produce extreme drug-resistant phenotypes. In 2010, NDM-1 positive isolates and blaNDM-1 genes were detected in surface waters across Delhi and have since been detected across the urban world. However, little is known about blaNDM-1 levels in more pristine locations, such as the headwaters of the Upper Ganges River. This area is of particular interest because it receives massive numbers of visitors during seasonal pilgrimages in May/June, including visitors from urban India. Here we quantified blaNDM-1 abundances, other AR genes (ARG), and coliform bacteria in sediments and water column samples from seven sites in the Rishikesh-Haridwar region of the Upper Ganges and five sites on the Yamuna River in Delhi to contrast blaNDM-1 levels and water quality conditions between season and region. Water quality in the Yamuna was very poor (e.g., anoxia at all sites), and blaNDM-1 abundances were high across sites in water (5.4 ± 0.4 log(blaNDM-1·mL–1); 95% confidence interval) and sediment (6.3 ± 0.7 log(blaNDM-1·mg–1)) samples from both seasons. In contrast, water column blaNDM-1 abundances were very low across all sites in the Upper Ganges in February (2.1 ± 0.6 log(blaNDM-1·mL–1)), and water quality was good (e.g., near saturation oxygen). However, per capita blaNDM-1 levels were 20 times greater in June in the Ganges water column relative to February, and blaNDM-1 levels significantly correlated with fecal coliform levels (r = 0.61; p = 0.007). Given that waste management infrastructure is limited in Rishikesh-Haridwar, data imply blaNDM-1 levels are higher in visitor’s wastes than local residents, which results in seasonally higher blaNDM-1 levels in the

  1. The Dramatic Methods of Hans van Dam.

    ERIC Educational Resources Information Center

    van de Water, Manon

    1994-01-01

    Interprets for the American reader the untranslated dramatic methods of Hans van Dam, a leading drama theorist in the Netherlands. Discusses the functions of drama as a method, closed dramatic methods, open dramatic methods, and applying van Dam's methods. (SR)

  2. Salt licks do not increase local densities of the deer ked, Lipoptena cervi, an abundant ectoparasite of cervids.

    PubMed

    Paakkonen, T; Nieminen, P; Roininen, H; Mustonen, A-M

    2014-09-01

    The deer ked, Lipoptena cervi (Diptera: Hippoboscidae), is a common ectoparasite of the moose, Alces alces (Artiodactyla: Cervidae). Salt licks are widely used to manipulate moose movements to prevent damage to saplings and traffic accidents. They may cause moose to gather in small areas, which could create aggregates of deer ked pupae as the parasite is a short-distance flyer and its dispersion depends on its hosts. We investigated whether the population density of flying deer keds could be influenced by manipulating salt licks and how environmental variables affect parasite density. Densities were estimated in 40 experimental sites with four treatments (no salt licks, introduced salt licks, removed salt licks, permanent salt licks) in September during 2007-2010. Forest edges, mixed forests on mineral soil and coniferous forests on peat soil were the habitats with high numbers of parasites. The manipulation of salt licks seemed to be ineffective in reducing the density of deer keds as the only factor to show statistical significance with parasite numbers in the mixed-model analysis was year of determination. Annual deer ked densities correlated with the abundance of moose in the region. Moreover, high spring and summer temperatures seemed to increase the numbers of flying imagos.

  3. Association of anthropogenic land use change and increased abundance of the Chagas disease vector Rhodnius pallescens in a rural landscape of Panama.

    PubMed

    Gottdenker, Nicole L; Calzada, José E; Saldaña, Azäel; Carroll, C Ronald

    2011-01-01

    Anthropogenic disturbance is associated with increased vector-borne infectious disease transmission in wildlife, domestic animals, and humans. The objective of this study was to evaluate how disturbance of a tropical forest landscape impacts abundance of the triatomine bug Rhodnius pallescens, a vector of Chagas disease, in the region of the Panama Canal in Panama. Rhodnius pallescens was collected (n = 1,186) from its primary habitat, the palm Attalea butyracea, in five habitat types reflecting a gradient of anthropogenic disturbance. There was a high proportion of palms infested with R. pallescens across all habitat types (range = 77.1-91.4%). Results show that disturbed habitats are associated with increased vector abundance compared with relatively undisturbed habitats. Bugs collected in disturbed sites, although in higher abundance, tended to be in poor body condition compared with bugs captured in protected forest sites. Abundance data suggests that forest remnants may be sources for R. pallescens populations within highly disturbed areas of the landscape.

  4. Dramatic Education, An Interdisciplinary Approach to Learning.

    ERIC Educational Resources Information Center

    Landy, Robert Jay

    This thesis argues that dramatic education is a subject matter whose content is four interrelated disciplines: theater, language arts, humanistic education, and social-psychology. It is also a process of learning crucial artistic, linguistic, humanistic, and scientific issues through the basic dramatic method of dramatization. The history of…

  5. Increased Abundance of Proteins Involved in Phytosiderophore Production in Boron-Tolerant Barley1[C][W

    PubMed Central

    Patterson, John; Ford, Kris; Cassin, Andrew; Natera, Siria; Bacic, Antony

    2007-01-01

    Boron (B) phytotoxicity affects cereal-growing regions worldwide. Although B-tolerant barley (Hordeum vulgare) germplasm is available, molecules responsible for this tolerance mechanism have not been defined. We describe and use a new comparative proteomic technique, iTRAQ peptide tagging (iTRAQ), to compare the abundances of proteins from B-tolerant and -intolerant barley plants from a ‘Clipper’ × ‘Sahara’ doubled-haploid population selected on the basis of a presence or absence of two B-tolerance quantitative trait loci. iTRAQ was used to identify three enzymes involved in siderophore production (Iron Deficiency Sensitive2 [IDS2], IDS3, and a methylthio-ribose kinase) as being elevated in abundance in the B-tolerant plants. Following from this result, we report a potential link between iron, B, and the siderophore hydroxymugineic acid. We believe that this study highlights the potency of the iTRAQ approach to better understand mechanisms of abiotic stress tolerance in cereals, particularly when applied in conjunction with bulked segregant analysis. PMID:17478636

  6. Ecosystem size structure response to 21st century climate projection: large fish abundance decreases in the central North Pacific and increases in the California Current.

    PubMed

    Woodworth-Jefcoats, Phoebe A; Polovina, Jeffrey J; Dunne, John P; Blanchard, Julia L

    2013-03-01

    Output from an earth system model is paired with a size-based food web model to investigate the effects of climate change on the abundance of large fish over the 21st century. The earth system model, forced by the Intergovernmental Panel on Climate Change (IPCC) Special report on emission scenario A2, combines a coupled climate model with a biogeochemical model including major nutrients, three phytoplankton functional groups, and zooplankton grazing. The size-based food web model includes linkages between two size-structured pelagic communities: primary producers and consumers. Our investigation focuses on seven sites in the North Pacific, each highlighting a specific aspect of projected climate change, and includes top-down ecosystem depletion through fishing. We project declines in large fish abundance ranging from 0 to 75.8% in the central North Pacific and increases of up to 43.0% in the California Current (CC) region over the 21st century in response to change in phytoplankton size structure and direct physiological effects. We find that fish abundance is especially sensitive to projected changes in large phytoplankton density and our model projects changes in the abundance of large fish being of the same order of magnitude as changes in the abundance of large phytoplankton. Thus, studies that address only climate-induced impacts to primary production without including changes to phytoplankton size structure may not adequately project ecosystem responses.

  7. A Doubling of Microphytobenthos Biomass Coincides with a Tenfold Increase in Denitrifier and Total Bacterial Abundances in Intertidal Sediments of a Temperate Estuary

    PubMed Central

    Decleyre, Helen; Heylen, Kim; Sabbe, Koen; Tytgat, Bjorn; Deforce, Dieter; Van Nieuwerburgh, Filip; Van Colen, Carl; Willems, Anne

    2015-01-01

    Surface sediments are important systems for the removal of anthropogenically derived inorganic nitrogen in estuaries. They are often characterized by the presence of a microphytobenthos (MPB) biofilm, which can impact bacterial communities in underlying sediments for example by secretion of extracellular polymeric substances (EPS) and competition for nutrients (including nitrogen). Pyrosequencing and qPCR was performed on two intertidal surface sediments of the Westerschelde estuary characterized by a two-fold difference in MPB biomass but no difference in MPB composition. Doubling of MPB biomass was accompanied by a disproportionately (ten-fold) increase in total bacterial abundances while, unexpectedly, no difference in general community structure was observed, despite significantly lower bacterial richness and distinct community membership, mostly for non-abundant taxa. Denitrifier abundances corresponded likewise while community structure, both for nirS and nirK denitrifiers, remained unchanged, suggesting that competition with diatoms for nitrate is negligible at concentrations in the investigated sediments (appr. 1 mg/l NO3-). This study indicates that MPB biomass increase has a general, significantly positive effect on total bacterial and denitrifier abundances, with stimulation or inhibition of specific bacterial groups that however do not result in a re-structured community. PMID:25961719

  8. Association of anthropogenic land use change and increased abundance of the Chagas disease vector Rhodnius pallescens in a rural landscape of Panama.

    PubMed

    Gottdenker, Nicole L; Calzada, José E; Saldaña, Azäel; Carroll, C Ronald

    2011-01-01

    Anthropogenic disturbance is associated with increased vector-borne infectious disease transmission in wildlife, domestic animals, and humans. The objective of this study was to evaluate how disturbance of a tropical forest landscape impacts abundance of the triatomine bug Rhodnius pallescens, a vector of Chagas disease, in the region of the Panama Canal in Panama. Rhodnius pallescens was collected (n = 1,186) from its primary habitat, the palm Attalea butyracea, in five habitat types reflecting a gradient of anthropogenic disturbance. There was a high proportion of palms infested with R. pallescens across all habitat types (range = 77.1-91.4%). Results show that disturbed habitats are associated with increased vector abundance compared with relatively undisturbed habitats. Bugs collected in disturbed sites, although in higher abundance, tended to be in poor body condition compared with bugs captured in protected forest sites. Abundance data suggests that forest remnants may be sources for R. pallescens populations within highly disturbed areas of the landscape. PMID:21212205

  9. Association of Anthropogenic Land Use Change and Increased Abundance of the Chagas Disease Vector Rhodnius pallescens in a Rural Landscape of Panama

    PubMed Central

    Gottdenker, Nicole L.; Calzada, José E.; Saldaña, Azäel; Carroll, C. Ronald

    2011-01-01

    Anthropogenic disturbance is associated with increased vector-borne infectious disease transmission in wildlife, domestic animals, and humans. The objective of this study was to evaluate how disturbance of a tropical forest landscape impacts abundance of the triatomine bug Rhodnius pallescens, a vector of Chagas disease, in the region of the Panama Canal in Panama. Rhodnius pallescens was collected (n = 1,186) from its primary habitat, the palm Attalea butyracea, in five habitat types reflecting a gradient of anthropogenic disturbance. There was a high proportion of palms infested with R. pallescens across all habitat types (range = 77.1–91.4%). Results show that disturbed habitats are associated with increased vector abundance compared with relatively undisturbed habitats. Bugs collected in disturbed sites, although in higher abundance, tended to be in poor body condition compared with bugs captured in protected forest sites. Abundance data suggests that forest remnants may be sources for R. pallescens populations within highly disturbed areas of the landscape. PMID:21212205

  10. Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting.

    PubMed

    Hashimoto, Ayako; Ohkura, Katsuma; Takahashi, Masakazu; Kizu, Kumiko; Narita, Hiroshi; Enomoto, Shuichi; Miyamae, Yusaku; Masuda, Seiji; Nagao, Masaya; Irie, Kazuhiro; Ohigashi, Hajime; Andrews, Glen K; Kambe, Taiho

    2015-12-01

    Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans.

  11. Abundance of some skeletal muscle mitochondrial proteins is associated with increased blood serum insulin in bovine fetuses.

    PubMed

    Pajak, Beata; Pawlikowska, Patrycja; Cassar-Malek, Isabelle; Picard, Brigitte; Hocquette, Jean-François; Orzechowski, Arkadiusz

    2010-12-01

    The aim of this study was to investigate the evolution of the abundance of cytochrome oxidase c subunit IV (NCOIV) and beta subunit of ATP synthase (β-ATP) during the last third of gestation in bovine skeletal muscles. Semitendinosus, longissimus thoracis and rectus abdominis muscles were chosen for the immunoblotting of the respective protein levels. Muscle and blood samples from bovine fetuses of randomly selected breeds were collected at 180, 210, and 260 days post-conception (dpc). The muscle tissue expressions of NCOIV, β-ATP were compared to blood glucose and insulin. At 260 dpc, protein levels of NCOIV raised in skeletal muscles. Additionally, β-ATP in semitendinosus and longissimus thoracis were elevated and paralleled by higher concentrations of blood serum insulin. It corroborates our previous observations indicating that accelerated metabolic differentiation of bovine skeletal muscles is associated with elevated blood insulin and occurs during the last trimester of gestation. Our observations point to the connection between insulin-sensitivity and the molecular mechanisms of mitochondrial contribution to ontogenesis of skeletal muscles.

  12. Dramatic Play in Childhood: Rehearsal for Life.

    ERIC Educational Resources Information Center

    Koste, Virginia Glasgow

    The purpose of this book is to help parents and teachers recognize and understand dramatic play in childhood as a process whereby the child acts out human experience in an attempt to order, clarify, and understand it. Written by a person experienced in theatre and drama, the book considers the following aspects of dramatic play: the importance of…

  13. Dramatic Developments in the Neurosciences Challenge Educators.

    ERIC Educational Resources Information Center

    Sylwester, Robert

    1986-01-01

    Recent dramatic developments in brain research and technology suggest that a comprehensive understanding of how the human brain works may soon be within reach. Just as the ability of the medical profession to treat patients improved dramatically with the advent of effective research skills and technology concerning the structure, biochemistry, and…

  14. Increased abundance of translation machinery in stem cell–derived neural progenitor cells from four schizophrenia patients

    PubMed Central

    Topol, A; English, J A; Flaherty, E; Rajarajan, P; Hartley, B J; Gupta, S; Desland, F; Zhu, S; Goff, T; Friedman, L; Rapoport, J; Felsenfeld, D; Cagney, G; Mackay-Sim, A; Savas, J N; Aronow, B; Fang, G; Zhang, B; Cotter, D; Brennand, K J

    2015-01-01

    The genetic and epigenetic factors contributing to risk for schizophrenia (SZ) remain unresolved. Here we demonstrate, for the first time, perturbed global protein translation in human-induced pluripotent stem cell (hiPSC)-derived forebrain neural progenitor cells (NPCs) from four SZ patients relative to six unaffected controls. We report increased total protein levels and protein synthesis, together with two independent sets of quantitative mass spectrometry evidence indicating markedly increased levels of ribosomal and translation initiation and elongation factor proteins, in SZ hiPSC NPCs. We posit that perturbed levels of global protein synthesis in SZ hiPSC NPCs represent a novel post-transcriptional mechanism that might contribute to disease progression. PMID:26485546

  15. Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

    PubMed Central

    Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

    2015-01-01

    Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon – Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning. PMID:26396042

  16. Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling.

    PubMed

    Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

    2015-09-23

    Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon - Simpson's indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning.

  17. Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

    2015-09-01

    Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon - Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning.

  18. Dramatic Increases in Maternal Opioid Use and Neonatal Abstinence Syndrome

    MedlinePlus

    ... Commonly Abused Drugs Charts Emerging Trends and Alerts Alcohol Club Drugs Cocaine Hallucinogens Heroin Inhalants Marijuana MDMA ( ... Monitoring the Future 2015 Survey Results Drug and Alcohol Use in College-Age Adults in 2014 View ...

  19. Large and abundant flowers increase indirect costs of corollas: a study of coflowering sympatric Mediterranean species of contrasting flower size.

    PubMed

    Teixido, Alberto L; Valladares, Fernando

    2013-09-01

    Large floral displays receive more pollinator visits but involve higher production and maintenance costs. This can result in indirect costs which may negatively affect functions like reproductive output. In this study, we explored the relationship between floral display and indirect costs in two pairs of coflowering sympatric Mediterranean Cistus of contrasting flower size. We hypothesized that: (1) corolla production entails direct costs in dry mass, N and P, (2) corollas entail significant indirect costs in terms of fruit set and seed production, (3) indirect costs increase with floral display, (4) indirect costs are greater in larger-flowered sympatric species, and (5) local climatic conditions influence indirect costs. We compared fruit set and seed production of petal-removed flowers and unmanipulated control flowers and evaluated the influence of mean flower number and mean flower size on relative fruit and seed gain of petal-removed and control flowers. Fruit set and seed production were significantly higher in petal-removed flowers in all the studied species. A positive relationship was found between relative fruit gain and mean individual flower size within species. In one pair of species, fruit gain was higher in the large-flowered species, as was the correlation between fruit gain and mean number of open flowers. In the other pair, the correlation between fruit gain and mean flower size was also higher in the large-flowered species. These results reveal that Mediterranean environments impose significant constraints on floral display, counteracting advantages of large flowers from the pollination point of view with increased indirect costs of such flowers.

  20. ASCA Observation of the Poor Cluster of Galaxies AWM 7: Evidence of an Abundance Increase in the Intra-Cluster Medium at the Center

    NASA Astrophysics Data System (ADS)

    Xu, Haiguang; Ezawa, Hajime; Fukazawa, Yasushi; Kikuchi, Ken'ichi; Makishima, Kazuo; Ohashi, Takaya; Tamura, Takayuki

    1997-02-01

    We present the results of the ASCA central-pointing observation of the poor cD cluster AWM 7. The Performance Verification phase data of GIS 2, GIS 3, SIS 0 chip 1, and SIS 1 chip 3 were used to study the properties of the intra-cluster medium (ICM) within 16' around the X-ray centroid. We found that, compared with the outer regions, the equivalent width of the Fe-K lines increases in the central 4' ( ~ 123 h(-1_{50) kpc)} region by a factor of ~ 1.5. Although the ICM temperature tends to decrease in the same region, the observed increase in the Fe-K line equivalent width cannot be explained away by a possible temperature drop. The model fitting indicates that the abundance increases from ~ 0.4 solar outside 4' to ~ 0.6 solar at the center. Thus, after the Centaurus cluster and the Virgo cluster, AWM 7 is the third poor cD cluster confirmed to show an abundance increase in the central region. The 0.5--3 keV flux of the cool emission within 4' is constrained to be <8*E(42) h(-2}_{50) erg s(-1) , or <21% of the total 0.5--3 keV flux from the same spatial region. We discuss possible relations of these phenomena to the cD galaxy.

  1. Daily injection of tumor necrosis factor-{alpha} increases hepatic triglycerides and alters transcript abundance of metabolic genes in lactating dairy cattle.

    PubMed

    Bradford, Barry J; Mamedova, Laman K; Minton, J Ernest; Drouillard, James S; Johnson, Bradley J

    2009-08-01

    To determine whether inflammation can induce bovine fatty liver, we administered recombinant bovine tumor necrosis factor-alpha (rbTNF) to late-lactation Holstein cows. Cows (n = 5/treatment) were blocked by feed intake and parity and randomly assigned within block to control (CON; saline), rbTNF at 2 microg/(kg.d), or pair-fed control (saline, intake matched) treatments. Treatments were administered once daily by subcutaneous injection for 7 d. Plasma samples were collected daily for analysis of glucose and FFA and a liver biopsy was collected on d 7 for triglyceride (TG) and quantitative RT-PCR analyses. Data were analyzed using treatment contrasts to assess effects of tumor necrosis factor-alpha (TNFalpha) and decreased feed intake. By d 7, feed intake of both rbTNF and pair-fed cows was approximately 15% less than CON (P < 0.01). Administration of rbTNF resulted in greater hepatic TNFalpha mRNA and protein abundance and 103% higher liver TG content (P < 0.05) without affecting the plasma FFA concentration. Hepatic carnitine palmitoyltransferase 1 transcript abundance tended to be lower (P = 0.09) and transcript abundance of fatty acid translocase and 1-acyl-glycerol-3-phosphate acyltransferase was higher (both P < 0.05) after rbTNF treatment, consistent with increased FFA uptake and storage as TG. Transcript abundance of glucose-6-phosphatase (P < 0.05) and phosphoenolpyruvate carboxykinase 1 (P = 0.09), genes important for gluconeogenesis, was lower for rbTNF-treated cows. These findings indicate that TNFalpha promotes liver TG accumulation and suggest that inflammatory pathways may also be responsible for decreased glucose production in cows with fatty liver.

  2. Release of extraction-resistant mRNA in stationary phase Saccharomyces cerevisiae produces a massive increase in transcript abundance in response to stress

    PubMed Central

    Aragon, Anthony D; Quiñones, Gabriel A; Thomas, Edward V; Roy, Sushmita; Werner-Washburne, Margaret

    2006-01-01

    Background As carbon sources are exhausted, Saccharomyces cerevisiae cells exhibit reduced metabolic activity and cultures enter the stationary phase. We asked whether cells in stationary phase cultures respond to additional stress at the level of transcript abundance. Results Microarrays were used to quantify changes in transcript abundance in cells from stationary phase cultures in response to stress. More than 800 mRNAs increased in abundance by one minute after oxidative stress. A significant number of these mRNAs encode proteins involved in stress responses. We tested whether mRNA increases were due to new transcription, rapid poly-adenylation of message (which would not be detected by microarrays), or potential release of mature mRNA present in the cell but resistant to extraction during RNA isolation. Examination of the response to oxidative stress in an RNA polymerase II mutant, rpb1-1, suggested that new transcription was not required. Quantitative RT-PCR analysis of a subset of these transcripts further suggested that the transcripts present in isolated total RNA from stationary phase cultures were polyadenylated. In contrast, over 2,000 transcripts increased after protease treatment of cell-free lysates from stationary phase but not exponentially growing cultures. Different subsets of transcripts were released by oxidative stress and temperature upshift, suggesting that mRNA release is stress-specific. Conclusions Cells in stationary phase cultures contain a large number of extraction-resistant mRNAs in a protease-labile, rapidly releasable form. The transcript release appears to be stress-specific. We hypothesize that these transcripts are associated with P-bodies. PMID:16507144

  3. Dramatic Cataplexy Improvement Following Right Parietal Surgery

    PubMed Central

    Fam, David J.; Shammi, Prathiba; Mainprize, Todd G.; Murray, Brian J.

    2015-01-01

    This is the case of a 34-year-old woman with severe narcolepsy with cataplexy who experienced a dramatic reduction in cataplexy symptoms after resection of a right parietal astrocytoma. The patient underwent detailed neurological exam, neuropsychological testing, polysomnography and multiple sleep latency testing following surgery. Citation: Fam DJ, Shammi P, Mainprize TG, Murray BJ. Dramatic cataplexy improvement following right parietal surgery. J Clin Sleep Med 2015;11(7):829–830. PMID:25902819

  4. Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding.

    PubMed

    Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D

    2015-06-01

    Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR

  5. Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding.

    PubMed

    Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D

    2015-06-01

    Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR

  6. Maverick Comet Splits during Dramatic Outburst

    NASA Astrophysics Data System (ADS)

    1996-01-01

    New ESO Observations of P/Schwassmann-Wachmann 3 A few months ago, Periodic Comet Schwassmann-Wachmann 3 underwent a dramatic and completely unexpected, thousand-fold brightening. At that time, the cause for this interesting event was unknown. However, observations with the two largest ESO telescopes have now shown that the ``dirty snowball'' nucleus of this comet has recently split into at least four individual pieces [1]. There is little doubt that the outburst and the splitting event(s) are closely related and that the greatly increased dust and gas production is due to ``fresh'' material of the icy cometary nucleus becoming exposed to the surrounding space for the first time. A Comet with a Troubled History Comet Schwassmann-Wachmann 3 was discovered on May 2, 1930, on a photographic plate obtained at the Hamburg Observatory (Germany) by two astronomers at this institution, Arnold Schwassmann and Arthur Arno Wachmann. The subsequent observations showed that the comet moved in an elliptical orbit with a revolution period of somewhat more than 5 years. Great efforts were expended to observe the comet during the next returns, but it was not recovered until nearly 50 years and eight revolutions later, when its faint image was found of a plate obtained in August 1979 with a telescope at the Perth Observatory in Western Australia. It was missed in 1984, but was sighted again in 1989 and most recently in 1994. Thus this comet has only been observed during four out of thirteen approaches since 1930. While this may be partly due to a less advantageous location in the sky at some returns, it is also a strong indication that the comet behaves unpredictably and must have a quite variable brightness. For the sake of convenience this comet is often referred to as ``SW-3'' by professional astronomers. Recent orbital calculations have shown that it was inserted into the present, short-period orbit by the strong gravitational pull of Jupiter during several, relatively close

  7. The Psychodrama-Social Dramatics Separation.

    ERIC Educational Resources Information Center

    Klepac, Richard L.

    Social dramatics is a therapeutic and educational program that can act as a mirror to reflect images of the self in action with others. It is the modality for experiential learning to correct social dysfunction by providing models for imitation, opportunities to practice and develop individual forms from that model, and risk free environments for…

  8. Windows into Children's Thinking: A Guide to Storytelling and Dramatization

    ERIC Educational Resources Information Center

    Wright, Cheryl; Bacigalupa, Chiara; Black, Tyler; Burton, Michael

    2008-01-01

    Telling and dramatizing stories is an increasingly popular addition to the preschool curriculum, largely due to the attention this activity has received through the writings of Vivian Paley (Bad guys don't have birthdays: fantasy play at four. The University of Chicago Press, Chicago, 1988; The boy who would be a helicopter: the uses of…

  9. Knockout of the abundant Trichomonas vaginalis hydrogenosomal membrane protein TvHMP23 increases hydrogenosome size but induces no compensatory up-regulation of paralogous copies.

    PubMed

    Brás, Xavier Pereira; Zimorski, Verena; Bolte, Kathrin; Maier, Uwe-G; Martin, William F; Gould, Sven B

    2013-05-01

    The Trichomonas vaginalis genome encodes up to 60000 genes, many of which stem from genome duplication events. Paralogous copies thus accompany most T. vaginalis genes, a phenomenon that limits genetic manipulation. We characterized one of the parasite's most abundant hydrogenosomal membrane proteins, TvHMP23, which is phylogenetically distinct from canonical metabolite carriers, and which localizes to the inner hydrogenosomal membrane as shown through sub-organellar fractionation and protease protection assays. Knockout of Tvhmp23 through insertion of the selectable neomycin marker led to a size increase of hydrogenosomes, the first knockout-induced phenotypes reported for Trichomonas, but no growth impairment. The transcriptional response of its four paralogous copies then analyzed revealed that they are not up-regulated, and hence do not compensate for the Tvhmp23 knockout. PMID:23499435

  10. Increase of marine juvenile fish abundances in the middle Gironde estuary related to warmer and more saline waters, due to global changes

    NASA Astrophysics Data System (ADS)

    Pasquaud, Stéphanie; Béguer, Mélanie; Larsen, Maja Hjort; Chaalali, Aurélie; Cabral, Henrique; Lobry, Jérémy

    2012-06-01

    Estuaries have an essential ecological function for several marine fish species, that use these systems as nurseries. Previous studies in the Gironde estuary have reported an increase in water temperature and an extended seawater intrusion associated to global changes. In this study, we evaluated whether these changes impact the nursery function in the middle part of the system, based on the analyses of long-term data series (1991-2009) collected in that area. Trend analysis, correlations and generalized additive models (GAM) were computed in order to study the influence of water temperature and salinity changes on marine juveniles occurrence/densities. Results showed that densities of all the studied species (i.e. Engraulis encrasicolus, Sprattus sprattus, Dicentrarchus labrax, Solea solea, Argyrosomus regius, Merlangius merlangus) significantly increased over the period considered. Changes in water temperature and seawater intrusion contributed to explain the variability in presence/absence and in densities of the majority of these species. However, the deviance explained by GAM and the relevance of these two explanatory variables differed considerably according to species. For most species, it was suggested that the interaction of these two factors, and their effects on other variables, may explain the increase in abundance in the middle part of the Gironde. The effects of global changes in this estuarine system may favour its nursery function for marine juveniles, but some evidence of effects at a wider scale (community and ecosystem levels) may alter the structure and functioning of this system.

  11. Care initiation area yields dramatic results.

    PubMed

    2009-03-01

    The ED at Gaston Memorial Hospital in Gastonia, NC, has achieved dramatic results in key department metrics with a Care Initiation Area (CIA) and a physician in triage. Here's how the ED arrived at this winning solution: Leadership was trained in and implemented the Kaizen method, which eliminates redundant or inefficient process steps. Simulation software helped determine additional space needed by analyzing arrival patterns and other key data. After only two days of meetings, new ideas were implemented and tested.

  12. Dramatic Response of Nail Psoriasis to Infliximab

    PubMed Central

    Safa, Gilles; Darrieux, Laure

    2011-01-01

    Nail psoriasis, affecting up to 50% of psoriatic patients, is an important cause of serious psychological and physical distress. Traditional treatments for nail psoriasis, which include topical or intralesional corticosteroids, topical vitamin D analogues, photochemotherapy, oral retinoids, methotrexate, and cyclosporin, can be time-consuming, painful, or limited by significant toxicities. Biological agents may have the potential to revolutionize the management of patients with disabling nail psoriasis. We present another case of disabling nail psoriasis that responded dramatically to infliximab. PMID:21629846

  13. An Increased Abundance of Tumor-Infiltrating Regulatory T Cells Is Correlated with the Progression and Prognosis of Pancreatic Ductal Adenocarcinoma

    PubMed Central

    Tang, Yichen; Xu, Xuejun; Guo, Shixiang; Zhang, Chaobin; Tang, Yan; Tian, Yi; Ni, Bing; Lu, Binfeng; Wang, Huaizhi

    2014-01-01

    CD4+CD25+Foxp3+ regulatory T cells (Tregs) can inhibit cytotoxic responses. Though several studies have analyzed Treg frequency in the peripheral blood mononuclear cells (PBMCs) of pancreatic ductal adenocarcinoma (PDA) patients using flow cytometry (FCM), few studies have examined how intratumoral Tregs might contribute to immunosuppression in the tumor microenvironment. Thus, the potential role of intratumoral Tregs in PDA patients remains to be elucidated. In this study, we found that the percentages of Tregs, CD4+ T cells and CD8+ T cells were all increased significantly in tumor tissue compared to control pancreatic tissue, as assessed via FCM, whereas the percentages of these cell types in PBMCs did not differ between PDA patients and healthy volunteers. The percentages of CD8+ T cells in tumors were significantly lower than in PDA patient PBMCs. In addition, the relative numbers of CD4+CD25+Foxp3+ Tregs and CD8+ T cells were negatively correlated in the tissue of PDA patients, and the abundance of Tregs was significantly correlated with tumor differentiation. Additionally, Foxp3+ T cells were observed more frequently in juxtatumoral stroma (immediately adjacent to the tumor epithelial cells). Patients showing an increased prevalence of Foxp3+ T cells had a poorer prognosis, which was an independent factor for patient survival. These results suggest that Tregs may promote PDA progression by inhibiting the antitumor immunity of CD8+ T cells at local intratumoral sites. Moreover, a high proportion of Tregs in tumor tissues may reflect suppressed antitumor immunity. PMID:24637664

  14. Increases in soil aggregation following phosphorus additions in a tropical premontane forest are not driven by root and arbuscular mycorrhizal fungal abundances

    NASA Astrophysics Data System (ADS)

    Camenzind, Tessa; Papathanasiou, Helena; Foerster, Antje; Dietrich, Karla; Hertel, Dietrich; Homeier, Juergen; Oelmann, Yvonne; Olsson, Pål Axel; Suárez, Juan; Rillig, Matthias

    2015-12-01

    Tropical ecosystems have an important role in global change scenarios, in part because they serve as a large terrestrial carbon pool. Carbon protection is mediated by soil aggregation processes, whereby biotic and abiotic factors influence the formation and stability of aggregates. Nutrient additions may affect soil structure indirectly by simultaneous shifts in biotic factors, mainly roots and fungal hyphae, but also via impacts on abiotic soil properties. Here, we tested the hypothesis that soil aggregation will be affected by nutrient additions primarily via changes in arbuscular mycorrhizal fungal (AMF) hyphae and root length in a pristine tropical forest system. Therefore, the percentage of water-stable macroaggregates (> 250µm) (WSA) and the soil mean weight diameter (MWD) was analyzed, as well as nutrient contents, pH, root length and AMF abundance. Phosphorus additions significantly increased the amount of WSA, which was consistent across two different sampling times. Despite a positive effect of phosphorus additions on extraradical AMF biomass, no relationship between WSA and extra-radical AMF nor roots was revealed by regression analyses, contrary to the proposed hypothesis. These findings emphasize the importance of analyzing soil structure in understudied tropical systems, since it might be affected by increasing nutrient deposition expected in the future.

  15. Dramatic Improvements to Feature Based Stereo

    NASA Technical Reports Server (NTRS)

    Smelyansky, V. N.; Morris, R. D.; Kuehnel, F. O.; Maluf, D. A.; Cheeseman, P.

    2004-01-01

    The camera registration extracted from feature based stereo is usually considered sufficient to accurately localize the 3D points. However, for natural scenes the feature localization is not as precise as in man-made environments. This results in small camera registration errors. We show that even very small registration errors result in large errors in dense surface reconstruction. We describe a method for registering entire images to the inaccurate surface model. This gives small, but crucially important improvements to the camera parameters. The new registration gives dramatically better dense surface reconstruction.

  16. Chronic high fat feeding increases anxiety-like behaviour and reduces transcript abundance of glucocorticoid signalling genes in the hippocampus of female rats.

    PubMed

    Sivanathan, Shathveekan; Thavartnam, Kabriya; Arif, Shahneen; Elegino, Trisha; McGowan, Patrick O

    2015-06-01

    The consumption of diets high in saturated fats and obesity have been associated with impaired physical and mental health. Previous studies indicate that chronic high fat diet consumption leads to systemic inflammation in humans and non-human animal models. Studies in non-human animals suggest that altered physiological responses to stress are also a consequence of high fat diet consumption. Glucocorticoid signalling mechanisms may link immune and stress-related pathways in the brain, and were shown to be significantly altered in the brains of female rat offspring of mothers exposed to chronic high fat diet during pregnancy and lactation. For adult females, the consequence of chronic high fat diet consumption on these signalling pathways and their relationship to stress-related behaviour is not known. In this study, we examined the effects of chronic consumption of a high fat diet compared to a low fat control diet among adult female Long Evans rats. We found significant differences in weight gain, caloric intake, anxiety-related behaviours, and glucocorticoid-related gene expression over a 10-week exposure period. As expected, rats in the high fat diet group gained the most weight and consumed the greatest number of calories. Rats in the high fat diet group showed significantly greater levels of anxiety-related behaviour in the Light Dark and Open Field tasks compared to rats in the low fat diet group. Rats consuming high fat diet also exhibited reduced transcript abundance in the hippocampus of stress-related mineralocorticoid receptor and glucocorticoid receptor genes, as well as nuclear factor kappa beta gene expression, implicated in inflammatory processes. Together, these data indicate that chronic high fat diet consumption may increase anxiety-like behaviour at least in part via alterations in glucocorticoid signalling mechanisms in limbic brain regions.

  17. Ozonated laundering: Radical concept claims dramatic savings

    SciTech Connect

    Christensen, B.

    1993-12-31

    An innovative commercial laundering technology that uses no hot water and no detergent holds promise of dramatic savings in energy, water, chemicals, labor, and sewage fees. Users report good results, but the conservative laundry industry is likely to be skeptical, especially in light of the powerful role played by chemical and equipment manufacturers. While ozonated laundering technology uses more electricity than conventional approaches in some applications, the reported advantages in terms of overall resource efficiency and cost savings could make it an attractive option from the perspective of end-users and utility companies alike. As yet, there are many unanswered questions about the process. There is no theoretical basis to explain how ozone cleans, and no third-party testing to verify these impressive savings. Reports from installations at two Marriott hotels, however, appear to corroborate the manufacturer`s claims. This report assesses the controversial elements of the ozonated laundering process, compiles users` comments and concerns, and reports on current research about how the process works. More independent study will be needed, however, to provide a basis for acceptance of such a radical divergence from the norm in commercial laundering.

  18. Increased Abundance of Proteins Involved in Resistance to Oxidative and Nitrosative Stress at the Last Stages of Growth and Development of Leishmania amazonensis Promastigotes Revealed by Proteome Analysis

    PubMed Central

    Alonso, Ana; García-Tabares, Francisco; Mena, María C.; Ciordia, Sergio; Larraga, Vicente

    2016-01-01

    Leishmania amazonensis is one of the major etiological agents of the neglected, stigmatizing disease termed american cutaneous leishmaniasis (ACL). ACL is a zoonosis and rodents are the main reservoirs. Most cases of ACL are reported in Brazil, Bolivia, Colombia and Peru. The biological cycle of the parasite is digenetic because sand fly vectors transmit the motile promastigote stage to the mammalian host dermis during blood meal intakes. The amastigote stage survives within phagocytes of the mammalian host. The purpose of this study is detection and identification of changes in protein abundance by 2DE/MALDI-TOF/TOF at the main growth phases of L. amazonensis promastigotes in axenic culture and the differentiation process that takes place simultaneously. The average number of proteins detected per gel is 202 and the non-redundant cumulative number is 339. Of those, 63 are differentially abundant throughout growth and simultaneous differentiation of L. amazonensis promastigotes. The main finding is that certain proteins involved in resistance to nitrosative and oxidative stress are more abundant at the last stages of growth and differentiation of cultured L. amazonensis promastigotes. These proteins are the arginase, a light variant of the tryparedoxin peroxidase, the iron superoxide dismutase, the regulatory subunit of the protein kinase A and a light HSP70 variant. These data taken together with the decrease of the stress-inducible protein 1 levels are additional evidence supporting the previously described pre-adaptative hypothesis, which consists of preparation in advance towards the amastigote stage. PMID:27776144

  19. Dramatic effects of stress on metamorphic reactions

    NASA Astrophysics Data System (ADS)

    Wheeler, John

    2014-05-01

    controlled by fluid pressure not confining pressure: implications of dehydration experiments with gypsum. Contributions To Mineralogy And Petrology 164, 69-79. Sheldon, H. A. & Wheeler, J. 2003. Influence of pore fluid chemistry on the state of stress in sedimentary basins. Geology 31(1), 59-62. Wheeler, J. 1987. The significance of grain-scale stresses in the kinetics of metamorphism. Contributions to Mineralogy and Petrology 97, 397-404. Wheeler, J. 1992. The importance of pressure solution and Coble creep in the deformation of polymineralic rocks. Journal of Geophysical Research 97, 4579-4586. Wheeler, J. submitted. Dramatic effects of stress on metamorphic reactions. Geology.

  20. Dramatic Outburst Reveals Nearest Black Hole

    NASA Astrophysics Data System (ADS)

    2000-01-01

    Scientists have discovered the closest black hole yet, a mere 1,600 light years from Earth. Its discovery was heralded by four of the most dramatic rapid X-ray intensity changes ever seen from one star. Astronomers from the Massachusetts Institute of Technology (MIT) and the National Science Foundation's National Radio Astronomy Observatory (NRAO) announced their findings at the American Astronomical Society's meeting in Atlanta. The black hole in the constellation Sagittarius, along with a normal star dubbed V4641 Sgr, form a violent system that briefly flooded part of our Milky Way Galaxy with X-rays and ejected subatomic particles moving at nearly the speed of light one day last September. At the peak of its X-ray output, V4641 Sgr was the brightest X-ray emitter in the sky. Astronomers call this type of system an X-ray nova because it suddenly becomes a bright source of X-rays, but this object shows characteristics never seen in an X-ray nova. "V4641 Sgr turns on and off so fast that it seems to represent a new subclass of X-ray novae," said Donald A. Smith, postdoctoral associate in MIT's Center for Space Research. Smith worked on data from this object with MIT principal research scientist Ronald Remillard and NRAO astronomer Robert Hjellming. "In X-rays, the intensity rose by a factor of more than 1,000 in seven hours, then dropped by a factor of 100 in two hours," Remillard said. The radio emission was seen as an image of an expanding "jet" of particles shooting out from the binary system. After reaching a maximum, the radio intensity dropped by a factor of nearly 40 within two days. "Radio telescopes give us a quick glimpse of something moving at a fantastically high velocity," Hjellming said. Black holes harbor enormous gravitational force that can literally rip the gas away from a nearby star. This transfer of gas is visible in many forms of radiation. Both orbiting X-ray telescopes and ground-based radio and optical telescopes saw the outburst of V4641

  1. Abundance of the Multiheme c-Type Cytochrome OmcB Increases in Outer Biofilm Layers of Electrode-Grown Geobacter sulfurreducens

    PubMed Central

    Stephen, Camille S.; LaBelle, Edward V.; Brantley, Susan L.; Bond, Daniel R.

    2014-01-01

    When Geobacter sulfurreducens utilizes an electrode as its electron acceptor, cells embed themselves in a conductive biofilm tens of microns thick. While environmental conditions such as pH or redox potential have been shown to change close to the electrode, less is known about the response of G. sulfurreducens to growth in this biofilm environment. To investigate whether respiratory protein abundance varies with distance from the electrode, antibodies against an outer membrane multiheme cytochrome (OmcB) and cytoplasmic acetate kinase (AckA) were used to determine protein localization in slices spanning ∼25 µm-thick G. sulfurreducens biofilms growing on polished electrodes poised at +0.24 V (vs. Standard Hydrogen Electrode). Slices were immunogold labeled post-fixing, imaged via transmission electron microscopy, and digitally reassembled to create continuous images allowing subcellular location and abundance per cell to be quantified across an entire biofilm. OmcB was predominantly localized on cell membranes, and 3.6-fold more OmcB was detected on cells 10–20 µm distant from the electrode surface compared to inner layers (0–10 µm). In contrast, acetate kinase remained constant throughout the biofilm, and was always associated with the cell interior. This method for detecting proteins in intact conductive biofilms supports a model where the utilization of redox proteins changes with depth. PMID:25090411

  2. Insulin increases mRNA abundance of the amino acid transporter SLC7A5/LAT1 via an mTORC1‐dependent mechanism in skeletal muscle cells

    PubMed Central

    Walker, Dillon K.; Drummond, Micah J.; Dickinson, Jared M.; Borack, Michael S.; Jennings, Kristofer; Volpi, Elena; Rasmussen, Blake B.

    2014-01-01

    Abstract Amino acid transporters (AATs) provide a link between amino acid availability and mammalian/mechanistic target of rapamycin complex 1 (mTORC1) activation although the direct relationship remains unclear. Previous studies in various cell types have used high insulin concentrations to determine the role of insulin on mTORC1 signaling and AAT mRNA abundance. However, this approach may limit applicability to human physiology. Therefore, we sought to determine the effect of insulin on mTORC1 signaling and whether lower insulin concentrations stimulate AAT mRNA abundance in muscle cells. We hypothesized that lower insulin concentrations would increase mRNA abundance of select AAT via an mTORC1‐dependent mechanism in C2C12 myotubes. Insulin (0.5 nmol/L) significantly increased phosphorylation of the mTORC1 downstream effectors p70 ribosomal protein S6 kinase 1 (S6K1) and ribosomal protein S6 (S6). A low rapamycin dose (2.5 nmol/L) significantly reduced the insulin‐(0.5 nmol/L) stimulated S6K1 and S6 phosphorylation. A high rapamycin dose (50 nmol/L) further reduced the insulin‐(0.5 nmol/L) stimulated phosphorylation of S6K1 and S6. Insulin (0.5 nmol/L) increased mRNA abundance of SLC38A2/SNAT2 (P ≤ 0.043) and SLC7A5/LAT1 (P ≤ 0.021) at 240 min and SLC36A1/PAT1 (P = 0.039) at 30 min. High rapamycin prevented an increase in SLC38A2/SNAT2 (P = 0.075) and SLC36A1/PAT1 (P ≥ 0.06) mRNA abundance whereas both rapamycin doses prevented an increase in SLC7A5/LAT1 (P ≥ 0.902) mRNA abundance. We conclude that a low insulin concentration increases SLC7A5/LAT1 mRNA abundance in an mTORC1‐dependent manner in skeletal muscle cells. PMID:24760501

  3. Adolescence: the period of dramatic bone growth.

    PubMed

    Weaver, Connie M

    2002-02-01

    Adolescence is a period of rapid skeletal growth during which nearly half of the adult skeletal mass is accrued. This life stage is a window of opportunity for influencing peak bone mass and reducing the risk of osteoporosis later in life. Endocrine factors that may influence peak bone mass include insulin-like growth factor-1, which regulates skeletal growth, and gonadotropic hormones, which stimulate epiphyseal maturation. Estrogen deficiency and amenorrhea can reduce skeletal mass. Weight-bearing exercise can increase bone mass. Appropriate mineralization of the skeleton requires adequate dietary intakes of minerals involved in the formation of hydroxyapatite; the most likely to be deficient is calcium.

  4. Food intake inhibition in rainbow trout induced by activation of serotonin 5-HT2C receptors is associated with increases in POMC, CART and CRF mRNA abundance in hypothalamus.

    PubMed

    Pérez-Maceira, Jorge J; Otero-Rodiño, Cristina; Mancebo, María J; Soengas, José L; Aldegunde, Manuel

    2016-04-01

    In rainbow trout, the food intake inhibition induced by serotonin occurs through 5-HT2C and 5-HT1A receptors, though the mechanisms involved are still unknown. Therefore, we assessed if a direct stimulation of 5-HT2C and 5-HT1A serotonin receptors (resulting in decreased food intake in rainbow trout), affects gene expression of neuropeptides involved in the control of food intake, such as pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), corticotrophin releasing factor (CRF), and agouti-related peptide (AgRP). In a first set of experiments, the injection of the 5-HT2C receptor agonists MK212 (60 μg kg(-1) icv) and WAY 161503 (1 mg kg(-1) ip), and of the 5-HT1A receptor agonist 8-OH-DPAT (1 mg kg(-1) ip and 30 μg kg(-1) icv) induced food intake inhibition. In a second set of experiments, we observed that the injection of MK212 or WAY 161503 (1 and 3 mg kg(-1)) significantly increased hypothalamic POMC mRNA abundance. CART mRNA abundance in hypothalamus was enhanced by treatment with MK212 and unaffected by WAY 161503. The administration of the 5-HT1A receptor agonist 8-OH-DPAT did not induce any significant variation in the hypothalamic POMC or CART mRNA levels. CRF mRNA abundance was only affected by MK212 that increased hypothalamic values. Finally, hypothalamic AgRP mRNA abundance was only evaluated with the agonist 5-HT2C MK212 resulting in no significant effects. The results show that the reduction in food intake mediated by 5-HT2C receptors is associated with increases in hypothalamic POMC, CART and CRF mRNA abundance.

  5. Effects of Experimental High Flow Releases and Increased Fluctuations in Flow from Glen Canyon Dam on Abundance, Growth, and Survival Rates of Early Life Stages of Rainbow Trout in the Lee's Ferry Reach of the Colorado River

    NASA Astrophysics Data System (ADS)

    Korman, Josh

    2010-05-01

    The abundance of adult fish populations is controlled by the growth and survival rates of early life stages. Evaluating the effects of flow regimes on early life stages is therefore critical to determine how these regimes affect the abundance of adult populations. Experimental high flow releases from Glen Canyon Dam, primarily intended to conserve fine sediment and improve habitat conditions for native fish in the Colorado River in Grand Canyon, AZ, have been conducted in 1996, 2004, and 2008. These flows potentially affect the Lee's Ferry reach rainbow trout population, located immediately downstream of the dam, which supports a highly valued fishery and likely influences the abundance of rainbow trout in Grand Canyon. Due to concerns about negative effects of high trout abundance on endangered native fish, hourly variation in flow from Glen Canyon Dam was experimentally increased between 2003 and 2005 to reduce trout abundance. This study reports on the effects of experimental high flow releases and fluctuating flows on early life stages of rainbow trout in the Lee's Ferry reach based on monthly sampling of redds (egg nests) and the abundance and growth of age-0 trout between 2003 and 2009. Data on spawn timing, spawning elevations, and intergravel temperatures were integrated in a model to estimate the magnitude and seasonal trend in incubation mortality resulting from redd dewatering due to fluctuations in flow. Experimental fluctuations from January through March promoted spawning at higher elevations where the duration of dewatering was longer and intergravel temperatures exceeded lethal thresholds. Flow-dependent incubation mortality rates were 24% (2003) and 50% (2004) in years with higher flow fluctuations, compared to 5-11% under normal operations (2006-2009). Spatial and temporal predictions of mortality were consistent with direct observations of egg mortality determined from the excavation of 125 redds. The amount of variation in backcalculated hatch

  6. Few apparent short-term effects of elevated soil temperature and increased frequency of summer precipitation on the abundance and taxonomic diversity of desert soil micro- and meso-fauna

    USGS Publications Warehouse

    Darby, B.J.; Neher, D.A.; Housman, D.C.; Belnap, J.

    2011-01-01

    Frequent hydration and drying of soils in arid systems can accelerate desert carbon and nitrogen mobilization due to respiration, microbial death, and release of intracellular solutes. Because desert microinvertebrates can mediate nutrient cycling, and the autotrophic components of crusts are known to be sensitive to rapid desiccation due to elevated temperatures after wetting events, we studied whether altered soil temperature and frequency of summer precipitation can also affect the composition of food web consumer functional groups. We conducted a two-year field study with experimentally-elevated temperature and frequency of summer precipitation in the Colorado Plateau desert, measuring the change in abundance of nematodes, protozoans, and microarthropods. We hypothesized that microfauna would be more adversely affected by the combination of elevated temperature and frequency of summer precipitation than either effect alone, as found previously for phototrophic crust biota. Microfauna experienced normal seasonal fluctuations in abundance, but the effect of elevated temperature and frequency of summer precipitation was statistically non-significant for most microfaunal groups, except amoebae. The seasonal increase in abundance of amoebae was reduced with combined elevated temperature and increased frequency of summer precipitation compared to either treatment alone, but comparable with control (untreated) plots. Based on our findings, we suggest that desert soil microfauna are relatively more tolerant to increases in ambient temperature and frequency of summer precipitation than the autotrophic components of biological soil crust at the surface.

  7. Cognitive Psychology and Audience-Oriented Dramatic Theory.

    ERIC Educational Resources Information Center

    Bratt, David

    Cognitive psychology's most useful contribution to dramatic theory is the concept of schemata, or the mental structures that make up part of the perceptual cycle. In regard to an audience-oriented dramatic theory, this suggests that analysis of a script ought to identify the sorts of schemata that are to be aroused in the audience's minds and the…

  8. Infrared measurements of HF and HCl total column abundances above Kitt Peak, 1977-1990: seasonal cycles, long-term increases, and comparisons with model calculations.

    PubMed

    Rinsland, C P; Levine, J S; Goldman, A; Sze, N D; Ko, M K; Johnson, D W

    1991-08-20

    Series of high-resolution (approximately 0.01 cm-1) solar absorption spectra recorded with the McMath Fourier transform spectrometer on Kitt Peak (altitude 2.09 km, 31.9 degrees N, 111.6 degrees W) have been analyzed to deduce total column amounts of HF on 93 different days and HCl on 35 different days between May 1977 and June 1990. The results are based on the analysis of the HF and H35Cl (1-0) vibration-rotation band R(1) lines which are located at 4038.9625 and 2925.8970 cm-1, respectively. All of the data were analyzed using a multilayer, nonlinear least squares spectral fitting procedure and a consistent set of spectroscopic line parameters. The results indicate a rapid increase in total HF and a more gradual increase in total HCl with both trends superimposed on short-term variability. In addition, the total columns of both gases undergo a seasonal cycle with an early spring maximum and an early fall minimum, with peak-to-peak amplitudes equal to 25% for HF and 13% for HCl. In the case of HF, the changes over the 13 years of measurement are sufficiently large to determine that a better fit is obtained assuming a linear rather than an exponential increase with time. For HCl, linear and exponential models fit the data equally well. Referenced to calendar year 1981.0 and assuming a sinusoidal seasonal cycle superimposed on a linear total column increase with time, HF and HCl increase rates of (10.9 +/- 1.1)% yr-1 and (5.1 +/- 0.7)% yr-1 and total columns of (3.17 +/- 0.11) x 10(14) and (1.92 +/- 0.06) x 10(15) molecules cm-2 (2 sigma) are derived, respectively; the corresponding best fit mean exponential increase rates are equal to (7.6 +/- 0.6)% yr-1 and (4.2 +/- 0.5)% yr-1 (2 sigma). Over the 13-year observing period, the HF and HCl total columns increased by factors of 3.2 and 1.8, respectively. Based on HF and HCl total columns deduced from measurements on the same day, the HF/HCl total columns ratio increased from 0.14 in May 1977 to 0.23 in June 1990

  9. Differentially Expressed in Chondrocytes 2 (DEC2) Increases the Expression of IL-1β and Is Abundantly Present in Synovial Membrane in Rheumatoid Arthritis

    PubMed Central

    Olkkonen, Juri; Kouri, Vesa-Petteri; Hynninen, Joel; Mandelin, Jami

    2015-01-01

    Objective Patients with rheumatoid arthritis (RA) have altered circadian rhythm of circulating serum cortisol, melatonin and IL-6, as well as disturbance in the expression of clock genes ARNTL2 and NPAS2. In humans, TNFα increases the expression ARNTL2 and NPAS2 but paradoxically suppresses clock output genes DPB and PER3. Our objective was to investigate the expression of direct clock suppressors DEC1 and DEC2 (BHLHE 40 and 41 proteins) in response to TNFα and investigate their role during inflammation. Methods Cultured primary fibroblasts were stimulated with TNFα. Effects on DEC2 were studied using RT-qPCR and immunofluorescence staining. The role of NF-κB in DEC2 increase was analyzed using IKK-2 specific inhibitor IMD-0354. Cloned DEC2 was transfected into HEK293 cells to study its effects on gene expression. Transfections into primary human fibroblasts were used to confirm the results. The presence of DEC2 was analyzed in (RA) and osteoarthritis (OA) synovial membranes by immunohistochemistry. Results TNFα increased DEC2 mRNA and DEC2 was mainly detected at nuclei after the stimulus. The effects of TNFα on DEC2 expression were mediated via NF-κB. Overexpression, siRNA and promoter activity studies disclosed that DEC2 directly regulates IL-1β, in both HEK293 cells and primary human fibroblasts. DEC2 was increased in synovial membrane in RA compared to OA. Conclusion Not only ARNTL2 and NPAS2 but also DEC2 is regulated by TNFα in human fibroblasts. NF-κB mediates the effect on DEC2, which upregulates IL-1β. Circadian clock has a direct effect on inflammation in human fibroblasts. PMID:26710124

  10. Schistosoma mansoni Infection in Ugandan Men Is Associated with Increased Abundance and Function of HIV Target Cells in Blood, but Not the Foreskin: A Cross-sectional Study

    PubMed Central

    Prodger, Jessica L.; Ssemaganda, Aloysious; Ssetaala, Ali; Kitandwe, Paul K.; Muyanja, Enoch; Mpendo, Juliet; Nanvubya, Annet; Wambuzi, Mathias; Nielsen, Leslie; Kiwanuka, Noah; Kaul, Rupert

    2015-01-01

    Background Schistosoma mansoni infection has been associated with an increased HIV prevalence in humans and SHIV incidence in primate models. We hypothesized that immune activation from this gastrointestinal mucosa infection would increase highly HIV-susceptible CD4 T cell subsets in the blood and the foreskin through common mucosal homing. Methodology/Principal Findings Foreskin tissue and blood were obtained from 34 HIV- and malaria-uninfected Ugandan men who volunteered for elective circumcision, 12 of whom were definitively positive for S. mansoni eggs in stool and 12 definitively negative for both S. mansoni eggs and worm antigen. Tissue and blood T cell subsets were characterized by flow cytometry and immunohistochemistry (IHC). Th17 and Th1 cells from both the blood and foreskin expressed higher levels of CCR5 and were more activated than other CD4 T cell subsets. S. mansoni-infected men had a higher frequency of systemic Th1 cells (22.9 vs. 16.5% of blood CD4 T cells, p<0.05), Th17 cells (2.3 vs. 1.5%, p<0.05), and Th22 cells (0.5 vs. 0.3%, p<0.01) than uninfected men. Additionally, Th17 cells in the blood of S. mansoni-infected men demonstrated enhanced function (28.1 vs. 16.3% producing multiple cytokines, p = 0.046). However, these immune alterations were not observed in foreskin tissue. Conclusions/Significance S. mansoni infection was associated with an increased frequency of highly HIV-susceptible Th1, Th17 and Th22 cell subsets in the blood, but these T cell immune differences did not extend to the foreskin. S. mansoni induced changes in T cell immunology mediated through the common mucosal immune system are not likely to increase HIV susceptibility in the foreskin. PMID:26335139

  11. Elevated CO2 decreases the response of the ethylene signaling pathway in Medicago truncatula and increases the abundance of the pea aphid.

    PubMed

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Liu, Xianghui; Zhang, Wenhao; Ge, Feng

    2014-01-01

    The performance of herbivorous insects is greatly affected by plant nutritional quality and resistance, which are likely to be altered by rising concentrations of atmospheric CO2 . We previously reported that elevated CO2 enhanced biological nitrogen (N) fixation of Medicago truncatula, which could result in an increased supply of amino acids to the pea aphid (Acyrthosiphon pisum). The current study examined the N nutritional quality and aphid resistance of sickle, an ethylene-insensitive mutant of M. truncatula with supernodulation, and its wild-type control A17 under elevated CO2 in open-top field chambers. Regardless of CO2 concentration, growth and amino acid content were greater and aphid resistance was lower in sickle than in A17. Elevated CO2 up-regulated N assimilation and transamination-related enzymes activities and increased phloem amino acids in both genotypes. Furthermore, elevated CO2 down-regulated expression of 1-amino-cyclopropane-carboxylic acid (ACC), sickle gene (SKL) and ethylene response transcription factors (ERF) genes in the ethylene signaling pathway of A17 when infested by aphids and decreased resistance against aphids in terms of lower activities of superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO). Our results suggest that elevated CO2 suppresses the ethylene signaling pathway in M. truncatula, which results in an increase in plant nutritional quality for aphids and a decrease in plant resistance against aphids.

  12. Dietary supplementation of Bifidobacterium longum strain AH1206 increases its cecal abundance and elevates intestinal interleukin-10 expression in the neonatal piglet.

    PubMed

    Herfel, Tina M; Jacobi, Sheila K; Lin, Xi; Jouni, Zeina E; Chichlowski, Maciej; Stahl, Chad H; Odle, Jack

    2013-10-01

    Intestinal microbiota of infants differ in response to gestational age, delivery mode and feeding regimen. Dietary supplementation of probiotic bacteria is one method of promoting healthy populations. We examined the impact of a novel probiotic strain of Bifidobacterium longum (AH1206) on the health, growth and development of neonatal pigs as a model for infants. Day-old pigs were fed milk-based formula containing AH1206 at 0, 10⁹, or 10¹¹ CFU/d for 18 d (n=10/treatment). Differences were not detected in growth, organ weights or body temperatures (P>0.1); however pigs fed the high dose showed a small (2%) reduction in feed intake. Bacterial translocation was not affected as indicated by total anaerobic and aerobic counts (CFU) in samples of spleen, liver and mesenteric lymph nodes (P>0.1). Feeding AH1206 had no effects on fecal consistency, but increased the density of B. longum in the cecum. Ileal TNF expression tended to increase (P=0.08) while IL-10 expression increased linearly (P=0.01) with supplementation. Based upon findings in the suckling piglet model, we suggest that dietary supplementation with B. longum (AH1206) may be safe for human infants based on a lack of growth, development or deleterious immune-related effects observed in piglets. PMID:23872134

  13. Elevated CO2 decreases the response of the ethylene signaling pathway in Medicago truncatula and increases the abundance of the pea aphid.

    PubMed

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Liu, Xianghui; Zhang, Wenhao; Ge, Feng

    2014-01-01

    The performance of herbivorous insects is greatly affected by plant nutritional quality and resistance, which are likely to be altered by rising concentrations of atmospheric CO2 . We previously reported that elevated CO2 enhanced biological nitrogen (N) fixation of Medicago truncatula, which could result in an increased supply of amino acids to the pea aphid (Acyrthosiphon pisum). The current study examined the N nutritional quality and aphid resistance of sickle, an ethylene-insensitive mutant of M. truncatula with supernodulation, and its wild-type control A17 under elevated CO2 in open-top field chambers. Regardless of CO2 concentration, growth and amino acid content were greater and aphid resistance was lower in sickle than in A17. Elevated CO2 up-regulated N assimilation and transamination-related enzymes activities and increased phloem amino acids in both genotypes. Furthermore, elevated CO2 down-regulated expression of 1-amino-cyclopropane-carboxylic acid (ACC), sickle gene (SKL) and ethylene response transcription factors (ERF) genes in the ethylene signaling pathway of A17 when infested by aphids and decreased resistance against aphids in terms of lower activities of superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO). Our results suggest that elevated CO2 suppresses the ethylene signaling pathway in M. truncatula, which results in an increase in plant nutritional quality for aphids and a decrease in plant resistance against aphids. PMID:24015892

  14. Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance

    PubMed Central

    2012-01-01

    Background The mechanisms by which nitrate is transported into the roots have been characterized both at physiological and molecular levels. It has been demonstrated that nitrate is taken up in an energy-dependent way by a four-component uptake machinery involving high- and low- affinity transport systems. In contrast very little is known about the physiology of nitrate transport towards different plant tissues and in particular at the leaf level. Results The mechanism of nitrate uptake in leaves of cucumber (Cucumis sativus L. cv. Chinese long) plants was studied and compared with that of the root. Net nitrate uptake by roots of nitrate-depleted cucumber plants proved to be substrate-inducible and biphasic showing a saturable kinetics with a clear linear non saturable component at an anion concentration higher than 2 mM. Nitrate uptake by leaf discs of cucumber plants showed some similarities with that operating in the roots (e.g. electrogenic H+ dependence via involvement of proton pump, a certain degree of induction). However, it did not exhibit typical biphasic kinetics and was characterized by a higher Km with values out of the range usually recorded in roots of several different plant species. The quantity and activity of plasma membrane (PM) H+-ATPase of the vesicles isolated from leaf tissues of nitrate-treated plants for 12 h (peak of nitrate foliar uptake rate) increased with respect to that observed in the vesicles isolated from N-deprived control plants, thus suggesting an involvement of this enzyme in the leaf nitrate uptake process similar to that described in roots. Molecular analyses suggest the involvement of a specific isoform of PM H+-ATPase (CsHA1) and NRT2 transporter (CsNRT2) in root nitrate uptake. At the leaf level, nitrate treatment modulated the expression of CsHA2, highlighting a main putative role of this isogene in the process. Conclusions Obtained results provide for the first time evidence that a saturable and substrate

  15. Cellulolytic protist numbers rise and fall dramatically in termite queens and kings during colony foundation.

    PubMed

    Shimada, Keisuke; Lo, Nathan; Kitade, Osamu; Wakui, Akane; Maekawa, Kiyoto

    2013-04-01

    Among the best-known examples of mutualistic symbioses is that between lower termites and the cellulolytic flagellate protists in their hindguts. Although the symbiosis in worker termites has attracted much attention, there have been only a few studies of protists in other castes. We have performed the first examination of protist population dynamics in queens and kings during termite colony foundation. Protist numbers, as well as measurements of hindgut and reproductive tissue sizes, were undertaken at five time points over 400 days in incipient colonies of Reticulitermes speratus, as well as in other castes of mature colonies of this species. We found that protist numbers increased dramatically in both queens and kings during the first 50 days of colony foundation but began to decrease by day 100, eventually disappearing by day 400. Hindgut width followed a pattern similar to that of protist numbers, while ovary and testis widths increased significantly only at day 400. Kings were found to contain higher numbers of protists than queens in incipient colonies, which may be linked to higher levels of nutrient transfer from kings to queens than vice versa, as is known in some other termite species. Protists were found to be abundant in soldiers from mature colonies but absent in neotenics. This probably reflects feeding of soldiers by workers via proctodeal trophallaxis and of reproductives via stomodeal trophallaxis. The results reveal the dynamic nature of protist numbers during colony foundation and highlight the trade-offs that exist between reproduction and parental care during this critical phase of the termite life cycle.

  16. Video Taping and Abnormal Psychology: Dramatized Clinical Interviews.

    ERIC Educational Resources Information Center

    Lyons, Michael J.; And Others

    1984-01-01

    Students in an abnormal psychology course worked in teams to produce dramatizations of diagnostic interviews and then presented them in class. Positive and negative aspects of the activity are discussed. (RM)

  17. Some Practical Guidelines for Teaching Dramatic Analysis to Beginning Students

    ERIC Educational Resources Information Center

    Pelias, Ronald J.; Ralph, Stephen D.

    1985-01-01

    Outlines common abuses that occur when students first use dramatic analysis in oral interpretation. Offers guidelines to help make students' efforts more productive; uses William Carlos Williams's poem "The Red Wheelbarrow" as an example. (PD)

  18. Anions dramatically enhance proton transfer through aqueous interfaces

    PubMed Central

    Mishra, Himanshu; Enami, Shinichi; Nielsen, Robert J.; Hoffmann, Michael R.; Goddard, William A.; Colussi, Agustín J.

    2012-01-01

    Proton transfer (PT) through and across aqueous interfaces is a fundamental process in chemistry and biology. Notwithstanding its importance, it is not generally realized that interfacial PT is quite different from conventional PT in bulk water. Here we show that, in contrast with the behavior of strong nitric acid in aqueous solution, gas-phase HNO3 does not dissociate upon collision with the surface of water unless a few ions (> 1 per 106 H2O) are present. By applying online electrospray ionization mass spectrometry to monitor in situ the surface of aqueous jets exposed to HNO3(g) beams we found that production increases dramatically on > 30-μM inert electrolyte solutions. We also performed quantum mechanical calculations confirming that the sizable barrier hindering HNO3 dissociation on the surface of small water clusters is drastically lowered in the presence of anions. Anions electrostatically assist in drawing the proton away from lingering outside the cluster, whose incorporation is hampered by the energetic cost of opening a cavity therein. Present results provide both direct experimental evidence and mechanistic insights on the counterintuitive slowness of PT at water-hydrophobe boundaries and its remarkable sensitivity to electrostatic effects. PMID:22689964

  19. Dramatic long-term X-ray variability in AGNs

    NASA Astrophysics Data System (ADS)

    Moran, Edward C.

    2016-04-01

    Dramatic X-ray and optical variability on ˜ 10 year timescales has been discovered recently in a handful of quasars, which may provide important new insight into the issue of how luminous AGNs are fueled. We have assembled a new sample of extremely variable X-ray sources from archival Einstein and ROSAT data that could increase substantially the number of such objects known. The sources in our sample varied in X-ray flux by at least a factor of 7-8 over a 10-year span, and most exhibited significantly larger variability amplitudes (10 to over 100). We present the details of how our sample was assembled and preliminary results regarding the identifications, properties, and X-ray histories of the objects. Although a heterogeneous population is expected, some sources in the sample are associated with broad-line AGNs, including a radio-quiet quasar at z = 1.3 that decreased in X-ray luminosity by a factor of 40.

  20. Chemical abundances of solar-type dwarfs in open clusters

    NASA Astrophysics Data System (ADS)

    Schuler, Simon C.

    Open clusters have proven continuously to be invaluable tools to the studies of stellar physics and Galactic evolution. Until recently, however, the chemical abundances of the populous and astrophysically important late-F, G, and K open cluster dwarfs have gone largely unanalyzed. In this thesis I report on the study of the chemical abundances derived from high-resolution, moderate-to-high signal-to-noise echelle spectra obtained with the 10-m Keck I, 9.2-m Hobby- Eberly, 8.2-m VLT, 4.0-m KPNO, 2.7-m Harlan J. Smith, and the 2.1-m Otto Struve telescopes of cool dwarfs in the Pleiades, Hyades, and M34 open clusters. The main result of the study is the identification of excitation-related abundance trends found among cool open cluster dwarfs ( T eff <= 5500 K), as well as an overionization of Fe- abundances derived from singly ionized lines are greater than those derived from neutral lines- among the cool Hyades dwarfs; the trends are such that abundances derived from high-excitation (h >= 4.0 eV) spectral lines and using atmospheric models assuming local thermodynamic equilibrium (LTE) increase with decreasing T eff . Particular attention is given to the high-excitation (h = 9.15 eV) near-IR ll7774 O I triplet, a line used often in the derivation of stellar O abundances and known to be susceptible to non-LTE (NLTE) effects. The O I triplet-based abundances show a dramatic increase with decreasing T eff in all three clusters, behavior that is in stark contrast to expectations from canonical NLTE calculations. Other elements with lines of various excitation potentials are also analyzed and are found to exhibit abundance trends that are qualitatively similar to those of the O I triplet. Possible explanations for the observed cool open cluster dwarf abundance anomalies are investigated, and photospheric surface temperature inhomogeneities possibly due to spots, faculae, and/or plages are found to be a plausible culprit. Indeed, multi-component LTE model atmospheres are

  1. Dorsal Raphe Neuroinflammation Promotes Dramatic Behavioral Stress Dysregulation

    PubMed Central

    Howerton, Alexis R.; Roland, Alison V.

    2014-01-01

    Impulsivity, risk-taking behavior, and elevated stress responsivity are prominent symptoms of mania, a behavioral state common to schizophrenia and bipolar disorder. Though inflammatory processes activated within the brain are involved in the pathophysiology of both disorders, the specific mechanisms by which neuroinflammation drives manic behavior are not well understood. Serotonin cell bodies originating within the dorsal raphe (DR) play a major role in the regulation of behavioral features characteristic of mania. Therefore, we hypothesized that the link between neuroinflammation and manic behavior may be mediated by actions on serotonergic neurocircuitry. To examine this, we induced local neuroinflammation in the DR by viral delivery of Cre recombinase into interleukin (IL)-1βXAT transgenic male and female mice, resulting in overexpressing of the proinflammatory cytokine, IL-1β. For assertion of brain-region specificity of these outcomes, the prefrontal cortex (PFC), as a downstream target of DR serotonergic projections, was also infused. Inflammation within the DR, but not the PFC, resulted in a profound display of manic-like behavior, characterized by increased stress-induced locomotion and responsivity, and reduced risk-aversion/fearfulness. Microarray analysis of the DR revealed a dramatic increase in immune-related genes, and dysregulation of genes important in GABAergic, glutamatergic, and serotonergic neurotransmission. Behavioral and physiological changes were driven by a loss of serotonergic neurons and reduced output as measured by high-performance liquid chromatography, demonstrating inflammation-induced serotonergic hypofunction. Behavioral changes were rescued by acute selective serotonin reuptake inhibitor treatment, supporting the hypothesis that serotonin dysregulation stemming from neuroinflammation in the DR underlies manic-like behaviors. PMID:24849347

  2. Dramatically changing rates and reasons for hospitalization in multiple sclerosis

    PubMed Central

    Elliott, Lawrence; Marriott, James; Cossoy, Michael; Blanchard, James; Tennakoon, Aruni; Yu, Nancy

    2014-01-01

    Objective: We aimed to describe hospitalizations in the multiple sclerosis (MS) population, and to evaluate temporal trends in hospitalizations in the MS population compared to the general population. Methods: Using population-based administrative data, we identified 5,797 persons with MS and a matched general population cohort of 28,769 persons. Using general linear models, we evaluated temporal trends in hospitalization rates and length of stay in the 2 populations over the period 1984–2011. Results: In 1984 the hospitalization rate was 35 per 100 person-years in the MS population and 10.5 in the matched population (relative risk [RR] 3.33; 95% confidence interval: 1.67–6.64). Over the study period hospitalizations declined 75% in the MS population but only 41% in the matched population. The proportion of hospitalizations due to MS declined substantially from 43.4% in 1984 to 7.8% in 2011. The 3 most common non–MS-related reasons for admission in the MS population were diseases of the digestive, genitourinary, and circulatory systems. Admissions for bacterial pneumonia, influenza, urinary tract infections, and pressure ulcers occurred more often in the MS population than in the general population, while admissions for circulatory system disease and neoplasms occurred less often. Older age, male sex, and lower socioeconomic status were associated with increased hospitalization rates for non–MS-related reasons. Conclusions: Although hospitalization rates have declined dramatically in the MS population over the last quarter century, they remain higher than in the general population. Admissions for MS-related reasons now constitute only a small proportion of the reasons for hospitalization. PMID:25085638

  3. Piaget in Performance: The Role of "Games" in Creative Dramatics.

    ERIC Educational Resources Information Center

    Ratliff, Gerald Lee

    Jean Piaget's theories of child development and the nature of intelligence are adapted to creative dramatics in this description of two games for children aged 6 through 12. The first game discussed incorporates a "touchy-feely box," a cardboard construction with openings on two sides so that a child may reach inside, select, and describe an…

  4. The Dramatic Difference: Drama in the Preschool and Kindergarten Classroom.

    ERIC Educational Resources Information Center

    Brown, Victoria; Pleydell, Sarah

    Noting that there are few resources available for preschool or kindergarten teachers committed to providing high-quality drama experiences to students, this book explores ways teachers can maximize the drama experience in preschool and kindergarten classrooms. Topics discussed in the book's introduction include dramatic play and early development,…

  5. Building Family and Community Demand for Dramatic Change in Schools

    ERIC Educational Resources Information Center

    Brinson, Dana; Steiner, Lucy

    2012-01-01

    District-led, dramatic change efforts in failing schools--including turnarounds and school closures--often face strong resistance from families and communities. Resistance may be based on years of tension and distrust between districts and communities, failed past school improvement efforts, or a lack of understanding about the chasm between a…

  6. Soaps and Suspicious Activity: Dramatic Experiences in British Classrooms.

    ERIC Educational Resources Information Center

    Ferree, Angela M.

    2001-01-01

    Offers examples of dramatic experiences (student produced soap operas) in two classrooms in British comprehensive secondary schools. Concludes that students in other countries would find such experiences as meaningful and enjoyable as their British counterparts. Notes that the two teachers managed to be flexible, appropriating effective…

  7. Dramatic Play: Root Meaning of Drama/Theatre.

    ERIC Educational Resources Information Center

    Koste, Virginia Glasgow

    The processes involved in drama and the dramatic play of children are essentially the same in that they rely on an imitation of nature, involve a transformation of reality through imagination, connect seemingly irrelevant elements creatively, and bring a temporary, limited order to an emotional experience. When child's play is used as a basis for…

  8. Astronaut to Zoologist: Changing the Dramatic Play Area!

    ERIC Educational Resources Information Center

    Brouette, Scott J.

    Changing the dramatic play area in a child care setting promotes creativity and gives children the chance to experience a place they may never experience in real life. Whenever possible, the children should be involved in the process of changing the area, by moving furniture and exchanging props, as well as brainstorming ideas for changes. The…

  9. Burke Bingo: Using Active Learning to Introduce Dramatism

    ERIC Educational Resources Information Center

    Krueger, Ben

    2011-01-01

    Kenneth Burke is typically regarded as the single most significant figure in 20th-century rhetorical studies. Undergraduate textbooks in rhetorical criticism, rhetorical theory, and communication theory typically include coverage of Burke's theory of dramatism. In this article, the author describes a classroom activity dubbed "Burke Bingo" that…

  10. Frost Bite: A Dramatic Tale of Research in Aesthetic Education

    ERIC Educational Resources Information Center

    Hirsch, Miriam

    2008-01-01

    This article follows the author's research on the integration of an aesthetic arts initiative in a private elementary school with an established traditional arts program. The narrative describes the sequence of events, interpersonal interactions, and learning experiences in the format of a full-length dramatic performance. Informed by Ben Peretz's…

  11. Collaborative College Playwriting and Performance: A Core Course "Trespassing" onto the Dramatic Arts

    ERIC Educational Resources Information Center

    Bedetti, Gabriella

    2015-01-01

    Arts integration is relevant in the context of the increased demand for creative thinkers in a global economy. However, reaching across disciplinary boundaries is less common in higher education. Arts integration is one way that a literature class can "trespass" onto the dramatic arts. This paper reports on a study of integrating the…

  12. Examining Young Children's Perception toward Augmented Reality-Infused Dramatic Play

    ERIC Educational Resources Information Center

    Han, Jeonghye; Jo, Miheon; Hyun, Eunja; So, Hyo-jeong

    2015-01-01

    Amid the increasing interest in applying augmented reality (AR) in educational settings, this study explores the design and enactment of an AR-infused robot system to enhance children's satisfaction and sensory engagement with dramatic play activities. In particular, we conducted an exploratory study to empirically examine children's perceptions…

  13. The effects of acoustic misclassification on cetacean species abundance estimation.

    PubMed

    Caillat, Marjolaine; Thomas, Len; Gillespie, Douglas

    2013-09-01

    To estimate the density or abundance of a cetacean species using acoustic detection data, it is necessary to correctly identify the species that are detected. Developing an automated species classifier with 100% correct classification rate for any species is likely to stay out of reach. It is therefore necessary to consider the effect of misidentified detections on the number of observed data and consequently on abundance or density estimation, and develop methods to cope with these misidentifications. If misclassification rates are known, it is possible to estimate the true numbers of detected calls without bias. However, misclassification and uncertainties in the level of misclassification increase the variance of the estimates. If the true numbers of calls from different species are similar, then a small amount of misclassification between species and a small amount of uncertainty around the classification probabilities does not have an overly detrimental effect on the overall variance. However, if there is a difference in the encounter rate between species calls and/or a large amount of uncertainty in misclassification rates, then the variance of the estimates becomes very large and this dramatically increases the variance of the final abundance estimate.

  14. Dramatic changes in electronic structure revealed by fractionally charged nuclei

    SciTech Connect

    Cohen, Aron J.; Mori-Sánchez, Paula

    2014-01-28

    Discontinuous changes in the electronic structure upon infinitesimal changes to the Hamiltonian are demonstrated. These are revealed in one and two electron molecular systems by full configuration interaction (FCI) calculations when the realm of the nuclear charge is extended to be fractional. FCI electron densities in these systems show dramatic changes in real space and illustrate the transfer, hopping, and removal of electrons. This is due to the particle nature of electrons seen in stretched systems and is a manifestation of an energy derivative discontinuity at constant number of electrons. Dramatic errors of density functional theory densities are seen in real space as this physics is missing from currently used approximations. The movements of electrons in these simple systems encapsulate those in real physical processes, from chemical reactions to electron transport and pose a great challenge for the development of new electronic structure methods.

  15. Non-small cell lung cancer is characterized by dramatic changes in phospholipid profiles

    PubMed Central

    Marien, Eyra; Meister, Michael; Muley, Thomas; Fieuws, Steffen; Bordel, Sergio; Derua, Rita; Spraggins, Jeffrey; Van de Plas, Raf; Dehairs, Jonas; Wouters, Jens; Bagadi, Muralidhararao; Dienemann, Hendrik; Thomas, Michael; Schnabel, Philipp A; Caprioli, Richard M; Waelkens, Etienne; Swinnen, Johannes V

    2015-01-01

    Non-small cell lung cancer (NSCLC) is the leading cause of cancer death globally. To develop better diagnostics and more effective treatments, research in the past decades has focused on identification of molecular changes in the genome, transcriptome, proteome, and more recently also the metabolome. Phospholipids, which nevertheless play a central role in cell functioning, remain poorly explored. Here, using a mass spectrometry (MS)-based phospholipidomics approach, we profiled 179 phospholipid species in malignant and matched non-malignant lung tissue of 162 NSCLC patients (73 in a discovery cohort and 89 in a validation cohort). We identified 91 phospholipid species that were differentially expressed in cancer versus non-malignant tissues. Most prominent changes included a decrease in sphingomyelins (SMs) and an increase in specific phosphatidylinositols (PIs). Also a decrease in multiple phosphatidylserines (PSs) was observed, along with an increase in several phosphatidylethanolamine (PE) and phosphatidylcholine (PC) species, particularly those with 40 or 42 carbon atoms in both fatty acyl chains together. 2D-imaging MS of the most differentially expressed phospholipids confirmed their differential abundance in cancer cells. We identified lipid markers that can discriminate tumor versus normal tissue and different NSCLC subtypes with an AUC (area under the ROC curve) of 0.999 and 0.885, respectively. In conclusion, using both shotgun and 2D-imaging lipidomics analysis, we uncovered a hitherto unrecognized alteration in phospholipid profiles in NSCLC. These changes may have important biological implications and may have significant potential for biomarker development. What’s new? Cellular membranes are subject to extensive modification in cancer, often with marked alterations in phospholipid metabolism. The extent and nature of those changes are not fully known, however, particularly for non-small cell lung cancer (NSCLC). In this study, lipidomics analysis

  16. Dramatic reduction of culture time of Mycobacterium tuberculosis

    NASA Astrophysics Data System (ADS)

    Ghodbane, Ramzi; Raoult, Didier; Drancourt, Michel

    2014-02-01

    Mycobacterium tuberculosis culture, a critical technique for routine diagnosis of tuberculosis, takes more than two weeks. Here, step-by-step improvements in the protocol including a new medium, microaerophlic atmosphere or ascorbic-acid supplement and autofluorescence detection dramatically shortened this delay. In the best case, primary culture and rifampicin susceptibility testing were achieved in 72 hours when specimens were inoculated directly on the medium supplemented by antibiotic at the beginning of the culture.

  17. The spatial structure of hunter access determines the local abundance of forest elephants (Loxodonta africana cyclotis).

    PubMed

    Yackulic, Charles B; Strindberg, Samantha; Maisels, Fiona; Blake, Stephen

    2011-06-01

    In many previously remote regions in the world, increasing and often unregulated access is leading to dramatic increases in hunting pressure and declines in the densities of prey species, sometimes to the point of local extinction. Not surprisingly, numerous studies have found a correlation between the distance to the closest access point and prey densities. Here we hypothesized that, for many wide-ranging species, local abundances are reduced by hunting associated with multiple access points as opposed to just the closest access points. We also hypothesized that the distribution of hunter access determines both patterns of occupancy and abundance in occupied areas and that these two patterns (occupancy and abundance) respond to access at different spatial scales. Using data on the distribution of abundances of African forest elephant (Loxodonta africana cyclotis) in and around five national parks in Central Africa, we tested these hypotheses using a model comparison framework. We found that models including an index based on the distance to multiple roads outperformed models including other access-based covariates, including a model based on distance to the closest road only. We also found that models that allowed us to model occupancy and abundance separately outperformed simpler models. Occupancy responds to access at the same scale as previous estimates of average maximum displacement in the subspecies, while the scale of the response of abundance is more ambiguous, but appears to be greater. Lastly, we show that incorporating indices based on multiple access points and modeling abundance and occupancy has important practical consequences for our understanding of overall regional abundances and the distribution of abundances within regions.

  18. Dramatic increase in the oxygen reduction reaction for platinum cathodes from tuning the solvent dielectric constant.

    PubMed

    Fortunelli, Alessandro; Goddard, William A; Sha, Yao; Yu, Ted H; Sementa, Luca; Barcaro, Giovanni; Andreussi, Oliviero

    2014-06-23

    Hydrogen fuel cells (FC) are considered essential for a sustainable economy based on carbon-free energy sources, but a major impediment are the costs. First-principles quantum mechanics (density functional theory including solvation) is used to predict how the energies and barriers for the mechanistic steps of the oxygen reduction reaction (ORR) over the fcc(111) platinum surface depend on the dielectric constant of the solvent. The ORR kinetics can be strongly accelerated by decreasing the effective medium polarizability from the high value it has in water. Possible ways to realize this experimentally are suggested. The calculated volcano structure for the dependence of rate on solvent polarization is considered to be general, and should be observed in other electrochemical systems.

  19. Increasing Marriage Will Dramatically Reduce Child Poverty. A Report of the Heritage Center for Data Analysis.

    ERIC Educational Resources Information Center

    Rector, Robert E.; Johnson, Kirk A.; Fagan, Patrick F.; Noyes, Lauren R.

    This report uses data from the Fragile Families and Child Well-Being Study (a nationwide survey that collects data on married and non-married parents at the time of the child's birth) to determine how much marriage could reduce poverty among couples who are not married at the time of birth. To determine the impact of marriage on children's and…

  20. A Dramatic Increase in Seismic Observations in the Central and Eastern US

    NASA Astrophysics Data System (ADS)

    Woodward, R.; Busby, R.; Simpson, D.; Alvarez, M.; Vernon, F.

    2009-05-01

    The USArray Transportable Array (TA) is a network of 400 seismograph stations that is systematically moving west-to-east across the contiguous United States. The TA is part of the National Science Foundation's multi- disciplinary EarthScope program. The TA has already occupied over 700 stations in the western US, and is continuing its multi-year migration towards the Atlantic coast before heading for Alaska. The stations use a grid-like deployment with 70 km separation between stations. At any given time there are approximately 400 stations operational, occupying a nominal 800 km by 2000 km "footprint." Each station is operated for two years. TA stations consist of three component broadband seismometers, with a few sites in the westernmost United States also including three component strong motion instruments. The instruments are installed about two meters below the surface, in thermally stable vaults. All stations transmit continuous data in near-real-time, and the data are freely distributed through the IRIS Data Management Center. TA stations can be upgraded to incorporate high frequency or strong motion instrument. Organizations can also "adopt" stations after installation by reimbursing the cost of the hardware, so that the stations become permanent. The TA is presently operating in the swath of the country extending from Texas to Montana. From 2010 to 2013 the TA will occupy ~800 sites in the central and eastern US. The array will be centered on the New Madrid, MO region during the bicentennial of the 1811-1812 earthquakes. During the TA deployment every existing or planned nuclear plant in the eastern US will be within 70 km of at least four new seismic stations. Thus, this station deployment in the eastern half of the US presents an unprecedented opportunity for improving source characterization, modeling the regional velocity and attenuation structure, and mapping seismic zones down to low magnitude thresholds. We will provide an overview of TA installation plans, instrumentation, and data so that scientists and decision makers are better prepared to capitalize on the unique opportunity presented by the TA moving through the central and eastern US. We will provide examples of TA station performance, as well as examples of data quality and seismic detection thresholds observed in the western US.

  1. Biosolids amendment dramatically increases sequestration of crop residue-carbon in agricultural soils in western Illinois

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Release of carbon dioxide through microbial respiration from the world’s crop residues (non-edible plant parts left in the field after harvest) represents an important form of carbon transfer from terrestrial ecosystems to the atmosphere. We hypothesized that alleviation of environmental stress (moi...

  2. Increasing magnetite contents of polymeric magnetic particles dramatically improves labeling of neural stem cell transplant populations.

    PubMed

    Adams, Christopher F; Rai, Ahmad; Sneddon, Gregor; Yiu, Humphrey H P; Polyak, Boris; Chari, Divya M

    2015-01-01

    Safe and efficient delivery of therapeutic cells to sites of injury/disease in the central nervous system is a key goal for the translation of clinical cell transplantation therapies. Recently, 'magnetic cell localization strategies' have emerged as a promising and safe approach for targeted delivery of magnetic particle (MP) labeled stem cells to pathology sites. For neuroregenerative applications, this approach is limited by the lack of available neurocompatible MPs, and low cell labeling achieved in neural stem/precursor populations. We demonstrate that high magnetite content, self-sedimenting polymeric MPs [unfunctionalized poly(lactic acid) coated, without a transfecting component] achieve efficient labeling (≥90%) of primary neural stem cells (NSCs)-a 'hard-to-label' transplant population of major clinical relevance. Our protocols showed high safety with respect to key stem cell regenerative parameters. Critically, labeled cells were effectively localized in an in vitro flow system by magnetic force highlighting the translational potential of the methods used.

  3. Overexpression of two cambium-abundant Chinese fir (Cunninghamia lanceolata) α-expansin genes ClEXPA1 and ClEXPA2 affect growth and development in transgenic tobacco and increase the amount of cellulose in stem cell walls.

    PubMed

    Wang, Guifeng; Gao, Yan; Wang, Jinjun; Yang, Liwei; Song, Rentao; Li, Xiaorong; Shi, Jisen

    2011-05-01

    Expansins are unique plant cell wall proteins that possess the ability to induce immediately cell wall extension in vitro and cell expansion in vivo. To investigate the biological functions of expansins that are abundant in wood-forming tissues, we cloned two expansin genes from the differentiating xylem of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook). Phylogenetic reconstruction indicated that they belong to α-expansin (EXPA), named ClEXPA1 and ClEXPA2. Expression pattern analysis demonstrated that they are preferentially expressed in the cambium region. Overexpression of ClEXPA1 and ClEXPA2 in tobacco plants yielded pleiotropic phenotypes of plant height, stem diameter, leaf number and seed pod. The height and diameter growth of the 35S(pro) :ClEXPA1 and 35S(pro) :ClEXPA2 transgenic plants were increased drastically, exhibiting an enlargement of pith parenchyma cell size. Isolated cell walls of ClEXPA1 and ClEXPA2 overexpressors contained 30%-50% higher cellulose contents than the wild type, accompanied by a thickening of the cell walls in the xylem region. Both ClEXPA1 and ClEXPA2 are involved in plant growth and development, with a partially functional overlap. Expansins are not only able to induce cell expansion in different tissues/organs in vivo, but they also can act as a potential activator during secondary wall formation by directly or indirectly affecting cellulose metabolism, probably in a cell type-dependent manner.

  4. Dramatic response to levetiracetam in post-ischaemic Holmes’ tremor

    PubMed Central

    Striano, P; Elefante, Andrea; Coppola, Antonietta; Tortora, Fabio; Zara, Federico; Minetti, Carlo

    2009-01-01

    Holmes’ tremor refers to an unusual combination of rest, postural and kinetic tremor of extremities. Common causes of Holmes’ tremor include stroke, trauma, vascular malformations and multiple sclerosis, with lesions involving the thalamus, brain stem or cerebellum. Although some drugs (eg, levodopa and dopaminergic drugs, clonazepam and propranolol) have been occasionally reported to give some benefit, medical treatment of Holmes’ tremor is unsatisfactory, and many patients require thalamic surgery to achieve satisfactory control. We report a patient in whom post-ischaemic Holmes’ tremor dramatically responded to levetiracetam treatment. PMID:21686707

  5. Solar abundance of osmium

    PubMed Central

    Jacoby, George; Aller, Lawrence H.

    1976-01-01

    The abundance parameter, log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance (by numbers of atoms with respect to hydrogen), has been derived for three lines of osmium by a method of spectrum synthesis. An apparent discordance of the derived abundance with that found from the carbonaceous chondrites is probably to be attributed primarily to errors in the f-values, and blending with unknown contributors. PMID:16592314

  6. Abundance of introduced species at home predicts abundance away in herbaceous communities

    USGS Publications Warehouse

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  7. Isotopic evidence for dramatic climatic changes in East Africa during the Pleistocene.

    PubMed

    Cerling, T E; Hay, R L; O'Neil, J R

    1977-05-12

    Rainfall decreased dramatically in the Lake Turkana region 1.8-2.0 Myr ago and in the Olduvai Gorge region 0.5-0.6 Myr ago. This is documented by a major increase in the delta18O values of pedogenic and groundwater carbonates at these times. The data suggest that meteoric water of the earlier, more humid climate was 2-4 per mil lower in 18O content than modern waters of these regions. PMID:16073417

  8. Microalloying Boron Carbide with Silicon to Achieve Dramatically Improved Ductility.

    PubMed

    An, Qi; Goddard, William A

    2014-12-01

    Boron carbide (B4C) is a hard material whose value for extended engineering applications such as body armor; is limited by its brittleness under impact. To improve the ductility while retaining hardness, we used density functional theory to examine modifying B4C ductility through microalloying. We found that replacing the CBC chain in B4C with Si-Si, denoted as (B11Cp)-Si2, dramatically improves the ductility, allowing a continuous shear to a large strain of 0.802 (about twice of B4C failure strain) without brittle failure. Moreover, (B11C)-Si2 retains low density and high hardness. This ductility improvement arises because the Si-Si linkages enable the icosahedra accommodate additional shear by rotating instead of breaking bonds.

  9. Increased Reactive Oxygen Species Production and Lower Abundance of Complex I Subunits and Carnitine Palmitoyltransferase 1B Protein Despite Normal Mitochondrial Respiration in Insulin-Resistant Human Skeletal Muscle

    PubMed Central

    Lefort, Natalie; Glancy, Brian; Bowen, Benjamin; Willis, Wayne T.; Bailowitz, Zachary; De Filippis, Elena A.; Brophy, Colleen; Meyer, Christian; Højlund, Kurt; Yi, Zhengping; Mandarino, Lawrence J.

    2010-01-01

    OBJECTIVE The contribution of mitochondrial dysfunction to skeletal muscle insulin resistance remains elusive. Comparative proteomics are being applied to generate new hypotheses in human biology and were applied here to isolated mitochondria to identify novel changes in mitochondrial protein abundance present in insulin-resistant muscle. RESEARCH DESIGN AND METHODS Mitochondria were isolated from vastus lateralis muscle from lean and insulin-sensitive individuals and from obese and insulin-resistant individuals who were otherwise healthy. Respiration and reactive oxygen species (ROS) production rates were measured in vitro. Relative abundances of proteins detected by mass spectrometry were determined using a normalized spectral abundance factor method. RESULTS NADH- and FADH2-linked maximal respiration rates were similar between lean and obese individuals. Rates of pyruvate and palmitoyl-dl-carnitine (both including malate) ROS production were significantly higher in obesity. Mitochondria from obese individuals maintained higher (more negative) extramitochondrial ATP free energy at low metabolic flux, suggesting that stronger mitochondrial thermodynamic driving forces may underlie the higher ROS production. Tandem mass spectrometry identified protein abundance differences per mitochondrial mass in insulin resistance, including lower abundance of complex I subunits and enzymes involved in the oxidation of branched-chain amino acids (BCAA) and fatty acids (e.g., carnitine palmitoyltransferase 1B). CONCLUSIONS We provide data suggesting normal oxidative capacity of mitochondria in insulin-resistant skeletal muscle in parallel with high rates of ROS production. Furthermore, we show specific abundance differences in proteins involved in fat and BCAA oxidation that might contribute to the accumulation of lipid and BCAA frequently associated with the pathogenesis of insulin resistance. PMID:20682693

  10. The Relationship between Dramatic Play and Self-Concept in Middle Class Kindergarten Children.

    ERIC Educational Resources Information Center

    Gootman, Marilyn Eisenstadt

    This study attempted to determine the relationships between the dramatic play of children aged three to seven and their self-concept; between dramatic play and two components of self-concept--self-esteem and identification with friends; between dramatic play ability and self-concept; and between dramatic play and the teacher's attitude toward…

  11. New therapies for hereditary angioedema: disease outlook changes dramatically.

    PubMed

    Frank, Michael M; Jiang, Haixiang

    2008-01-01

    Hereditary angioedema (HAE) is an autosomal dominant disease associated with episodic attacks of nonpitting edema that may affect any external or mucosal body surface. Attacks most often affect the extremities, causing local swelling, the GI tract, leading to severe abdominal pain, and the mouth and throat, at times causing asphyxiation. Most patients with HAE have low levels of the plasma serine protease inhibitor C1 inhibitor. The edema in these patients is caused by unregulated generation of bradykinin. Effective chronic therapy of patients with impeded androgens or plasmin inhibitors has been available for decades, but in the United States, we do not have therapy for acute attacks. Five companies have completed or are in the process of conducting phase 3 clinical trials, double-blind, placebo-controlled studies of products designed to terminate acute attacks or to be used in prophylaxis. Two companies, Lev Pharmaceuticals and CSL Behring, have preparations of C1 inhibitor purified from plasma that have been used in Europe for decades (trade names Cinryze and Berinert P, respectively). One company, Pharming, has developed a recombinant C1 inhibitor preparation. One company, Dyax, is testing a kallikrein inhibitor (ecallantide), and one company, Jerini, is completing testing of a bradykinin type 2 receptor antagonist (Icatibant). Although little has been published thus far, all of these products may prove effective. It is likely that HAE treatment will change dramatically within the next few years.

  12. New therapies for hereditary angioedema: disease outlook changes dramatically.

    PubMed

    Frank, Michael M; Jiang, Haixiang

    2008-01-01

    Hereditary angioedema (HAE) is an autosomal dominant disease associated with episodic attacks of nonpitting edema that may affect any external or mucosal body surface. Attacks most often affect the extremities, causing local swelling, the GI tract, leading to severe abdominal pain, and the mouth and throat, at times causing asphyxiation. Most patients with HAE have low levels of the plasma serine protease inhibitor C1 inhibitor. The edema in these patients is caused by unregulated generation of bradykinin. Effective chronic therapy of patients with impeded androgens or plasmin inhibitors has been available for decades, but in the United States, we do not have therapy for acute attacks. Five companies have completed or are in the process of conducting phase 3 clinical trials, double-blind, placebo-controlled studies of products designed to terminate acute attacks or to be used in prophylaxis. Two companies, Lev Pharmaceuticals and CSL Behring, have preparations of C1 inhibitor purified from plasma that have been used in Europe for decades (trade names Cinryze and Berinert P, respectively). One company, Pharming, has developed a recombinant C1 inhibitor preparation. One company, Dyax, is testing a kallikrein inhibitor (ecallantide), and one company, Jerini, is completing testing of a bradykinin type 2 receptor antagonist (Icatibant). Although little has been published thus far, all of these products may prove effective. It is likely that HAE treatment will change dramatically within the next few years. PMID:18206518

  13. Taming Self-Organization Dynamics to Dramatically Control Porous Architectures.

    PubMed

    Daly, Ronan; Sader, John E; Boland, John J

    2016-03-22

    We demonstrate templating of functional materials with unexpected and intricate micro- and nanostructures by controlling the condensation, packing, and evaporation of water droplets on a polymer solution. Spontaneous evaporation of a polymer solution induces cooling of the liquid surface and water microdroplet condensation from the ambient vapor. These droplets pack together and act as a template to imprint an entangled polymer film. This breath figure (BF) phenomenon is an example of self-organization that involves the long-range ordering of droplets. Equilibrium-based analysis provides many insights into contact angles and drop stability of individual drops, but the BF phenomenon remains poorly understood thus far, preventing translation to real applications. Here we investigate the dynamics of this phenomenon to separate out the competing influences and then introduce a modulation scheme to ultimately manipulate the water vapor-liquid equilibrium independently from the solvent evaporation. This approach to BF control provides insights into the mechanism, a rationale for microstructure design, and evidence for the benefits of dynamical control of self-organization systems. We finally present dramatically different porous architectures from this approach reminiscent of microscale Petri dishes, conical flasks, and test tubes. PMID:26828573

  14. Polyanhydride Nanoparticle Delivery Platform Dramatically Enhances Killing of Filarial Worms

    PubMed Central

    Binnebose, Andrea M.; Haughney, Shannon L.; Martin, Richard; Imerman, Paula M.; Narasimhan, Balaji; Bellaire, Bryan H.

    2015-01-01

    Filarial diseases represent a significant social and economic burden to over 120 million people worldwide and are caused by endoparasites that require the presence of symbiotic bacteria of the genus Wolbachia for fertility and viability of the host parasite. Targeting Wolbachia for elimination is a therapeutic approach that shows promise in the treatment of onchocerciasis and lymphatic filariasis. Here we demonstrate the use of a biodegradable polyanhydride nanoparticle-based platform for the co-delivery of the antibiotic doxycycline with the antiparasitic drug, ivermectin, to reduce microfilarial burden and rapidly kill adult worms. When doxycycline and ivermectin were co-delivered within polyanhydride nanoparticles, effective killing of adult female Brugia malayi filarial worms was achieved with approximately 4,000-fold reduction in the amount of drug used. Additionally the time to death of the macrofilaria was also significantly reduced (five-fold) when the anti-filarial drug cocktail was delivered within polyanhydride nanoparticles. We hypothesize that the mechanism behind this dramatically enhanced killing of the macrofilaria is the ability of the polyanhydride nanoparticles to behave as a Trojan horse and penetrate the cuticle, bypassing excretory pumps of B. malayi, and effectively deliver drug directly to both the worm and Wolbachia at high enough microenvironmental concentrations to cause death. These provocative findings may have significant consequences for the reduction in the amount of drug and the length of treatment required for filarial infections in terms of patient compliance and reduced cost of treatment. PMID:26496201

  15. OXYGEN ABUNDANCES IN CEPHEIDS

    SciTech Connect

    Luck, R. E.; Andrievsky, S. M.; Korotin, S. N.; Kovtyukh, V. V. E-mail: serkor@skyline.od.ua E-mail: scan@deneb1.odessa.ua

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  16. Interstellar Abundance Standards Revisited

    NASA Astrophysics Data System (ADS)

    Sofia, Ulysses J.; Meyer, David M.

    2001-06-01

    We evaluate the stellar abundances often used to represent the total (gas plus dust) composition of the interstellar medium. Published abundances for B stars, young later type (F and G) stars, and the Sun are compared to the modeled dust-phase and measured gas-phase compositions of the interstellar medium. This study uses abundances for the five most populous elements in dust grains-C, O, Mg, Si, and Fe-and the cosmically abundant element, N. We find that B stars have metal abundances that are too low to be considered valid representations of the interstellar medium. The commonly invoked interstellar standard that is two-thirds of the solar composition is also rejected by recent observations. Young (<=2 Gyr) F and G disk stars and the Sun, however, cannot be ruled out as reliable proxies for the total interstellar composition. If their abundances are valid representations of the interstellar medium, then the apparent underabundance of carbon with respect to that required by dust models, i.e., the carbon crisis, is substantially eased.

  17. Boron Abundances Across the “Li–Be Dip” in the Hyades Cluster

    NASA Astrophysics Data System (ADS)

    Boesgaard, Ann Merchant; Lum, Michael G.; Deliyannis, Constantine P.; King, Jeremy R.; Pinsonneault, Marc H.; Somers, Garrett

    2016-10-01

    Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the Hyades. Using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we investigate B abundances in the Hyades F stars to look for a potential B dip using the B i resonance line at 2496.8 Å. The light elements Li, Be, and B are destroyed inside stars at increasingly hotter temperatures: 2.5, 3.5, and 5 × 106 K, respectively. Consequently, these elements survive to increasingly greater depths in a star and their surface abundances indicate the depth and thoroughness of mixing in the star. We have (re)determined Li abundances/upper limits for 79 Hyades dwarfs, Be for 43 stars, and B for 5 stars. We find evidence for a small drop in the B abundance across the Li–Be dip. The B abundances for the four stars in the temperature range 6100–6730 K fit the B–Be correlation found previously by Boesgaard et al. Models of rotational mixing produce good agreement with the relative depletions of Be and B in the dip region. We have compared our nLTE B abundances for the three high B stars on either side of the Li–Be dip with those found by Duncan et al. for the two Hyades giants. This confirms the factor of 10 decline in the B abundance in the Hyades giants as predicted by dilution due to the deepening of the surface convection zone. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #HST-G0-12294.

  18. Impacts on coralligenous outcrop biodiversity of a dramatic coastal storm.

    PubMed

    Teixidó, Núria; Casas, Edgar; Cebrián, Emma; Linares, Cristina; Garrabou, Joaquim

    2013-01-01

    Extreme events are rare, stochastic perturbations that can cause abrupt and dramatic ecological change within a short period of time relative to the lifespan of organisms. Studies over time provide exceptional opportunities to detect the effects of extreme climatic events and to measure their impacts by quantifying rates of change at population and community levels. In this study, we show how an extreme storm event affected the dynamics of benthic coralligenous outcrops in the NW Mediterranean Sea using data acquired before (2006-2008) and after the impact (2009-2010) at four different sites. Storms of comparable severity have been documented to occur occasionally within periods of 50 years in the Mediterranean Sea. We assessed the effects derived from the storm comparing changes in benthic community composition at sites exposed to and sheltered from this extreme event. The sites analyzed showed different damage from severe to negligible. The most exposed and impacted site experienced a major shift immediately after the storm, represented by changes in the species richness and beta diversity of benthic species. This site also showed higher compositional variability immediately after the storm and over the following year. The loss of cover of benthic species resulted between 22% and 58%. The damage across these species (e.g. calcareous algae, sponges, anthozoans, bryozoans, tunicates) was uneven, and those with fragile forms were the most impacted, showing cover losses up to 50 to 100%. Interestingly, small patches survived after the storm and began to grow slightly during the following year. In contrast, sheltered sites showed no significant changes in all the studied parameters, indicating no variations due to the storm. This study provides new insights into the responses to large and rare extreme events of Mediterranean communities with low dynamics and long-lived species, which are among the most threatened by the effects of global change.

  19. Impacts on Coralligenous Outcrop Biodiversity of a Dramatic Coastal Storm

    PubMed Central

    Teixidó, Núria; Casas, Edgar; Cebrián, Emma; Linares, Cristina; Garrabou, Joaquim

    2013-01-01

    Extreme events are rare, stochastic perturbations that can cause abrupt and dramatic ecological change within a short period of time relative to the lifespan of organisms. Studies over time provide exceptional opportunities to detect the effects of extreme climatic events and to measure their impacts by quantifying rates of change at population and community levels. In this study, we show how an extreme storm event affected the dynamics of benthic coralligenous outcrops in the NW Mediterranean Sea using data acquired before (2006–2008) and after the impact (2009–2010) at four different sites. Storms of comparable severity have been documented to occur occasionally within periods of 50 years in the Mediterranean Sea. We assessed the effects derived from the storm comparing changes in benthic community composition at sites exposed to and sheltered from this extreme event. The sites analyzed showed different damage from severe to negligible. The most exposed and impacted site experienced a major shift immediately after the storm, represented by changes in the species richness and beta diversity of benthic species. This site also showed higher compositional variability immediately after the storm and over the following year. The loss of cover of benthic species resulted between 22% and 58%. The damage across these species (e.g. calcareous algae, sponges, anthozoans, bryozoans, tunicates) was uneven, and those with fragile forms were the most impacted, showing cover losses up to 50 to 100%. Interestingly, small patches survived after the storm and began to grow slightly during the following year. In contrast, sheltered sites showed no significant changes in all the studied parameters, indicating no variations due to the storm. This study provides new insights into the responses to large and rare extreme events of Mediterranean communities with low dynamics and long-lived species, which are among the most threatened by the effects of global change. PMID:23326496

  20. Abundance estimation and conservation biology

    USGS Publications Warehouse

    Nichols, J.D.; MacKenzie, D.I.

    2004-01-01

    Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001). The initial capture–recapture models developed for partially (Darroch, 1959) and completely (Jolly, 1965; Seber, 1965) open populations represented efforts to relax the restrictive assumption of population closure for the purpose of estimating abundance. Subsequent emphases in capture–recapture work were on survival rate estimation in the 1970’s and 1980’s (e.g., Burnham et al., 1987; Lebreton et al.,1992), and on movement estimation in the 1990’s (Brownie et al., 1993; Schwarz et al., 1993). However, from the mid–1990’s until the present time, capture–recapture investigators have expressed a renewed interest in abundance and related parameters (Pradel, 1996; Schwarz & Arnason, 1996; Schwarz, 2001). The focus of this session was abundance, and presentations covered topics ranging from estimation of abundance and rate of change in abundance, to inferences about the demographic processes underlying changes in abundance, to occupancy as a surrogate of abundance. The plenary paper by Link & Barker (2004) is provocative and very interesting, and it contains a number of important messages and suggestions. Link & Barker (2004) emphasize that the increasing complexity of capture–recapture models has resulted in large numbers of parameters and that a challenge to ecologists is to extract ecological signals from this complexity. They offer hierarchical models as a natural approach to inference in which traditional parameters are viewed as realizations of stochastic processes. These processes are governed by hyperparameters, and the inferential approach focuses on these hyperparameters. Link & Barker (2004) also suggest that our attention

  1. Decadal changes in zooplankton abundance and phenology of Long Island Sound reflect interacting changes in temperature and community composition.

    PubMed

    Rice, Edward; Stewart, Gillian

    2016-09-01

    Between 1939 and 1982, several surveys indicated that zooplankton in Long Island Sound, NY (LIS) appeared to follow an annual cycle typical of the Mid-Atlantic coast of North America. Abundance peaked in both early spring and late summer and the peaks were similar in magnitude. In recent decades, this cycle appeared to have shifted. Only one large peak tended to occur, and summer copepod abundance was consistently reduced by ∼60% from 1939 to 1982 levels. In other Mid-Atlantic coastal systems such a dramatic shift has been attributed to the earlier appearance of ctenophores, particularly Mnemiopsis leidyi, during warmer spring months. However, over a decade of surveys in LIS have consistently found near-zero values in M. leidyi biomass during spring months. Our multiple linear regression model indicates that summer M. leidyi biomass during this decade explains <25% of the variation in summer copepod abundance. During these recent, warmer years, summer copepod community shifts appear to explain the loss of copepod abundance. Although Acartia tonsa in 2010-2011 appeared to be present all year long, it was no longer the dominant summer zooplankton species. Warmer summers have been associated with an increase in cyanobacteria and flagellates, which are not consumed efficiently by A. tonsa. This suggests that in warming coastal systems multiple environmental and biological factors interact and likely underlie dramatic alterations to copepod phenology, not single causes. PMID:27552121

  2. Solar abundance of platinum

    PubMed Central

    Burger, Harry; Aller, Lawrence H.

    1975-01-01

    Three lines of neutral platinum, located at λ 2997.98 Å, λ 3064.71 Å, and λ 3301.86 Å have been used to determine the solar platinum abundance by the method of spectral synthesis. On the scale, log A(H) = 12.00, the thus-derived solar platinum abundance is 1.75 ± 0.10, in fair accord with Cameron's value of log A(Pt) = 1.69 derived by Mason from carbonaceous chondrites and calculated on the assumption that log A(Si) = 7.55 in the sun. PMID:16592278

  3. Abundances of light elements.

    PubMed Central

    Pagel, B E

    1993-01-01

    Recent developments in the study of abundances of light elements and their relevance to cosmological nucleosynthesis are briefly reviewed. The simplest model, based on standard cosmology and particle physics and assuming homogeneous baryon density at the relevant times, continues to stand up well. PMID:11607388

  4. Impacts of large herbivorous mammals on bird diversity and abundance in an African savanna.

    PubMed

    Ogada, D L; Gadd, M E; Ostfeld, R S; Young, T P; Keesing, F

    2008-05-01

    Large native mammals are declining dramatically in abundance across Africa, with strong impacts on both plant and animal community dynamics. However, the net effects of this large-scale loss in megafauna are poorly understood because responses by several ecologically important groups have not been assessed. We used a large-scale, replicated exclusion experiment in Kenya to investigate the impacts of different guilds of native and domestic large herbivores on the diversity and abundance of birds over a 2-year period. The exclusion of large herbivorous native mammals, including zebras (Equus burchelli), giraffes (Giraffa camelopardalis), elephants (Loxodonta africana), and buffalos (Syncerus caffer), increased the diversity of birds by 30%. Most of this effect was attributable to the absence of elephants and giraffes; these megaherbivores reduced both the canopy area of subdominant woody vegetation and the biomass of ground-dwelling arthropods, and both of these factors were good predictors of the diversity of birds. The canopy area of subdominant trees was positively correlated with the diversity of granivorous birds. The biomass of ground-dwelling arthropods was positively correlated with the diversity of insectivorous birds. Our results suggest that most native large herbivores are compatible with an abundant and diverse bird fauna, as are cattle if they are at a relatively low stocking rate. Future research should focus on determining the spatial arrangements and densities of megaherbivores that will optimize both megaherbivore abundance and bird diversity.

  5. Solar abundance of iridium

    PubMed Central

    Drake, Stephen; Aller, Lawrence H.

    1976-01-01

    By a method of spectrum synthesis, which yields log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance, an attempt is made to deduce the solar iridium abundance from one relatively unblended, but fairly weak IrI line, λ 3220.78 Å. If the Corliss-Bozman f-value for this line is adopted, we find log A(Ir) = 0.82 on the scale log A(H) = 12.00. The discordance with the value found from carbonaceous chondrites may arise from faulty f-values or from difficulties arising from line blending in this far ultraviolet domain of the solar spectrum. PMID:16578735

  6. World-Wide Effort Produces Dramatic "Movie" of Cosmic Jet

    NASA Astrophysics Data System (ADS)

    2001-05-01

    Astronomers using a world-wide collection of radio telescopes, including the National Science Foundation's Very Long Baseline Array (VLBA) of the National Radio Astronomy Observatory (NRAO), have made a dramatic "movie" of a voracious, superdense neutron star repeatedly spitting out subatomic particles at nearly the speed of light into two narrow jets as it pulls material from a companion star. The movie shows these jets ejecting clouds of hot plasma that are then "zapped" by pulses of energy in the jets as they move away from the neutron star. Frame from Radio-Telescope 'Movie' of Scorpius X-1 "We have directly measured the speed of energy flow in a cosmic jet for the first time," said Ed Fomalont, an astronomer at the NRAO in Charlottesville, Virginia. Fomalont worked with Barry Geldzahler and Charles Bradshaw of George Mason University in Fairfax, Virginia. The astronomers used the VLBA, the NSF's Very Large Array (VLA) and the Green Bank 140-foot telescope, along with radio telescopes from the European VLBI Network, Australia, Japan and South Africa to record the double-star system's eruptions continuously for 56 hours. "This study is going to be extremely valuable in helping us understand a phenomenon that we see throughout the universe," Fomalont said. Cosmic jets of superfast particles are ejected from the cores of numerous galaxies. On a smaller scale, similar jets are ejected from binary-star systems closer to home, in our own Milky Way Galaxy. While the jets from galaxy cores are thought to be powered by supermassive black holes millions of times more massive than the Sun, the closer "microquasars" are powered by much smaller black holes or by neutron stars only a few times more massive than the sun. "Studying one of the closer, smaller examples will help us understand how they all work, including the bigger ones," Geldzahler said. "The jets coming from distant galaxies are harder to study because of their much greater distance and the slowness of their

  7. DRAMATIC CHANGE IN JUPITER'S GREAT RED SPOT FROM SPACECRAFT OBSERVATIONS

    SciTech Connect

    Simon, Amy A.; Wong, Michael H.; De Pater, Imke; Rogers, John H.; Orton, Glenn S.; Carlson, Robert W.; Asay-Davis, Xylar; Marcus, Philip S.

    2014-12-20

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here we show that this change has been accompanied by an increase in cloud/haze reflectance as sensed in methane gas absorption bands, increased absorption at wavelengths shorter than 500 nm, and increased spectral slope between 500 and 630 nm. These changes occurred between 2012 and 2014, without a significant change in internal tangential wind speeds; the decreased size results in a 3.2 day horizontal cloud circulation period, shorter than previously observed. As the GRS has narrowed in latitude, it interacts less with the jets flanking its north and south edges, perhaps allowing for less cloud mixing and longer UV irradiation of cloud and aerosol particles. Given its long life and observational record, we expect that future modeling of the GRS's changes, in concert with laboratory flow experiments, will drive our understanding of vortex evolution and stability in a confined flow field crucial for comparison with other planetary atmospheres.

  8. Dramatic Change in Jupiter's Great Red Spot from Spacecraft Observations

    NASA Technical Reports Server (NTRS)

    Simon, Amy A.; Wong, Michael H.; Rogers, John H.; Orton, Glenn S.; de Pater, Imke; Asay-Davis, Xylar; Carlson, Robert W.; Marcus, Philip S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here we show that this change has been accompanied by an increase in cloud/haze reflectance as sensed in methane gas absorption bands, increased absorption at wavelengths shorter than 500 nanometers, and increased spectral slope between 500 and 630 nanometers. These changes occurred between 2012 and 2014, without a significant change in internal tangential wind speeds; the decreased size results in a 3.2 day horizontal cloud circulation period, shorter than previously observed. As the GRS has narrowed in latitude, it interacts less with the jets flanking its north and south edges, perhaps allowing for less cloud mixing and longer UV irradiation of cloud and aerosol particles. Given its long life and observational record, we expect that future modeling of the GRS's changes, in concert with laboratory flow experiments, will drive our understanding of vortex evolution and stability in a confined flow field crucial for comparison with other planetary atmospheres.

  9. Abundance of field galaxies

    NASA Astrophysics Data System (ADS)

    Klypin, Anatoly; Karachentsev, Igor; Makarov, Dmitry; Nasonova, Olga

    2015-12-01

    We present new measurements of the abundance of galaxies with a given circular velocity in the Local Volume: a region centred on the Milky Way Galaxy and extending to distance ˜10 Mpc. The sample of ˜750 mostly dwarf galaxies provides a unique opportunity to study the abundance and properties of galaxies down to absolute magnitudes MB ≈ -10 and virial masses M_vir= 109{ M_{⊙}}. We find that the standard Λ cold dark matter (ΛCDM) model gives remarkably accurate estimates for the velocity function of galaxies with circular velocities V ≳ 70 kms-1 and corresponding virial masses M_vir≳ 5× 10^{10}{ M_{⊙}}, but it badly fails by overpredicting ˜5 times the abundance of large dwarfs with velocities V = 30-40 kms-1. The warm dark matter (WDM) models cannot explain the data either, regardless of mass of WDM particle. Just as in previous observational studies, we find a shallow asymptotic slope dN/dlog V ∝ Vα, α ≈ -1 of the velocity function, which is inconsistent with the standard ΛCDM model that predicts the slope α = -3. Though reminiscent to the known overabundance of satellite problem, the overabundance of field galaxies is a much more difficult problem. For the standard ΛCDM model to survive, in the 10 Mpc radius of the Milky Way there should be 1000 not yet detected galaxies with virial mass M_vir≈ 10^{10}{ M_{⊙}}, extremely low surface brightness and no detectable H I gas. So far none of this type of galaxies have been discovered.

  10. Late embryogenesis abundant proteins

    PubMed Central

    Olvera-Carrillo, Yadira; Reyes, José Luis

    2011-01-01

    Late Embryogenesis Abundant (LEA) proteins accumulate at the onset of seed desiccation and in response to water deficit in vegetative plant tissues. The typical LEA proteins are highly hydrophilic and intrinsically unstructured. They have been classified in different families, each one showing distinctive conserved motifs. In this manuscript we present and discuss some of the recent findings regarding their role in plant adaptation to water deficit, as well as those concerning to their possible function, and how it can be related to their intrinsic structural flexibility. PMID:21447997

  11. Dramatic pressure-driven enhancement of bulk skyrmion stability.

    PubMed

    Levatić, I; Popčević, P; Šurija, V; Kruchkov, A; Berger, H; Magrez, A; White, J S; Rønnow, H M; Živković, I

    2016-01-01

    The recent discovery of magnetic skyrmion lattices initiated a surge of interest in the scientific community. Several novel phenomena have been shown to emerge from the interaction of conducting electrons with the skyrmion lattice, such as a topological Hall-effect and a spin-transfer torque at ultra-low current densities. In the insulating compound Cu2OSeO3, magneto-electric coupling enables control of the skyrmion lattice via electric fields, promising a dissipation-less route towards novel spintronic devices. One of the outstanding fundamental issues is related to the thermodynamic stability of the skyrmion lattice. To date, the skyrmion lattice in bulk materials has been found only in a narrow temperature region just below the order-disorder transition. If this narrow stability is unavoidable, it would severely limit applications. Here we present the discovery that applying just moderate pressure on Cu2OSeO3 substantially increases the absolute size of the skyrmion pocket. This insight demonstrates directly that tuning the electronic structure can lead to a significant enhancement of the skyrmion lattice stability. We interpret the discovery by extending the previously employed Ginzburg-Landau approach and conclude that change in the anisotropy is the main driver for control of the size of the skyrmion pocket. PMID:26892190

  12. Dramatic pressure-driven enhancement of bulk skyrmion stability

    PubMed Central

    Levatić, I.; Popčević, P.; Šurija, V.; Kruchkov, A.; Berger, H.; Magrez, A.; White, J. S.; Rønnow, H. M.; Živković, I.

    2016-01-01

    The recent discovery of magnetic skyrmion lattices initiated a surge of interest in the scientific community. Several novel phenomena have been shown to emerge from the interaction of conducting electrons with the skyrmion lattice, such as a topological Hall-effect and a spin-transfer torque at ultra-low current densities. In the insulating compound Cu2OSeO3, magneto-electric coupling enables control of the skyrmion lattice via electric fields, promising a dissipation-less route towards novel spintronic devices. One of the outstanding fundamental issues is related to the thermodynamic stability of the skyrmion lattice. To date, the skyrmion lattice in bulk materials has been found only in a narrow temperature region just below the order-disorder transition. If this narrow stability is unavoidable, it would severely limit applications. Here we present the discovery that applying just moderate pressure on Cu2OSeO3 substantially increases the absolute size of the skyrmion pocket. This insight demonstrates directly that tuning the electronic structure can lead to a significant enhancement of the skyrmion lattice stability. We interpret the discovery by extending the previously employed Ginzburg-Landau approach and conclude that change in the anisotropy is the main driver for control of the size of the skyrmion pocket. PMID:26892190

  13. Dramatic alteration of Tg of polystyrene confined in cylindrical nanopores

    NASA Astrophysics Data System (ADS)

    Xue, Gi; Teng, Chao; Xu, Jie; Li, Linling

    2014-03-01

    Vitrification of polystyrene melt infiltrated in AAO template was greatly altered by geometrical confinement. DSC detected two distinguish Tgs for PS slowly cooled from the melt in nanopores. One was at a lower temperature than the bulk Tg and the other was at a higher temperature. The deviation between the two Tgs could reach as big as 60 °C and increased with decreasing pore size. Surprisingly, Tg for the PS nanorodes recovered back to the bulk value when the template was removed, indicating the importance of the interfacial interaction. The major factor which induced such a strong confinement is the cooling rate. The coefficient of thermal expansion (CTE) of AAO template is about one order lower than that for PS. The mismatch of CTEs causes a strain induced stress during cooling: the PS chains tend to shrink and to de-wet from the walls; meanwhile the interfacial interaction tends to hold the chains back. The chains are subjected to a high residual stress by a fast cooling and would peel off from the wall. When the cooling rate is sufficiently slow, and the stress was relaxed during cooling. Then the chains were still stick on the wall, resulting in a strong interfacial constraints for chains.

  14. Product Binding Varies Dramatically between Processive and Nonprocessive Cellulase Enzymes

    SciTech Connect

    Bu, L.; Nimlos, M. R.; Shirts, M. R.; Stahlberg, J.; Himmel, M. E.; Crowley, M. F.; Beckham, G. T.

    2012-07-13

    Cellulases hydrolyze {beta}-1,4 glycosidic linkages in cellulose, which are among the most prevalent and stable bonds in Nature. Cellulases comprise many glycoside hydrolase families and exist as processive or nonprocessive enzymes. Product inhibition negatively impacts cellulase action, but experimental measurements of product-binding constants vary significantly, and there is little consensus on the importance of this phenomenon. To provide molecular level insights into cellulase product inhibition, we examine the impact of product binding on processive and nonprocessive cellulases by calculating the binding free energy of cellobiose to the product sites of catalytic domains of processive and nonprocessive enzymes from glycoside hydrolase families 6 and 7. The results suggest that cellobiose binds to processive cellulases much more strongly than nonprocessive cellulases. We also predict that the presence of a cellodextrin bound in the reactant site of the catalytic domain, which is present during enzymatic catalysis, has no effect on product binding in nonprocessive cellulases, whereas it significantly increases product binding to processive cellulases. This difference in product binding correlates with hydrogen bonding between the substrate-side ligand and the cellobiose product in processive cellulase tunnels and the additional stabilization from the longer tunnel-forming loops. The hydrogen bonds between the substrate- and product-side ligands are disrupted by water in nonprocessive cellulase clefts, and the lack of long tunnel-forming loops results in lower affinity of the product ligand. These findings provide new insights into the large discrepancies reported for binding constants for cellulases and suggest that product inhibition will vary significantly based on the amount of productive binding for processive cellulases on cellulose.

  15. Product Binding Varies Dramatically between Processive and Nonprocessive Cellulase Enzymes*

    PubMed Central

    Bu, Lintao; Nimlos, Mark R.; Shirts, Michael R.; Ståhlberg, Jerry; Himmel, Michael E.; Crowley, Michael F.; Beckham, Gregg T.

    2012-01-01

    Cellulases hydrolyze β-1,4 glycosidic linkages in cellulose, which are among the most prevalent and stable bonds in Nature. Cellulases comprise many glycoside hydrolase families and exist as processive or nonprocessive enzymes. Product inhibition negatively impacts cellulase action, but experimental measurements of product-binding constants vary significantly, and there is little consensus on the importance of this phenomenon. To provide molecular level insights into cellulase product inhibition, we examine the impact of product binding on processive and nonprocessive cellulases by calculating the binding free energy of cellobiose to the product sites of catalytic domains of processive and nonprocessive enzymes from glycoside hydrolase families 6 and 7. The results suggest that cellobiose binds to processive cellulases much more strongly than nonprocessive cellulases. We also predict that the presence of a cellodextrin bound in the reactant site of the catalytic domain, which is present during enzymatic catalysis, has no effect on product binding in nonprocessive cellulases, whereas it significantly increases product binding to processive cellulases. This difference in product binding correlates with hydrogen bonding between the substrate-side ligand and the cellobiose product in processive cellulase tunnels and the additional stabilization from the longer tunnel-forming loops. The hydrogen bonds between the substrate- and product-side ligands are disrupted by water in nonprocessive cellulase clefts, and the lack of long tunnel-forming loops results in lower affinity of the product ligand. These findings provide new insights into the large discrepancies reported for binding constants for cellulases and suggest that product inhibition will vary significantly based on the amount of productive binding for processive cellulases on cellulose. PMID:22648408

  16. Chemical abundance of comets

    NASA Technical Reports Server (NTRS)

    Wyckoff, Susan; Wehinger, Peter

    1988-01-01

    Observations of NH2, (OI) and molecular ion spectra in comets represent virtually all of the volatile fraction of a comet nucleus. Their study leads to the N2, NH3, H2O, CO2, CO content of the nucleus, and thus to important constraints on models of comet formation and chemical processing in the primitive solar nebula. The observations of Comet Halley provide the opportunity for the first comprehensive determination of the abundances in a comet nucleus. The carbon isotope abundance ratio 12 C/13 C = 65 plus or minus 8 has been determined for Comet Halley from resolved rotational line structure in the CN B-X (0,0) band. The ratio is approximately 30 pct lower than the solar system value, 89, indicating either an enhancement of 13CN or a depletion of 12CN in the comet. Scenarios consistent with the observed carbon isotope ratio are: (1) formation of the comet at the periphery of the solar nebula in a fractionation-enriched 13CN region, or hidden from 12CN enrichment sources, and (2) capture of an interestellar comet. Long-slit charge coupled device (CCD) spectra obtained at the time of the spacecraft encounter of Comet Halley have also been analyzed. Scale lengths, production rates and column densities of CH, CN, C2 and NH2 were determined.

  17. Flare Plasma Iron Abundance

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.

    2008-01-01

    The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

  18. Distribution and abundance of zooplankton populations in Crater Lake, Oregon

    USGS Publications Warehouse

    Larson, G.L.; McIntire, C.D.; Buktenica, M.W.; Girdner, S.F.; Truitt, R.E.

    2007-01-01

    The zooplankton assemblages in Crater Lake exhibited consistency in species richness and general taxonomic composition, but varied in density and biomass during the period between 1988 and 2000. Collectively, the assemblages included 2 cladoceran taxa and 10 rotifer taxa (excluding rare taxa). Vertical habitat partitioning of the water column to a depth of 200 m was observed for most species with similar food habits and/or feeding mechanisms. No congeneric replacement was observed. The dominant species in the assemblages were variable, switching primarily between periods of dominance of Polyarthra-Keratella cochlearis and Daphnia. The unexpected occurrence and dominance of Asplanchna in 1991 and 1992 resulted in a major change in this typical temporal shift between Polyarthra-K. cochlearis and Daphnia. Following a collapse of the zooplankton biomass in 1993 that was probably caused by predation from Asplanchna, Kellicottia dominated the zooplankton assemblage biomass between 1994 and 1997. The decline in biomass of Kellicottia by 1998 coincided with a dramatic increase in Daphnia biomass. When Daphnia biomass declined by 2000, Keratella biomass increased again. Thus, by 1998 the assemblage returned to the typical shift between Keratella-Polyarthra and Daphnia. Although these observations provided considerable insight about the interannual variability of the zooplankton assemblages in Crater Lake, little was discovered about mechanisms behind the variability. When abundant, kokanee salmon may have played an important role in the disappearance of Daphnia in 1990 and 2000 either through predation, inducing diapause, or both. ?? 2007 Springer Science+Business Media B.V.

  19. Abundances in Sagittarius Stars

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Zaggia, S.; Sbordone, L.; Santin, P.; Monaco, L.; Monai, S.; Molaro, P.; Marconi, G.; Girardi, L.; Ferraro, F.; di Marcantonio, P.; Caffau, E.; Bellazzini, M.

    The Sagittarius dwarf spheroidal is a very complex galaxy, which has undergone prolonged star formation. From the very first high resolution chemical analysis of Sgr stars, conducted using spectra obtained during the commissioning of UVES at VLT, it was clear that the star had undergone a high level of chemical processing, at variance with most of the other Local Group dwarf spheroidals. Thanks to FLAMES at VLT we now have accurate metallicities and abundances of alpha-chain elements for about 150 stars, which provide the first reliable metallicity distribution for this galaxy. Besides the already known high metallicity tail the existence of a metal-poor population has also been highlighted, although an assessment of the fraction of Sgr stars which belong to this population requires a larger sample. From our data it is also obvious that Sagittarius is a nucleated galaxy and that the centre of the nucleus coincides with M54, as already shown by Monaco et al.

  20. Report on carbon and nitrogen abundance studies

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1991-01-01

    The aim of the proposal was to determine the nitrogen to carbon abundance ratios from transition layer lines in stars with different T(sub eff) and luminosities. The equations which give the surface emission line fluxes and the measured ratio of the NV to CIV emission line fluxes are presented and explained. The abundance results are compared with those of photospheric abundance studies for stars in common with the photospheric investigations. The results show that the analyses are at least as accurate as the photospheric determinations. These studies can be extended to F and early G stars for which photospheric abundance determinations for giants are hard to do because molecular bands become too weak. The abundance determination in the context of stellar evolution is addressed. The N/C abundance ratio increases steeply at the point of evolution for which the convection zone reaches deepest. Looking at the evolution of the rotation velocities v sin i, a steep decrease in v sin i is related to the increasing depth of the convection zone. It is concluded that the decrease in v sin i for T(sub eff) less than or approximately = 5800 K is most probably due to the rearrangement of the angular momentum in the stars due to deep convective mixing. It appears that the convection zone is rotating with nearly depth independent angular momentum. Other research results and ongoing projects are discussed.

  1. Zinc Abundances in Galactic Bulge Stars

    NASA Astrophysics Data System (ADS)

    Silveira, C. R.; Barbuy, B.

    2014-10-01

    Zinc is overabundant in metal-poor stars (Cayrel et al. 2004), being partially produced by neutron addition. It decreases with increasing metallicity, similarly to alpha-elements. In order to trace its abundance, the derivation of Zn abundance in different stellar populations, and varying metallicities, helps understanding its nucleosynthesis processes. Zn is also the main element of reference to derive the metallicity from absorption lines in quasars (QSOs), which allows to compare their evolution as a function of redshift and metallicity in metal-poor stars. In the present work, we derive Zn abundances for a sample of 56 bulge field stars, observed at high resolution with the FLAMES-UVES spectrograph. The mean wavelength coverage is 4800-6800 Å, at a resolution R ˜ 45000. The atmospheric parameters effective temperature, gravity and metallicity were derived in Zoccali et al. (2008) and Hill et al. (2011). Recently we have analysed the manganese abundances of this sample (Barbuy et al. 2013). To compute the Zn abundances we use spectrum synthesis, for the lines ZnI 4810.53 and 6362.34 Å. The analysis of our data shows that the abundance of [Zn/Fe] decreases with increasing metallicity, in agreement with the data obtained from the literature. The details of Zn behaviour for the metal-rich bulge stars of the present work are under analysis.

  2. Dramatic Photosynthesis.

    ERIC Educational Resources Information Center

    Carlsson, Britta

    2003-01-01

    Presents a creative way to teach photosynthesis. Revolves around the growth of a lily planted and stored in the classroom. Combines the concepts of particle theory, transformation, and changes of phase and mass in a holistic approach. The six-step teaching sequence is founded on the notions of challenge, variation, and drama. (Author/NB)

  3. Effect of dramatic land use change on gaseous pollutant emissions from biomass burning in Northeastern China

    NASA Astrophysics Data System (ADS)

    Zhao, Hongmei; Tong, Daniel Q.; Gao, Chuanyu; Wang, Guoping

    2015-02-01

    Biomass burning contributes a substantial amount of gas and particle emissions to the atmosphere. As China's breadbasket, northeast China has experienced dramatic land use change in the past century, converting approximately 55 × 104 ha of wetland into farmland to feed a rapidly growing population. This study combines measured emission factors of dominant crops (rice and soybean) and wetland plants (Calamagrostis angu-stifolia, Carex lasiocarpa, Carex pseudo-curaica) and remote sensing land use data to estimate the effect of the unprecedented land use change on gaseous pollutants emissions from biomass burning. Our biomass burning emission estimates resulting from land use changes have increased because of increased post-harvest crop residue burning and decreased burning of wetland plants. From 1986 to 2005, the total emissions of CO2, CO, CXHY, SO2 and NO have increased by 18.6%, 35.7%, 26.8%, 66.2% and 33.2%, respectively. We have found two trends in agricultural burning: increased dryland crop residue burning and decreased wetland (rice paddy) burning. Our results revealed that the large scale land use change in northeastern China has induced more active biomass-burning emissions. The regional emission inventory of gaseous pollutants derived from this work may be used to support further examination of the subsequent effects on regional climate and air quality simulations with numerical atmospheric models.

  4. Actinide abundances in ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hagee, B.; Bernatowicz, T. J.; Podosek, F. A.; Johnson, M. L.; Burnett, D. S.

    1990-01-01

    Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also used to compare directly the Pu/U ratio with the earlier obtained ratio determined indirectly, as (Pu/Nd)x(Nd/U), assuming that Pu behaves chemically as a LREE. The data, combined with high-accuracy isotope-dilution data from the literature, show that the degree of gram-scale variability of the Th, U, and LREE abundances for equilibrated ordinary chondrites is a factor of 2-3 for absolute abundances and up to 50 percent for relative abundances. The observed variations are interpreted as reflecting the differences in the compositions and/or proportions of solar nebula components accreted to ordinary chondrite parent bodies.

  5. "I Did Not Wash My Feet with that Woman": Using Dramatic Performance to Teach Biblical Studies

    ERIC Educational Resources Information Center

    Torbett, David

    2010-01-01

    The student dramatic performance is an effective way for undergraduates to learn biblical studies. In this article I will give an example of a dramatic performance assignment that I developed over a number of courses and used most recently and most successfully in an undergraduate course in the Hebrew Bible at a small liberal arts college in the…

  6. The Impact of Dramatic Play Centre on Promoting the Development of Children's Early Writing Skills

    ERIC Educational Resources Information Center

    Ihmeideh, Fathi

    2015-01-01

    The purpose of this study is to examine the impact of dramatic play centre (DPC) on promoting the development of children's early writing skills in the Jordanian context. It also intends to investigate the forms of children's writing skills that emerge through the use of dramatic play. Observations and interviews were conducted to obtain…

  7. Guiding the Noticing: Using a Dramatic Performance Experience to Promote Tellability in Narrative Writing

    ERIC Educational Resources Information Center

    Clark, Shanetia

    2012-01-01

    In this article, the author describes her use of dramatic performance to promote tellability in narrative writing within a seventh and eighth grade English and language arts classroom. By experiencing dramatic performance, the students were able to actively and physically perform the writing process: brainstorming, drafting, revising, and editing.…

  8. Use of Dramatization to Teach Cardiac Cycle Physiology to Medical Students

    ERIC Educational Resources Information Center

    Dowlati, Ehsan; Musick, David W.; Zhang, Lin; Thornton, Katherine; Carvalho, Helena

    2016-01-01

    Part of the educator's mission is to develop new methodologies that promote active learning. This study examines the use of dramatization of the cardiac cycle in medical school. Two groups (n = 42, 21 each) of first-year medical students participated. Group A was initially taught through dramatization alone, while Group B was taught through…

  9. Dramatic variations in emergent wetland area in China's largest freshwater lake, Poyang Lake

    NASA Astrophysics Data System (ADS)

    Mei, Xuefei; Dai, Zhijun; Fagherazzi, Sergio; Chen, Jiyu

    2016-10-01

    Freshwater wetlands are important ecosystems experiencing rapid degradation around the world. As much as 64% of world's wetland area has been lost since 1900; the situation is even more serious in Asia, where land reclamation and anthropogenic modifications of rivers are increasing the rate of wetland disappearance. In this study, we provide a first complete estimation of daily Emergent Wetland Area (EWA) in Poyang Lake, China's largest freshwater lake, from 1955 to 2012. A wavelet analysis indicates a strong periodicity in the monthly EWA time series with two oscillations having a period of 12 and 60-72 months, respectively. A dramatic increase in mean annual EWA is detected since 2003, when the Three Gorges Dam (TGD) was completed, mainly due to the seasonal drying of 1078 km2 of wetlands in October. It is found that the timing of wetland emergence during the dry season has been anticipated of one month, from November to October, since the establishment of TGD. It is argued that a significant increase in wetland exposure and an observable shift in the seasonal timing of flooding and drying will seriously degrade the wetland system and threaten the endangered migratory birds that inhabit it unless effective countermeasures are implemented.

  10. Linking potential denitrification rates to microbial gene abundances in multiple boreal ecosystems

    NASA Astrophysics Data System (ADS)

    Petersen, D. G.; Blazewicz, S.; Herman, D. J.; Firestone, M. K.; Waldrop, M. P.

    2010-12-01

    The composition and functioning of boreal ecosystems are vulnerable to changes in climate, leading to changes in season length, fire regimes, and soil moisture status. To investigate the influence of vegetation and soil moisture on microbial nitrogen cycling several disparate boreal ecosystems was studied. The two primary objectives were to: (1) determine whether process rates could be predicted solely from soil physical and chemical characteristics and (2) determine if the abundance of functional genes could be an additional explanatory variable. Surface soils were sampled along an elevation-driven hydrologic gradient at the Bonanza Creek LTER that corresponds with five plant communities typical of interior Alaska. The plant communities included a black spruce stand, a deciduous stand, a tussock grassland, an emergent fen, and a rich fen. We examined the chemical composition of the surface organic moss and soil, measured gross N-mineralization, potential rates of nitrification and denitrification (DEA), and abundances of several functional groups of microorganisms from soil cores collected in mid summer. We used quantitative PCR to assess the gene abundances of ammonia oxidizers and denitrifiers based on a functional gene approach. Here, we focus on potential denitrification rates (PDR), and abundance of denitrifyers carrying NirS and NirK genes (nitrate reductase) and NosZ genes (nitrous oxide reductase). PDR increased dramatically with increasing soil moisture along the gradient, from 1 mg N/m2/h at the dry black spruce site to 300 mg N/m2/h in the rich fen, which is very high compared to other poorly drained soil environments. PDR were linearly related to the abundance of functional genes from the microorganisms responsible for this process. Abundances of NirS, NirK and NosZ genes correlated significantly to PDR (r2 = 0.61 p < 0.0001, r2 = 0.45 p < 0.0003, r2 = 0.81 p < 0.0001, respectively). In addition, PDR were better explained by functional gene abundances

  11. Urbanization dramatically altered the water balances of a paddy field dominated basin in Southern China

    NASA Astrophysics Data System (ADS)

    Hao, L.; Sun, G.; Liu, Y.; Wan, J.; Qin, M.; Qian, H.; Liu, C.; John, R.; Fan, P.; Chen, J.

    2015-02-01

    Rice paddy fields provide important ecosystem services (e.g., food production, water retention, carbon sequestration) to a large population globally. However, these benefits are declining as a result of rapid environmental and socioeconomic transformations characterized by population growth, urbanization, and climate change in many Asian countries. This case study examined the responses of streamflow and watershed water balances to the decline of rice paddy fields due to urbanization in the Qinhuai River Basin in southern China where massive industrialization has occurred in the region during the past three decades. We found that streamflow increased by 58% and evapotranspiration (ET) decreased by 23% during 1986-2013 as a result of an increase in urban areas of three folds and reduction of rice paddy field by 27%. Both highflows and lowflows increased significantly by about 28% from 2002 to 2013. The increases in streamflow were consistent with the decreases in ET and leaf area index monitored by independent remote sensing MODIS data. The reduction in ET and increase in streamflow was attributed to the large cropland conversion that overwhelmed the effects of regional climate warming and climate variability. Converting traditional rice paddy fields to urban use dramatically altered land surface conditions from a water-dominated to a human-dominated landscape, and thus was considered as one of the extreme types of contemporary hydrologic disturbances. The ongoing large-scale urbanization in the rice paddy-dominated regions in the humid southern China, and East Asia, will likely elevate stormflow volume, aggravate flood risks, and intensify urban heat island effects. Understanding the linkage between land use change and changes in hydrological processes is essential for better management of urbanizing watersheds.

  12. Who gets custody now? Dramatic changes in children's living arrangements after divorce.

    PubMed

    Cancian, Maria; Meyer, Daniel R; Brown, Patricia R; Cook, Steven T

    2014-08-01

    This article reexamines the living arrangements of children following their parents' divorce, using Wisconsin Court Records, updating an analysis that showed relatively small but significant increases in shared custody in the late 1980s and early 1990s. These changes have accelerated markedly in the intervening years: between 1988 and 2008, the proportion of mothers granted sole physical custody fell substantially, the proportion of parents sharing custody increased dramatically, and father-sole custody remained relatively stable. We explore changes in the correlates of alternative custody outcomes, showing that some results from the earlier analysis still hold (for example, cases with higher total family income are more likely to have shared custody), but other differences have lessened (shared-custody cases have become less distinctive as they have become more common). Despite the considerable changes in marriage and divorce patterns over this period, we do not find strong evidence that the changes in custody are related to changes in the characteristics of families experiencing a divorce; rather, changes in custody may be the result of changes in social norms and the process by which custody is determined.

  13. Altering Antimalarial Drug Regimens May Dramatically Enhance and Restore Drug Effectiveness.

    PubMed

    Kay, Katherine; Hodel, Eva Maria; Hastings, Ian M

    2015-10-01

    There is considerable concern that malaria parasites are starting to evolve resistance to the current generation of antimalarial drugs, the artemisinin-based combination therapies (ACTs). We use pharmacological modeling to investigate changes in ACT effectiveness likely to occur if current regimens are extended from 3 to 5 days or, alternatively, given twice daily over 3 days. We show that the pharmacology of artemisinins allows both regimen changes to substantially increase the artemisinin killing rate. Malaria patients rarely contain more than 10(12) parasites, while the standard dosing regimens allow approximately 1 in 10(10) parasites to survive artemisinin treatment. Parasite survival falls dramatically, to around 1 in 10(17) parasites if the dose is extended or split; theoretically, this increase in drug killing appears to be more than sufficient to restore failing ACT efficacy. One of the most widely used dosing regimens, artemether-lumefantrine, already successfully employs a twice-daily dosing regimen, and we argue that twice-daily dosing should be incorporated into all ACT regimen design considerations as a simple and effective way of ensuring the continued long-term effectiveness of ACTs. PMID:26239993

  14. Altering Antimalarial Drug Regimens May Dramatically Enhance and Restore Drug Effectiveness

    PubMed Central

    Hastings, Ian M.

    2015-01-01

    There is considerable concern that malaria parasites are starting to evolve resistance to the current generation of antimalarial drugs, the artemisinin-based combination therapies (ACTs). We use pharmacological modeling to investigate changes in ACT effectiveness likely to occur if current regimens are extended from 3 to 5 days or, alternatively, given twice daily over 3 days. We show that the pharmacology of artemisinins allows both regimen changes to substantially increase the artemisinin killing rate. Malaria patients rarely contain more than 1012 parasites, while the standard dosing regimens allow approximately 1 in 1010 parasites to survive artemisinin treatment. Parasite survival falls dramatically, to around 1 in 1017 parasites if the dose is extended or split; theoretically, this increase in drug killing appears to be more than sufficient to restore failing ACT efficacy. One of the most widely used dosing regimens, artemether-lumefantrine, already successfully employs a twice-daily dosing regimen, and we argue that twice-daily dosing should be incorporated into all ACT regimen design considerations as a simple and effective way of ensuring the continued long-term effectiveness of ACTs. PMID:26239993

  15. Abundance coefficients, a new method for measuring microorganism relative abundance

    USGS Publications Warehouse

    Forester, R.M.

    1977-01-01

    A new method of measuring the relative abundance of microorganisms by using a set of interrelated coefficients, termed 'abundance coefficients' or 'AC', is proposed. These coefficients provide a means of recording abundance for geometric density categories, and each density measurement represents an approximation of the Poisson parameter ??t. The AC is the natural logarithm of a 'characteristic value,' which is a particular number for each geometric density category. The 'characteristic values' are based upon a probabilistic error statement derived from the Poisson formula, and they present evidence for separation of the geometric category boundaries by e = 2.71828. The proposed AC provide a means for recording species abundance in a manner suitable for arithmetic manipulation, for population structure studies, and for the determination of practical limits for defining the presence or absence of a species. Further, these coefficients provide for both intrasample and intersample abundance comparisons. ?? 1977 Plenum Publishing Corporation.

  16. SEASONAL CHANGES IN TITAN'S POLAR TRACE GAS ABUNDANCE OBSERVED BY CASSINI

    SciTech Connect

    Teanby, N. A.; Irwin, P. G. J.; De Kok, R.; Nixon, C. A.

    2010-11-20

    We use a six-year data set (2004-2010) of mid-infrared spectra measured by Cassini's Composite InfraRed Spectrometer to search for seasonal variations in Titan's atmospheric temperature and composition. During most of Cassini's mission Titan's northern hemisphere has been in winter, with an intense stratospheric polar vortex highly enriched in trace gases, and a single south-to-north circulation cell. Following northern spring equinox in mid-2009, dramatic changes in atmospheric temperature and composition were expected, but until now the temporal coverage of polar latitudes has been too sparse to discern trends. Here, we show that during equinox and post-equinox periods, abundances of trace gases at both poles have begun to increase. We propose that increases in north polar trace gases are due to a seasonal reduction in gas depletion by horizontal mixing across the vortex boundary. A simultaneous south polar abundance increase suggests that Titan is now entering, or is about to enter, a transitional circulation regime with two branches, rather than the single branch circulation pattern previously observed.

  17. The Interview: Dramatization Techniques in Dance--A New Approach to Teaching Modern Dance.

    ERIC Educational Resources Information Center

    Hamm, Gwendolyn Croom; Snygg, Fran

    1979-01-01

    The use of the interview dramatization as a teaching technique for presenting historical and chronological background information in the field of modern dance is described. Samples of the interviews are included. (JMF)

  18. A Case Report of Dramatically Increased Thyroglobulin after Lymph Node Biopsy in Thyroid Carcinoma after Total Thyroidectomy and Radioiodine

    PubMed Central

    Moosavi, Mandana; Kreisman, Stuart

    2016-01-01

    Thyroglobulin (Tg) is an important modality for monitoring patients with thyroid cancers, especially after thyroidectomy followed by radioiodine (RAI). It is also used as a marker for burden of thyroid tissue whether malignant or benign. Although there have been several reports of rising serum Tg transiently after thyroid biopsy in intact glands and following palpation or trauma, there are no reports in the literature of elevation in Tg after biopsy of suspicious lesions in thyroidectomized patients. In this paper we report a fascinating case of a considerable and initially worrying, although ultimately transient, rise in Tg in a patient 2 years after total thyroidectomy and RAI ablation after fine needle aspiration (FNA) of a suspicious thyroid bed nodule that was proven positive. PMID:27034856

  19. Metabolic engineering of hydroxy fatty acid production in plants: rcdgat2 drives dramatic increases in ricinoleate levels in seed oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A central goal of green chemistry is to produce industrially-useful fatty acids in oilseed crops. Although genes encoding suitable modification enzymes are available from many wild species, progress has been stymied because expression of these in transgenic plants produces poor yields of the desire...

  20. Erratum: Interstellar Abundance Standards Revisited

    NASA Astrophysics Data System (ADS)

    Sofia, U. J.; Meyer, D. M.

    2001-09-01

    In the Letter ``Interstellar Abundance Standards Revisited'' by U. J. Sofia and D. M. Meyer (ApJ, 554, L221 [2001]), Table 2 and its footnotes contain several typographical errors. The corrected table is shown below. We note that the solar reference standard now implies a positive abundance of nitrogen in halo dust.

  1. STABILIZING CLOUD FEEDBACK DRAMATICALLY EXPANDS THE HABITABLE ZONE OF TIDALLY LOCKED PLANETS

    SciTech Connect

    Yang Jun; Abbot, Dorian S.; Cowan, Nicolas B.

    2013-07-10

    The habitable zone (HZ) is the circumstellar region where a planet can sustain surface liquid water. Searching for terrestrial planets in the HZ of nearby stars is the stated goal of ongoing and planned extrasolar planet surveys. Previous estimates of the inner edge of the HZ were based on one-dimensional radiative-convective models. The most serious limitation of these models is the inability to predict cloud behavior. Here we use global climate models with sophisticated cloud schemes to show that due to a stabilizing cloud feedback, tidally locked planets can be habitable at twice the stellar flux found by previous studies. This dramatically expands the HZ and roughly doubles the frequency of habitable planets orbiting red dwarf stars. At high stellar flux, strong convection produces thick water clouds near the substellar location that greatly increase the planetary albedo and reduce surface temperatures. Higher insolation produces stronger substellar convection and therefore higher albedo, making this phenomenon a stabilizing climate feedback. Substellar clouds also effectively block outgoing radiation from the surface, reducing or even completely reversing the thermal emission contrast between dayside and nightside. The presence of substellar water clouds and the resulting clement surface conditions will therefore be detectable with the James Webb Space Telescope.

  2. Insights on dramatic radial fluctuations in track formation by energetic ions

    DOE PAGES

    Sachan, Ritesh; Lang, Maik; Trautmann, Christina; Zhang, Yanwen; Chisholm, Matthew F.; Weber, William J.; Zarkadoula, Eva

    2016-06-02

    We discuss the insights on the unexpected dramatic radial variations in the ion tracks formed by energetic ion (2.3 GeV 208Pb) irradiation at a constant electronic energy-loss (~42 keV/nm) in pyrochlore structured Gd2TiZrO7. Though previous studies have shown track formation and average track diameter measurements, this work brings further clarity on why quantitative analysis of ion track formation in Gd2TixZr(1-x)O7 systems can be more complicated than the currently accepted behavior for ion tracks. The ion track profile is usually considered to be diametrically uniform at constant values of the electronic energy-loss. This study shows the diameter variations to be asmore » large as ~40% within an extremely short incremental track length of ~20 nm. Our molecular dynamics simulations show that these fluctuations in diameter of amorphous core and overall track diameter are attributed to (i) the stochastic nature of inelastic energy loss along the track and (ii) the random substitution of Ti atoms by Zr atoms on the B-site in the pyrochlore lattice. Furthermore, the partial substitution of Ti by Zr increases the favorability of the defect-fluorite structure formation over amorphous phase stochastically, by introducing localized inhomogeneity in atomic structure, density and strain.« less

  3. Dramatic enhancement of superconductivity in single-crystalline nanowire arrays of Sn

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Wong, Chi Ho; Shen, Junying; Sze, Sin Ting; Zhang, Bing; Zhang, Haijing; Dong, Yan; Xu, Hui; Yan, Zifeng; Li, Yingying; Hu, Xijun; Lortz, Rolf

    2016-09-01

    Sn is a classical superconductor on the border between type I and type II with critical temperature of 3.7 K. We show that its critical parameters can be dramatically increased if it is brought in the form of loosely bound bundles of thin nanowires. The specific heat displays a pronounced double phase transition at 3.7 K and 5.5 K, which we attribute to the inner ‘bulk’ contribution of the nanowires and to the surface contribution, respectively. The latter is visible only because of the large volume fraction of the surface layer in relation to the bulk volume. The upper transition coincides with the onset of the resistive transition, while zero resistance is gradually approached below the lower transition. In contrast to the low critical field Hc = 0.03 T of Sn in its bulk form, a magnetic field of more than 3 T is required to fully restore the normal state.

  4. Platinum and Palladium Overlayers Dramatically Enhance the Activity of Ruthenium Nanotubes for Alkaline Hydrogen Oxidation

    SciTech Connect

    St. John, Samuel; Atkinson, Robert W.; Unocic, Kinga A.; Unocic, Raymond R.; Zawodzinski, Thomas A.; Papandrew, Alexander B.

    2015-10-18

    Templated vapor synthesis and thermal annealing were used to synthesize unsupported metallic Ru nanotubes with Pt or Pd overlayers. By controlling the elemental composition and thickness of these overlayers, we obtain nanostructures with very high alkaline hydrogen oxidation activity. For nanotubes with a nominal atomic composition of Ru0.90Pt0.10 display a surface-specific activity (2.4 mA/cm2) that is 35 times greater than that of pure Ru nanotubes at a 50 mV overpotential and 2.5 times greater than that of pure Pt nanotubes (0.98 mA/cm2). The surface-segregated structure also confers dramatically increased Pt utilization efficiency. We find a platinum-mass-specific activity of 1240 A/gPt for the optimized nanotube versus 280 A/gPt for carbon-supported Pt nanoparticles and 109 A/gPt for monometallic Pt nanotubes. Here, we attribute the enhancement of both area- and platinum-mass-specific activity to the atomic-scale homeomorphism of the nanotube form factor with adlayer-modified polycrystals. Subsurface ligand and bifunctional effects previously observed on segregated, adlayer-modified polycrystals are translated to nanoscale catalysts.

  5. Dramatic enhancement of superconductivity in single-crystalline nanowire arrays of Sn

    PubMed Central

    Zhang, Ying; Wong, Chi Ho; Shen, Junying; Sze, Sin Ting; Zhang, Bing; Zhang, Haijing; Dong, Yan; Xu, Hui; Yan, Zifeng; Li, Yingying; Hu, Xijun; Lortz, Rolf

    2016-01-01

    Sn is a classical superconductor on the border between type I and type II with critical temperature of 3.7 K. We show that its critical parameters can be dramatically increased if it is brought in the form of loosely bound bundles of thin nanowires. The specific heat displays a pronounced double phase transition at 3.7 K and 5.5 K, which we attribute to the inner ‘bulk’ contribution of the nanowires and to the surface contribution, respectively. The latter is visible only because of the large volume fraction of the surface layer in relation to the bulk volume. The upper transition coincides with the onset of the resistive transition, while zero resistance is gradually approached below the lower transition. In contrast to the low critical field Hc = 0.03 T of Sn in its bulk form, a magnetic field of more than 3 T is required to fully restore the normal state. PMID:27595646

  6. Platinum and Palladium Overlayers Dramatically Enhance the Activity of Ruthenium Nanotubes for Alkaline Hydrogen Oxidation

    DOE PAGES

    St. John, Samuel; Atkinson, Robert W.; Unocic, Kinga A.; Unocic, Raymond R.; Zawodzinski, Thomas A.; Papandrew, Alexander B.

    2015-10-18

    Templated vapor synthesis and thermal annealing were used to synthesize unsupported metallic Ru nanotubes with Pt or Pd overlayers. By controlling the elemental composition and thickness of these overlayers, we obtain nanostructures with very high alkaline hydrogen oxidation activity. For nanotubes with a nominal atomic composition of Ru0.90Pt0.10 display a surface-specific activity (2.4 mA/cm2) that is 35 times greater than that of pure Ru nanotubes at a 50 mV overpotential and 2.5 times greater than that of pure Pt nanotubes (0.98 mA/cm2). The surface-segregated structure also confers dramatically increased Pt utilization efficiency. We find a platinum-mass-specific activity of 1240 A/gPtmore » for the optimized nanotube versus 280 A/gPt for carbon-supported Pt nanoparticles and 109 A/gPt for monometallic Pt nanotubes. Here, we attribute the enhancement of both area- and platinum-mass-specific activity to the atomic-scale homeomorphism of the nanotube form factor with adlayer-modified polycrystals. Subsurface ligand and bifunctional effects previously observed on segregated, adlayer-modified polycrystals are translated to nanoscale catalysts.« less

  7. Dramatic enhancement of superconductivity in single-crystalline nanowire arrays of Sn.

    PubMed

    Zhang, Ying; Wong, Chi Ho; Shen, Junying; Sze, Sin Ting; Zhang, Bing; Zhang, Haijing; Dong, Yan; Xu, Hui; Yan, Zifeng; Li, Yingying; Hu, Xijun; Lortz, Rolf

    2016-01-01

    Sn is a classical superconductor on the border between type I and type II with critical temperature of 3.7 K. We show that its critical parameters can be dramatically increased if it is brought in the form of loosely bound bundles of thin nanowires. The specific heat displays a pronounced double phase transition at 3.7 K and 5.5 K, which we attribute to the inner 'bulk' contribution of the nanowires and to the surface contribution, respectively. The latter is visible only because of the large volume fraction of the surface layer in relation to the bulk volume. The upper transition coincides with the onset of the resistive transition, while zero resistance is gradually approached below the lower transition. In contrast to the low critical field Hc = 0.03 T of Sn in its bulk form, a magnetic field of more than 3 T is required to fully restore the normal state. PMID:27595646

  8. Atmospheric drying as the main driver of dramatic glacier wastage in the southern Indian Ocean

    PubMed Central

    Favier, V.; Verfaillie, D.; Berthier, E.; Menegoz, M.; Jomelli, V.; Kay, J. E.; Ducret, L.; Malbéteau, Y.; Brunstein, D.; Gallée, H.; Park, Y.-H.; Rinterknecht, V.

    2016-01-01

    The ongoing retreat of glaciers at southern sub-polar latitudes is particularly rapid and widespread. Akin to northern sub-polar latitudes, this retreat is generally assumed to be linked to warming. However, no long-term and well-constrained glacier modeling has ever been performed to confirm this hypothesis. Here, we model the Cook Ice Cap mass balance on the Kerguelen Islands (Southern Indian Ocean, 49°S) since the 1850s. We show that glacier wastage during the 2000s in the Kerguelen was among the most dramatic on Earth. We attribute 77% of the increasingly negative mass balance since the 1960s to atmospheric drying associated with a poleward shift of the mid-latitude storm track. Because precipitation modeling is very challenging for the current generation of climate models over the study area, models incorrectly simulate the climate drivers behind the recent glacier wastage in the Kerguelen. This suggests that future glacier wastage projections should be considered cautiously where changes in atmospheric circulation are expected. PMID:27580801

  9. Dramatic enhancement of superconductivity in single-crystalline nanowire arrays of Sn.

    PubMed

    Zhang, Ying; Wong, Chi Ho; Shen, Junying; Sze, Sin Ting; Zhang, Bing; Zhang, Haijing; Dong, Yan; Xu, Hui; Yan, Zifeng; Li, Yingying; Hu, Xijun; Lortz, Rolf

    2016-01-01

    Sn is a classical superconductor on the border between type I and type II with critical temperature of 3.7 K. We show that its critical parameters can be dramatically increased if it is brought in the form of loosely bound bundles of thin nanowires. The specific heat displays a pronounced double phase transition at 3.7 K and 5.5 K, which we attribute to the inner 'bulk' contribution of the nanowires and to the surface contribution, respectively. The latter is visible only because of the large volume fraction of the surface layer in relation to the bulk volume. The upper transition coincides with the onset of the resistive transition, while zero resistance is gradually approached below the lower transition. In contrast to the low critical field Hc = 0.03 T of Sn in its bulk form, a magnetic field of more than 3 T is required to fully restore the normal state.

  10. Atmospheric drying as the main driver of dramatic glacier wastage in the southern Indian Ocean

    NASA Astrophysics Data System (ADS)

    Favier, V.; Verfaillie, D.; Berthier, E.; Menegoz, M.; Jomelli, V.; Kay, J. E.; Ducret, L.; Malbéteau, Y.; Brunstein, D.; Gallée, H.; Park, Y.-H.; Rinterknecht, V.

    2016-09-01

    The ongoing retreat of glaciers at southern sub-polar latitudes is particularly rapid and widespread. Akin to northern sub-polar latitudes, this retreat is generally assumed to be linked to warming. However, no long-term and well-constrained glacier modeling has ever been performed to confirm this hypothesis. Here, we model the Cook Ice Cap mass balance on the Kerguelen Islands (Southern Indian Ocean, 49°S) since the 1850s. We show that glacier wastage during the 2000s in the Kerguelen was among the most dramatic on Earth. We attribute 77% of the increasingly negative mass balance since the 1960s to atmospheric drying associated with a poleward shift of the mid-latitude storm track. Because precipitation modeling is very challenging for the current generation of climate models over the study area, models incorrectly simulate the climate drivers behind the recent glacier wastage in the Kerguelen. This suggests that future glacier wastage projections should be considered cautiously where changes in atmospheric circulation are expected.

  11. Atmospheric drying as the main driver of dramatic glacier wastage in the southern Indian Ocean.

    PubMed

    Favier, V; Verfaillie, D; Berthier, E; Menegoz, M; Jomelli, V; Kay, J E; Ducret, L; Malbéteau, Y; Brunstein, D; Gallée, H; Park, Y-H; Rinterknecht, V

    2016-01-01

    The ongoing retreat of glaciers at southern sub-polar latitudes is particularly rapid and widespread. Akin to northern sub-polar latitudes, this retreat is generally assumed to be linked to warming. However, no long-term and well-constrained glacier modeling has ever been performed to confirm this hypothesis. Here, we model the Cook Ice Cap mass balance on the Kerguelen Islands (Southern Indian Ocean, 49°S) since the 1850s. We show that glacier wastage during the 2000s in the Kerguelen was among the most dramatic on Earth. We attribute 77% of the increasingly negative mass balance since the 1960s to atmospheric drying associated with a poleward shift of the mid-latitude storm track. Because precipitation modeling is very challenging for the current generation of climate models over the study area, models incorrectly simulate the climate drivers behind the recent glacier wastage in the Kerguelen. This suggests that future glacier wastage projections should be considered cautiously where changes in atmospheric circulation are expected. PMID:27580801

  12. Modeling attitude towards drug treament: the role of internal motivation, external pressure, and dramatic relief.

    PubMed

    Conner, Bradley T; Longshore, Douglas; Anglin, M Douglas

    2009-04-01

    Motivation for change has historically been viewed as the crucial element affecting responsiveness to drug treatment. Various external pressures, such as legal coercion, may engender motivation in an individual previously resistant to change. Dramatic relief may be the change process that is most salient as individuals internalize such external pressures. Results of structural equation modeling on data from 465 drug users (58.9% male; 21.3% Black, 34.2% Hispanic/Latino, and 35.1% White) entering drug treatment indicated that internal motivation and external pressure significantly and positively predicted dramatic relief and that dramatic relief significantly predicted attitudes towards drug treatment: chi (2) = 142.20, df = 100, p < 0.01; Robust Comparative Fit Index = 0.97, Root Mean Squared Error of Approximation = 0.03. These results indicate that when external pressure and internal motivation are high, dramatic relief is also likely to be high. When dramatic relief is high, attitudes towards drug treatment are likely to be positive. The findings indicate that interventions to get individuals into drug treatment should include processes that promote Dramatic Relief. Implications for addictions health services are discussed.

  13. Seasonal and interannual dynamics of microzooplankton abundances in the Gulf of Trieste (Northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Monti, Marina; Minocci, Marco; Milani, Luisella; Fonda Umani, Serena

    2012-12-01

    Abundance and composition of microzooplankton were studied over a 15 years period (from March 1986 to December 1990 and from July 1998 to December 2010) in the Gulf of Trieste (Adriatic Sea, NE Mediterranean Sea). Sampling was conducted biweekly-monthly at the surface at the historical station C1, 200 m offshore (bottom depth 17.5 m). Aloricate ciliates dominated in both periods (median 117 and 243 ind. L-1 in the first and second period respectively) while tintinnids were more abundant in the first period (median 55 ind. L-1vs 16 ind. L-1). For heterotrophic dinoflagellates there are no data during the first period and in the second one they represented the second major group. Micrometazoans remained almost constant over time. In the first period all microzooplankton groups showed a maximum in April, while in the last period the peak has shifted to September. This is particularly evident for both aloricate ciliates and micrometazoans. Tintinnids, that in the past had the absolute maximum in spring, in the second period maintained the only, lower peak in October. Tintinnids in the first period were constituted by 27 species and dominated by the genera Tintinnopsis, Stenosemella and Salpingella. In the last 10 years we registered a dramatic decrease in abundance, paralleling an increase in species (40) with some "new entries" as well as the almost complete disappearance of genera Helicostomella, Favella, Coxiella and Steenstrupiella. The observed changes of the seasonal dynamics of microzooplankton abundance, as well as of the tintinnids composition over the long period considered in our study, might suggest a climatic forcing together with the known anthropogenic oligotrophication of the entire North Adriatic.

  14. Shrub encroachment affects mammalian carnivore abundance and species richness in semiarid rangelands

    NASA Astrophysics Data System (ADS)

    Blaum, Niels; Rossmanith, Eva; Popp, Alexander; Jeltsch, Florian

    2007-01-01

    Shrub encroachment due to overgrazing has led to dramatic changes of savanna landscapes and is considered to be one of the most threatening forms of rangeland degradation e.g. via habitat fragmentation. Mammalian carnivores are particularly vulnerable to local extinction in fragmented landscapes. However, our understanding of how shrub encroachment affects mammalian carnivores is poor. Here we investigated the relative sensitivities of ten native carnivores to different levels of shrub cover ranging from low (<5%) to high shrub cover (>25%) in 20 southern Kalahari rangeland sites. Relative abundance of carnivores was monitored along 40 sand transects (5 m × 250 m) for each site. Our results show that increasing shrub cover affects carnivore species differently. African wild cats, striped polecats, cape foxes and suricates were negatively affected, whereas we found hump-shaped responses for yellow mongooses, bat-eared foxes and small-spotted genets with maximum abundance at shrub covers between 10 and 18%. In contrast, black-backed jackals, slender mongooses and small spotted cats were not significantly affected by increasing shrub cover. However, a negative impact of high shrub cover above 18% was congruent for all species. We conclude that intermediate shrub cover (10-18%) in savanna landscapes sustain viable populations of small carnivores.

  15. Will Abundant Natural Gas Solve Climate Change?

    NASA Astrophysics Data System (ADS)

    McJeon, H. C.; Edmonds, J.; Bauer, N.; Leon, C.; Fisher, B.; Flannery, B.; Hilaire, J.; Krey, V.; Marangoni, G.; Mi, R.; Riahi, K.; Rogner, H.; Tavoni, M.

    2015-12-01

    The rapid deployment of hydraulic fracturing and horizontal drilling technologies enabled the production of previously uneconomic shale gas resources in North America. Global deployment of these advanced gas production technologies could bring large influx of economically competitive unconventional gas resources to the energy system. It has been hoped that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions, which in turn could reduce climate forcing. Other researchers countered that the non-CO2 greenhouse gas (GHG) emissions associated with shale gas production make its lifecycle emissions higher than those of coal. In this study, we employ five state-of-the-art integrated assessment models (IAMs) of energy-economy-climate systems to assess the full impact of abundant gas on climate change. The models show large additional natural gas consumption up to +170% by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2% to +11%), and a majority of the models reported a small increase in climate forcing (from -0.3% to +7%) associated with the increased use of abundant gas. Our results show that while globally abundant gas may substantially change the future energy market equilibrium, it will not significantly mitigate climate change on its own in the absence of climate policies.

  16. Correcting Inadequate Model Snow Process Descriptions Dramatically Improves Mountain Hydrology Simulations

    NASA Astrophysics Data System (ADS)

    Pomeroy, J. W.; Fang, X.

    2014-12-01

    The vast effort in hydrology devoted to parameter calibration as a means to improve model performance assumes that the models concerned are not fundamentally wrong. By focussing on finding optimal parameter sets and ascribing poor model performance to parameter or data uncertainty, these efforts may fail to consider the need to improve models with more intelligent descriptions of hydrological processes. To test this hypothesis, a flexible physically based hydrological model including a full suite of snow hydrology processes as well as warm season, hillslope and groundwater hydrology was applied to Marmot Creek Research Basin, Canadian Rocky Mountains where excellent driving meteorology and basin biophysical descriptions exist. Model parameters were set from values found in the basin or from similar environments; no parameters were calibrated. The model was tested against snow surveys and streamflow observations. The model used algorithms that describe snow redistribution, sublimation and forest canopy effects on snowmelt and evaporative processes that are rarely implemented in hydrological models. To investigate the contribution of these processes to model predictive capability, the model was "falsified" by deleting parameterisations for forest canopy snow mass and energy, blowing snow, intercepted rain evaporation, and sublimation. Model falsification by ignoring forest canopy processes contributed to a large increase in SWE errors for forested portions of the research basin with RMSE increasing from 19 to 55 mm and mean bias (MB) increasing from 0.004 to 0.62. In the alpine tundra portion, removing blowing processes resulted in an increase in model SWE MB from 0.04 to 2.55 on north-facing slopes and -0.006 to -0.48 on south-facing slopes. Eliminating these algorithms degraded streamflow prediction with the Nash Sutcliffe efficiency dropping from 0.58 to 0.22 and MB increasing from 0.01 to 0.09. These results show dramatic model improvements by including snow

  17. Urbanization dramatically altered the water balances of a paddy field-dominated basin in southern China

    NASA Astrophysics Data System (ADS)

    Hao, L.; Sun, G.; Liu, Y.; Wan, J.; Qin, M.; Qian, H.; Liu, C.; Zheng, J.; John, R.; Fan, P.; Chen, J.

    2015-07-01

    Rice paddy fields provide important ecosystem services (e.g., food production, water retention, carbon sequestration) to a large population globally. However, these benefits are diminishing as a result of rapid environmental and socioeconomic transformations, characterized by population growth, urbanization, and climate change in many Asian countries. This case study examined the responses of stream flow and watershed water balances to the decline of rice paddy fields due to urbanization in the Qinhuai River basin in southern China, where massive industrialization has occurred during the past 3 decades. We found that stream flow increased by 58 % and evapotranspiration (ET) decreased by 23 % during 1986-2013 as a result of a three-fold increase in urban areas and a reduction of rice paddy fields by 27 %. Both high flows and low flows increased significantly by about 28 % from 2002 to 2013. The increases in stream flow were consistent with the decreases in ET and leaf area index monitored by independent remote sensing MODIS (Moderate Resolution Imaging Spectroradiometer) data. Attribution analysis, based on two empirical models, indicated that land-use/land-cover change contributed about 82-108 % of the observed increase in stream flow from 353 ± 287 mm yr-1 during 1986-2002 to 556 ± 145 during 2003-2013. We concluded that the reduction in ET was largely attributed to the conversion of cropland to urban use. The effects of land-use change overwhelmed the effects of regional climate warming and climate variability. Converting traditional rice paddy fields to urban use dramatically altered land surface conditions from an artificial wetland-dominated landscape to an urban land-use- dominated one, and thus was considered an extreme type of contemporary hydrologic disturbance. The ongoing large-scale urbanization of the rice paddy-dominated regions, in humid southern China and East Asia, will likely elevate storm-flow volume, aggravate flood risks, and intensify urban

  18. Mineral Abundance Near Aristarchus Crater

    NASA Astrophysics Data System (ADS)

    Bradford, Alison; Storrs, A.

    2007-12-01

    Mineral Abundance Near Aristarchus Crater Alison Bradford and Alex Storrs Towson University We analyze Hubble Space Telescope (HST) images to determine the abundance of minerals near Aristarchus crater. Following the calibration of Robinson et al. (2007) we present ratio maps of images obtained in August of 2005 showing the abundance of TiO2 and other minerals in this interesting area in the middle of Oceanus Procellarum. A prominent cleft (Schroter's Valley, presumably a collapsed lava tube) makes this region of special interest for analyzing the formation of mare basalts. Reference: Robinson, M.S., et al. (2007): "High resolution mapping of TiO2 abundances on the Moon using the Hubble Space Telescope", GRL 34, L13203

  19. The boron abundance of Procyon

    NASA Technical Reports Server (NTRS)

    Lemke, Michael; Lambert, David L.; Edvardsson, Bengt

    1993-01-01

    The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (Alpha Canis Minoris), Theta Ursae Majoris, and Iota Pegasi. The B abundance of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox (1978) from the B II resonance line in spectra of A- and B-type stars. These two dwarfs show normal abundances of Li, Be, and B. Procyon, which is highly depleted in Li and Be, is depleted in B by a factor of at least 3. Comparison of the spectra of Procyon and the halo dwarf HD 140283 shows that the B abundance assigned by Duncan et al. (1992) to three halo dwarfs is not greatly overestimated as a result of contamination of the B I line by an unidentified line.

  20. Urea may regulate urea transporter protein abundance during osmotic diuresis.

    PubMed

    Kim, Dongun; Klein, Janet D; Racine, Sandy; Murrell, Brian P; Sands, Jeff M

    2005-01-01

    Rats with diabetes mellitus have an increase in UT-A1 urea transporter protein abundance and absolute urea excretion, but the relative amount (percentage) of urea in total urinary solute is actually decreased due to the marked glucosuria. Urea-specific signaling pathways have been identified in mIMCD3 cells and renal medulla, suggesting the possibility that changes in the percentage or concentration of urea could be a factor that regulates UT-A1 abundance. In this study, we tested the hypothesis that an increase in a urinary solute other than urea would increase UT-A1 abundance, similar to diabetes mellitus, whereas an increase in urine urea would not. In both inner medullary base and tip, UT-A1 protein abundance increased during NaCl- or glucose-induced osmotic diuresis but not during urea-induced osmotic diuresis. Next, rats undergoing NaCl or glucose diuresis were given supplemental urea to increase the percentage of urine urea to control values. UT-A1 abundance did not increase in these urea-supplemented rats compared with control rats. Additionally, both UT-A2 and UT-B protein abundances in the outer medulla increased during urea-induced osmotic diuresis but not in NaCl or glucose diuresis. We conclude that during osmotic diuresis, UT-A1 abundance increases when the percentage of urea in total urinary solute is low and UT-A2 and UT-B abundances increase when the urea concentration in the medullary interstitium is high. These findings suggest that a reduction in urine or interstitial urea results in an increase in UT-A1 protein abundance in an attempt to restore inner medullary interstitial urea and preserve urine-concentrating ability.

  1. Non-small cell lung cancer is characterized by dramatic changes in phospholipid profiles.

    PubMed

    Marien, Eyra; Meister, Michael; Muley, Thomas; Fieuws, Steffen; Bordel, Sergio; Derua, Rita; Spraggins, Jeffrey; Van de Plas, Raf; Dehairs, Jonas; Wouters, Jens; Bagadi, Muralidhararao; Dienemann, Hendrik; Thomas, Michael; Schnabel, Philipp A; Caprioli, Richard M; Waelkens, Etienne; Swinnen, Johannes V

    2015-10-01

    Non-small cell lung cancer (NSCLC) is the leading cause of cancer death globally. To develop better diagnostics and more effective treatments, research in the past decades has focused on identification of molecular changes in the genome, transcriptome, proteome, and more recently also the metabolome. Phospholipids, which nevertheless play a central role in cell functioning, remain poorly explored. Here, using a mass spectrometry (MS)-based phospholipidomics approach, we profiled 179 phospholipid species in malignant and matched non-malignant lung tissue of 162 NSCLC patients (73 in a discovery cohort and 89 in a validation cohort). We identified 91 phospholipid species that were differentially expressed in cancer versus non-malignant tissues. Most prominent changes included a decrease in sphingomyelins (SMs) and an increase in specific phosphatidylinositols (PIs). Also a decrease in multiple phosphatidylserines (PSs) was observed, along with an increase in several phosphatidylethanolamine (PE) and phosphatidylcholine (PC) species, particularly those with 40 or 42 carbon atoms in both fatty acyl chains together. 2D-imaging MS of the most differentially expressed phospholipids confirmed their differential abundance in cancer cells. We identified lipid markers that can discriminate tumor versus normal tissue and different NSCLC subtypes with an AUC (area under the ROC curve) of 0.999 and 0.885, respectively. In conclusion, using both shotgun and 2D-imaging lipidomics analysis, we uncovered a hitherto unrecognized alteration in phospholipid profiles in NSCLC. These changes may have important biological implications and may have significant potential for biomarker development. PMID:25784292

  2. Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status.

    PubMed

    Schafer, Anne L; Weaver, Connie M; Black, Dennis M; Wheeler, Amber L; Chang, Hanling; Szefc, Gina V; Stewart, Lygia; Rogers, Stanley J; Carter, Jonathan T; Posselt, Andrew M; Shoback, Dolores M; Sellmeyer, Deborah E

    2015-08-01

    Roux-en-Y gastric bypass (RYGB) surgery has negative effects on bone, mediated in part by effects on nutrient absorption. Not only can RYGB result in vitamin D malabsorption, but the bypassed duodenum and proximal jejunum are also the predominant sites of active, transcellular, 1,25(OH)2 D-mediated calcium (Ca) uptake. However, Ca absorption occurs throughout the intestine, and those who undergo RYGB might maintain sufficient Ca absorption, particularly if vitamin D status and Ca intake are robust. We determined the effects of RYGB on intestinal fractional Ca absorption (FCA) while maintaining ample 25OHD levels (goal ≥30 ng/mL) and Ca intake (1200 mg daily) in a prospective cohort of 33 obese adults (BMI 44.7 ± 7.4 kg/m(2)). FCA was measured preoperatively and 6 months postoperatively with a dual stable isotope method. Other measures included calciotropic hormones, bone turnover markers, and BMD by DXA and QCT. Mean 6-month weight loss was 32.5 ± 8.4 kg (25.8% ± 5.2% of preoperative weight). FCA decreased from 32.7% ± 14.0% preoperatively to 6.9% ± 3.8% postoperatively (p < 0.0001), despite median (interquartile range) 25OHD levels of 41.0 (33.1 to 48.5) and 36.5 (28.8 to 40.4) ng/mL, respectively. Consistent with the FCA decline, 24-hour urinary Ca decreased, PTH increased, and 1,25(OH)2 D increased (p ≤ 0.02). Bone turnover markers increased markedly, areal BMD decreased at the proximal femur, and volumetric BMD decreased at the spine (p < 0.001). Those with lower postoperative FCA had greater increases in serum CTx (ρ = -0.43, p = 0.01). Declines in FCA and BMD were not correlated over the 6 months. In conclusion, FCA decreased dramatically after RYGB, even with most 25OHD levels ≥30 ng/mL and with recommended Ca intake. RYGB patients may need high Ca intake to prevent perturbations in Ca homeostasis, although the approach to Ca supplementation needs further study. Decline in FCA could contribute to

  3. Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status

    PubMed Central

    Schafer, Anne L; Weaver, Connie M; Black, Dennis M; Wheeler, Amber L; Chang, Hanling; Szefc, Gina V; Stewart, Lygia; Rogers, Stanley J; Carter, Jonathan T; Posselt, Andrew M; Shoback, Dolores M; Sellmeyer, Deborah E

    2015-01-01

    Roux-en-Y gastric bypass (RYGB) surgery has negative effects on bone, mediated in part by effects on nutrient absorption. Not only can RYGB result in vitamin D malabsorption, but the bypassed duodenum and proximal jejunum are also the predominant sites of active, transcellular, 1,25(OH)2D-mediated calcium (Ca) uptake. However, Ca absorption occurs throughout the intestine, and those who undergo RYGB might maintain sufficient Ca absorption, particularly if vitamin D status and Ca intake are robust. We determined the effects of RYGB on intestinal fractional Ca absorption (FCA) while maintaining ample 25OHD levels (goal ≥30 ng/mL) and Ca intake (1200 mg daily) in a prospective cohort of 33 obese adults (BMI 44.7 ± 7.4 kg/m2). FCA was measured preoperatively and 6 months postoperatively with a dual stable isotope method. Other measures included calciotropic hormones, bone turnover markers, and BMD by DXA and QCT. Mean 6-month weight loss was 32.5 ± 8.4 kg (25.8% ± 5.2% of preoperative weight). FCA decreased from 32.7% ± 14.0% preoperatively to 6.9% ± 3.8% postoperatively (p < 0.0001), despite median (interquartile range) 25OHD levels of 41.0 (33.1 to 48.5) and 36.5 (28.8 to 40.4) ng/mL, respectively. Consistent with the FCA decline, 24-hour urinary Ca decreased, PTH increased, and 1,25(OH)2D increased (p ≤ 0.02). Bone turnover markers increased markedly, areal BMD decreased at the proximal femur, and volumetric BMD decreased at the spine (p < 0.001). Those with lower postoperative FCA had greater increases in serum CTx (ρ = −0.43, p = 0.01). Declines in FCA and BMD were not correlated over the 6 months. In conclusion, FCA decreased dramatically after RYGB, even with most 25OHD levels ≥30 ng/mL and with recommended Ca intake. RYGB patients may need high Ca intake to prevent perturbations in Ca homeostasis, although the approach to Ca supplementation needs further study. Decline in FCA could contribute to the decline in BMD after RYGB, and strategies to

  4. Dramatic Decomposition Weakening of Simulated Faults in Carrara Marble at Seismic Slip-rates

    NASA Astrophysics Data System (ADS)

    Han, R.; Shimamoto, T.; Hirose, T.; Ree, J.

    2005-12-01

    Evolution of fault-zone strength and its weakening mechanisms during an earthquake are critical for understanding of earthquake rupture process. We report dramatic weakening of dry simulated faults in Carrara marble at seismic slip-rates, with frictional coefficient as low as 0.04 (probably the lowest record as rock friction). Calcite decomposition was confirmed by in-situ CO2 detection and other methods and the weakening may require new weakening mechanisms other than currently suggested ones such as frictional melting, thermal pressurization and silica gel formation. We conducted rotary-shear friction experiments on Carrara marble at slip-rates (V) of 0.09-1.24 m/s and normal stresses (σn) of 2.5-13.4 MPa. For preventing a thermal fracturing and applying a high normal load, we used solid cylindrical specimens jacketed with aluminum tubes. Narrow gap was left between the two aluminum tubes to avoid metal-to-metal contact. Our main results can be summarized as follows: (1) Slip weakening occurs in all experiments except for the runs at the lowest V (0.09 m/s); (2) Steady-state friction coefficient (μss) decreases as slip-rate and normal load increase; (3) At the highest V (1.13-1.24 m/s) and σn = 7.3 MPa, the average friction coefficient of initial peak friction (μp) is 0.61 (± 0.02), but the average μss is 0.04! (± 0.01) which is much lower than μp; (4) Decrease in average temperature of sliding surfaces corresponds to increase in friction, and strength recovery occurs very rapidly and completely upon cooling of specimens; (5) XRD and EPMA data show that the gouge for the specimens at V > 0.09 m/s is composed of calcite, lime (CaO) and/or hydrated lime (Ca(OH)2); (6) CO2 gas was detected with sensors during the weakening; (7) Decomposed calcite forms a fault zone consisting of ultrafine-grained gouge, but no melt or amorphous material was identified by optical microscopy or XRD analysis. Calcite decomposition clearly indicates that temperature in the fault

  5. Column abundance measurements of atmospheric hydroxyl at 45 deg S

    NASA Technical Reports Server (NTRS)

    Wood, S. W.; Keep, D. J.; Burnett, C. R.; Burnett, E. B.

    1994-01-01

    The first Southern Hemisphere measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been obtained at Lauder, New Zealand (45 deg S) with a PEPSIOS instrument measuring the absorption of sunlight at 308 nm. The variation of column OH with solar zenith angle is similar to that measured at other sites. However average annual abundances of OH are about 20% higher than those found by similar measurements at 40 deg N. Minimum OH abundances about 10% less than average levels at 40 deg N, are observed during austral spring. The OH abundance abruptly increases by 30% in early summer and remains at the elevated level until late the following winter.

  6. Abiotic mediation of a mutualism drives herbivore abundance.

    PubMed

    Mooney, Emily H; Phillips, Joseph S; Tillberg, Chadwick V; Sandrow, Cheryl; Nelson, Annika S; Mooney, Kailen A

    2016-01-01

    Species abundance is typically determined by the abiotic environment, but the extent to which such effects occur through the mediation of biotic interactions, including mutualisms, is unknown. We explored how light environment (open meadow vs. shaded understory) mediates the abundance and ant tending of the aphid Aphis helianthi feeding on the herb Ligusticum porteri. Yearly surveys consistently found aphids to be more than 17-fold more abundant on open meadow plants than on shaded understory plants. Manipulations demonstrated that this abundance pattern was not due to the direct effects of light environment on aphid performance, or indirectly through host plant quality or the effects of predators. Instead, open meadows had higher ant abundance and per capita rates of aphid tending and, accordingly, ants increased aphid population growth in meadow but not understory environments. The abiotic environment thus drives the abundance of this herbivore exclusively through the mediation of a protection mutualism.

  7. A Case of Aripiprazole-Induced Tardive Dyskinesia with Dramatic Evolution

    PubMed Central

    Heitzmann, Edwige; Weiner, Luisa; Michel, Bruno

    2016-01-01

    Aripiprazole is reported to be a good clinical safety profile antipsychotic. However, recent data suggest that the risk of tardive dyskinesia could be higher than initially thought. We report the case of aripiprazole-induced tardive dyskinesia with dramatic evolution in a patient with several risk factors, including older age and exposure to antipsychotic over a period longer than six months. This case and its dramatic evolution, associated with other cases recently published, suggest reconsidering the real risk of tardive dyskinesia associated with aripiprazole, particularly in the elderly.

  8. Heavy element abundances and massive star formation

    NASA Technical Reports Server (NTRS)

    Wang, Boqi; Silk, Joseph

    1993-01-01

    The determination of the stellar initial mass function (IMF) remains a great challenge in astronomy. In the solar neighborhood, the IMF is reasonable well determined for stellar masses from about 0.1 to 60 solar mass. However, outside the solar neighborhood, the IMF is poorly known. Among those frequently discussed arguments favoring a different IMF outside the solar neighborhood are the estimated time to consume the remaining gas in spiral galaxies, and the high rate of forming massive stars in starburst galaxies. An interesting question then is whether there may be an independent way of testing possible variations in the IMF. Indeed, the heavy elements in the interstellar medium are mostly synthesized in massive stars, so increasing, or decreasing, the fraction of massive stars naturally leads to a variation in the heavy element yield, and thus, the metallicity. The observed abundance should severely constrain any deviations of the IMF from the locally determined IMF. We focus on element oxygen, which is the most abundant heavy element in the interstellar medium. Oxygen is ejected only by massive stars that can become Type 1 supernovae, and the oxygen abundance is, therefore, a sensitive function of the fraction of massive stars in the IMF. Adopting oxygen enables us to avoid uncertainties in Type 1 supernovae. We use the nucleosynthesis results to calculate the oxygen yield for given IMF. We then calculate the oxygen abundance in the interstellar medium assuming instantaneous recycling of oxygen.

  9. Dramatic decline of unionid bivalves in offshore waters of western Lake Erie after infestation by the zebra mussel, Dreissena polymorpha

    USGS Publications Warehouse

    Schloesser, Don W.; Nalepa, Thomas F.

    1994-01-01

    Unionid bivalves and attached epizoic zebra mussels (Dreissena polymorpha) were collected at one index station in 1989, 1990, and 1991 and at 17 stations in 1991 in offshore waters of western Lake Erie of the Laurentian Great Lakes. Sampling at the index station revealed that the proportion of live unionids declined from 53% in September 1989 to 17% in May–June 1990 and to 0% in September 1990: this 100% mortality coincided with heavy infestation by zebra mussels. Quantitative sampling with a Ponar grab at the 17 stations in 1991 revealed a widespread and dramatic reduction in unionid populations. In 1982, five unionid species occurred at 35% of the stations at a density of 4/m2, whereas in 1991, no live unionid species were found. Qualitative sampling with an epibenthic sled at the 17 stations in 1991 yielded only 4 live specimens of 2 species (Amblema plicata plicata and Fusconaia flava) and 187 dead specimens of 10 species. These and other results indicate that unionid populations are being negatively affected by zebra mussels in the Great Lakes. Similar impacts on unionids are expected to occur where zebra mussels become abundant throughout North America.

  10. Reach-scale distribution dynamics of a grazing stream insect, Micrasema quadriloba Martynov (Brachycentridae, Trichoptera), in relation to current velocity and periphyton abundance.

    PubMed

    Katano, Izumi; Mitsuhashi, Hiromune; Isobe, Yu; Sato, Hiroaki; Oishi, Tadashi

    2005-08-01

    Reach-scale temporal shifts in the distribution of larvae of a grazing caddisfly, Micrasema quadriloba (Brachycentridae), were investigated in a Japanese mountain stream. The larvae showed an aggregated distribution within the reach at the beginning of the immigration, then became randomly dispersed throughout the reach as the immigration progressed. The abundance of periphyton in the reach decreased dramatically with increasing dispersal of the larvae. Simple regression analyses revealed that the stream's flow regime was the most important environmental factor that determined the reach-scale distribution of the larvae and that the relationship between the flow regime and the distribution of the larvae shifted temporally. In addition, our results suggest that only this species of grazing insect, which was dominant in the study reach, controlled the reach-scale abundance of the periphyton.

  11. Occupational Awareness through Dramatic Play: A Curriculum Guide for Primary Grades: Parts 1 and 2.

    ERIC Educational Resources Information Center

    Golden, Loretta

    Designed for grades K-3, the career education curriculum guide focuses on dramatic play to create an environment which will stimulate children to explore various occupations within the community. At the beginning of the program, the community includes only a few structures. As the students realize the need for more buildings and services, the…

  12. Playing around with Improvisation: An Analysis of the Text Creation Processes Used within Preadolescent Dramatic Play

    ERIC Educational Resources Information Center

    Dunn, Julie

    2008-01-01

    When children come together to play dramatically they are involved in the creation of an improvised text. This text emerges spontaneously via the moment-by-moment contributions of individual players who must operate in a highly collaborative way in order to achieve cohesion. This paper reports on a research project involving several groups of 11-…

  13. Language through the Seasons: Dramatic Play Activities for Early Childhood Learners.

    ERIC Educational Resources Information Center

    Amdur, Judith

    This workbook brings together activities to aid in motivating children to concentrate, listen, respond, think, and learn. The activities rely upon play-like tasks involving drama, music, and other forms of creative expression. The activities are organized by the season in which they are appropriate and include songs, dramatic sequences, stories,…

  14. Art-House Cinema, Avant-Garde Film, and Dramatic Modernism

    ERIC Educational Resources Information Center

    Cardullo, Bert

    2011-01-01

    In this article, the author talks about art-house cinema, avant-garde film, and dramatic modernism. He believes that the most important modes of film practice are art-house cinema and the avant-garde, both of which contrast with the classical Hollywood mode of film practice. While the latter is characterized by its commercial imperative, corporate…

  15. Teenagers' Significant Experiences in Aesthetic Areas: Some Empirical Observations Regarding the Role of Dramatic Art

    ERIC Educational Resources Information Center

    Finnas, Leif

    2008-01-01

    Fifteen sixteen-year-old Fenno-Swedish compulsory school pupils' descriptions and evaluations of significant, i.e. more or less "strong", experiences relating to dramatic art (film, theatre) were analysed and compared with reported experiences in other aesthetic areas (music, nature etc.). The drama area was represented in many experiences, but…

  16. Lord Kelvin and the Age-of-the-Earth Debate: A Dramatization.

    ERIC Educational Resources Information Center

    Stinner, Art; Tecihman, Jurgen

    2003-01-01

    Presents a dramatization of a fictitious debate about the age of the earth that takes place at the Royal Institution, London, England, in the year 1872 among Sir William Thomson, T.H. Huxley, Sir Charles Lyell, and Hermann von Helmholtz. (Contains 17 references.) (Author/YDS)

  17. How to Know when Dramatic Change Is on Track: Leading Indicators of School Turnarounds

    ERIC Educational Resources Information Center

    Kowal, Julie; Ableidinger, Joe

    2011-01-01

    In recent years, national policymakers have placed new emphasis on "school turnarounds" as a strategy for rapid, dramatic improvement in chronically failing schools, calling on education leaders to turn around performance in the 5,000 lowest-achieving schools nationwide. This goal may seem daunting, given the dismal success rates of school…

  18. Athenian and Shakespearean Tragedies in Oceania: Teaching Dramatic Literatures in Fiji

    ERIC Educational Resources Information Center

    Anae, Nicole

    2013-01-01

    This paper presents a theorised classroom-based narrative discussing the author's interdisciplinary approach to the teaching of English dramatic literatures--in particular, Sophocles' "Oedipus the King" and Shakespeare's "Macbeth"--to i-Taukei, Indo-Fijian and Pacific Islander tertiary students at a South Pacific…

  19. Erotic Language as Dramatic Action in Plays by Lyly and Shakespeare

    ERIC Educational Resources Information Center

    Knoll, Gillian

    2012-01-01

    This study closely examines the language of desire in the dramatic works of John Lyly and William Shakespeare, and argues that contemplative and analytical speeches about desire function as modes of action in their plays. Erotic speeches do more than express desire in a purely descriptive or perlocutionary capacity distinct from the action of the…

  20. Creating Drama with Poetry: Teaching English as a Second Language through Dramatization and Improvisation. ERIC Digest.

    ERIC Educational Resources Information Center

    Gasparro, Marie; Falletta, Bernadette

    The use of poetry as drama in the English as a Second Language (ESL) classroom enables students to explore the linguistic and conceptual aspects of the written text without concentrating on the mechanics of language. Students are able to develop a sense of awareness of self in the target culture through dramatic interpretations of the poems.…

  1. Engaging in Dramatic Activities in English as a Foreign Language Classes at the University Level

    ERIC Educational Resources Information Center

    Algarra Carrasco, Victoria

    2012-01-01

    In this article, we discuss how, through dramatic activities, fiction and reality can work together to help the English as a Foreign language learner communicate in a more personal and meaningful way. The kind of activities proposed are designed to help engender a space where students can personally engage with each other in an atmosphere that is…

  2. Mantle of the Expert: Integrating Dramatic Inquiry and Visual Arts in Social Studies

    ERIC Educational Resources Information Center

    Johnson, Edric C.; Liu, Katrina; Goble, Kristin

    2015-01-01

    This article introduces the social studies field to Dorothy Heatchote's Mantle of Expert (MOE). MOE is a dramatic inquiry approach used in several subject areas and can work at all levels in the social studies curriculum. The authors go into the development of using this approach in an elementary and middle teacher education program. After sharing…

  3. Some Therapeutic Uses of Dramatic Play with the Aggressive Child in the Preschool Classroom.

    ERIC Educational Resources Information Center

    Ginnane, Patrick

    The primary purpose of this master's thesis is to describe some therapeutic uses of dramatic play with the mildly aggressive preschool child. The child for whom the suggested play interventions are considered appropriate is characterized by sociality and attachment to both peers and adults, and is not chronically aggressive. After the first…

  4. The Accessibility of Socio-Dramatic Play to Culturally and Linguistically Diverse Australian Preschoolers

    ERIC Educational Resources Information Center

    Scrafton, Eleanor; Whitington, Victoria

    2015-01-01

    Socio-dramatic play is preschool children's leading learning activity (Karpov 2005; Vygotsky 1978). Yet entering play often poses challenges (Corsaro 2003), particularly for culturally and linguistically diverse (CALD) children (Hruska 2007). At preschool four-year-old CALD children are both acquiring a new language, and learning new rules, social…

  5. Effects of Dramatized Depictions of Accidents on Grade School Children's Reception of Safety Guidelines.

    ERIC Educational Resources Information Center

    Omdahl, Becky L.; Cantor, Joanne

    A study examined a format for fear appeal messages that introduced a threat through one medium (i.e., a segment of dramatic television programming) and the recommended action through another medium (i.e., the verbal presentation of safety guidelines by an adult to a child). Subjects, 138 elementary school children from a middle-class elementary…

  6. An Investigation of the Effects of Creative Dramatics on Ninth Grade Students.

    ERIC Educational Resources Information Center

    Ridel, Shelby Jean Harvey

    The purposes of this study were to describe the use of creative dramatics within an average ninth grade arts class and to document the behavior changes in verbal and nonverbal communications, creative thinking and behavior, feeling of group closeness, self-confidence, and attitude toward the course. A teacher inexperienced in drama conducted the…

  7. Do Props Matter in the Dramatic Play Center? The Effects of Prop Realism on Children's Play.

    ERIC Educational Resources Information Center

    Hogan, Claudia; Howe, Nina

    2001-01-01

    This study investigated the effects of prop realism on the play of 24 preschoolers. Observations of play sessions revealed that highly realistic props and low-realism props elicited equal amounts of group dramatic play. However, low- realism props generated greater diversity of play themes, more fantasy role enactments, and more nonintended use of…

  8. "Welcome to Philadelphia": An Original Dramatization of Life in the 1780s.

    ERIC Educational Resources Information Center

    Stakes, Mary E.

    Teachers can create an interest in the founding period of U.S. history and present students with an authentic view of this time period through the presentation of this play. The dramatic pretense of the play is that the audience, by their presence, is part of the drama. The audience plays the part of travelers visiting a Philadelphia home in the…

  9. National Lighting Bureau Reports Dramatic Energy Savings Possible through Minor Lighting Modifications.

    ERIC Educational Resources Information Center

    College Store Journal, 1979

    1979-01-01

    Dramatic savings are possible by implementing minor modifications including: energy efficient light bulbs and tubes, ballasts, luminaires (fixtures), controls, operating practices, and revised maintenance. Many different changes can be made without affecting productivity, safety and security, visual comfort, aesthetic appeal, consumer discretion,…

  10. Phosphorylation-related modification at the dimer interface of 14-3-3ω dramatically alters monomer interaction dynamics.

    PubMed

    Denison, Fiona C; Gökirmak, Tufan; Ferl, Robert J

    2014-01-01

    14-3-3 proteins are generally believed to function as dimers in a broad range of eukaryotic signaling pathways. The consequences of altering dimer stability are not fully understood. Phosphorylation at Ser58 in the dimer interface of mammalian 14-3-3 isoforms has been reported to destabilise dimers. An equivalent residue, Ser62, is present across most Arabidopsis isoforms but the effects of phosphorylation have not been studied in plants. Here, we assessed the effects of phosphorylation at the dimer interface of Arabidopsis 14-3-3ω. Protein kinase A phosphorylated 14-3-3ω at Ser62 and also at a previously unreported residue, Ser67, resulting in a monomer-sized band on native-PAGE. Phosphorylation at Ser62 alone, or with additional Ser67 phosphorylation, was investigated using phosphomimetic versions of 14-3-3ω. In electrophoretic and chromatographic analyses, these mutants showed mobilities intermediate between dimers and monomers. Mobility was increased by detergents, by reducing protein concentration, or by increasing pH or temperature. Urea gradient gels showed complex structural transitions associated with alterations of dimer stability, including a previously unreported 14-3-3 aggregation phenomenon. Overall, our analyses showed that dimer interface modifications such as phosphorylation reduce dimer stability, dramatically affecting the monomer-dimer equilibrium and denaturation trajectory. These findings may have dramatic implications for 14-3-3 structure and function in vivo.

  11. Nitrogen abundance in Comet Halley

    NASA Technical Reports Server (NTRS)

    Wyckoff, Susan; Tegler, Stephen C.; Engel, Lisa

    1991-01-01

    Data on the nitrogen-containing compounds that observed spectroscopically in the coma of Comet Halley are summarized, and the elemental abundance of nitrogen in the Comet Halley nucleus is derived. It is found that 90 percent of elemental nitrogen is in the dust fraction of the coma, while in the gas fraction, most of the nitrogen is contained in NH3 and CN. The elemental nitrogen abundance in the ice component of the nucleus was found to be deficient by a factor of about 75, relative to the solar photosphere, indicating that the chemical partitioning of N2 into NH3 and other nitrogen compounds during the evolution of the solar nebula cannot account completely for the low abundance ratio N2/NH3 = 0.1, observed in the comet. It is suggested that the low N2/NH3 ratio in Comet Halley may be explained simply by physical fractionation and/or thermal diffusion.

  12. Solar and stellar photospheric abundances

    NASA Astrophysics Data System (ADS)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  13. Robust Abundance Estimation in Animal Abundance Surveys with Imperfect Detection

    EPA Science Inventory

    Surveys of animal abundance are central to the conservation and management of living natural resources. However, detection uncertainty complicates the sampling process of many species. One sampling method employed to deal with this problem is depletion (or removal) surveys in whi...

  14. Three energy variables predict ant abundance at a geographical scale.

    PubMed

    Kaspari, M; Alonso, L; O'Donnell, S

    2000-03-01

    Energy theory posits three processes that link local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World habitats found a two order of magnitude span in the abundance (nests m(-2)) of ground nesting ants (Formicidae). Abundance increased with net primary productivity (r2=0.55), a measure of the baseline supply of harvestable energy. Abundance further increased with mean temperature (r2=0.056), a constraint on foraging activity for this thermophilic taxon. Finally for a given mean temperature, ants were more abundant in seasonal sites with longer, colder winters (r2 = 0.082) that help ectotherm taxa sequester harvested energy in non-productive months. All three variables are currently changing on a global scale. All should be useful in predicting biotic responses to climate change.

  15. Coronal Abundances and Their Variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1996-01-01

    This contract supported the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study were a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This is the Final Report, summarizing the data analysis and reporting activities which occurred during the period of performance, June 1993 - December 1996.

  16. Chemical Abundances of Symbiotic Giants

    NASA Astrophysics Data System (ADS)

    Gałan, C.; Mikołajewska, J.; Hinkle, K. H.; Joyce, R. R.

    2015-12-01

    High resolution (R ˜ 50000), near-IR spectra were used to measure photospheric abundances of CNO and elements around the iron peak for 24 symbiotic giants. Spectrum synthesis was employed using local thermal equilibrium and hydrostatic model atmospheres. The metallicities are distributed in a wide range with maximum around [Fe/H] ˜-0.4 - - 0.3 dex. Enrichment in 14N indicates that all the sample giants have experienced the first dredge-up. The relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  17. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1994-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft x-ray spectra from the Flat Crystal Spectrometer (FCS) on the Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred during the first ten months of the contract, 15 Jun. 1993 to 15 Apr. 1994.

  18. The solar abundance of beryllium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    The solar abundance of beryllium is deduced from high-resolution Kitt Peak observations of the 3130.43- and 3131.08-A lines of Be II interpreted by the method of spectrum synthesis. The results are in good agreement with those previously obtained by Grevesse (1968) and by Hauge and Engvold (1968) and indicate that in the photospheric layers, beryllium is depleted below the chondritic value by a factor of about two. It is found that the beryllium abundance is equal to logN(Be)/N(H) + 12 = 1.08 plus or minus 0.05.

  19. SOLAR MODELS WITH REVISED ABUNDANCE

    SciTech Connect

    Bi, S. L.; Li, T. D.; Yang, W. M.; Li, L. H.

    2011-04-20

    We present new solar models in which we use the latest low abundances and further include the effects of rotation, magnetic fields, and extra-mixing processes. We assume that the extra-element mixing can be treated as a diffusion process, with the diffusion coefficient depending mainly on the solar internal configuration of rotation and magnetic fields. We find that such models can well reproduce the observed solar rotation profile in the radiative region. Furthermore, the proposed models can match the seismic constraints better than the standard solar models, also when these include the latest abundances, but neglect the effects of rotation and magnetic fields.

  20. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot.

    PubMed

    Hirschfeld, Mareike; Blackburn, David C; Doherty-Bone, Thomas M; Gonwouo, LeGrand Nono; Ghose, Sonia; Rödel, Mark-Oliver

    2016-01-01

    Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004-2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon's frog diversity.

  1. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot

    PubMed Central

    Hirschfeld, Mareike; Blackburn, David C.; Doherty-Bone, Thomas M.; Gonwouo, LeGrand Nono; Ghose, Sonia; Rödel, Mark-Oliver

    2016-01-01

    Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004–2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon’s frog diversity. PMID:27149624

  2. The primordial helium abundance from updated emissivities

    SciTech Connect

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.; Porter, R.L. E-mail: olive@umn.edu E-mail: skillman@astro.umn.edu

    2013-11-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y{sub p}. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y{sub p}. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y{sub p} = 0.2465 ± 0.0097, in good agreement with the BBN result, Y{sub p} = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.

  3. Climatic effects on mosquito abundance in Mediterranean wetlands

    PubMed Central

    2014-01-01

    Background The impact of climate change on vector-borne diseases is highly controversial. One of the principal points of debate is whether or not climate influences mosquito abundance, a key factor in disease transmission. Methods To test this hypothesis, we analysed ten years of data (2003–2012) from biweekly surveys to assess inter-annual and seasonal relationships between the abundance of seven mosquito species known to be pathogen vectors (West Nile virus, Usutu virus, dirofilariasis and Plasmodium sp.) and several climatic variables in two wetlands in SW Spain. Results Within-season abundance patterns were related to climatic variables (i.e. temperature, rainfall, tide heights, relative humidity and photoperiod) that varied according to the mosquito species in question. Rainfall during winter months was positively related to Culex pipiens and Ochlerotatus detritus annual abundances. Annual maximum temperatures were non-linearly related to annual Cx. pipiens abundance, while annual mean temperatures were positively related to annual Ochlerotatus caspius abundance. Finally, we modelled shifts in mosquito abundances using the A2 and B2 temperature and rainfall climate change scenarios for the period 2011–2100. While Oc. caspius, an important anthropophilic species, may increase in abundance, no changes are expected for Cx. pipiens or the salt-marsh mosquito Oc. detritus. Conclusions Our results highlight that the effects of climate are species-specific, place-specific and non-linear and that linear approaches will therefore overestimate the effect of climate change on mosquito abundances at high temperatures. Climate warming does not necessarily lead to an increase in mosquito abundance in natural Mediterranean wetlands and will affect, above all, species such as Oc. caspius whose numbers are not closely linked to rainfall and are influenced, rather, by local tidal patterns and temperatures. The final impact of changes in vector abundance on disease frequency

  4. Top consumer abundance influences lake methane efflux

    PubMed Central

    Devlin, Shawn P.; Saarenheimo, Jatta; Syväranta, Jari; Jones, Roger I.

    2015-01-01

    Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This reduction in zooplankton density increases the abundance of methanotrophic bacteria, which in turn reduce CH4 efflux rates by roughly 10 times. Given that globally there are millions of lakes emitting methane, an important greenhouse gas, our findings that aquatic trophic interactions significantly influence the biogeochemical cycle of methane has important implications. PMID:26531291

  5. Top consumer abundance influences lake methane efflux.

    PubMed

    Devlin, Shawn P; Saarenheimo, Jatta; Syväranta, Jari; Jones, Roger I

    2015-01-01

    Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This reduction in zooplankton density increases the abundance of methanotrophic bacteria, which in turn reduce CH4 efflux rates by roughly 10 times. Given that globally there are millions of lakes emitting methane, an important greenhouse gas, our findings that aquatic trophic interactions significantly influence the biogeochemical cycle of methane has important implications. PMID:26531291

  6. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  7. Change in gene abundance in the nitrogen biogeochemical cycle with temperature and nitrogen addition in Antarctic soils.

    PubMed

    Jung, Jaejoon; Yeom, Jinki; Kim, Jisun; Han, Jiwon; Lim, Hyoun Soo; Park, Hyun; Hyun, Seunghun; Park, Woojun

    2011-12-01

    The microbial community (bacterial, archaeal, and fungi) and eight genes involved in the nitrogen biogeochemical cycle (nifH, nitrogen fixation; bacterial and archaeal amoA, ammonia oxidation; narG, nitrate reduction; nirS, nirK, nitrite reduction; norB, nitric oxide reduction; and nosZ, nitrous oxide reduction) were quantitatively assessed in this study, via real-time PCR with DNA extracted from three Antarctic soils. Interestingly, AOB amoA was found to be more abundant than AOA amoA in Antarctic soils. The results of microcosm studies revealed that the fungal and archaeal communities were diminished in response to warming temperatures (10 °C) and that the archaeal community was less sensitive to nitrogen addition, which suggests that those two communities are well-adapted to colder temperatures. AOA amoA and norB genes were reduced with warming temperatures. The abundance of only the nifH and nirK genes increased with both warming and the addition of nitrogen. NirS-type denitrifying bacteria outnumbered NirK-type denitrifiers regardless of the treatment used. Interestingly, dramatic increases in both NirS and NirK-types denitrifiers were observed with nitrogen addition. NirK types increase with warming, but NirS-type denitrifiers tend to be less sensitive to warming. Our findings indicated that the Antarctic microbial nitrogen cycle could be dramatically altered by temperature and nitrogen, and that warming may be detrimental to the ammonia-oxidizing archaeal community. To the best of our knowledge, this is the first report to investigate genes associated with each process of the nitrogen biogeochemical cycle in an Antarctic terrestrial soil environment.

  8. Fire, grazing history, lichen abundance, and winter distribution of caribou in Alaska's taiga

    USGS Publications Warehouse

    Collins, W.B.; Dale, B.W.; Adams, L.G.; McElwain, D.E.; Joly, Kyle

    2011-01-01

    In the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with >20% lichen cover (P < 0.001), greater than 1,250 kg/ha (P < 0.001) forage lichen biomass and stands older than 80 yr postfire (P < 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after ???60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis-idaea) were necessary for predicting caribou use of winter range. ?? 2011 The Wildlife Society.

  9. Actinide abundances in ordinary chondrites

    USGS Publications Warehouse

    Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

    1990-01-01

    Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

  10. Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona

    NASA Astrophysics Data System (ADS)

    Landi, E.; Testa, P.

    2015-02-01

    In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017 this value is lower than the transition region determinations from the quiet Sun used to infer the neon photospheric abundance from the oxygen photospheric abundance. Also, the Ne/O ratio we determined from SUMER is in excellent agreement with in situ determinations from ACE/SWICS. In 2005-2008, the Ne/O abundance ratio increased with time and reached 0.25 ± 0.05, following the same trend found in the slowest wind analyzed by ACE/SWICS. Further, we measure the absolute abundance in the corona for both oxygen and neon from the data set of 1996 November 22, obtaining A o = 8.99 ± 0.04 and A Ne = 7.92 ± 0.03, and we find that both elements are affected by the first ionization potential (FIP) effect, with oxygen being enhanced by a factor of 1.4-2.1 over its photospheric abundance, and neon being changed by a factor of 0.75-1.20. We conclude that the Ne/O ratio is not constant in the solar atmosphere, both in time and at different heights, and that it cannot be reliably used to infer the neon abundance in the photosphere. Also, we argue that the FIP effect was less effective during the minimum of solar cycle 24, and that the Ne/O = 0.25 ± 0.05 value measured at that time is closer to the true photospheric value, leading to a neon photospheric abundance larger than assumed by ≈40%. We discuss the implications of these results for the solar abundance problem, for the FIP effect, and for the identification of the source regions of the solar wind.

  11. DRAMATIC IMPROVEMENTS IN CAUSTIC-SIDE SOLVENT EXTRACTION OF CESIUM THROUGH MORE EFFICIENT STRIPPING

    SciTech Connect

    Delmau, Laetitia Helene; Bazelaire, Eve; Bonnesen, Peter V; Engle, Nancy L; Gorbunova, Maryna; Haverlock, Tamara; Moyer, Bruce A; Ensor, Dale; Meadors, Viola M; Harmon, Ben; Bartsch, Richard A.; Surowiec, Malgorzata A.; Zhou, Hui

    2008-01-01

    Dramatic potential improvements to the chemistry of the Caustic-Side Solvent Extraction (CSSX) process are presented as related to enhancement of cesium stripping. The current process for removing cesium from the alkaline high-level waste (HLW) at the USDOE Savannah River Site employs acidic scrub and strip stages and shows remarkable extraction and selectivity properties for cesium. It was determined that cesium stripping can be greatly improved with caustic or near-neutral stages using sodium hydroxide and boric acid as scrub and strip solutions, respectively. Improvements can also be achieved by appending pH-sensitive functional groups to the calix[4]arene-crown-6 extractant. Addition of a proton-ionizable group to the calixarene frame leads to a dramatic "pH swing" of up to 6 orders of magnitude change in cesium distribution ratio.

  12. Consequential classes of resources: Subtle global bifurcation with dramatic ecological consequences in a simple population model.

    PubMed

    Vandermeer, John; King, Aaron

    2010-03-21

    Numerous situations exist in which a consumer uses two different kinds of resources, one fixed, the other renewable, e.g., nesting resources and food resources. With an elementary modification of the basic Lotka-Volterra consumer resource equations, we investigate the population dynamics of a consumer dependent on two resources, one fixed, the other renewable. Emerging from this structure is a situation of alternative attractors that remain qualitatively robust over a significant range of parameter values. However, a dramatic change in basins of attraction is induced by very small changes in parameters due to a global bifurcation. Noteworthy is the fact that the qualitative nature of the alternative equilibria remains constant but the dramatic change in the basins does not arise from subtle differences in initial conditions. Rather, there is a major restructuring of the vector field such that a permanent change involving large sets of initial conditions results from very small changes in parameters.

  13. Dramatic reduction in tumor burden with neoadjuvant sunitinib prior to bilateral nephron-sparing surgery.

    PubMed

    Gorin, Michael A; Ekwenna, Obi; Soloway, Mark S; Ciancio, Gaetano

    2012-02-01

    Neoadjuvant sunitinib has recently been described for the management of renal cell carcinoma. We present the pre and posttreatment images of a 49-year-old male with bilateral biopsy-proven clear cell renal cell carcinoma who underwent treatment with sunitinib prior to nephron-sparing surgery. After four four-week cycles of daily 50 mg sunitinib, the patient demonstrated a dramatic reduction in tumor burden allowing for successful bilateral partial nephrectomy.

  14. Discrimination, developmental science, and the law: addressing dramatic shifts in civil rights jurisprudence.

    PubMed

    Levesque, Roger J R

    2014-01-01

    The civil rights movement fostered dramatic shifts in legal responses to discrimination based on race, gender, and a host of other group characteristics. The legal system now evinces yet another dramatic shift, as it moves from considering difference to focusing on neutrality, from efforts that seek to counter subjugation to those that adopt a "color-blind" approach. The shifting approach already has reached laws regulating responses to the group that spurred massive civil rights reform: minority youth. The shift requires a different body of empirical evidence to address it and a new look at equality jurisprudence. This article notes the need to turn to the current understanding of prejudice and discrimination for guidance, and uses, as illustration, developmental science to shed light on the development, manifestation, and alleviation of invidious discrimination. Using that understanding, the analysis details how the legal system can benefit from that research and better address discrimination in light of dramatic changes in law. The article articulates the need to address discrimination by recognizing and enlisting the law's inculcative powers through multiple sites of inculcation, ranging from families, schools, health and justice systems to religious and community groups. The discussion concludes with brief suggestions for reform benefiting from understandings of prejudice and its expression.

  15. Discrimination, developmental science, and the law: addressing dramatic shifts in civil rights jurisprudence.

    PubMed

    Levesque, Roger J R

    2014-01-01

    The civil rights movement fostered dramatic shifts in legal responses to discrimination based on race, gender, and a host of other group characteristics. The legal system now evinces yet another dramatic shift, as it moves from considering difference to focusing on neutrality, from efforts that seek to counter subjugation to those that adopt a "color-blind" approach. The shifting approach already has reached laws regulating responses to the group that spurred massive civil rights reform: minority youth. The shift requires a different body of empirical evidence to address it and a new look at equality jurisprudence. This article notes the need to turn to the current understanding of prejudice and discrimination for guidance, and uses, as illustration, developmental science to shed light on the development, manifestation, and alleviation of invidious discrimination. Using that understanding, the analysis details how the legal system can benefit from that research and better address discrimination in light of dramatic changes in law. The article articulates the need to address discrimination by recognizing and enlisting the law's inculcative powers through multiple sites of inculcation, ranging from families, schools, health and justice systems to religious and community groups. The discussion concludes with brief suggestions for reform benefiting from understandings of prejudice and its expression. PMID:24826823

  16. Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan.

    PubMed

    Dutcher, James D; Karar, Haider; Abbas, Ghulam

    2012-01-01

    Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006-2011) from full leaf expansion in May to leaf fall in October in "Desirable" variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids. PMID:26466738

  17. Environmental factors shaping ungulate abundances in Poland.

    PubMed

    Borowik, Tomasz; Cornulier, Thomas; Jędrzejewska, Bogumiła

    2013-01-01

    Population densities of large herbivores are determined by the diverse effects of density-dependent and independent environmental factors. In this study, we used the official 1998-2003 inventory data on ungulate numbers from 462 forest districts and 23 national parks across Poland to determine the roles of various environmental factors in shaping country-wide spatial patterns of ungulate abundances. Spatially explicit generalized additive mixed models showed that different sets of environmental variables explained 39 to 50 % of the variation in red deer Cervus elaphus, wild boar Sus scrofa, and roe deer Capreolus capreolus abundances. For all of the studied species, low forest cover and the mean January temperature were the most important factors limiting their numbers. Woodland cover above 40-50 % held the highest densities for these species. Wild boar and roe deer were more numerous in deciduous or mixed woodlands within a matrix of arable land. Furthermore, we found significant positive effects of marshes and water bodies on wild boar abundances. A juxtaposition of obtained results with ongoing environmental changes (global warming, increase in forest cover) may indicate future growth in ungulate distributions and numbers.

  18. Absolute Quantification of Endogenous Ras Isoform Abundance

    PubMed Central

    Mageean, Craig J.; Griffiths, John R.; Smith, Duncan L.; Clague, Michael J.; Prior, Ian A.

    2015-01-01

    Ras proteins are important signalling hubs situated near the top of networks controlling cell proliferation, differentiation and survival. Three almost identical isoforms, HRAS, KRAS and NRAS, are ubiquitously expressed yet have differing biological and oncogenic properties. In order to help understand the relative biological contributions of each isoform we have optimised a quantitative proteomics method for accurately measuring Ras isoform protein copy number per cell. The use of isotopic protein standards together with selected reaction monitoring for diagnostic peptides is sensitive, robust and suitable for application to sub-milligram quantities of lysates. We find that in a panel of isogenic SW48 colorectal cancer cells, endogenous Ras proteins are highly abundant with ≥260,000 total Ras protein copies per cell and the rank order of isoform abundance is KRAS>NRAS≥HRAS. A subset of oncogenic KRAS mutants exhibit increased total cellular Ras abundance and altered the ratio of mutant versus wild type KRAS protein. These data and methodology are significant because Ras protein copy number is required to parameterise models of signalling networks and informs interpretation of isoform-specific Ras functional data. PMID:26560143

  19. Abundances of 23 field RR Lyrae stars

    NASA Astrophysics Data System (ADS)

    Liu, Shu; Zhao, Gang; Chen, Yu-Qin; Takeda, Yoichi; Honda, Satoshi

    2013-11-01

    We present stellar parameters and abundances of 15 elements (Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Y and Ba) for 23 field RR Lyrae variables based on high-resolution (R ~ 60 000) and high signal-to-noise (S/N~ 200) spectra obtained using the High Dispersion Spectrograph on the Subaru Telescope. Six stars in the sample have more than one spectrum observed at different pulsation phases. The derived abundance ratios of [X/Fe] for 14 elements (except for Ba) do not vary during the pulsation cycle. An interesting curve of [Ba/Fe] versus phase is detected for the first time and it shows decreasing [Ba/Fe] with increasing temperature at a given metallicity. Combining with data in the literature, abundances of most RR Lyrae stars as a function of [Fe/H] follow the same trends as those of dwarf stars, but [Sc/Fe] and [Y/Fe] ratios of RR Lyrae stars at solar metallicity are lower than those of dwarf stars. The kinematics of RR Lyrae stars indicate that three comparatively metal-rich RR Lyrae stars might originate from the thick disk and they show higher [α/Fe] ratios than RR Lyrae stars with thin disk kinematics. Among 23 RR Lyrae stars, two special objects are found with abnormal abundances; TV Lib has high [α/Fe], [Sc/Fe], [Y/Fe] and [Ba/Fe] ratios while TW Her has solar [α/Fe] but significantly lower [Sc/Fe], [Y/Fe] and [Ba/Fe] ratios as compared with other RR Lyrae stars.

  20. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1994-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution software X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred since the last report, submitted two months early, in April 1994, to facilitate evaluation of the first year's progress for contract renewal. Hence this report covers the period 15 April 1994 - 15 December 1994. A list of publications resulting from this research is included.

  1. The solar abundance of thulium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    Consideration of one relatively unblended line of the solar spectrum, namely, the 3131.258-A line of Tm II, which yields a thulium abundance of 0.80 plus or minus 0.10 with the Corliss and Bozman (1962) f-value. The uncertainty of this figure is discussed in conjunction with the contradictory findings of some other investigators. The need for further detailed study of the lanthanides by the method of spectrum synthesis is pointed out.

  2. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  3. The Bliss of Motor Abundance

    PubMed Central

    Latash, Mark L.

    2012-01-01

    Motor control is an area of natural science exploring how the nervous system interacts with other body parts and the environment to produce purposeful, coordinated actions. A central problem of motor control – the problem of motor redundancy – was formulated by Nikolai Bernstein as the problem of elimination of redundant degrees-of-freedom. Traditionally, this problem has been addressed using optimization methods based on a variety of cost functions. This review draws attention to a body of recent findings suggesting that the problem has been formulated incorrectly. An alternative view has been suggested as the principle of abundance, which considers the apparently redundant degrees-of-freedom as useful and even vital for many aspects of motor behavior. Over the past ten years, dozens of publications have provided support for this view based on the ideas of synergic control, computational apparatus of the uncontrolled manifold hypothesis, and the equilibrium-point (referent configuration) hypothesis. In particular, large amounts of “good variance” – variance in the space of elements that has no effect on the overall performance – have been documented across a variety of natural actions. “Good variance” helps an abundant system to deal with secondary tasks and unexpected perturbations; its amount shows adaptive modulation across a variety of conditions. These data support the view that there is no problem of motor redundancy; there is bliss of motor abundance. PMID:22246105

  4. The dramatic effect of small pH changes on the properties of chitosan hydrogels crosslinked with genipin.

    PubMed

    Delmar, Keren; Bianco-Peled, Havazelet

    2015-01-01

    We report on intriguing new phenomena related to the creation of chitosan hydrogels crosslinked with genipin. We found that the reaction between chitosan and genipin is very slow, sometimes requiring more than four days until completed. Further, we discovered that altering the pH within the small range of 4.00-5.50 dramatically affects the reaction, leading to hydrogels differing both in appearance and in properties. Increasing the pH by 1.5 units led to an almost fourfold decrease in the gelation time and more than tenfold equilibrium swelling. A correlation between the percentage of unreacted genipin molecules and the hydrogel properties was identified. The strong pH dependency was attributed to the degree of chitosan protonation and to the inability of protonated chitosan to react with genipin. This research shows, for the first time, that minor changes in the pH can lead to substantially different hydrogels.

  5. The Abundance of Interstellar Fluorine

    NASA Technical Reports Server (NTRS)

    Lauroesch, James T.

    2005-01-01

    The primary objective of this program was to obtain FUSE observations of the interstellar absorption lines of F I at 951 and 954 Angstroms to derive the abundance of fluorine toward the star HD 164816. The nucleosynthetic source(s) of fluorine are still a matter of debate - the present day abundance of fluorine can potentially constrain models for pulsationally driven dredge-up in asymptotic giant branch stars. An accurate measure for the depletion behavior of fluorine will determine whether it may be detectable in QSO absorption line systems - an unambiguous detection of fluorine at suitably high redshifts would provide the best evidence to date for the neutrino process in massive stars. Furthermore, due to its extreme reactivity, measurement of the gas-phase interstellar fluorine abundance is important for models of grain chemistry. Despite the importance of measuring the interstellar fluorine abundance, at the time of our proposal only one previous detection has been made due to the low relative abundance of fluorine, the lack of lines outside the far-UV, and the blending of the available F I transitions with lines of Hz. The star HD 164816 is associated with the Lagoon nebula (M8), and at a distance of approximately 1.5 kpc probes both distant and local gas. Beginning April 8th, 2004 FUSE FP-Split observations of the star HD 164816 were obtained for this program. This data became available in the FUSE data archive May 21, 2004, and these observations were then downloaded and we began our analysis. Our analysis procedure has involved (1) fitting stellar models to the FUSE spectra, (2) using the multiple lines of Hz and N I at other wavelengths in the FUSE bandpass to derive column densities for the lines of H2 and N I which are blended with the F I features at 951 and 954 angstroms (3) the measurement of the column densities of F I and the species O I and C1 I which are important species for the dis-entangling of dust and nucleosynthetic effects. As discussed in

  6. FGF-21, a novel metabolic regulator, has a robust neuroprotective role and is dramatically elevated in neurons by mood stabilizers

    PubMed Central

    Leng, Yan; Wang, Zhifei; Tsai, Li-Kai; Leeds, Peter; Fessler, Emily Bame; Wang, Junyu; Chuang, De-Maw

    2013-01-01

    Fibroblast growth factor-21 (FGF-21) is a new member of the FGF super-family and an important endogenous regulator of glucose and lipid metabolism. It has been proposed as a therapeutic target for diabetes and obesity. Its function in the central nervous system (CNS) remains unknown. Previous studies from our laboratory demonstrated that aging primary neurons are more vulnerable to glutamate-induced excitotoxicity, and that co-treatment with the mood stabilizers lithium and valproic acid (VPA) induces synergistic neuroprotective effects. This study sought to identify molecule(s) involved in these synergistic effects. We found that FGF-21 mRNA was selectively and dramatically elevated by co-treatment with lithium and VPA in primary rat brain neurons. FGF-21 protein levels were also robustly increased in neuronal lysates and culture medium following lithium-VPA co-treatment. Combining glycogen synthase kinase-3 (GSK-3) inhibitors with VPA or histone deacetylase (HDAC) inhibitors with lithium synergistically increased FGF-21 mRNA levels, supporting that synergistic effects of lithium and VPA are mediated via GSK-3 and HDAC inhibition, respectively. Exogenous FGF-21 protein completely protected aging neurons from glutamate challenge. This neuroprotection was associated with enhanced Akt-1 activation and GSK-3 inhibition. Lithium-VPA co-treatment dramatically prolonged lithium-induced Akt-1 activation and augmented GSK-3 inhibition. Akt-1 knockdown markedly decreased FGF-21 mRNA levels, and reduced the neuroprotection induced by FGF-21 or lithium-VPA co-treatment. In addition, FGF-21 knockdown reduced lithium-VPA co-treatment-induced Akt-1 activation and neuroprotection against excitotoxicity. Together, our novel results suggest that FGF-21 is a key mediator of the effects of these mood stabilizers, and a potential new therapeutic target for CNS disorders. PMID:24468826

  7. Gorham-Stout Disease of the Skull Base With Hearing Loss: Dramatic Recovery and Antiangiogenic Therapy.

    PubMed

    Nozawa, Akifumi; Ozeki, Michio; Kuze, Bunya; Asano, Takahiko; Matsuoka, Kentaro; Fukao, Toshiyuki

    2016-05-01

    Gorham-Stout disease (GSD) is a rare disorder of unknown etiology. We present a 6-year-old male with GSD involving the skull base who presented with recurrent cerebrospinal fluid (CSF) rhinorrhea, severe hearing loss, and facial palsy secondary to cerebellar herniation into the internal auditory canal. After 2 months of treatment with pegylated interferon (IFN) α-2b (50 μg/week), his hearing recovered dramatically. Two years later, new bone formation appeared radiologically and IFN was switched to sirolimus. One year after the switch, CSF rhinorrhea disappeared. Antiangiogenic therapy might inhibit proliferation of vascular endothelial cells in osteolytic lesions and lead to new bone formation.

  8. Dramatic role of critical current anisotropy on flux avalanches in MgB2 films.

    PubMed

    Albrecht, J; Matveev, A T; Strempfer, J; Habermeier, H-U; Shantsev, D V; Galperin, Y M; Johansen, T H

    2007-03-16

    Anisotropic penetration of magnetic flux in MgB(2) films grown on vicinal sapphire substrates is investigated using magneto-optical imaging. Regular penetration above 10 K proceeds more easily along the substrate surface steps, the anisotropy of the critical current being 6%. At lower temperatures the penetration occurs via abrupt dendritic avalanches that preferentially propagate perpendicular to the surface steps. This inverse anisotropy in the penetration pattern becomes dramatic very close to 10 K where all flux avalanches propagate in the strongest pinning direction. The observed behavior is fully explained using a thermomagnetic model of the dendritic instability.

  9. Gorham-Stout Disease of the Skull Base With Hearing Loss: Dramatic Recovery and Antiangiogenic Therapy.

    PubMed

    Nozawa, Akifumi; Ozeki, Michio; Kuze, Bunya; Asano, Takahiko; Matsuoka, Kentaro; Fukao, Toshiyuki

    2016-05-01

    Gorham-Stout disease (GSD) is a rare disorder of unknown etiology. We present a 6-year-old male with GSD involving the skull base who presented with recurrent cerebrospinal fluid (CSF) rhinorrhea, severe hearing loss, and facial palsy secondary to cerebellar herniation into the internal auditory canal. After 2 months of treatment with pegylated interferon (IFN) α-2b (50 μg/week), his hearing recovered dramatically. Two years later, new bone formation appeared radiologically and IFN was switched to sirolimus. One year after the switch, CSF rhinorrhea disappeared. Antiangiogenic therapy might inhibit proliferation of vascular endothelial cells in osteolytic lesions and lead to new bone formation. PMID:26713883

  10. Dramatic changes in the magnetic coupling mechanism for La-doped CaMnO3.

    PubMed

    Granado, E; Moreno, N O; Martinho, H; García, A; Sanjurjo, J A; Torriani, I; Rettori, C; Neumeier, J J; Oseroff, S B

    2001-06-01

    The exchange interactions in polycrystalline samples of Ca1-xLaxMnO3 (0.00< or =x< or =0.05) are studied by means of Raman scattering and electron paramagnetic resonance. Dramatic reductions in the spin-phonon interactions and magnetic correlations are observed for La doping levels as small as approximately 2%-3%. These results show that the charge carriers play an important role in the overall exchange coupling in the electron-doped manganites, even at very low doping levels.

  11. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    NASA Technical Reports Server (NTRS)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  12. The solar abundance of Oxygen

    NASA Astrophysics Data System (ADS)

    Grevesse, N.

    2009-07-01

    With Martin Asplund (Max Planck Institute of Astrophysics, Garching) and Jacques Sauval (Observatoire Royal de Belgique, Brussels) I recently published detailed reviews on the solar chemical composition ({Asplund et al. 2005}, {Grevesse et al. 2007}). A new one, with Pat Scott (Stockholm University) as additional co-author, will appear in Annual Review of Astronomy and Astrophysics ({Asplund et al. 2009}). Here we briefly analyze recent works on the solar abundance of Oxygen and recommend a value of 8.70 in the usual astronomical scale.

  13. Abundance measurements in stellar environments

    NASA Astrophysics Data System (ADS)

    Leone, F.

    2014-05-01

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  14. Abundance measurements in stellar environments

    SciTech Connect

    Leone, F.

    2014-05-09

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  15. Energetic-Energetic Cocrystals of Diacetone Diperoxide (DADP): Dramatic and Divergent Sensitivity Modifications via Cocrystallization.

    PubMed

    Landenberger, Kira B; Bolton, Onas; Matzger, Adam J

    2015-04-22

    Here we report a series of energetic-energetic cocrystals that incorporate the primary explosive diacetone diperoxide (DADP) with a series of trihalotrinitrobenzene explosives: 1:1 DADP/1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 1:1 DADP/1,3,5-tribromo-2,4,6-trinitrobenzene (TBTNB), and 1:1 DADP/1,3,5-triiodo-2,4,6-trinitrobenzene (TITNB). Acetone peroxides are attractive for their inexpensive and facile synthesis, but undesirable properties such as poor stability, intractably high sensitivity and low density, an indicator for low explosive power, have limited their application. Here through cocrystallization the density, oxygen balance, and stability of DADP are dramatically improved. Regarding sensitivity, in the case of the DADP/TCTNB cocrystal, the high impact sensitivity of DADP is retained by the cocrystal, making it a denser and less volatile form of DADP that remains viable as a primary explosive. Conversely, the DADP/TITNB cocrystal features impact sensitivity that is greatly reduced relative to both pure DADP and pure TITNB, demonstrating for the first time an energetic cocrystal that is less sensitive to impact than either of its pure components. This dramatic difference in cocrystal sensitivities may stem from the significantly different halogen-peroxide interactions seen in each cocrystal structure. These results highlight how sensitivity is defined by complex relationships between inherent bond strengths and solid-state properties, and cocrystal series such as that presented here provide a powerful experimental platform to probe this relationship.

  16. Elemental Abundances of Mercury-Manganese Stars

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.

    We propose to obtain a carefully planned set of multiple high dispersion exposures of three MercuryManganese stars in both the SWP and LWP cameras. These observations will be coadded to increase the S/N ratio so that accurate elemental abundances can be derived for these examples of HgMn stars, each of which represents some extreme class aspect. This will increase of sample of HgMn stars from four to seven. Of particular interest are the abundances of N and Co in which some HgMn stars have shown remarkable underabundances. Comparison of the UV and optical spectra features due to light elements such as N (and C and 0) provide an observational framework to test NLTE models such as those of Takada (1993). This work has already shed some light on some of earlier findings for normal stars. The ability to accurately determine the surface chemical composition of the late B stars through such studies will lead to better tests for theories purporting to explain the origin of the chemical peculiarities seen in this temperature domain.

  17. Li-7 abundances in halo stars: Testing stellar evolution models and the primordial Li-7 abundance

    NASA Technical Reports Server (NTRS)

    Chaboyer, Brian; Demarque, P.

    1994-01-01

    A large number of stellar evolution models with (Fe/H) = -2.3 and -3.3 have been calculated in order to determine the primordial Li-7 abundance and to test current stellar evolution models by a comparison to the extensive database of accurate Li abundances in extremely metal-poor halo stars observed by Thorburn (1994). Standard models with gray atmospheres do a very good job of fitting the observed Li abundances in stars hotter than approximately 5600 K. They predict a primordial. Li-7 abundance of log N(Li) = 2.24 +/- 0.03. Models which include microscopic diffusion predict a downward curvature in the Li-7 destruction isochrones at hot temperatures which is not present in the observations. Thus, the observations clearly rule out models which include uninhibited microscopic diffusion of Li-7 from the surface of the star. Rotational mixing inhibits the microscopic diffusion and the (Fe/H) = -2.28 stellar models which include both diffusion and rotational mixing provide an excellent match to the mean trend in T(sub eff) which is present in the observations. Both the plateau stars and the heavily depleted cool stars are well fit by these models. The rotational mixing leads to considerable Li-7 depletion in these models and the primordial Li-7 abundance inferred from these models is log N(Li) = 3.08 +/- 0.1. However, the (Fe/H) = -3.28 isochrones reveal problems with the combined models. These isochrones predict a trend of decreasing log N(Li) with increasing T(sub eff) which is not present in the observations. Possible causes for this discrepancy are discussed.

  18. Shifting phenology and abundance under experimental warming alters trophic relationships and plant reproductive capacity.

    PubMed

    Liu, Yinzhan; Reich, Peter B; Li, Guoyong; Sun, Shucun

    2011-06-01

    Phenological mismatches due to climate change may have important ecological consequences. In a three-year study, phenological shifts due to experimental warming markedly altered trophic relationships between plants and insect herbivores, causing a dramatic decline of reproductive capacity for one of the plant species. In a Tibetan meadow, the gentian (Gentiana formosa) typically flowers after the peak larva density of a noctuid moth (Melanchra pisi) that primarily feeds on a dominant forb (anemone, Anemone trullifolia var. linearis). However, artificial warming of approximately 1.5 degrees C advanced gentian flower phenology and anemone vegetative phenology by a week, but delayed moth larvae emergence by two weeks. The warming increased larval density 10-fold, but decreased anemone density by 30%. The phenological and density shifts under warmed conditions resulted in the insect larvae feeding substantially on the gentian flowers and ovules; there was approximately 100-fold more damage in warmed than in unwarmed chambers. This radically increased trophic connection reduced gentian plant reproduction and likely contributed to its reduced abundance in the warmed chambers.

  19. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  20. Relative nuclei abundance inside the International Space Station

    NASA Astrophysics Data System (ADS)

    Larsson, Oscar

    2012-07-01

    The Sileye3/Alteino experiment was first operational on-board the International Space Station, ISS, 27 April 2002. From 2006 through 2009 it was activated for long duration measurements of relative particle abundance as part of the ESA ALTCRISS project. Measuring the relative abundance of different nuclei species inside the ISS gives important clues as to how the known cosmic ray spectrum outside the space station changes when traversing the hull, i.e. giving indications as to how the hadronic interactions in the hull gives rise to changes in the expected radiation environment for the astronauts, which is of great interest for risk assessments for future long duration deep space missions. In our work the relative abundance for nuclei species with energies above ≃ 60 MeV/n and 5 ≤ Z ≤ 26 are presented for different places and detector orientations inside the ISS, also with and without shielding of the detector. What can be seen when comparing with the relative abundance of nuclei in the cosmic rays, is a significant difference in abundance for odd Z nuclei, whereas even numbered are in better agreement. Odd Z nuclei are much more abundant inside the ISS. This is an update from our previous report with increased statistics and with relative abundance on more nuclei.

  1. Depletion of Abundant Plasma Proteins and Limitations of Plasma Proteomics

    PubMed Central

    Tu, Chengjian; Rudnick, Paul A.; Martinez, Misti Y.; Cheek, Kristin L.; Stein, Stephen E.; Slebos, Robbert J. C.; Liebler, Daniel C.

    2010-01-01

    Immunoaffinity depletion with antibodies to the top 7 or top 14 high abundance plasma proteins is used to enhance detection of lower abundance proteins in both shotgun and targeted proteomic analyses. We evaluated the effects of top 7/top 14 immunodepletion on the shotgun proteomic analysis of human plasma. Our goal was to evaluate the impact of immunodepletion on detection of proteins across detectable ranges of abundance. The depletion columns afforded highly repeatable and efficient plasma protein fractionation. Relatively few nontargeted proteins were captured by the depletion columns. Analyses of unfractionated and immunodepleted plasma by peptide isoelectric focusing (IEF), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) demonstrated enrichment of nontargeted plasma proteins by an average of 4-fold, as assessed by MS/MS spectral counting. Either top 7 or top 14 immunodepletion resulted in a 25% increase in identified proteins compared to unfractionated plasma. Although 23 low abundance (<10 ng mL−1) plasma proteins were detected, they accounted for only 5–6% of total protein identifications in immunodepleted plasma. In both unfractionated and immunodepleted plasma, the 50 most abundant plasma proteins accounted for 90% of cumulative spectral counts and precursor ion intensities, leaving little capacity to sample lower abundance proteins. Untargeted proteomic analyses using current LC-MS/MS platforms—even with immunodepletion—cannot be expected to efficiently discover low abundance, disease-specific biomarkers in plasma. PMID:20677825

  2. Socio-Dramatic Affective-Relational Intervention for Adolescents with Asperger Syndrome & High Functioning Autism: Pilot Study

    ERIC Educational Resources Information Center

    Lerner, Matthew D.; Mikami, Amori Yee; Levine, Karen

    2011-01-01

    This study examined the effectiveness of a novel intervention called "socio-dramatic affective-relational intervention" (SDARI), intended to improve social skills among adolescents with Asperger syndrome and high functioning autism diagnoses. SDARI adapts dramatic training activities to focus on in vivo practice of areas of social skill deficit…

  3. The Impact of Songwriting, Dramatization, and Performance on Third Graders' Ability To Learn and Retain Social Studies Concepts.

    ERIC Educational Resources Information Center

    Carpenter, Deborah

    A study examined the impact of song writing, dramatization, and performance on third graders' ability to learn and retain social studies concepts. Students (n=18) were taught a unit on natural land forms and bodies of water in which they dramatized and performed songs which incorporated the main ideas of each unit. Upon completion of each unit,…

  4. Bumble Bees (Bombus spp) along a Gradient of Increasing Urbanization

    PubMed Central

    Ahrné, Karin; Bengtsson, Jan; Elmqvist, Thomas

    2009-01-01

    Background Bumble bees and other wild bees are important pollinators of wild flowers and several cultivated crop plants, and have declined in diversity and abundance during the last decades. The main cause of the decline is believed to be habitat destruction and fragmentation associated with urbanization and agricultural intensification. Urbanization is a process that involves dramatic and persistent changes of the landscape, increasing the amount of built-up areas while decreasing the amount of green areas. However, urban green areas can also provide suitable alternative habitats for wild bees. Methodology/Principal Findings We studied bumble bees in allotment gardens, i.e. intensively managed flower rich green areas, along a gradient of urbanization from the inner city of Stockholm towards more rural (periurban) areas. Keeping habitat quality similar along the urbanization gradient allowed us to separate the effect of landscape change (e.g. proportion impervious surface) from variation in habitat quality. Bumble bee diversity (after rarefaction to 25 individuals) decreased with increasing urbanization, from around eight species on sites in more rural areas to between five and six species in urban allotment gardens. Bumble bee abundance and species composition were most affected by qualities related to the management of the allotment areas, such as local flower abundance. The variability in bumble bee visits between allotment gardens was higher in an urban than in a periurban context, particularly among small and long-tongued bumble bee species. Conclusions/Significance Our results suggest that allotment gardens and other urban green areas can serve as important alternatives to natural habitats for many bumble bee species, but that the surrounding urban landscape influences how many species that will be present. The higher variability in abundance of certain species in the most urban areas may indicate a weaker reliability of the ecosystem service pollination in

  5. Recent increases in the large glacial-relict calanoid Limnocalanus macrurus in Lake Michigan

    USGS Publications Warehouse

    Barbiero, R.P.; Bunnell, D.B.; Rockwell, D.C.; Tuchman, M.L.

    2009-01-01

    Since 2004, population density of the large hypolimnetic calanoid Limnocalanus macrurus Sars. has increased dramatically in Lake Michigan. The average summer biomass of this species between 2004 and 2006 was roughly three times that of the period 1984–2003, and at levels unprecedented in our 22-year dataset, making L. macrurus the dominant zooplankter in the lake in terms of biomass. These increases have been accentuated by coincident population declines of the main daphnid, Daphnia mendotae, in the lake with the result that in 2006, L. macrurus accounted for 75% and 50% of the large (> 0.9 mm) crustacean biomass in the northern and southern basins of Lake Michigan, respectively. The increases in L. macrurus populations have closely coincided with equally dramatic increases in summer water clarity. Recent extinction coefficients are among the lowest recorded for the lake, and deepening light penetration has permitted increases in the size of the deep chlorophyll layer. In addition, planktivorous fish populations have declined coincidently with the increases in L. macrurus. It seems likely that an increase in sub-epilimnetic production has resulted in increased food resources for the deep-living L. macrurus, while low planktivore abundances have reduced predation loss, permitting L. macrurus to respond to these increases in sub-epilimnetic production.

  6. Abundance anomalies in tidal disruption events

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-05-01

    The ˜10 per cent of tidal disruption events (TDEs) due to stars more massive than M* ≳ M⊙ should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ˜25 per cent on average because it becomes inaccessible once it is sequestered in the high-density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main-sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle - stars with M* ≳ M⊙ quickly show an increase in their average N/C ratio by factors of 3-10. Because low-mass stars evolve slowly and high-mass stars are rare, TDEs showing high N/C will almost all be due to ˜1-2 M⊙ stars disrupted on the main sequence. Like helium, portions of the debris will show still larger changes in C and N, and the anomalies decline as the star leaves the main sequence. The enhanced [N/C] abundance ratio of these TDEs provides the first natural explanation for the rare, nitrogen-rich quasars and may also explain the strong nitrogen emission seen in ultraviolet spectra of ASASSN-14li.

  7. How ants drop out: ant abundance on tropical mountains.

    PubMed

    Longino, John T; Branstetter, Michael G; Colwell, Robert K

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

  8. How Ants Drop Out: Ant Abundance on Tropical Mountains

    PubMed Central

    Longino, John T.; Branstetter, Michael G.; Colwell, Robert K.

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

  9. Stronger warming effects on microbial abundances in colder regions

    PubMed Central

    Chen, Ji; Luo, Yiqi; Xia, Jianyang; Jiang, Lifen; Zhou, Xuhui; Lu, Meng; Liang, Junyi; Shi, Zheng; Shelton, Shelby; Cao, Junji

    2015-01-01

    Soil microbes play critical roles in regulating terrestrial carbon (C) cycle and its feedback to climate change. However, it is still unclear how the soil microbial community and abundance respond to future climate change scenarios. In this meta-analysis, we synthesized the responses of microbial community and abundance to experimental warming from 64 published field studies. Our results showed that warming significantly increased soil microbial abundance by 7.6% on average. When grouped by vegetation or soil types, tundras and histosols had the strongest microbial responses to warming with increased microbial, fungal, and bacterial abundances by 15.0%, 9.5% and 37.0% in tundra, and 16.5%, 13.2% and 13.3% in histosols, respectively. We found significant negative relationships of the response ratios of microbial, fungal and bacterial abundances with the mean annual temperature, indicating that warming had stronger effects in colder than warmer regions. Moreover, the response ratios of microbial abundance to warming were positively correlated with those of soil respiration. Our findings therefore indicate that the large quantities of C stored in colder regions are likely to be more vulnerable to climate warming than the soil C stored in other warmer regions. PMID:26658882

  10. Stronger warming effects on microbial abundances in colder regions

    SciTech Connect

    Chen, Ji; Luo, Yiqi; Xia, Jianyang; Jiang, Lifen; Zhou, Xuhui; Lu, Meng; Liang, Junyi; Shi, Zheng; Shelton, Shelby; Cao, Junji

    2015-12-10

    Soil microbes play critical roles in regulating terrestrial carbon (C) cycle and its feedback to climate change. However, it is still unclear how the soil microbial community and abundance respond to future climate change scenarios. In this meta-analysis, we synthesized the responses of microbial community and abundance to experimental warming from 64 published field studies. Our results showed that warming significantly increased soil microbial abundance by 7.6% on average. When grouped by vegetation or soil types, tundras and histosols had the strongest microbial responses to warming with increased microbial, fungal, and bacterial abundances by 15.0%, 9.5% and 37.0% in tundra, and 16.5%, 13.2% and 13.3% in histosols, respectively. We found significant negative relationships of the response ratios of microbial, fungal and bacterial abundances with the mean annual temperature, indicating that warming had stronger effects in colder than warmer regions. Moreover, the response ratios of microbial abundance to warming were positively correlated with those of soil respiration. Our results therefore indicate that the large quantities of C stored in colder regions are likely to be more vulnerable to climate warming than the soil C stored in other warmer regions.

  11. Stronger warming effects on microbial abundances in colder regions

    DOE PAGES

    Chen, Ji; Luo, Yiqi; Xia, Jianyang; Jiang, Lifen; Zhou, Xuhui; Lu, Meng; Liang, Junyi; Shi, Zheng; Shelton, Shelby; Cao, Junji

    2015-12-10

    Soil microbes play critical roles in regulating terrestrial carbon (C) cycle and its feedback to climate change. However, it is still unclear how the soil microbial community and abundance respond to future climate change scenarios. In this meta-analysis, we synthesized the responses of microbial community and abundance to experimental warming from 64 published field studies. Our results showed that warming significantly increased soil microbial abundance by 7.6% on average. When grouped by vegetation or soil types, tundras and histosols had the strongest microbial responses to warming with increased microbial, fungal, and bacterial abundances by 15.0%, 9.5% and 37.0% in tundra,more » and 16.5%, 13.2% and 13.3% in histosols, respectively. We found significant negative relationships of the response ratios of microbial, fungal and bacterial abundances with the mean annual temperature, indicating that warming had stronger effects in colder than warmer regions. Moreover, the response ratios of microbial abundance to warming were positively correlated with those of soil respiration. Our results therefore indicate that the large quantities of C stored in colder regions are likely to be more vulnerable to climate warming than the soil C stored in other warmer regions.« less

  12. On the potentially dramatic history of the super-Earth ρ 55 Cancri e

    NASA Astrophysics Data System (ADS)

    Hansen, Bradley M. S.; Zink, Jonathon

    2015-07-01

    We demonstrate that tidal evolution of the inner planet (`e') of the system orbiting the star ρ 55 Cancri could have led to passage through two secular resonances with other planets in the system. The consequence of this evolution is excitation of both the planetary eccentricity and inclination relative to the original orbital plane. The large mass ratio between the innermost planet and the others means that these excitations can be of substantial amplitude and can have dramatic consequences for the system organization. Such evolution can potentially explain the large observed mutual inclination between the innermost and outermost planets in the system, and implies that tidal heating could have substantially modified the structure of planet e, and possibly reduced its mass by Roche lobe overflow. Similar inner secular resonances may be found in many multiple planet systems and suggest that many of the innermost planets in these systems could have suffered similar evolutions.

  13. Dramatic Response to Cisplatin Window Therapy in a Boy With Advanced Metastatic Ewing Sarcoma

    PubMed Central

    Trizzino, Antonino; Ziino, Ottavio; Parafioriti, Antonina; Podda, Marta; Tropia, Serena; Luksch, Roberto

    2013-01-01

    Ewing sarcoma (ES) is the second most common type of primary bone malignancy, and retains a high propensity to metastasize; the prognosis of patients with disseminated disease is very poor, with an event-free survival rate of <20%. Current multimodality treatment for ES consists of combined chemotherapy before and concurrent with surgery and local radiotherapy for the involved bone. Cisplatin is one of the most widely used drugs for the treatment of bone tumors in children, but is not currently used in ES. We describe a child with multifocal ES, treated with a phase II trial including a single-drug window therapy, which displayed a dramatic response to 2 courses of cisplatin and had a favorable outcome. PMID:23892353

  14. Intractable chronic motor tics dramatically respond to Clerodendrum inerme (L) Gaertn.

    PubMed

    Fan, Pi-Chuan; Huang, Wei-Jan; Chiou, Lih-Chu

    2009-07-01

    Tics are characterized by involuntary, sudden, rapid, repetitive, nonrhythmic, stereotyped movements or phonic productions. Those who suffer from either motor or phonic tics, but not both, for more than 1 year are diagnosed with chronic tic disorder. Several pharmacological interventions have been proposed for the treatment of tic disorder. Dopamine D2 receptor blockers and dopamine depletors are thought to be the most effective ones clinically. However, such treatments are suboptimal in terms of effectiveness and side effects, such as body weight gain and extrapyramidal symptoms. We report on a 13-year-old girl, with chronic motor tic disorder refractory to multiple anti-tic therapies, who showed dramatic improvement and remission after taking the crude leaf extract of Clerodendrum inerme (L) Gaertn. No side effects were observed during a follow-up of more than 2 years. To the best of our knowledge, this is the first report on the anti-tic effect of Clerodendrum inerme.

  15. Emulating a crowded intracellular environment in vitro dramatically improves RT-PCR performance

    SciTech Connect

    Lareu, Ricky R.; Harve, Karthik S.; Raghunath, Michael

    2007-11-09

    The polymerase chain reaction's (PCR) phenomenal success in advancing fields as diverse as Medicine, Agriculture, Conservation, or Paleontology is based on the ability of using isolated prokaryotic thermostable DNA polymerases in vitro to copy DNA irrespective of origin. This process occurs intracellularly and has evolved to function efficiently under crowded conditions, namely in an environment packed with macromolecules. However, current in vitro practice ignores this important biophysical parameter of life. In order to more closely emulate conditions of intracellular biochemistry in vitro we added inert macromolecules into reverse transcription (RT) and PCR. We show dramatic improvements in all parameters of RT-PCR including 8- to 10-fold greater sensitivity, enhanced polymerase processivity, higher specific amplicon yield, greater primer annealing and specificity, and enhanced DNA polymerase thermal stability. The faster and more efficient reaction kinetics was a consequence of the cumulative molecular and thermodynamic effects of the excluded volume effect created by macromolecular crowding.

  16. Dramatic niche shifts and morphological change in two insular bird species

    PubMed Central

    Alström, Per; Jønsson, Knud A.; Fjeldså, Jon; Ödeen, Anders; Ericson, Per G. P.; Irestedt, Martin

    2015-01-01

    Colonizations of islands are often associated with rapid morphological divergence. We present two previously unrecognized cases of dramatic morphological change and niche shifts in connection with colonization of tropical forest-covered islands. These evolutionary changes have concealed the fact that the passerine birds madanga, Madanga ruficollis, from Buru, Indonesia, and São Tomé shorttail, Amaurocichla bocagii, from São Tomé, Gulf of Guinea, are forest-adapted members of the family Motacillidae (pipits and wagtails). We show that Madanga has diverged mainly in plumage, which may be the result of selection for improved camouflage in its new arboreal niche, while selection pressures for other morphological changes have probably been weak owing to preadaptations for the novel niche. By contrast, we suggest that Amaurocichla's niche change has led to divergence in both structure and plumage. PMID:26064613

  17. Dramatic Improvement of Diabetes Mellitus Following the Treatment of Coexisting Acromegaly and Cushing's Syndrome.

    PubMed

    Kim, Soo Kyoung; Kim, Bo Ra; Kim, Kyongyoung; Kim, Sungsu; Jung, Jung Hwa; Hahm, Jong Ryeal; Jung, Jaehoon

    2015-01-01

    Endocrine diseases are frequently accompanied by diabetes mellitus and treatment of an underlying endocrine disease often improves glucose control. The co-occurrence of acromegaly and Cushing's syndrome is extremely rare. We herein describe a patient who showed a dramatic improvement in glucose control following treatment for co-existing acromegaly and Cushing's syndrome. An adrenal mass was incidentally discovered during a routine evaluation of a 56-year-old woman who was subsequently diagnosed with acromegaly and a unilateral cortisol-producing adrenal adenoma. Her blood glucose was poorly controlled despite receiving high-dose insulin therapy. After undergoing adrenalectomy for Cushing's syndrome, her insulin dosage was decreased by almost 50%. The insulin treatment was discontinued following the treatment of acromegaly.

  18. Dramatic niche shifts and morphological change in two insular bird species.

    PubMed

    Alström, Per; Jønsson, Knud A; Fjeldså, Jon; Ödeen, Anders; Ericson, Per G P; Irestedt, Martin

    2015-03-01

    Colonizations of islands are often associated with rapid morphological divergence. We present two previously unrecognized cases of dramatic morphological change and niche shifts in connection with colonization of tropical forest-covered islands. These evolutionary changes have concealed the fact that the passerine birds madanga, Madanga ruficollis, from Buru, Indonesia, and São Tomé shorttail, Amaurocichla bocagii, from São Tomé, Gulf of Guinea, are forest-adapted members of the family Motacillidae (pipits and wagtails). We show that Madanga has diverged mainly in plumage, which may be the result of selection for improved camouflage in its new arboreal niche, while selection pressures for other morphological changes have probably been weak owing to preadaptations for the novel niche. By contrast, we suggest that Amaurocichla's niche change has led to divergence in both structure and plumage. PMID:26064613

  19. Dramatic inundation changes of China's two largest freshwater lakes linked to the Three Gorges Dam.

    PubMed

    Feng, Lian; Hu, Chuanmin; Chen, Xiaoling; Zhao, Xi

    2013-09-01

    Ever since its planning in the 1990s, the Three Gorges Dam (TGD) caused endless debate in China on its potential impacts on the environment and humans. However, to date, synoptic assessment of environmental changes and their potential linkage with the TGD is still lacking. Here, we combine remote sensing, meteorological, and hydrological observations to investigate the potential influence of the TGD on the downstream freshwater lakes. A 10 year Moderate Resolution Imaging Spectroradiometer (MODIS) time series from 2000 to 2009 revealed significantly decreasing trends (3.3 and 3.6%/year) in the inundation areas of the two largest freshwater lakes of China (Poyang Lake and Dongting Lake) downstream of the TGD since its impoundment in 2003, after which both relative humidity and surface runoff coefficient of the lakes' drainages also dropped dramatically. These environmental changes appear to be linked to the TGD.

  20. Dramatic Improvement of Diabetes Mellitus Following the Treatment of Coexisting Acromegaly and Cushing's Syndrome.

    PubMed

    Kim, Soo Kyoung; Kim, Bo Ra; Kim, Kyongyoung; Kim, Sungsu; Jung, Jung Hwa; Hahm, Jong Ryeal; Jung, Jaehoon

    2015-01-01

    Endocrine diseases are frequently accompanied by diabetes mellitus and treatment of an underlying endocrine disease often improves glucose control. The co-occurrence of acromegaly and Cushing's syndrome is extremely rare. We herein describe a patient who showed a dramatic improvement in glucose control following treatment for co-existing acromegaly and Cushing's syndrome. An adrenal mass was incidentally discovered during a routine evaluation of a 56-year-old woman who was subsequently diagnosed with acromegaly and a unilateral cortisol-producing adrenal adenoma. Her blood glucose was poorly controlled despite receiving high-dose insulin therapy. After undergoing adrenalectomy for Cushing's syndrome, her insulin dosage was decreased by almost 50%. The insulin treatment was discontinued following the treatment of acromegaly. PMID:26424306

  1. Idiopathic myenteric ganglionitis underlying acute 'dramatic' intestinal pseudoobstruction: report of an exceptional case.

    PubMed

    Racalbuto, A; Magro, G; Lanteri, R; Aliotta, I; Santangelo, M; Di Cataldo, A

    2008-09-01

    Inflammation of the myenteric plexus of the gastrointestinal tract is a very rare pathological condition, with few reports in the medical literature. This pathological condition causes atonic gut motor dysfunction and is principally secondary to other diseases, being reported nearly solely as a paraneoplastic phenomenon in neuroendocrine lung tumors, including small cell carcinomas or neuroblastomas. In addition it can also be associated with disorders of the central nervous system, although it has rarely been described in Chagas disease. It has been named 'idiopathic myenteric ganglionitis' because no apparent causes can be demonstrated. We report the clinicopathologic findings of an exceptional case of a young woman affected by severe chronic constipation suddenly changing into acute intestinal pseudoobstruction with dramatic evolution. Relationships between ganglionitis, idiopathic constipation and acute intestinal pseudoobstruction as well as therapeutic implications are discussed.

  2. Dramatic inundation changes of China's two largest freshwater lakes linked to the Three Gorges Dam.

    PubMed

    Feng, Lian; Hu, Chuanmin; Chen, Xiaoling; Zhao, Xi

    2013-09-01

    Ever since its planning in the 1990s, the Three Gorges Dam (TGD) caused endless debate in China on its potential impacts on the environment and humans. However, to date, synoptic assessment of environmental changes and their potential linkage with the TGD is still lacking. Here, we combine remote sensing, meteorological, and hydrological observations to investigate the potential influence of the TGD on the downstream freshwater lakes. A 10 year Moderate Resolution Imaging Spectroradiometer (MODIS) time series from 2000 to 2009 revealed significantly decreasing trends (3.3 and 3.6%/year) in the inundation areas of the two largest freshwater lakes of China (Poyang Lake and Dongting Lake) downstream of the TGD since its impoundment in 2003, after which both relative humidity and surface runoff coefficient of the lakes' drainages also dropped dramatically. These environmental changes appear to be linked to the TGD. PMID:23919680

  3. Carbon and oxygen abundances in stellar populations

    NASA Astrophysics Data System (ADS)

    Nissen, P. E.; Chen, Y. Q.; Carigi, L.; Schuster, W. J.; Zhao, G.

    2014-08-01

    Context. Carbon and oxygen abundances in stars are important in many fields of astrophysics including nucleosynthesis, stellar structure, evolution of galaxies, and formation of planetary systems. Still, our knowledge of the abundances of these elements in different stellar populations is uncertain because of difficulties in observing and analyzing atomic and molecular lines of C and O. Aims: Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood with metallicities in the range -1.6 < [Fe/H] < +0.4 in order to study trends and possible systematic differences in the C/Fe, O/Fe, and C/O ratios for thin- and thick-disk stars as well as high- and low-alpha halo stars. In addition, we investigate if there is any connection between C and O abundances in stellar atmospheres and the occurrence of planets. Methods: Carbon abundances are determined from the λλ 5052,5380 C i lines and oxygen abundances from the λ7774 O i triplet and the forbidden [O i] line at 6300 Å. MARCS model atmospheres are applied and non-LTE corrections for the O i triplet are included. Results: Systematic differences between high- and low-alpha halo stars and between thin- and thick-disk stars are seen in the trends of [C/Fe] and [O/Fe]. The two halo populations and thick-disk stars show the same trend of [C/O] versus [O/H], whereas the thin-disk stars are shifted to higher [C/O] values. Furthermore, we find some evidence of higher C/O and C/Fe ratios in stars hosting planets than in stars for which no planets have been detected. Conclusions: The results suggest that C and O in both high- and low-alpha halo stars and in thick-disk stars are made mainly in massive (M> 8 M⊙) stars, whereas thin-disk stars have an additional carbon contribution from low-mass AGB and massive stars of high metallicity causing a rising trend of the C/O ratio with increasing metallicity. However, at the highest metallicities investigated ([Fe/H] ≃ + 0.4), C/O does not

  4. Fish abundance, distribution, and habitat use

    NASA Astrophysics Data System (ADS)

    Hoffnagle, Timothy L.; Valdez, Richard A.; Speas, David W.

    The 1996 controlled flood in the Colorado River, Grand Canyon, was designed, in part, to improve conditions for juvenile native fishes by reshaping habitat and displacing non-native fishes. We examined changes in abundance and distributions of native and non-native fishes immediately before and after the controlled flood and recovery of affected species 2.5 and 6 months after. Catch-per-unit-effort (CPUE) of humpback chub and flannelmouth sucker did not differ in pre- versus post-flood periods. CPUE of plains killifish, bluehead sucker and fathead minnow decreased following the flood, and CPUE of speckled dace and rainbow trout increased. Juvenile humpback chub remained primarily along talus shorelines at all discharges, while at higher discharges, speckled dace shifted from mid-channel riffles to debris fans and talus and fathead minnows used primarily vegetated shorelines. There was evidence of some downstream displacement of plains killifish, fathead minnows and rainbow trout. Catch rates of all species showed seasonal variation following the flood, with summer recruitment of young-of-the-year, particularly fathead minnows and plains killifish. Although short-term reductions in catch rates of fathead minnows and plains killifish occurred, these populations returned to pre-flood densities by 6 months after the flood. Catch rates of all species before and after the flood were similar to those recorded in previous years. We determined that the controlled flood did not significantly alter native fish distributions or abundances through Grand Canyon.

  5. Cessation of daily exercise dramatically alters precursors of hepatic steatosis in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

    PubMed

    Rector, R Scott; Thyfault, John P; Laye, Matthew J; Morris, R Tyler; Borengasser, Sarah J; Uptergrove, Grace M; Chakravarthy, Manu V; Booth, Frank W; Ibdah, Jamal A

    2008-09-01

    The purpose of this study was to delineate potential mechanisms initiating the onset of hepatic steatosis following the cessation of daily physical activity. Four-week-old, hyperphagic/obese Otsuka Long-Evans Tokushima Fatty rats were given access to voluntary running wheels for 16 weeks to prevent the development of hepatic steatosis. The animals were then suddenly transitioned to a sedentary condition as wheels were locked (wheel lock; WL) for 5 h (WL5), 53 h (WL53) or 173 h (WL173). Importantly after the cessation of daily exercise (5-173 h), no changes occurred in body weight, fat pad mass (omental and retroperitoneal), food intake, serum insulin, hepatic triglycerides or in the exercise-suppressed hepatic stearoyl-CoA desaturase-1 and peroxisome proliferator-activated receptor-gamma protein content. However, complete hepatic fatty acid oxidation and mitochondrial enzyme activities were highest at WL5 and WL53 and dropped significantly to SED levels by WL173. In addition, cessation of daily exercise quickly increased the hepatic protein contents of fatty acid synthase and acetyl-coenzyme A carboxylase (ACC), reduced ACC phosphorylation status, and dramatically increased hepatic malonyl-CoA concentration. This study is the first to show that the sudden cessation of daily exercise in a hyperphagic/obese model activates a subgroup of precursors and processes known to initiate hepatic steatosis, including decreased hepatic mitochondrial oxidative capacity, increased hepatic expression of de novo lipogenesis proteins, and increased hepatic malonyl CoA levels; each probably increasing the susceptibility to non-alcoholic fatty liver disease.

  6. New evidence for a dramatic rise in atmosphere oxygen ca. 1,900 m.y. ago

    NASA Technical Reports Server (NTRS)

    Holland, H. D.; Macfarlane, A. W.

    1991-01-01

    Several lines of geologic evidence have pointed to a significant increase in P sub O2 about 2,000 m.y. ago, but the magnitude of P sub O2 before and after that time has been quite uncertain. The data that we have recently accumulated suggest that P sub O2 was approximately less than 2 x 10 (exp -3) atm more than 2,000 m.y. ago, and approximately greater than 0.03 atm more recently than ca. 1,900 m.y. ago. These estimates are based on the behavior of iron in Precambrian weathering horizons. More than ca. 2,000 m.y. ago, Fe(+2), released during the weathering of basalts was not oxidized to Fe(+3), and was removed in ground water from the upper layers of soil horizons. More recently than ca. 1,850 m.y. ago, Fe(+2) was oxidized to Fe(+3) and precipitated as iron oxides and hydroxides in such soil horizons and in the weathering products of a carbonate facies banded iron formation in Griqualand West, South Africa. The O2 content of the atmosphere must have increased dramatically about 1,900 m.y. ago to explain these observations. The reasons for the increase are still obscure, but are probably related to changes in the biologic productivity of the oceans. Eukaryotes appear to have developed shortly after the increase in P sub O2, perhaps in response to the subsequent increase in the supply of nitrate from the atmosphere to the oceans.

  7. Lithium Abundance in Planet Search Stars

    NASA Astrophysics Data System (ADS)

    Myles, Justin; Yale Exoplanets

    2016-01-01

    Since most lithium in the universe is primordial and is destroyed in stars, lithium abundance can be used as a stellar age indicator. Some research seems to show that planet formation may also affect lithium abundance in exoplanet host stars (EHS). However, small and heterogenous samples have made both of these phenomena unclear. Further study of lithium abundance in EHS is needed to better understand possible physical roles of lithium in planet formation theory. We use a large homogenous sample with accurate stellar parameters on which we will use equivalent width analysis to determine precise lithium abundances. From these abundance values we determine an age vs. abundance relation. Additionally, we aim to explore correlation between lithium abundance and planet formation.

  8. Late embryogenesis abundant proteins protect human hepatoma cells during acute desiccation

    PubMed Central

    Li, Shumin; Chakraborty, Nilay; Borcar, Apurva; Menze, Michael A.; Toner, Mehmet; Hand, Steven C.

    2012-01-01

    Expression of late embryogenesis abundant (LEA) proteins is highly correlated with desiccation tolerance in anhydrobiotic animals, selected land plants, and bacteria. Genes encoding two LEA proteins, one localized to the cytoplasm/nucleus (AfrLEA2) and one targeted to mitochondria (AfrLEA3m), were stably transfected into human HepG2 cells. A trehalose transporter was used for intracellular loading of this disaccharide. Cells were rapidly and uniformly desiccated to low water content (<0.12 g H2O/g dry weight) with a recently developed spin-drying technique. Immediately on rehydration, control cells without LEA proteins or trehalose exhibited 0% membrane integrity, compared with 98% in cells loaded with trehalose and expressing AfrLEA2 or AfrLEA3m; surprisingly, AfrLEA3m without trehalose conferred 94% protection. Cell proliferation across 7 d showed an 18-fold increase for cells dried with AfrLEA3m and trehalose, compared with 27-fold for nondried controls. LEA proteins dramatically enhance desiccation tolerance in mammalian cells and offer the opportunity for engineering biostability in the dried state. PMID:23185012

  9. Dramatic shifts in benthic microbial eukaryote communities following the Deepwater Horizon oil spill.

    PubMed

    Bik, Holly M; Halanych, Kenneth M; Sharma, Jyotsna; Thomas, W Kelley

    2012-01-01

    Benthic habitats harbour a significant (yet unexplored) diversity of microscopic eukaryote taxa, including metazoan phyla, protists, algae and fungi. These groups are thought to underpin ecosystem functioning across diverse marine environments. Coastal marine habitats in the Gulf of Mexico experienced visible, heavy impacts following the Deepwater Horizon oil spill in 2010, yet our scant knowledge of prior eukaryotic biodiversity has precluded a thorough assessment of this disturbance. Using a marker gene and morphological approach, we present an intensive evaluation of microbial eukaryote communities prior to and following oiling around heavily impacted shorelines. Our results show significant changes in community structure, with pre-spill assemblages of diverse Metazoa giving way to dominant fungal communities in post-spill sediments. Post-spill fungal taxa exhibit low richness and are characterized by an abundance of known hydrocarbon-degrading genera, compared to prior communities that contained smaller and more diverse fungal assemblages. Comparative taxonomic data from nematodes further suggests drastic impacts; while pre-spill samples exhibit high richness and evenness of genera, post-spill communities contain mainly predatory and scavenger taxa alongside an abundance of juveniles. Based on this community analysis, our data suggest considerable (hidden) initial impacts across Gulf beaches may be ongoing, despite the disappearance of visible surface oil in the region.

  10. Mechanisms of organelle biogenesis govern stochastic fluctuations in organelle abundance.

    PubMed

    Mukherji, Shankar; O'Shea, Erin K

    2014-06-10

    Fluctuations in organelle abundance can profoundly limit the precision of cell biological processes from secretion to metabolism. We modeled the dynamics of organelle biogenesis and predicted that organelle abundance fluctuations depend strongly on the specific mechanisms that increase or decrease the number of a given organelle. Our model exactly predicts the size of experimentally measured Golgi apparatus and vacuole abundance fluctuations, suggesting that cells tolerate the maximum level of variability generated by the Golgi and vacuole biogenesis pathways. We observe large increases in peroxisome abundance fluctuations when cells are transferred from glucose-rich to fatty acid-rich environments. These increased fluctuations are significantly diminished in mutants lacking peroxisome fission factors, leading us to infer that peroxisome biogenesis switches from de novo synthesis to primarily fission. Our work provides a general framework for exploring stochastic organelle biogenesis and using fluctuations to quantitatively unravel the biophysical pathways that control the abundance of subcellular structures.DOI: http://dx.doi.org/10.7554/eLife.02678.001.

  11. Observing chemical abundances in comets

    NASA Technical Reports Server (NTRS)

    Delsemme, A. H.

    1981-01-01

    The atomic resonance lines of the major elements were observed in the atmospheres of a few comets, by using vacuum ultraviolet spectrographs on board rockets or orbiting observatories. Dust-to-gas ratios were also deduced for two comets through a Finson-Probstein's analysis of their dust-tail isophotes. The geometric albedo of the dust for the phase angle alpha of the observations is not accurately known but, the dust-to-gas ratio is not overly sensitive to the actual value of this albedo. Infrared observations of the dust head of some comets show that the bulk of cometary dust must be silicates, although a minor component (5-10 percent) of carbon compounds is rather likely, because of poor dielectric properties of the grains. This interpretation is confirmed by the fact that interplanetary dust probably of cometary origin, that was collected in the stratosphere by NASA-U2 Spacecraft, is chondritic in nature. Metal abundances in the head of a sungrazing comet support the chondritic hypothesis.

  12. Molecular Abundances in CRL 618

    NASA Astrophysics Data System (ADS)

    Pardo, Juan R.; Cernicharo, José

    2007-01-01

    In previous works we have modeled the different gas regions of the proto-planetary nebula CRL 618 by studying the large number of lines from the cyanopolyynes detected in a millimeter-wave line survey of this object. In this work we retrieve the rotational temperatures (Tr) and abundance ratios R with respect to HC3N (used as reference) for all molecular species detected in the survey by running grids of models in the (R,Tr) space to find the minimum of a weighted χ2 defined for this analysis. This provides the best knowledge to date of the (polar) molecular composition of CRL 618 thanks to the uniform calibration of the whole survey and the large number of lines available from each species, allowing comparisons with predictions made by chemical models of C-rich post-AGB objects. A significantly lower value of the 12C/13C ratio has been revealed in the gas closest to central star with respect to the colder and outer envelope. It can be due to 13C-rich material, produced in a late CNO cycling occurred in the central star, being currently injected into this inner gas envelope.

  13. Increasing Reservation Attendance: Ganado's Approach.

    ERIC Educational Resources Information Center

    Foster, Carl; And Others

    Based on recommendations of a District Attendance Task Force, in 1980 the Ganado School District (a Navajo Reservation District) formulated an Attendance Improvement Plan which decreased the primary school's absentee rate 37% over previous years and which dramatically increased Friday attendance. The primary school targeted "high risk" chronic…

  14. Prickly business: abundance of sea urchins on breakwaters and coral reefs in Dubai.

    PubMed

    Bauman, Andrew G; Dunshea, Glenn; Feary, David A; Hoey, Andrew S

    2016-04-30

    Echinometra mathaei is a common echinoid on tropical reefs and where abundant plays an important role in the control of algal communities. Despite high prevalence of E. mathaei on southern Persian/Arabian Gulf reefs, their abundance and distribution is poorly known. Spatial and temporal patterns in population abundance were examined at 12 sites between breakwater and natural reef habitats in Dubai (UAE) every 3 months from 2008 to 2010. Within the breakwater habitat, densities were greatest at shallow wave-exposed sites, and reduced with both decreasing wave-exposure and increasing depth. Interestingly, E. mathaei were significantly more abundant on exposed breakwaters than natural reef sites, presumably due to differences in habitat structure and benthic cover. Population abundances differed seasonally, with peak abundances during summer (July-September) and lower abundances in winter (December-February). Seasonal fluctuations are likely the result of peak annual recruitment pulses coupled with increased fish predation from summer to winter. PMID:26563547

  15. Prickly business: abundance of sea urchins on breakwaters and coral reefs in Dubai.

    PubMed

    Bauman, Andrew G; Dunshea, Glenn; Feary, David A; Hoey, Andrew S

    2016-04-30

    Echinometra mathaei is a common echinoid on tropical reefs and where abundant plays an important role in the control of algal communities. Despite high prevalence of E. mathaei on southern Persian/Arabian Gulf reefs, their abundance and distribution is poorly known. Spatial and temporal patterns in population abundance were examined at 12 sites between breakwater and natural reef habitats in Dubai (UAE) every 3 months from 2008 to 2010. Within the breakwater habitat, densities were greatest at shallow wave-exposed sites, and reduced with both decreasing wave-exposure and increasing depth. Interestingly, E. mathaei were significantly more abundant on exposed breakwaters than natural reef sites, presumably due to differences in habitat structure and benthic cover. Population abundances differed seasonally, with peak abundances during summer (July-September) and lower abundances in winter (December-February). Seasonal fluctuations are likely the result of peak annual recruitment pulses coupled with increased fish predation from summer to winter.

  16. Patterns and potential drivers of dramatic changes in Tibetan lakes, 1972-2010.

    PubMed

    Li, Yingkui; Liao, Jingjuan; Guo, Huadong; Liu, Zewen; Shen, Guozhuang

    2014-01-01

    Most glaciers in the Himalayas and the Tibetan Plateau are retreating, and glacier melt has been emphasized as the dominant driver for recent lake expansions on the Tibetan Plateau. By investigating detailed changes in lake extents and levels across the Tibetan Plateau from Landsat/ICESat data, we found a pattern of dramatic lake changes from 1970 to 2010 (especially after 2000) with a southwest-northeast transition from shrinking, to stable, to rapidly expanding. This pattern is in distinct contrast to the spatial characteristics of glacier retreat, suggesting limited influence of glacier melt on lake dynamics. The plateau-wide pattern of lake change is related to precipitation variation and consistent with the pattern of permafrost degradation induced by rising temperature. More than 79% of lakes we observed on the central-northern plateau (with continuous permafrost) are rapidly expanding, even without glacial contributions, while lakes fed by retreating glaciers in southern regions (with isolated permafrost) are relatively stable or shrinking. Our study shows the limited role of glacier melt and highlights the potentially important contribution of permafrost degradation in predicting future water availability in this region, where understanding these processes is of critical importance to drinking water, agriculture, and hydropower supply of densely populated areas in South and East Asia. PMID:25372787

  17. Insights on dramatic radial fluctuations in track formation by energetic ions.

    PubMed

    Sachan, Ritesh; Zarkadoula, Eva; Lang, Maik; Trautmann, Christina; Zhang, Yanwen; Chisholm, Matthew F; Weber, William J

    2016-06-02

    We report on unexpected dramatic radial variations in ion tracks formed by irradiation with energetic ions (2.3 GeV (208)Pb) at a constant electronic energy-loss (~42 keV/nm) in pyrochlore-structured Gd2TiZrO7. Though previous studies have shown track formation and average track diameter measurements in the Gd2TixZr(1-x)O7 system, the present work clearly reveals the importance of the recrystallization process in ion track formation in this system, which leads to more morphological complexities in tracks than currently accepted behavior. The ion track profile is usually considered to be diametrically uniform for a constant value of electronic energy-loss. This study reveals the diameter variations to be as large as ~40% within an extremely short incremental track length of ~20 nm. Our molecular dynamics simulations show that these fluctuations in diameter of amorphous core and overall track diameter are attributed to the partial substitution of Ti atoms by Zr atoms, which have a large difference in ionic radii, on the B-site in pyrochlore lattice. This random distribution of Ti and Zr atoms leads to a local competition between amorphous phase formation (favored by Ti atoms) and defect-fluorite phase formation (favored by Zr atoms) during the recrystallization process and finally introduces large radial variations in track morphology.

  18. Dramatic Expression in Opera, and Its Implications for Conversational Agents. Chapter 7

    NASA Technical Reports Server (NTRS)

    Johnson, W. Lewis

    2007-01-01

    This article has discussed principles, techniques, and methods of dramatic portrayal in opera, and their application to the development of embodied conversational agents. Investigations such as this complement studies of natural human behavior, and offer insights as to how to make such behavior understandable and interesting when adapted for use by embodied conversational agents. However, one should use caution in applying such lessons. The unique characteristics of computer-based media are still being identified and explored. In any case, one must always be careful about applying principles blindly to any artistic form. Such principles are post-hoc analysis of the intuitive skill of great artists; this was as true in Aristotle's day as it is today. We should not let structural principles stand in the way of injecting creativity into the design of ECAs. Opera at its best possesses an element of magic that is difficult to describe, much less analytically reconstruct. We can only hope to achieve a similar result with conversational agents.

  19. Leaks can dramatically decrease FiO2 on home ventilators: a bench study

    PubMed Central

    2013-01-01

    Background Long term oxygen therapy improves survival in hypoxemic patients with chronic obstructive pulmonary disease (COPD). Because pressure support ventilation with a home care ventilator is largely unsupervised, there is considerable risk of leakage occurring, which could affect delivered FiO2. We have therefore conducted a bench study in order to measure the effect of different levels of O2 supply and degrees of leakage on delivered FiO2. Ventilator tested: Legendair® (Airox™, Pau, France). Thirty-six measures were performed in each four ventilators with zero, 5 and 10 l.min-1 leakage and 1,2,4 and 8 l O2 flow. Findings FiO2 decreased significantly with 5 l.min-1 leakage for all O2 flow rates, and with 10 l.min-1 at 4 and 8 l.min-1 O2. Conclusion During application of NIV on home ventilators, leakage can dramatically decrease inspired FiO2 making it less effective. It is important to know the FiO2 dispensed when NIV is used for COPD at home. We would encourage industry to develop methods for FiO2 regulation Chronic use of NIV for COPD with controlled FiO2 or SpO2 requires further studys. PMID:23870165

  20. Insights on dramatic radial fluctuations in track formation by energetic ions

    NASA Astrophysics Data System (ADS)

    Sachan, Ritesh; Zarkadoula, Eva; Lang, Maik; Trautmann, Christina; Zhang, Yanwen; Chisholm, Matthew F.; Weber, William J.

    2016-06-01

    We report on unexpected dramatic radial variations in ion tracks formed by irradiation with energetic ions (2.3 GeV 208Pb) at a constant electronic energy-loss (~42 keV/nm) in pyrochlore-structured Gd2TiZrO7. Though previous studies have shown track formation and average track diameter measurements in the Gd2TixZr(1-x)O7 system, the present work clearly reveals the importance of the recrystallization process in ion track formation in this system, which leads to more morphological complexities in tracks than currently accepted behavior. The ion track profile is usually considered to be diametrically uniform for a constant value of electronic energy-loss. This study reveals the diameter variations to be as large as ~40% within an extremely short incremental track length of ~20 nm. Our molecular dynamics simulations show that these fluctuations in diameter of amorphous core and overall track diameter are attributed to the partial substitution of Ti atoms by Zr atoms, which have a large difference in ionic radii, on the B-site in pyrochlore lattice. This random distribution of Ti and Zr atoms leads to a local competition between amorphous phase formation (favored by Ti atoms) and defect-fluorite phase formation (favored by Zr atoms) during the recrystallization process and finally introduces large radial variations in track morphology.

  1. Dramatic improvement of anti-SS-A/Ro-associated interstitial lung disease after immunosuppressive treatment.

    PubMed

    Paola, Caramaschi; Giuliana, Festi; Giovanni, Orsolini; Cristian, Caimmi; Domenico, Biasi

    2016-07-01

    The aim of the study was to report three patients affected by interstitial lung disease associated with positive anti-SS-A/Ro autoantibody who showed a dramatic improvement after immunosuppressive treatment. Medical charts were reviewed to obtain clinical data, laboratory parameters, lung function tests, high-resolution computed tomography results and response to immunosuppressive treatment. The three patients showed a clinical picture of a lung-dominant connective tissue disease characterized by a sudden onset with dyspnea, cough and subtle extrathoracic features together with positive anti-SS-A/Ro antibody and weak titer antinuclear antibodies. All three patients responded favorably to immunosuppressive therapy: Two cases were treated with a combination of corticosteroid and cyclophosphamide followed by mycophenolate mofetil; in the third patient, clinical benefit was obtained after rituximab was added to corticosteroid and immunosuppressant drug. In spite of an abrupt onset with significant lung function impairment, all three patients had a favorable clinical response to immunosuppressive therapy. This report may be useful in making therapeutic decisions in case of interstitial lung disease associated with anti-SS-A antibody.

  2. Patterns and potential drivers of dramatic changes in Tibetan lakes, 1972-2010.

    PubMed

    Li, Yingkui; Liao, Jingjuan; Guo, Huadong; Liu, Zewen; Shen, Guozhuang

    2014-01-01

    Most glaciers in the Himalayas and the Tibetan Plateau are retreating, and glacier melt has been emphasized as the dominant driver for recent lake expansions on the Tibetan Plateau. By investigating detailed changes in lake extents and levels across the Tibetan Plateau from Landsat/ICESat data, we found a pattern of dramatic lake changes from 1970 to 2010 (especially after 2000) with a southwest-northeast transition from shrinking, to stable, to rapidly expanding. This pattern is in distinct contrast to the spatial characteristics of glacier retreat, suggesting limited influence of glacier melt on lake dynamics. The plateau-wide pattern of lake change is related to precipitation variation and consistent with the pattern of permafrost degradation induced by rising temperature. More than 79% of lakes we observed on the central-northern plateau (with continuous permafrost) are rapidly expanding, even without glacial contributions, while lakes fed by retreating glaciers in southern regions (with isolated permafrost) are relatively stable or shrinking. Our study shows the limited role of glacier melt and highlights the potentially important contribution of permafrost degradation in predicting future water availability in this region, where understanding these processes is of critical importance to drinking water, agriculture, and hydropower supply of densely populated areas in South and East Asia.

  3. Use of microsecond current prepulse for dramatic improvements of wire array Z-pinch implosion

    NASA Astrophysics Data System (ADS)

    Calamy, H.; Lassalle, F.; Loyen, A.; Zucchini, F.; Chittenden, J. P.; Hamann, F.; Maury, P.; Georges, A.; Bedoch, J. P.; Morell, A.

    2008-01-01

    The Sphinx machine [F. Lassalle et al., "Status on the SPHINX machine based on the 1microsecond LTD technology"] based on microsecond linear transformer driver (LTD) technology is used to implode an aluminium wire array with an outer diameter up to 140mm and maximum current from 3.5to5MA. 700to800ns implosion Z-pinch experiments are performed on this driver essentially with aluminium. Best results obtained before the improvement described in this paper were 1-3TW radial total power, 100-300kJ total yield, and 20-30kJ energy above 1keV. An auxiliary generator was added to the Sphinx machine in order to allow a multi microsecond current to be injected through the wire array load before the start of the main current. Amplitude and duration of this current prepulse are adjustable, with maxima ˜10kA and 50μs. This prepulse dramatically changes the ablation phase leading to an improvement of the axial homogeneity of both the implosion and the final radiating column. Total power was multiplied by a factor of 6, total yield by a factor of 2.5 with a reproducible behavior. This paper presents experimental results, magnetohydrodynamic simulations, and analysis of the effect of such a long current prepulse.

  4. Combination of clopidogrel and everolimus dramatically reduced the development of transplant arteriosclerosis in murine aortic allografts.

    PubMed

    Eckl, Sebastian; Heim, Christian; Abele-Ohl, Silke; Hoffmann, Julia; Ramsperger-Gleixner, Martina; Weyand, Michael; Ensminger, Stephan M

    2010-09-01

    Our group has shown that platelet inhibition with clopidogrel, an antagonist of the P2Y12 adenosine diphosphate receptor on platelets, reduced the formation of transplant arteriosclerosis. The aim of this study was to investigate whether a combination of cyclosporin or everolimus with clopidogrel has a beneficial effect on the development of transplant arteriosclerosis. Fully MHC mismatched C57Bl/6 (H2(b)) donor aortas were transplanted into CBA.J (H2(k)) recipients and mice received either clopidogrel alone (1 mg/kg/day) or in combination with cyclosporin (2 mg/kg/day) or everolimus (0.05 mg/kg/day). Grafts were analysed by histology and morphometry on day 30 after transplantation. In mice treated with clopidogrel alone, transplant arteriosclerosis was significantly reduced [intima proliferation 56 +/- 11% vs. 81 +/- 7% (control)/n = 7]. Daily application of everolimus reduced the development of transplant arteriosclerosis compared with untreated controls [intima proliferation of 29 +/- 9% vs. 81 +/- 7% (control)/n = 7]. Strikingly, combination of clopidogrel and everolimus almost abolished the formation of transplant arteriosclerosis [intima proliferation: 11 +/- 8% vs. 81 +/- 7% (control)/n = 7]. By contrast, combination of cyclosporin and clopidogrel compared with clopidogrel alone showed no additive effect. These results demonstrate that combination of platelet- and mammalian target of Rapamycin-inhibition can dramatically reduce the development of transplant arteriosclerosis.

  5. Dramatic colour changes in a bird of paradise caused by uniquely structured breast feather barbules

    PubMed Central

    Stavenga, Doekele G.; Leertouwer, Hein L.; Marshall, N. Justin; Osorio, Daniel

    2011-01-01

    The breast-plate plumage of male Lawes' parotia (Parotia lawesii) produces dramatic colour changes when this bird of paradise displays on its forest-floor lek. We show that this effect is achieved not solely by the iridescence—that is an angular-dependent spectral shift of the reflected light—which is inherent in structural coloration, but is based on a unique anatomical modification of the breast-feather barbule. The barbules have a segmental structure, and in common with many other iridescent feathers, they contain stacked melanin rodlets surrounded by a keratin film. The unique property of the parotia barbules is their boomerang-like cross section. This allows each barbule to work as three coloured mirrors: a yellow-orange reflector in the plane of the feather, and two symmetrically positioned bluish reflectors at respective angles of about 30°. Movement during the parotia's courtship displays thereby achieves much larger and more abrupt colour changes than is possible with ordinary iridescent plumage. To our knowledge, this is the first example of multiple thin film or multi-layer reflectors incorporated in a single structure (engineered or biological). It nicely illustrates how subtle modification of the basic feather structure can achieve novel visual effects. The fact that the parotia's breast feathers seem to be specifically adapted to give much stronger colour changes than normal structural coloration implies that colour change is important in their courtship display. PMID:21159676

  6. Safety Improves Dramatically In Fluor Hanford Soil and Groundwater Remediation Project

    SciTech Connect

    Foster, A.L.; Gerber, M.S.; VonBargen, B.H.

    2008-07-01

    This paper describes dramatic improvements in the safety record of the Soil and Groundwater Remediation Project (SGRP) at the Hanford Site in southeast Washington state over the past four years. During a period of enormous growth in project work and scope, contractor Fluor Hanford reduced injuries, accidents, and other safety-related incidents and enhanced a safety culture that earned the SGRP Star Status in the Department of Energy's (DOE's) Voluntary Protection Program (VPP) in 2007. This paper outlines the complex and multi-faceted work of Fluor Hanford's SGRP and details the steps taken by the project's Field Operations and Safety organizations to improve safety. Holding field safety meetings and walk-downs, broadening safety inspections, organizing employee safety councils, intensively flowing down safety requirements to subcontractors, and adopting other methods to achieve remarkable improvement in safety are discussed. The roles of management, labor and subcontractors are detailed. Finally, SGRP's safety improvements are discussed within the context of overall safety enhancements made by Fluor Hanford in the company's 11 years of managing nuclear waste cleanup at the Hanford Site. (authors)

  7. A DRAMATICALLY REDUCED SIZE IN THE GANTRY DESIGN FOR THE PROTON-CARBON THERAPY.

    SciTech Connect

    TRBOJEVIC, D.; GUPTA, R.; PARKER, B.; KEIL, E.; SESSLER, A.M.

    2006-06-23

    Gantries in the proton/carbon cancer therapy machines represent the major cost and are of the largest size. This report explains a new way to the gantry design. The size and cost of the gantries are reduced and their use is simplified by using the fixed magnetic field. The ''new'' gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. Additional strong focusing magnets following the gantry have also to be adjustable to provide required spot size and radial scanning above the patients. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.

  8. Regulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery

    SciTech Connect

    Xiao, Xingcheng; Zhou, Weidong; Kim, Youngnam; Ryu, Ill; Gu, Meng; Wang, Chong M.; Liu, Gao; Liu, Zhongyi; Gao, Huajian

    2015-03-01

    Si is an attractive negative electrode material for lithium ion batteries due to its high specifi c capacity (≈3600 mAh g –1 ). However, the huge volume swelling and shrinking during cycling, which mimics a breathing effect at the material/electrode/cell level, leads to several coupled issues including fracture of Si particles, unstable solid electrolyte interphase, and low Coulombic effi ciency. In this work, the regulation of the breathing effect is reported by using Si–C yolk–shell nanocomposite which has been well-developed by other researchers. The focus is on understanding how the nanoscaled materials design impacts the mechanical and electrochemical response at electrode level. For the fi rst time, it is possible to observe one order of magnitude of reduction on breathing effect at the electrode level during cycling: the electrode thickness variation reduced down to 10%, comparing with 100% in the electrode with Si nanoparticles as active materials. The Si–C yolk–shell nanocomposite electrode exhibits excellent capacity retention and high cycle effi ciency. In situ transmission electron microscopy and fi nite element simulations consistently reveals that the dramatically enhanced performance is associated with the regulated breathing of the Si in the new composite, therefore the suppression of the overall electrode expansion.

  9. Optimal temperature for malaria transmission is dramatically lower than previously predicted

    USGS Publications Warehouse

    Mordecai, Erin A.; Paaijmans, Krijn P.; Johnson, Leah R.; Balzer, Christian; Ben-Horin, Tal; de Moor, Emily; McNally, Amy; Pawar, Samraat; Ryan, Sadie J.; Smith, Thomas C.; Lafferty, Kevin D.

    2013-01-01

    The ecology of mosquito vectors and malaria parasites affect the incidence, seasonal transmission and geographical range of malaria. Most malaria models to date assume constant or linear responses of mosquito and parasite life-history traits to temperature, predicting optimal transmission at 31 °C. These models are at odds with field observations of transmission dating back nearly a century. We build a model with more realistic ecological assumptions about the thermal physiology of insects. Our model, which includes empirically derived nonlinear thermal responses, predicts optimal malaria transmission at 25 °C (6 °C lower than previous models). Moreover, the model predicts that transmission decreases dramatically at temperatures > 28 °C, altering predictions about how climate change will affect malaria. A large data set on malaria transmission risk in Africa validates both the 25 °C optimum and the decline above 28 °C. Using these more accurate nonlinear thermal-response models will aid in understanding the effects of current and future temperature regimes on disease transmission.

  10. Membrane Proteins Are Dramatically Less Conserved than Water-Soluble Proteins across the Tree of Life

    PubMed Central

    Sojo, Victor; Dessimoz, Christophe; Pomiankowski, Andrew; Lane, Nick

    2016-01-01

    Membrane proteins are crucial in transport, signaling, bioenergetics, catalysis, and as drug targets. Here, we show that membrane proteins have dramatically fewer detectable orthologs than water-soluble proteins, less than half in most species analyzed. This sparse distribution could reflect rapid divergence or gene loss. We find that both mechanisms operate. First, membrane proteins evolve faster than water-soluble proteins, particularly in their exterior-facing portions. Second, we demonstrate that predicted ancestral membrane proteins are preferentially lost compared with water-soluble proteins in closely related species of archaea and bacteria. These patterns are consistent across the whole tree of life, and in each of the three domains of archaea, bacteria, and eukaryotes. Our findings point to a fundamental evolutionary principle: membrane proteins evolve faster due to stronger adaptive selection in changing environments, whereas cytosolic proteins are under more stringent purifying selection in the homeostatic interior of the cell. This effect should be strongest in prokaryotes, weaker in unicellular eukaryotes (with intracellular membranes), and weakest in multicellular eukaryotes (with extracellular homeostasis). We demonstrate that this is indeed the case. Similarly, we show that extracellular water-soluble proteins exhibit an even stronger pattern of low homology than membrane proteins. These striking differences in conservation of membrane proteins versus water-soluble proteins have important implications for evolution and medicine. PMID:27501943

  11. Insights on dramatic radial fluctuations in track formation by energetic ions.

    PubMed

    Sachan, Ritesh; Zarkadoula, Eva; Lang, Maik; Trautmann, Christina; Zhang, Yanwen; Chisholm, Matthew F; Weber, William J

    2016-01-01

    We report on unexpected dramatic radial variations in ion tracks formed by irradiation with energetic ions (2.3 GeV (208)Pb) at a constant electronic energy-loss (~42 keV/nm) in pyrochlore-structured Gd2TiZrO7. Though previous studies have shown track formation and average track diameter measurements in the Gd2TixZr(1-x)O7 system, the present work clearly reveals the importance of the recrystallization process in ion track formation in this system, which leads to more morphological complexities in tracks than currently accepted behavior. The ion track profile is usually considered to be diametrically uniform for a constant value of electronic energy-loss. This study reveals the diameter variations to be as large as ~40% within an extremely short incremental track length of ~20 nm. Our molecular dynamics simulations show that these fluctuations in diameter of amorphous core and overall track diameter are attributed to the partial substitution of Ti atoms by Zr atoms, which have a large difference in ionic radii, on the B-site in pyrochlore lattice. This random distribution of Ti and Zr atoms leads to a local competition between amorphous phase formation (favored by Ti atoms) and defect-fluorite phase formation (favored by Zr atoms) during the recrystallization process and finally introduces large radial variations in track morphology. PMID:27250764

  12. Dramatic changes in DNA conductance with stretching: structural polymorphism at a critical extension.

    PubMed

    Bag, Saientan; Mogurampelly, Santosh; Goddard Iii, William A; Maiti, Prabal K

    2016-09-21

    In order to interpret recent experimental studies of the dependence of conductance of ds-DNA as the DNA is pulled from the 3'end1-3'end2 ends, which find a sharp conductance jump for a very short (4.5%) stretching length, we carried out multiscale modeling to predict the conductance of dsDNA as it is mechanically stretched to promote various structural polymorphisms. We calculate the current along the stretched DNA using a combination of molecular dynamics simulations, non-equilibrium pulling simulations, quantum mechanics calculations, and kinetic Monte Carlo simulations. For 5'end1-5'end2 attachments we find an abrupt jump in the current within a very short stretching length (6 Å or 17%) leading to a melted DNA state. In contrast, for 3'end1-3'end2 pulling it takes almost 32 Å (84%) of stretching to cause a similar jump in the current. Thus, we demonstrate that charge transport in DNA can occur over stretching lengths of several nanometers. We find that this unexpected behaviour in the B to S conformational DNA transition arises from highly inclined base pair geometries that result from this pulling protocol. We found that the dramatically different conductance behaviors for two different pulling protocols arise from how the hydrogen bonds of DNA base pairs break. PMID:27545499

  13. SAFETY IMPROVES DRAMATICALLY IN FLUOR HANFORD SOIL AND GROUNDWATER REMEDIATION PROJECT

    SciTech Connect

    GERBER MS

    2007-12-05

    This paper describes dramatic improvements in the safety record of the Soil and Groundwater Remediation Project (SGRP) at the Hanford Site in southeast Washington state over the past four years. During a period of enormous growth in project work and scope, contractor Fluor Hanford reduced injuries, accidents, and other safety-related incidents and enhanced a safety culture that earned the SGRP Star Status in the Department of Energy's (DOE's) Voluntary Protection Program (VPP) in 2007. This paper outlines the complex and multi-faceted work of Fluor Hanford's SGRP and details the steps taken by the project's Field Operations and Safety organizations to improve safety. Holding field safety meetings and walkdowns, broadening safety inspections, organizing employee safety councils, intensively flowing down safety requirements to subcontractors, and adopting other methods to achieve remarkable improvement in safety are discussed. The roles of management, labor and subcontractors are detailed. Finally, SGRP's safety improvements are discussed within the context of overall safety enhancements made by Fluor Hanford in the company's 11 years of managing nuclear waste cleanup at the Hanford Site.

  14. Lord Kelvin and the Age-of-the-Earth Debate: A Dramatization

    NASA Astrophysics Data System (ADS)

    Stinner, Art; Teichmann, Jürgen

    This is a dramatization of a fictitious debate about the age of the earth that takes place in the Royal Institution, London, England, in the year 1872. The debate is among Sir William Thomson (later Kelvin), T.H. Huxley (Darwin's Bulldog), Sir Charles Lyell, and Hermann von Helmholtz. In 1862 Thomson published his celebrated and widely studied The Secular Cooling of the Earth that raised the post-Darwinian debate of the age of the earth above the level of popular controversy. He entered the debate with all the arrogance of a newly established science of the century, namely the recently drafted laws of thermodynamics. The debate is partly based on a lively exchange of comments and arguments that occurred between T.H. Huxley and William Thomson, starting in 1868, when Thomson addressed the Glasgow Geological Society. This long public discussion also involved the ideas and the work of geologist Charles Lyell and those of the celebrated German physicist Hermann von Helmholtz. The confrontation is between the unyielding physicists and the insecure biologists and geologists who required a much longer time for the age of the earth than the physicists were prepared to give them. However, the debate ends on a conciliatory note, suggesting that perhaps Sir William's storehouse of creation may contain a hereto undiscovered source of energy that is more bountiful than gravitational energy.

  15. Use of microsecond current prepulse for dramatic improvements of wire array Z-pinch implosion

    SciTech Connect

    Calamy, H.; Lassalle, F.; Loyen, A.; Zucchini, F.; Chittenden, J. P.; Hamann, F.; Maury, P.; Georges, A.; Bedoch, J. P.; Morell, A.

    2008-01-15

    The Sphinx machine [F. Lassalle et al., 'Status on the SPHINX machine based on the 1microsecond LTD technology'] based on microsecond linear transformer driver (LTD) technology is used to implode an aluminium wire array with an outer diameter up to 140 mm and maximum current from 3.5 to 5 MA. 700 to 800 ns implosion Z-pinch experiments are performed on this driver essentially with aluminium. Best results obtained before the improvement described in this paper were 1-3 TW radial total power, 100-300 kJ total yield, and 20-30 kJ energy above 1 keV. An auxiliary generator was added to the Sphinx machine in order to allow a multi microsecond current to be injected through the wire array load before the start of the main current. Amplitude and duration of this current prepulse are adjustable, with maxima {approx}10 kA and 50 {mu}s. This prepulse dramatically changes the ablation phase leading to an improvement of the axial homogeneity of both the implosion and the final radiating column. Total power was multiplied by a factor of 6, total yield by a factor of 2.5 with a reproducible behavior. This paper presents experimental results, magnetohydrodynamic simulations, and analysis of the effect of such a long current prepulse.

  16. 25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays

    PubMed Central

    Yu, Songlin; Cheng, Xinqi; Fang, Huiling; Zhang, Ruiping; Han, Jianhua; Qin, Xuzhen; Cheng, Qian; Su, Wei; Hou, Li’an; Xia, Liangyu; Qiu, Ling

    2015-01-01

    Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy. PMID:26420221

  17. Zeolite molecular sieves have dramatic acid-base effects on enzymes in nonaqueous media.

    PubMed

    Fontes, Nuno; Partridge, Johann; Halling, Peter J; Barreiros, Susana

    2002-02-01

    Zeolite molecular sieves very commonly are used as in situ drying agents in reaction mixtures of enzymes in nonaqueous media. They often affect enzyme behavior, and this has been interpreted in terms of altered hydration. Here, we show that zeolites can also have dramatic acid-base effects on enzymes in low water media, resulting from their cation-exchange ability. Initial rates of transesterification catalyzed by cross-linked crystals of subtilisin were compared in supercritical ethane, hexane, and acetonitrile with water activity fixed by pre-equilibration. Addition of zeolite NaA (4 A powder) still caused remarkable rate enhancements (up to 20-fold), despite the separate control of hydration. In the presence of excess of an alternative solid-state acid-base buffer, however, zeolite addition had no effect. The more commonly used Merck molecular sieves (type 3 A beads) had similar but somewhat smaller effects. All zeolites have ion-exchange ability and can exchange H+ for cations such as Na+ and K+. These exchanges will tend to affect the protonation state of acidic groups in the protein and, hence, enzymatic activity. Zeolites pre-equilibrated in aqueous suspensions of varying pH-pNa gave very different enzyme activities. Their differing basicities were demonstrated directly by equilibration with an indicator dissolved in toluene. The potential of zeolites as acid-base buffers for low-water media is discussed, and their ability to overcome pH memory is demonstrated.

  18. Fatal Haemoptysis Associated with Dramatic Response to Crizotinib in an ALK-Rearranged Lung Adenocarcinoma

    PubMed Central

    Mussat, Elodie; Giraud, Violaine; Julie, Catherine; Chinet, Thierry

    2016-01-01

    The presence of an ALK (Anaplastic Lymphoma Kinase) rearrangement is a rare molecular feature in Non-Small Cell Lung Carcinoma (NSCLC), and concerns mainly non- or light smokers, young patients, with adenocarcinoma histological type. These tumours are particularly sensitive to Alk-targeted therapies, as crizotinib. Crizotinib is usually well-tolerated. We report a case of fatal haemoptysis associated with dramatic response to crizotinib in a patient with an ALK-rearranged lung adenocarcinoma. The patient presented a mediastinal invasion with tracheal involvement and compression of the right pulmonary artery. The initial evolution under crizotinib was good with tumour response. At 6 weeks of crizotinib the patient presented a massive haemoptysis with a tracheobronchial fistula and pneumomediastinum. She died of acute respiratory failure. Our case is the first to report a fatal effect of crizotinib associated with tumour necrosis and good tumour response on a massive mediastinal infiltration. Precautions are recommended with the use of crizotinib in proximal lung tumours with vascular invasion. PMID:27134984

  19. Dramatic colour changes in a bird of paradise caused by uniquely structured breast feather barbules.

    PubMed

    Stavenga, Doekele G; Leertouwer, Hein L; Marshall, N Justin; Osorio, Daniel

    2011-07-22

    The breast-plate plumage of male Lawes' parotia (Parotia lawesii) produces dramatic colour changes when this bird of paradise displays on its forest-floor lek. We show that this effect is achieved not solely by the iridescence--that is an angular-dependent spectral shift of the reflected light--which is inherent in structural coloration, but is based on a unique anatomical modification of the breast-feather barbule. The barbules have a segmental structure, and in common with many other iridescent feathers, they contain stacked melanin rodlets surrounded by a keratin film. The unique property of the parotia barbules is their boomerang-like cross section. This allows each barbule to work as three coloured mirrors: a yellow-orange reflector in the plane of the feather, and two symmetrically positioned bluish reflectors at respective angles of about 30°. Movement during the parotia's courtship displays thereby achieves much larger and more abrupt colour changes than is possible with ordinary iridescent plumage. To our knowledge, this is the first example of multiple thin film or multi-layer reflectors incorporated in a single structure (engineered or biological). It nicely illustrates how subtle modification of the basic feather structure can achieve novel visual effects. The fact that the parotia's breast feathers seem to be specifically adapted to give much stronger colour changes than normal structural coloration implies that colour change is important in their courtship display.

  20. Preventing domestic violence in the african american community: assessing the impact of a dramatic radio serial.

    PubMed

    Wray, Ricardo J; Hornik, Robert M; Gandy, Oscar H; Stryker, Jo; Ghez, Marissa; Mitchell-Clark, Kelly

    2004-01-01

    This article reports on the evaluation of "It's Your Business," a dramatic radio serial promoting domestic violence prevention in the African-American community that was made available for national broadcast. Radio stations in 4 study cities committed to airing the broadcasts. However, in only 1 of the 4 was the broadcast carried out in even a limited way. Consequently, only data from one city could be used to assess impact. Even there only 9 percent of the sample could confidently be called exposed, answering a recall question correctly and claiming to hear more than 2 episodes. These moderately exposed respondents scored higher than non-exposed respondents on 21 out of 27 anti-domestic violence beliefs and behaviors; 10 differences were statistically significant. However, the moderate exposure group only displayed stronger outcomes than a group who claimed exposure but could not recall much about the program in 2 out of the 27 outcomes at a statistically significant level. We conclude that the association of moderate exposure and anti-domestic violence outcomes was most likely an artifact of selective perception, and not a result of exposure alone. The evaluation points to the need to better understand how exposure can be achieved to complement our work on developing messages.

  1. Insights on dramatic radial fluctuations in track formation by energetic ions

    PubMed Central

    Sachan, Ritesh; Zarkadoula, Eva; Lang, Maik; Trautmann, Christina; Zhang, Yanwen; Chisholm, Matthew F.; Weber, William J.

    2016-01-01

    We report on unexpected dramatic radial variations in ion tracks formed by irradiation with energetic ions (2.3 GeV 208Pb) at a constant electronic energy-loss (~42 keV/nm) in pyrochlore-structured Gd2TiZrO7. Though previous studies have shown track formation and average track diameter measurements in the Gd2TixZr(1−x)O7 system, the present work clearly reveals the importance of the recrystallization process in ion track formation in this system, which leads to more morphological complexities in tracks than currently accepted behavior. The ion track profile is usually considered to be diametrically uniform for a constant value of electronic energy-loss. This study reveals the diameter variations to be as large as ~40% within an extremely short incremental track length of ~20 nm. Our molecular dynamics simulations show that these fluctuations in diameter of amorphous core and overall track diameter are attributed to the partial substitution of Ti atoms by Zr atoms, which have a large difference in ionic radii, on the B-site in pyrochlore lattice. This random distribution of Ti and Zr atoms leads to a local competition between amorphous phase formation (favored by Ti atoms) and defect-fluorite phase formation (favored by Zr atoms) during the recrystallization process and finally introduces large radial variations in track morphology. PMID:27250764

  2. Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

    PubMed Central

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-01-01

    Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively. PMID:26657816

  3. Linkage between Three Gorges Dam impacts and the dramatic recessions in China's largest freshwater lake, Poyang Lake.

    PubMed

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-01-01

    Despite comprising a small portion of the earth's surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake's wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively. PMID:26657816

  4. PTEN deficiency in a luminal ErbB-2 mouse model results in dramatic acceleration of mammary tumorigenesis and metastasis.

    PubMed

    Schade, Babette; Rao, Trisha; Dourdin, Nathalie; Lesurf, Robert; Hallett, Michael; Cardiff, Robert D; Muller, William J

    2009-07-10

    Overexpression and/or amplification of the ErbB-2 oncogene as well as inactivation of the PTEN tumor suppressor are two important genetic events in human breast carcinogenesis. To address the biological impact of conditional inactivation of PTEN on ErbB-2-induced mammary tumorigenesis, we generated a novel transgenic mouse model that utilizes the murine mammary tumor virus (MMTV) promoter to directly couple expression of activated ErbB-2 and Cre recombinase to the same mammary epithelial cell (MMTV-NIC). Disruption of PTEN in the mammary epithelium of the MMTV-NIC model system dramatically accelerated the formation of multifocal and highly metastatic mammary tumors, which exhibited homogenous pathology. PTEN-deficient/NIC-induced tumorigenesis was associated with an increase in angiogenesis. Moreover, inactivation of PTEN in the MMTV-NIC mouse model resulted in hyperactivation of the phosphatidylinositol 3'-kinase/Akt signaling pathway. However, like the parental strain, tumors obtained from PTEN-deficient/NIC mice displayed histopathological and molecular features of the luminal subtype of primary human breast cancer. Taken together, our findings provide important implications in understanding the molecular determinants of mammary tumorigenesis driven by PTEN deficiency and ErbB-2 activation and could provide a valuable tool for testing the efficacy of therapeutic strategies that target these critical signaling pathways.

  5. High Emergency Lung Transplantation: dramatic decrease of waiting list death rate without relevant higher post-transplant mortality.

    PubMed

    Roux, Antoine; Beaumont-Azuar, Laurence; Hamid, Abdul Monem; De Miranda, Sandra; Grenet, Dominique; Briend, Guillaume; Bonnette, Pierre; Puyo, Philippe; Parquin, François; Devaquet, Jerome; Trebbia, Gregoire; Cuquemelle, Elise; Douvry, Benoit; Picard, Clément; Le Guen, Morgan; Chapelier, Alain; Stern, Marc; Sage, Edouard

    2015-09-01

    Many candidates for lung transplantation (LT) die on the waiting list, raising the question of graft availability and strategy for organ allocation. We report the experience of the new organ allocation program, "High Emergency Lung Transplantation" (HELT), since its implementation in our center in 2007. Retrospective analysis of 201 lung transplant patients, of whom 37 received HELT from 1st July 2007 to 31th May 2012. HELT candidates had a higher impairment grade on respiratory status and higher Lung Allocation Score (LAS). HELT patients had increased incidence of perioperative complications (e.g., perioperative bleeding) and extracorporeal circulatory assistance (75% vs. 36.6%, P = 0.0005). No significant difference was observed between HELT and non-HELT patients in mechanical ventilation duration (15.5 days vs. 11 days, P = 0.27), intensive care unit length of stay (15 days vs. 10 days, P = 0.22) or survival rate at 12 (81% vs. 80%), and 24 months post-LT (72.9% vs. 75.0%). Lastly, mortality on the waiting list was spectacularly reduced from 19% to 2% when compared to the non-HELT 2004-2007 group. Despite a more severe clinical status of patients on the waiting list, HELT provided similar results to conventional LT. These results were associated with a dramatic reduction in the mortality rate of patients on the waiting list.

  6. Linkage between Three Gorges Dam impacts and the dramatic recessions in China’s largest freshwater lake, Poyang Lake

    NASA Astrophysics Data System (ADS)

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-12-01

    Despite comprising a small portion of the earth’s surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake’s wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively.

  7. Linkage between Three Gorges Dam impacts and the dramatic recessions in China's largest freshwater lake, Poyang Lake.

    PubMed

    Mei, Xuefei; Dai, Zhijun; Du, Jinzhou; Chen, Jiyu

    2015-12-11

    Despite comprising a small portion of the earth's surface, lakes are vitally important for global ecosystem cycling. However, lake systems worldwide are extremely fragile, and many are shrinking due to changing climate and anthropogenic activities. Here, we show that Poyang Lake, the largest freshwater lake in China, has experienced a dramatic and prolonged recession, which began in late September of 2003. We further demonstrate that abnormally low levels appear during October, 28 days ahead of the normal initiation of the dry season, which greatly imperiled the lake's wetland areas and function as an ecosystem for wintering waterbirds. An increase in the river-lake water level gradient induced by the Three Gorges Dam (TGD) altered the lake balance by inducing greater discharge into the Changjiang River, which is probably responsible for the current lake shrinkage. Occasional episodes of arid climate, as well as local sand mining, will aggravate the lake recession crisis. Although impacts of TGD on the Poyang Lake recession can be overruled by episodic extreme droughts, we argue that the average contributions of precipitation variation, human activities in the Poyang Lake catchment and TGD regulation to the Poyang Lake recession can be quantified as 39.1%, 4.6% and 56.3%, respectively.

  8. Change in avian abundance predicted from regional forest inventory data

    USGS Publications Warehouse

    Twedt, Daniel J.; Tirpak, John M.; Jones-Farrand, D. Todd; Thompson, Frank R.; Uihlein, William B.; Fitzgerald, Jane A.

    2010-01-01

    An inability to predict population response to future habitat projections is a shortcoming in bird conservation planning. We sought to predict avian response to projections of future forest conditions that were developed from nationwide forest surveys within the Forest Inventory and Analysis (FIA) program. To accomplish this, we evaluated the historical relationship between silvicolous bird populations and FIA-derived forest conditions within 25 ecoregions that comprise the southeastern United States. We aggregated forest area by forest ownership, forest type, and tree size-class categories in county-based ecoregions for 5 time periods spanning 1963-2008. We assessed the relationship of forest data with contemporaneous indices of abundance for 24 silvicolous bird species that were obtained from Breeding Bird Surveys. Relationships between bird abundance and forest inventory data for 18 species were deemed sufficient as predictive models. We used these empirically derived relationships between regional forest conditions and bird populations to predict relative changes in abundance of these species within ecoregions that are anticipated to coincide with projected changes in forest variables through 2040. Predicted abundances of these 18 species are expected to remain relatively stable in over a quarter (27%) of the ecoregions. However, change in forest area and redistribution of forest types will likely result in changed abundance of some species within many ecosystems. For example, abundances of 11 species, including pine warbler (Dendroica pinus), brown-headed nuthatch (Sitta pusilla), and chuckwills- widow (Caprimulgus carolinensis), are projected to increase within more ecoregions than ecoregions where they will decrease. For 6 other species, such as blue-winged warbler (Vermivora pinus), Carolina wren (Thryothorus ludovicianus), and indigo bunting (Passerina cyanea), we projected abundances will decrease within more ecoregions than ecoregions where they will

  9. Dramatic effects of speech task on motor and linguistic planning in severely dysfluent parkinsonian speech

    PubMed Central

    Van Lancker Sidtis, Diana; Cameron, Krista; Sidtis, John J.

    2015-01-01

    In motor speech disorders, dysarthric features impacting intelligibility, articulation, fluency, and voice emerge more saliently in conversation than in repetition, reading, or singing. A role of the basal ganglia in these task discrepancies has been identified. Further, more recent studies of naturalistic speech in basal ganglia dysfunction have revealed that formulaic language is more impaired than novel language. This descriptive study extends these observations to a case of severely dysfluent dysarthria due to a parkinsonian syndrome. Dysfluencies were quantified and compared for conversation, two forms of repetition, reading, recited speech, and singing. Other measures examined phonetic inventories, word forms, and formulaic language. Phonetic, syllabic, and lexical dysfluencies were more abundant in conversation than in other task conditions. Formulaic expressions in conversation were reduced compared to normal speakers. A proposed explanation supports the notion that the basal ganglia contribute to formulation of internal models for execution of speech. PMID:22774929

  10. The Significance of Myriophyllum elatinoides for Swine Wastewater Treatment: Abundance and Community Structure of Ammonia-Oxidizing Microorganisms in Sediments

    PubMed Central

    Li, Xi; Zhang, Miaomiao; Liu, Feng; Li, Yong; He, Yang; Zhang, Shunan; Wu, Jinshui

    2015-01-01

    Myriophyllum elatinoides was reported to effectively treat wastewater by removing nitrogen (N) and phosphorus (P). However, little is known about the abundance and community structure of ammonia-oxidizing microorganisms associated with M. elatinoides purification systems. The objective of this research was to characterize the abundance and community structure of ammonia-oxidizing microorganisms in swine wastewater and determine the main nitrogen removal pathways. In this study, five different waters were treated by M. elatinoides in microcosms for one month. The five waters included tap water (Control), swine wastewater (SW), 50% diluted swine wastewater (50% SW), and two synthetic wastewaters: 200 mg NH4+-N L−1 (200 NH4+-N) and 400 mg NH4+-N L−1 (400 NH4+-N). The most dramatic changes were in NH4+-N and total N (TN) concentrations, with average removal rates of 84% and 90%, respectively, in the treatments containing swine wastewater. On days 7, 14, and 28, the dissolved oxygen (DO) increased by 81.8%, 210.4% and 136.5%, respectively, compared with on day 0, in the swine wastewater. The results also showed that the bacterial amoA (AOB) copy numbers in the sediments of the treatments were significantly higher than those of archaeal amoA (AOA) copy numbers (p = 0.015). In addition, the high DO concentrations in swine wastewater responded well to the high abundance of AOB. The AOA and AOB community distributions were positively related with NO3-N and were negatively related with DO in swine wastewater treatments. In summary, our experimental results suggested that the M. elatinoides purification system could improve the activity of ammonia-oxidizing microorganisms and consequently might contribute to the significant N removal from the swine wastewater. PMID:26444015

  11. Effects of urbanization on the distribution and abundance of amphibians and invasive species in southern California streams

    USGS Publications Warehouse

    Riley, S.P.D.; Busteed, G.T.; Kats, L.B.; Vandergon, T.L.; Lee, L.F.S.; Dagit, R.G.; Kerby, J.L.; Fisher, R.N.; Sauvajot, R.M.

    2005-01-01

    Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and exotic predators and characterized stream habitat and invertebratecommunities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish (Procambarus clarkii) and fish, and had fewer native species such as California newts (Taricha torosa) and California treefrogs (Hyla cadaverina). These effects seemed particularly evident above 8% development, a result coincident with other urban stream studies that show negative impacts beginning at 10-15% urbanization. For Pacific treefrogs (H. regilla), the most widespread native amphibian, abundance was lower in the presence of exotic crayfish, although direct urbanization effects were not found. Benthic macroinvertebrate communities were also less diverse in urban streams, especially for sensitive species. Faunal community changes in urban streams may be related to changes in physical stream habitat, such as fewer pool and more run habitats and increased water depth and flow, leading to more permanent streams. Variation in stream permanence was particularly evident in 2002, a dry year when many natural streams were dry but urban streams were relatively unchanged. Urbanization has significantly altered stream habitat in this region and may enhance invasion by exotic species and negatively affect diversity and abundance of native amphibians. ??2005 Society for Conservation Biology.

  12. Changes in marine dinoflagellate and diatom abundance under climate change

    NASA Astrophysics Data System (ADS)

    Hinder, Stephanie L.; Hays, Graeme C.; Edwards, Martin; Roberts, Emily C.; Walne, Anthony W.; Gravenor, Mike B.

    2012-04-01

    Marine diatoms and dinoflagellates play a variety of key ecosystem roles as important primary producers (diatoms and some dinoflagellates) and grazers (some dinoflagellates). Additionally some are harmful algal bloom (HAB) species and there is widespread concern that HAB species may be increasing accompanied by major negative socio-economic impacts, including threats to human health and marine harvesting. Using 92,263 samples from the Continuous Plankton Recorder survey, we generated a 50-year (1960-2009) time series of diatom and dinoflagellate occurrence in the northeast Atlantic and North Sea. Dinoflagellates, including both HAB taxa (for example, Prorocentrum spp.) and non-HAB taxa (for example, Ceratium furca), have declined in abundance, particularly since 2006. In contrast, diatom abundance has not shown this decline with some common diatoms, including both HAB (for example, Pseudo-nitzschia spp.) and non-HAB (for example, Thalassiosira spp.) taxa, increasing in abundance. Overall these changes have led to a marked increase in the relative abundance of diatoms versus dinoflagellates. Our analyses, including Granger tests to identify criteria of causality, indicate that this switch is driven by an interaction effect of both increasing sea surface temperatures combined with increasingly windy conditions in summer.

  13. Abundance anomalies of carbon and nitrogen in the IUE spectra of Algol-type interacting binaries

    NASA Technical Reports Server (NTRS)

    Mccluskey, Carolina P. S.

    1990-01-01

    There are two primary ways in which the products of nucleosynthesis in stellar interiors may appear at the surface of a star. These are mixing and/or loss of the original unburned stellar envelope. In interacting binaries, overflow can contribute dramatically to envelope loss. The simplest abundance anomalies to be expected from nuclear burning of hydrogen, helium, or carbon would be under or over abundances H, He, C, O, Ne, and Mg. In addition, it is expected that carbon is initially severely depleted, while nitrogen is enhanced during hydrogen burning via the CNO cycle in stars above two solar masses. Other, more subtle anomalies are also expected, and elements heavier than magnesium can be created during very late evolution by nuclear burning in massive stars. Consequently, it is expected that abundance anomalies of various kinds should occur in interacting binaries where one or both stars have lost significant amounts of mass.

  14. Stardust Abundance Variations among Interplanetary Dust Particles

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Walker, Robert M.

    2009-01-01

    Presolar grain abundances reflect the degree of processing primitive materials have experienced. This is evidenced by the wide range of silicate stardust abundances among primitive meteorites (10 to 300 ppm) [1], attributable to parent body hydrothermal processing. Stardust abundance variations are also pronounced in anhydrous interplanetary dust particles (CPIDPs), that have not experienced parent body processing (300 to > 10,000 ppm) [2-4]. The large range in stardust abundances among CP IDPs thus reflect nebular processing. Here we present results of a systematic search for stardust among cluster CP IDPs. Our goals are to establish mineralogical trends among IDPs with different stardust abundances. This may shed light into the nature of isotopically normal presolar grains (GEMS grains?; 5) if their abundances vary similarly to that of isotopically exotic stardust grains.

  15. Ammonia and nitrogen abundances in comets

    NASA Technical Reports Server (NTRS)

    Wyckoff, Susan

    1990-01-01

    Comets consist of pristine material preserved from an earlier galactic epoch. Determination of the molecular, elemental, and isotopic abundances in the dust and volatile components of comet nuclei produce vital clues to the chemical evolution of both interstellar and solar nebula matter. Here the abundances of nitrogen-containing molecules in comets are considered. The molecular abundances of NH3 in four comets are summarized (Tegler 1990, Wyckoff, Tegler, and Engel, 1990). From an inventory of nitrogen-containing compounds (Wyckoff, Engel, and Tegler 1990, Wyckoff, Engel, Womack, Ferro, Tegler and Peterson, 1990), an estimate of the elemental N abundance is also presented.

  16. The 5' noncoding sequences from a less virulent Theiler's virus dramatically attenuate GDVII neurovirulence.

    PubMed Central

    Lipton, H L; Calenoff, M; Bandyopadhyay, P; Miller, S D; Dal Canto, M C; Gerety, S; Jensen, K

    1991-01-01

    RNA transcripts derived from recombinant chimeras between the highly virulent GDVII virus and the less virulent BeAn virus were constructed to study the molecular pathogenesis of Theiler's murine encephalomyelitis virus infection. The presence of the BeAn 5' noncoding sequences in chimera 2 (BeAn 5' noncoding sequences joined with the GDVII nucleotides encoding the polyprotein and present in the 3' end) resulted in dramatic attenuation of GDVII neurovirulence and development of poliomyelitis in mice. This reduced neurovirulence was associated with slower virus growth and lower peak titers in the brain and spinal cord than with parental GDVII virus replication. On the other hand, the sites of replication following chimera 2 infection were the same as those seen in GDVII-infected mice; the distribution of virus antigen and histopathological changes indicated that chimera 2 replicates in neurons in the brain, e.g., in the neocortex, hippocampus, caudate putamen, and brain stem, as well as in anterior-horn cells in the spinal cord. Chimera 2 was efficiently cleared from the mouse central nervous system by day 30 postinfection, in marked contrast to the persistence of the BeAn parent in the central nervous system. This suggests that elements in the BeAn sequences that encode the polyprotein or are present in the 3' noncoding region are necessary for viral persistence. It is of interest that chimera 2-infected mice developed localized inflammatory, demyelinating lesions which were detected at day 28 postinfection but these lesions did not become larger with time. Thus, virus persistence appears to be required for maintenance and progression of immune-mediated demyelination. If the demyelinating lesions become sufficiently large, clinical signs and disease may develop. Images PMID:2072455

  17. The 5' noncoding sequences from a less virulent Theiler's virus dramatically attenuate GDVII neurovirulence.

    PubMed

    Lipton, H L; Calenoff, M; Bandyopadhyay, P; Miller, S D; Dal Canto, M C; Gerety, S; Jensen, K

    1991-08-01

    RNA transcripts derived from recombinant chimeras between the highly virulent GDVII virus and the less virulent BeAn virus were constructed to study the molecular pathogenesis of Theiler's murine encephalomyelitis virus infection. The presence of the BeAn 5' noncoding sequences in chimera 2 (BeAn 5' noncoding sequences joined with the GDVII nucleotides encoding the polyprotein and present in the 3' end) resulted in dramatic attenuation of GDVII neurovirulence and development of poliomyelitis in mice. This reduced neurovirulence was associated with slower virus growth and lower peak titers in the brain and spinal cord than with parental GDVII virus replication. On the other hand, the sites of replication following chimera 2 infection were the same as those seen in GDVII-infected mice; the distribution of virus antigen and histopathological changes indicated that chimera 2 replicates in neurons in the brain, e.g., in the neocortex, hippocampus, caudate putamen, and brain stem, as well as in anterior-horn cells in the spinal cord. Chimera 2 was efficiently cleared from the mouse central nervous system by day 30 postinfection, in marked contrast to the persistence of the BeAn parent in the central nervous system. This suggests that elements in the BeAn sequences that encode the polyprotein or are present in the 3' noncoding region are necessary for viral persistence. It is of interest that chimera 2-infected mice developed localized inflammatory, demyelinating lesions which were detected at day 28 postinfection but these lesions did not become larger with time. Thus, virus persistence appears to be required for maintenance and progression of immune-mediated demyelination. If the demyelinating lesions become sufficiently large, clinical signs and disease may develop.

  18. New Radar Altimeter Missions are Providing a Dramatically Sharper Image of Global Marine Tectonics

    NASA Astrophysics Data System (ADS)

    Sandwell, D. T.; Müller, D.; Garcia, E.; Matthews, K. J.; Smith, W. H. F.; Zaron, E.; Zhang, S.; Bassett, D.; Francis, R.

    2015-12-01

    Marine gravity, derived from satellite radar altimetry, is a powerful tool for mapping tectonic structures, especially in the deep ocean basins where the topography remains unmapped by ships or is buried by thick sediment. The ability to infer seafloor tectonics from space was first demonstrated in 1978 using Seasat altimeter data but the spatial coverage was incomplete because of the short three-month lifetime of the satellite. Most ocean altimeters have repeat ground tracks with spacings of hundreds of kilometers so they do not resolve tectonic structures. Adequate altimeter coverage became available in 1995 when the United States Navy declassified the Geosat radar altimeter data and the ERS-1 altimeter completed a 1-year mapping phase. These mid-1990's altimeter-derived images of the ocean basins remained static for 15 years because there were no new non-repeat altimeter missions. This situation changed dramatically in 2010 when CryoSat-2, with its advanced radar altimeter, was launched into a non-repeat orbit and continues to collect data until perhaps 2020. In addition the Jason-1 altimeter was placed into a 14-month geodetic phase at the end of its lifetime. More recently the 1.5 times higher precision measurements from the AltiKa altimeter aboard the SARAL spacecraft began to drift away from its 35-day repeat trackline. The Chinese HY-2 altimeter is scheduled to begin a dense mapping phase in early 2016. Moreover in 2020 we may enjoy significantly higher resolution maps of the ocean basins from the planned SWOT altimeter mission with its advanced swath mapping ability. All of this new data will provide a much sharper image of the tectonics of the deep ocean basins and continental margins. During this talk we will tour of the new tectonic structures revealed by CryoSat-2 and Jason-1 and speculate on the tectonic views of the ocean basins in 2020 and beyond.

  19. Hierarchical distance-sampling models to estimate population size and habitat-specific abundance of an island endemic

    USGS Publications Warehouse

    Sillett, Scott T.; Chandler, Richard B.; Royle, J. Andrew; Kéry, Marc; Morrison, Scott A.

    2012-01-01

    Population size and habitat-specific abundance estimates are essential for conservation management. A major impediment to obtaining such estimates is that few statistical models are able to simultaneously account for both spatial variation in abundance and heterogeneity in detection probability, and still be amenable to large-scale applications. The hierarchical distance-sampling model of J. A. Royle, D. K. Dawson, and S. Bates provides a practical solution. Here, we extend this model to estimate habitat-specific abundance and rangewide population size of a bird species of management concern, the Island Scrub-Jay (Aphelocoma insularis), which occurs solely on Santa Cruz Island, California, USA. We surveyed 307 randomly selected, 300 m diameter, point locations throughout the 250-km2 island during October 2008 and April 2009. Population size was estimated to be 2267 (95% CI 1613-3007) and 1705 (1212-2369) during the fall and spring respectively, considerably lower than a previously published but statistically problematic estimate of 12 500. This large discrepancy emphasizes the importance of proper survey design and analysis for obtaining reliable information for management decisions. Jays were most abundant in low-elevation chaparral habitat; the detection function depended primarily on the percent cover of chaparral and forest within count circles. Vegetation change on the island has been dramatic in recent decades, due to release from herbivory following the eradication of feral sheep (Ovis aries) from the majority of the island in the mid-1980s. We applied best-fit fall and spring models of habitat-specific jay abundance to a vegetation map from 1985, and estimated the population size of A. insularis was 1400-1500 at that time. The 20-30% increase in the jay population suggests that the species has benefited from the recovery of native vegetation since sheep removal. Nevertheless, this jay's tiny range and small population size make it vulnerable to natural

  20. Hierarchical distance-sampling models to estimate population size and habitat-specific abundance of an island endemic.

    PubMed

    Sillett, T Scott; Chandler, Richard B; Royle, J Andrew; Kery, Marc; Morrison, Scott A

    2012-10-01

    Population size and habitat-specific abundance estimates are essential for conservation management. A major impediment to obtaining such estimates is that few statistical models are able to simultaneously account for both spatial variation in abundance and heterogeneity in detection probability, and still be amenable to large-scale applications. The hierarchical distance-sampling model of J. A. Royle, D. K. Dawson, and S. Bates provides a practical solution. Here, we extend this model to estimate habitat-specific abundance and rangewide population size of a bird species of management concern, the Island Scrub-Jay (Aphelocoma insularis), which occurs solely on Santa Cruz Island, California, USA. We surveyed 307 randomly selected, 300 m diameter, point locations throughout the 250-km2 island during October 2008 and April 2009. Population size was estimated to be 2267 (95% CI 1613-3007) and 1705 (1212-2369) during the fall and spring respectively, considerably lower than a previously published but statistically problematic estimate of 12 500. This large discrepancy emphasizes the importance of proper survey design and analysis for obtaining reliable information for management decisions. Jays were most abundant in low-elevation chaparral habitat; the detection function depended primarily on the percent cover of chaparral and forest within count circles. Vegetation change on the island has been dramatic in recent decades, due to release from herbivory following the eradication of feral sheep (Ovis aries) from the majority of the island in the mid-1980s. We applied best-fit fall and spring models of habitat-specific jay abundance to a vegetation map from 1985, and estimated the population size of A. insularis was 1400-1500 at that time. The 20-30% increase in the jay population suggests that the species has benefited from the recovery of native vegetation since sheep removal. Nevertheless, this jay's tiny range and small population size make it vulnerable to natural

  1. Microbial abundance and community in subsurface flow constructed wetland microcosms: role of plant presence.

    PubMed

    Wang, Qian; Xie, Huijun; Ngo, Huu Hao; Guo, Wenshan; Zhang, Jian; Liu, Cui; Liang, Shuang; Hu, Zhen; Yang, Zhongchen; Zhao, Congcong

    2016-03-01

    In this research, the role of plants in improving microorganism growth conditions in subsurface flow constructed wetland (CW) microcosms was determined. In particular, microbial abundance and community were investigated during summer and winter in Phragmites australis-planted CW microcosms (PA) and unplanted CW microcosms (control, CT). Results revealed that the removal efficiencies of pollutants and microbial community structure varied in winter with variable microbial abundance. During summer, PA comprised more dominant phyla (e.g., Proteobacteria, Actinobacteria, and Bacteroidetes), whereas CT contained more Cyanobacteria and photosynthetic bacteria. During winter, the abundance of Proteobacteria was >40 % in PA but dramatically decreased in CT. Moreover, Cyanobacteria and photosynthetic bacterial dominance in CT decreased. In both seasons, bacteria were more abundant in root surfaces than in sand. Plant presence positively affected microbial abundance and community. The potential removal ability of CT, in which Cyanobacteria and photosynthetic bacteria were abundant during summer, was more significantly affected by temperature reduction than that of PA with plant presence. PMID:25772872

  2. Condom use increasing.

    PubMed

    Finger, W R

    1998-01-01

    Condom use is central to the prevention of AIDS among people at risk for contracting HIV. As such, condom use is increasing dramatically even though many men say that they do not like using them. Condom sales through social marketing campaigns have increased dramatically in some countries, where tens of millions of condoms are sold annually. For example, during the period 1991-96, annual social marketing sales increased about five-fold in Ethiopia to 21 million, and nine-fold in Brazil to 27 million. These sales reflect the success of condom social marketing campaigns in making condoms accessible and largely affordable. There is also a greater general awareness of AIDS than there used to be, and communication campaigns have shown that condoms are an effective solution. More condoms still need to be used in the ongoing struggle against HIV/AIDS. The author discusses the factors which affect the limited acceptance of condoms, condom use outside of marriage, social marketing, and family planning programs. PMID:12293530

  3. ZIRCONIUM, BARIUM, LANTHANUM, AND EUROPIUM ABUNDANCES IN OPEN CLUSTERS

    SciTech Connect

    Jacobson, Heather R.; Friel, Eileen D. E-mail: efriel@indiana.edu

    2013-04-15

    We present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines per species via both equivalent width and spectrum synthesis techniques. We investigate cluster mean neutron-capture abundance trends as a function of cluster age and location in the Milky Way disk and compare them to results found in other studies in the literature. We find a statistically significant trend of increasing cluster [Ba/Fe] as a function of decreasing cluster age, in agreement with recent findings for other open cluster samples, supporting the increased importance of low-mass asymptotic giant branch stars to the generation of s-process elements. However, the other s-process elements, [La/Fe] and [Zr/Fe], do not show similar dependences, in contrast to theoretical expectations and the limited observational data from other studies. Conversely, cluster [Eu/Fe] ratios show a slight increase with increasing cluster age, although with marginal statistical significance. Ratios of [s/r]-process abundances, [Ba/Eu] and [La/Eu], however, show more clearly the increasing efficiency of s-process relative to r-process enrichment in open cluster chemical evolution, with significant increases among younger clusters. Last, cluster neutron-capture element abundances appear to be independent of Galactocentric distance. We conclude that a homogeneous analysis of a larger sample of open clusters is needed to resolve the apparent discrepant conclusions between different studies regarding s-process element abundance trends with age to better inform models of galactic chemical evolution.

  4. Modeling avian abundance from replicated counts using binomial mixture models

    USGS Publications Warehouse

    Kery, M.; Royle, J. Andrew; Schmid, H.

    2005-01-01

    Abundance estimation in ecology is usually accomplished by capture-recapture, removal, or distance sampling methods. These may be hard to implement at large spatial scales. In contrast, binomial mixture models enable abundance estimation without individual identification, based simply on temporally and spatially replicated counts. Here, we evaluate mixture models using data from the national breeding bird monitoring program in Switzerland, where some 250 1-km(2) quadrats are surveyed using the territory mapping method three times during each breeding season. We chose eight species with contrasting distribution (wide-narrow), abundance (high-low), and detectability (easy-difficult). Abundance was modeled as a random effect with a Poisson or negative binomial distribution, with mean affected by forest cover, elevation, and route length. Detectability was a logit-linear function of survey date, survey date-by-elevation, and sampling effort (time per transect unit). Resulting covariate effects and parameter estimates were consistent with expectations. Detectability per territory (for three surveys) ranged from 0.66 to 0.94 (mean 0.84) for easy species, and from 0.16 to 0.83 (mean 0.53) for difficult species, depended on survey effort for two easy and all four difficult species, and changed seasonally for three easy and three difficult species. Abundance was positively related to route length in three high-abundance and one low-abundance (one easy and three difficult) species, and increased with forest cover in five forest species, decreased for two nonforest species, and was unaffected for a generalist species. Abundance estimates under the most parsimonious mixture models were between 1.1 and 8.9 (median 1.8) times greater than estimates based on territory mapping; hence, three surveys were insufficient to detect all territories for each species. We conclude that binomial mixture models are an important new approach for estimating abundance corrected for detectability

  5. Modeling avian abundance from replicated counts using binomial mixture models

    USGS Publications Warehouse

    Kery, Marc; Royle, J. Andrew; Schmid, Hans

    2005-01-01

    Abundance estimation in ecology is usually accomplished by capture–recapture, removal, or distance sampling methods. These may be hard to implement at large spatial scales. In contrast, binomial mixture models enable abundance estimation without individual identification, based simply on temporally and spatially replicated counts. Here, we evaluate mixture models using data from the national breeding bird monitoring program in Switzerland, where some 250 1-km2 quadrats are surveyed using the territory mapping method three times during each breeding season. We chose eight species with contrasting distribution (wide–narrow), abundance (high–low), and detectability (easy–difficult). Abundance was modeled as a random effect with a Poisson or negative binomial distribution, with mean affected by forest cover, elevation, and route length. Detectability was a logit-linear function of survey date, survey date-by-elevation, and sampling effort (time per transect unit). Resulting covariate effects and parameter estimates were consistent with expectations. Detectability per territory (for three surveys) ranged from 0.66 to 0.94 (mean 0.84) for easy species, and from 0.16 to 0.83 (mean 0.53) for difficult species, depended on survey effort for two easy and all four difficult species, and changed seasonally for three easy and three difficult species. Abundance was positively related to route length in three high-abundance and one low-abundance (one easy and three difficult) species, and increased with forest cover in five forest species, decreased for two nonforest species, and was unaffected for a generalist species. Abundance estimates under the most parsimonious mixture models were between 1.1 and 8.9 (median 1.8) times greater than estimates based on territory mapping; hence, three surveys were insufficient to detect all territories for each species. We conclude that binomial mixture models are an important new approach for estimating abundance corrected for

  6. Urban warming drives insect pest abundance on street trees.

    PubMed

    Meineke, Emily K; Dunn, Robert R; Sexton, Joseph O; Frank, Steven D

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

  7. Dramatic declines in neotropical salamander populations are an important part of the global amphibian crisis

    PubMed Central

    Rovito, Sean M.; Parra-Olea, Gabriela; Vásquez-Almazán, Carlos R.; Papenfuss, Theodore J.; Wake, David B.

    2009-01-01

    We document major declines of many species of salamanders at several sites in Central America and Mexico, with emphasis on the San Marcos region of Guatemala, one of the best studied and most diverse salamander communities in the Neotropics. Profound declines of several formerly abundant species, including 2 apparent extinctions, are revealed. Terrestrial microhabitat specialists at mid- to high elevations have declined more than microhabitat generalists. These terrestrial microhabitat specialists have largely disappeared from multiple sites in western Guatemala, including in well-protected areas, suggesting that the phenomenon cannot be explained solely by localized habitat destruction. Major declines in southern Mexican plethodontid salamanders occurred in the late 1970s to early 1980s, concurrent with or preceding many reported frog declines. The species in decline comprise several major evolutionary lineages of tropical salamanders, underscoring that significant portions of the phylogenetic diversity of Neotropical salamanders are at risk. Our results highlight the urgent need to document and understand Neotropical salamander declines as part of the larger effort to conserve global amphibian diversity. PMID:19204286

  8. Climate and local abundance in freshwater fishes

    PubMed Central

    Knouft, Jason H.; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  9. Climate and local abundance in freshwater fishes.

    PubMed

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  10. Enhanced Abundances in Spiral Galaxies of the Pegasus I Cluster

    NASA Astrophysics Data System (ADS)

    Robertson, Paul; Shields, Gregory A.; Blanc, Guillermo A.

    2012-03-01

    We study the influence of cluster environment on the chemical evolution of spiral galaxies in the Pegasus I cluster. We determine the gas-phase heavy element abundances of six galaxies in Pegasus derived from H II region spectra obtained from integral-field spectroscopy. These abundances are analyzed in the context of Virgo, whose spirals are known to show increasing interstellar metallicity as a function of H I deficiency. The galaxies in the Pegasus cluster, despite its lower density and velocity dispersion, also display gas loss due to interstellar-medium-intracluster-medium interaction, albeit to a lesser degree. Based on the abundances of three H I deficient spirals and two H I normal spirals, we observe a heavy element abundance offset of +0.13 ± 0.07 dex for the H I deficient galaxies. This abundance differential is consistent with the differential observed in Virgo for galaxies with a similar H I deficiency, and we observe a correlation between log (O/H) and the H I deficiency parameter DEF for the two clusters analyzed together. Our results suggest that similar environmental mechanisms are driving the heavy element enhancement in both clusters.

  11. New aerial survey and hierarchical model to estimate manatee abundance

    USGS Publications Warehouse

    Langimm, Cahterine A.; Dorazio, Robert M.; Stith, Bradley M.; Doyle, Terry J.

    2011-01-01

    Monitoring the response of endangered and protected species to hydrological restoration is a major component of the adaptive management framework of the Comprehensive Everglades Restoration Plan. The endangered Florida manatee (Trichechus manatus latirostris) lives at the marine-freshwater interface in southwest Florida and is likely to be affected by hydrologic restoration. To provide managers with prerestoration information on distribution and abundance for postrestoration comparison, we developed and implemented a new aerial survey design and hierarchical statistical model to estimate and map abundance of manatees as a function of patch-specific habitat characteristics, indicative of manatee requirements for offshore forage (seagrass), inland fresh drinking water, and warm-water winter refuge. We estimated the number of groups of manatees from dual-observer counts and estimated the number of individuals within groups by removal sampling. Our model is unique in that we jointly analyzed group and individual counts using assumptions that allow probabilities of group detection to depend on group size. Ours is the first analysis of manatee aerial surveys to model spatial and temporal abundance of manatees in association with habitat type while accounting for imperfect detection. We conducted the study in the Ten Thousand Islands area of southwestern Florida, USA, which was expected to be affected by the Picayune Strand Restoration Project to restore hydrology altered for a failed real-estate development. We conducted 11 surveys in 2006, spanning the cold, dry season and warm, wet season. To examine short-term and seasonal changes in distribution we flew paired surveys 1–2 days apart within a given month during the year. Manatees were sparsely distributed across the landscape in small groups. Probability of detection of a group increased with group size; the magnitude of the relationship between group size and detection probability varied among surveys. Probability

  12. Influence of Coronal Abundance Variations

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D. (Technical Monitor); Kashyap, Vinay

    2005-01-01

    The PI of this project was Jeff Scargle of NASA/Ames. Co-I's were Alma Connors of Eureka Scientific/Wellesley, and myself. Part of the work was subcontracted to Eureka Scientific via SAO, with Vinay Kashyap as PI. This project was originally assigned grant number NCC2-1206, and was later changed to NCC2-1350 for administrative reasons. The goal of the project was to obtain, derive, and develop statistical and data analysis tools that would be of use in the analyses of high-resolution, high-sensitivity data that are becoming available with new instruments. This is envisioned as a cross-disciplinary effort with a number of "collaborators" including some at SA0 (Aneta Siemiginowska, Peter Freeman) and at the Harvard Statistics department (David van Dyk, Rostislav Protassov, Xiao-li Meng, Epaminondas Sourlas, et al). We have developed a new tool to reliably measure the metallicities of thermal plasma. It is unfeasible to obtain high-resolution grating spectra for most stars, and one must make the best possible determination based on lower-resolution, CCD-type spectra. It has been noticed that most analyses of such spectra have resulted in measured metallicities that were significantly lower than when compared with analyses of high- resolution grating data where available (see, e.g., Brickhouse et al., 2000, ApJ 530,387). Such results have led to the proposal of the existence of so-called Metal Abundance Deficient, or "MAD" stars (e.g., Drake, J.J., 1996, Cool Stars 9, ASP Conf.Ser. 109, 203). We however find that much of these analyses may be systematically underestimating the metallicities, and using a newly developed method to correctly treat the low-counts regime at the high-energy tail of the stellar spectra (van Dyk et al. 2001, ApJ 548,224), have found that the metallicities of these stars are generally comparable to their photospheric values. The results were reported at the AAS (Sourlas, Yu, van Dyk, Kashyap, and Drake, 2000, BAAS 196, v32, #54.02), and at the

  13. Optical properties of high aspect ratio plasma etched silicon nanowires: fabrication-induced variability dramatically reduces reflectance.

    PubMed

    Smyrnakis, A; Almpanis, E; Constantoudis, V; Papanikolaou, N; Gogolides, E

    2015-02-27

    In this work we investigate both experimentally and theoretically the optical properties of aligned, perpendicular to the substrate, high aspect ratio (AR), plasma etched Si nanowires (SiNWs) with controlled variability. We focus on the role of imperfections in fabrication, which manifest themselves as dimensional variability of SiNW, lattice defects or positional randomization. SiNW arrays are fabricated by e-beam lithography (perfectly ordered array) or colloidal particle self-assembly (quasi-ordered array) followed by cryogenic Si plasma etching, which offers fast etch rate (up to 3 μm min(-1)) combined with clean, smooth, and controllable sidewall profile, but induces some dimensional variability on the diameters of the SiNWs. Sub-200 nm diameter SiNWs having AR as high as 37:1 are demonstrated. The total reflectance of SiNWs is below 2% in a wide range of the optical spectrum. We experimentally demonstrate improved light absorption when moving from a perfectly ordered (after e-beam lithography) to a defective and quasi-ordered (after colloidal self-assembly) SiNW array. In addition our measured reflectivity (for both ordered and quasi-ordered SiNWs) is much lower compared to the one predicted theoretically for a perfect SiNWs array, using full-electrodynamic calculations with the layer-multiple-scattering method. To explain such low reflectivity, we model the influence of disorder using the average T-matrix approximation and show that even small dimensional variability (10-20%) leads to dramatic reduction of the reflectance (matching the experimental results) and increased light trapping inside the SiNW justifying their possible application in photovoltaic devices. PMID:25648611

  14. Dramatic mass loss in extreme high-elevation areas of a western Himalayan glacier: observations and modeling.

    PubMed

    Zhao, Huabiao; Yang, Wei; Yao, Tandong; Tian, Lide; Xu, Baiqing

    2016-01-01

    Rapid climate change at high elevations has accelerated glacier retreat in the Himalayas and Tibetan Plateau. However, due to the lack of long-term glaciological measurements, there are still uncertainties regarding when the mass loss began and what the magnitude of mass loss is at such high elevations. Based on in situ glaciological observations during the past 9 years and a temperature-index mass balance model, this study investigates recent mass loss of the Naimona'nyi Glacier in the western Himalayas and reconstructs a 41-year (1973/74-2013/14) equilibrium line altitude (ELA) and glacier-wide mass loss. The result indicates that even at 6000 m above sea level (a.s.l.), the annual mass loss reaches ~0.73 m water equivalent (w.e.) during the past 9 years. Concordant with the abrupt climate shift in the end of 1980s, the ELA has dramatically risen from ~5969 ± 73 m a.s.l. during 1973/74-1988/89 to ~6193 ± 75 m a.s.l. during 1989/90-2013/14, suggesting that future ice cores containing uninterrupted climate records could only be recovered at least above 6200 m a.s.l. in the Naimona'nyi region. The glacier-wide mass balance over the past 41 years is averaged to be approximately -0.40 ± 0.17 m w.e., exhibiting a significant increase in the decadal average from -0.01 ± 0.15 to -0.69 ± 0.21 m w.e. PMID:27561411

  15. Dramatic mass loss in extreme high-elevation areas of a western Himalayan glacier: observations and modeling

    PubMed Central

    Zhao, Huabiao; Yang, Wei; Yao, Tandong; Tian, Lide; Xu, Baiqing

    2016-01-01

    Rapid climate change at high elevations has accelerated glacier retreat in the Himalayas and Tibetan Plateau. However, due to the lack of long-term glaciological measurements, there are still uncertainties regarding when the mass loss began and what the magnitude of mass loss is at such high elevations. Based on in situ glaciological observations during the past 9 years and a temperature-index mass balance model, this study investigates recent mass loss of the Naimona’nyi Glacier in the western Himalayas and reconstructs a 41-year (1973/74–2013/14) equilibrium line altitude (ELA) and glacier-wide mass loss. The result indicates that even at 6000 m above sea level (a.s.l.), the annual mass loss reaches ~0.73 m water equivalent (w.e.) during the past 9 years. Concordant with the abrupt climate shift in the end of 1980s, the ELA has dramatically risen from ~5969 ± 73 m a.s.l. during 1973/74–1988/89 to ~6193 ± 75 m a.s.l. during 1989/90–2013/14, suggesting that future ice cores containing uninterrupted climate records could only be recovered at least above 6200 m a.s.l. in the Naimona’nyi region. The glacier-wide mass balance over the past 41 years is averaged to be approximately −0.40 ± 0.17 m w.e., exhibiting a significant increase in the decadal average from −0.01 ± 0.15 to −0.69 ± 0.21 m w.e. PMID:27561411

  16. Optical properties of high aspect ratio plasma etched silicon nanowires: fabrication-induced variability dramatically reduces reflectance

    NASA Astrophysics Data System (ADS)

    Smyrnakis, A.; Almpanis, E.; Constantoudis, V.; Papanikolaou, N.; Gogolides, E.

    2015-02-01

    In this work we investigate both experimentally and theoretically the optical properties of aligned, perpendicular to the substrate, high aspect ratio (AR), plasma etched Si nanowires (SiNWs) with controlled variability. We focus on the role of imperfections in fabrication, which manifest themselves as dimensional variability of SiNW, lattice defects or positional randomization. SiNW arrays are fabricated by e-beam lithography (perfectly ordered array) or colloidal particle self-assembly (quasi-ordered array) followed by cryogenic Si plasma etching, which offers fast etch rate (up to 3 μm min-1) combined with clean, smooth, and controllable sidewall profile, but induces some dimensional variability on the diameters of the SiNWs. Sub-200 nm diameter SiNWs having AR as high as 37:1 are demonstrated. The total reflectance of SiNWs is below 2% in a wide range of the optical spectrum. We experimentally demonstrate improved light absorption when moving from a perfectly ordered (after e-beam lithography) to a defective and quasi-ordered (after colloidal self-assembly) SiNW array. In addition our measured reflectivity (for both ordered and quasi-ordered SiNWs) is much lower compared to the one predicted theoretically for a perfect SiNWs array, using full-electrodynamic calculations with the layer-multiple-scattering method. To explain such low reflectivity, we model the influence of disorder using the average T-matrix approximation and show that even small dimensional variability (10-20%) leads to dramatic reduction of the reflectance (matching the experimental results) and increased light trapping inside the SiNW justifying their possible application in photovoltaic devices.

  17. Dramatic mass loss in extreme high-elevation areas of a western Himalayan glacier: observations and modeling

    NASA Astrophysics Data System (ADS)

    Zhao, Huabiao; Yang, Wei; Yao, Tandong; Tian, Lide; Xu, Baiqing

    2016-08-01

    Rapid climate change at high elevations has accelerated glacier retreat in the Himalayas and Tibetan Plateau. However, due to the lack of long-term glaciological measurements, there are still uncertainties regarding when the mass loss began and what the magnitude of mass loss is at such high elevations. Based on in situ glaciological observations during the past 9 years and a temperature-index mass balance model, this study investigates recent mass loss of the Naimona’nyi Glacier in the western Himalayas and reconstructs a 41-year (1973/74–2013/14) equilibrium line altitude (ELA) and glacier-wide mass loss. The result indicates that even at 6000 m above sea level (a.s.l.), the annual mass loss reaches ~0.73 m water equivalent (w.e.) during the past 9 years. Concordant with the abrupt climate shift in the end of 1980s, the ELA has dramatically risen from ~5969 ± 73 m a.s.l. during 1973/74–1988/89 to ~6193 ± 75 m a.s.l. during 1989/90–2013/14, suggesting that future ice cores containing uninterrupted climate records could only be recovered at least above 6200 m a.s.l. in the Naimona’nyi region. The glacier-wide mass balance over the past 41 years is averaged to be approximately ‑0.40 ± 0.17 m w.e., exhibiting a significant increase in the decadal average from ‑0.01 ± 0.15 to ‑0.69 ± 0.21 m w.e.

  18. Response of rare, common and abundant bacterioplankton to anthropogenic perturbations in a Mediterranean coastal site.

    PubMed

    Baltar, Federico; Palovaara, Joakim; Vila-Costa, Maria; Salazar, Guillem; Calvo, Eva; Pelejero, Carles; Marrasé, Cèlia; Gasol, Josep M; Pinhassi, Jarone

    2015-06-01

    Bacterioplankton communities are made up of a small set of abundant taxa and a large number of low-abundant organisms (i.e. 'rare biosphere'). Despite the critical role played by bacteria in marine ecosystems, it remains unknown how this large diversity of organisms are affected by human-induced perturbations, or what controls the responsiveness of rare compared to abundant bacteria. We studied the response of a Mediterranean bacterioplankton community to two anthropogenic perturbations (i.e. nutrient enrichment and/or acidification) in two mesocosm experiments (in winter and summer). Nutrient enrichment increased the relative abundance of some operational taxonomic units (OTUs), e.g. Polaribacter, Tenacibaculum, Rhodobacteraceae and caused a relative decrease in others (e.g. Croceibacter). Interestingly, a synergistic effect of acidification and nutrient enrichment was observed on specific OTUs (e.g. SAR86). We analyzed the OTUs that became abundant at the end of the experiments and whether they belonged to the rare (<0.1% of relative abundance), the common (0.1-1.0% of relative abundance) or the abundant (>1% relative abundance) fractions. Most of the abundant OTUs at the end of the experiments were abundant, or at least common, in the original community of both experiments, suggesting that ecosystem alterations do not necessarily call for rare members to grow. PMID:26032602

  19. Study of Neutron-Capture Element Abundances in Metal-Poor Stars

    NASA Astrophysics Data System (ADS)

    Li, Hongjie; Shen, Xiaojing; Liang, Shuai; Cui, Wenyuan; Zhang, Bo

    2013-02-01

    This work describes a study of elemental abundances for 30 metal-poor stars whose chemical abundances provide excellent information for setting constraints on models of neutron-capture processes. Based on the abundances of main r- and weak r-process stars, the abundance patterns of main r-process and weak r-process are obtained. The two r-process component coefficients are defined to determine the relative contributions from individual neutron-capture process to abundances of metal-poor stars. Based on the component coefficients, we find that metal-poor stars BD+42621 and HD 4306 are also weak r-process stars, which means that the abundance pattern produced by weak r-process is stable. All metal-poor star abundances contain the contributions of both main r-process and weak r-process. The elements produced by weak r-process have increased along with Fe over the polluted history. Most of the metal-poor star abundances do not follow the pattern observed in the solar system, but there is a small fraction that do. For the low-[Sr/Fe] star BD-185550 ([Sr/Fe] lsim -1), neutron-capture element abundances can be explained by the mixture of two r-process components. Since lighter elements in this star cannot be fitted by the two components, the abundance pattern of P-component is estimated from those abundances.

  20. [Effects of sewage discharge on abundance and biomass of meiofauna].

    PubMed

    Huang, De-Ming; Liu, Xiao-Shou; Lin, Ming-Xian; Chen, Huai-Pu; Wei, Lian-Ming; Huang, Xin; Zhang, Zhi-Nan

    2014-10-01

    In order to elucidate the effects of sewage discharge on abundance and biomass of meio- fauna, a seasonal survey was carried out on meiofauna at stations with different distances to a sewage outlet in the middle intertidal zone of No. 1 bathing beach in Huiquan Bay, Qingdao in spring (April), summer (August), autumn (October) and winter (December), 2011. The results showed that the annual average meiofaunal abundance was (1859.9 ± 705.1) ind · 10 cm(-2), with higher values of (2444.9 ± 1220.5) ind · 10 cm(-2) at Station S2 (20 m to the sewage outlet) and (2492.2 ± 1839.9) ind · 10 cm(-2) at Station S3 (40 m to the sewage outlet), while the lowest value of (327.9 ± 183.2) ind · 10 cm(-2) was observed at Station S1 (0 m to the sewage outlet) in terms of horizontal distribution. The annual average biomass was (1513.4 ± 372.7) μg · 10 cm(-2). Meiofaunal abundance and biomass varied seasonally with the highest values in spring and the lowest values in summer. A total of 11 meiofaunal groups were identified, including nematodes, copepods, polychaetes, oligochaetes, tardigrades, halacaroideans, planarians, ostracods, isopods, crustacean nauplii and others. Free-living marine nematodes were the dominant group constituting 83. 1% of the total abundance, followed by benthic copepods, accounting for 12. 8% of the total abundance. In terms of vertical distribution, most of the meiofauna concentrated in the top 0-2 cm, and the meiofauna abundance decreased with increasing the sediment depth. Meiofauna was also noted to migrate deeper into the sediment in the winter. Pearson correlation analysis showed that meiofaunal abundance and biomass had highly significant negative correlations with sediment median particle diameter and organic matter content. In addition, tourism-induced activities affected meiofaunal abundance and distribution. A comparison with historical data from similar studies was carried out, and the applicability of the ratio of abundance of nematodes

  1. Dramatical Impact Of Low Amounts of Swelling Clays On The Rheology Of Alpine Debris Flows

    NASA Astrophysics Data System (ADS)

    Bardou, E.; Bowen, P.; Banfill, P. G.; Boivin, P.

    2004-12-01

    Field observations show that the role and amount of swelling clays in the complex hard suspensions of alpine debris flow type were underestimated (see Boivin et al., this session). This work aims at exploring to which extent the swelling clay content influences the global rheology of a flow of rock grains from which the size spectrum extends from clays to gravel. We made a sample from calibrated materials with a grain size distribution similar to that of a viscoplastic debris flow (Bardou et al., 2003). Four replicates were made with the same grading curve. The clay content of the samples was 2% dry weight only, and different 2:1 swelling clay to 1:1 clay ratio were used. The swelling clay ratio (SCR) was calculated as the percentage of 2:1 clay in the clay fraction of the bulk samples. The 1:1 clay was (industrial) kaolinite and the 2:1 clay was a natural soil smectite. The smectite content in the bulk sample ranged from 0% to 2% dry weight, corresponding to SCR ranging from 0 to 80%. The four prepared samples were sheared in the large-size apparatus fully described in Tattersall and Banfill (1983). This apparatus is based on the measure of the torque necessary to rotate an impeller immersed in the sample. The impeller has the form of an "H" and moves in a plane according to two parallel axes. The observed behaviour were very contrasted. The sample with SCR=0 was poorly sensitive to changes in the solid concentration, in contrast to the three samples with SCR>0. Moreover, a small change in the SCR of the clay fraction induced a dramatic change of the behaviour of the mixture. For SCR=0, only little changes in the rheological parameters of the bulk samples were observed with respect to changes in the solid concentration. On the contrary the rheological parameters of the bulk samples with SCR>0, apparently followed a power law according to solid concentration. These tests carried out in the laboratory accord with observations realised on natural debris flow material

  2. Why did watermills not have a dramatic effect on the Anthropocene sediment record of the Zwalm River, Belgium?

    NASA Astrophysics Data System (ADS)

    Notebaert, Bastiaan; D'Haese, Wouter

    2016-04-01

    Different studies demonstrated the dramatic effects of watermills on fluvial geomorphology in the Eastern US. Damming of floodplains and milldam lakes increased sediment deposition. Several authors attribute most of the so called post settlement legacy sediment to those milldam lakes. In Europe the role of milldams in the anthropogenic increased floodplain deposition rates during the last 1000 to 2000 years has gotten little attention until now. Therefore we studied the influence of watermills on Holocene floodplain deposition in the Zwalm catchment, Belgium. The Zwalm River is located in western part of the Belgian loess belt in an undulating landscape that had intensive agriculture for most of the last 2000 years. In total 9 watermills were present along the 17 km long main channel during the 19th century, while many were also present on tributaries. Historical records date several of the mills to the 10th century AD, although they might be older, and most of them remain to some degree active today. The influence of watermills on floodplain deposits was tested through coring transects of the Holocene deposits. Detailed transects were performed pairwise upstream and downstream 5 watermills. Samples were taken for grain size analysis using laser diffraction. A possible influence on floodplain topography was tested on a 5 m resolution DTM. Holocene floodplain architecture is similar to other floodplains in the region: a basal early to mid-Holocene peat and gyttja layer is covered by a fine grained sediment layer of more than 5 m thickness. The change between both can be attributed to increased soil erosion due to human land use, and can be considered to be the local legacy sediment. Comparison of transects upstream and downstream mills shows no significant difference in total Holocene or legacy sediment thickness. Texture analysis indicates that floodplain sediments are significant coarser downstream the mills.F Floodplains are not significant steeper around mills

  3. On protein abundance distributions in complex mixtures

    PubMed Central

    2013-01-01

    Mass spectrometry, an analytical technique that measures the mass-to-charge ratio of ionized atoms or molecules, dates back more than 100 years, and has both qualitative and quantitative uses for determining chemical and structural information. Quantitative proteomic mass spectrometry on biological samples focuses on identifying the proteins present in the samples, and establishing the relative abundances of those proteins. Such protein inventories create the opportunity to discover novel biomarkers and disease targets. We have previously introduced a normalized, label-free method for quantification of protein abundances under a shotgun proteomics platform (Griffin et al., 2010). The introduction of this method for quantifying and comparing protein levels leads naturally to the issue of modeling protein abundances in individual samples. We here report that protein abundance levels from two recent proteomics experiments conducted by the authors can be adequately represented by Sichel distributions. Mathematically, Sichel distributions are mixtures of Poisson distributions with a rather complex mixing distribution, and have been previously and successfully applied to linguistics and species abundance data. The Sichel model can provide a direct measure of the heterogeneity of protein abundances, and can reveal protein abundance differences that simpler models fail to show. PMID:23360617

  4. Monitoring Butterfly Abundance: Beyond Pollard Walks

    PubMed Central

    Pellet, Jérôme; Bried, Jason T.; Parietti, David; Gander, Antoine; Heer, Patrick O.; Cherix, Daniel; Arlettaz, Raphaël

    2012-01-01

    Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly reflect population sizes and trends. This study compares capture-mark-recapture (absolute abundance) and count-index (relative abundance) monitoring methods in three species (Maculinea nausithous and Iolana iolas: Lycaenidae; Minois dryas: Satyridae) in contrasted habitat types. We demonstrate that intraspecific variability in individual detectability under standard monitoring conditions is probably the rule rather than the exception, which questions the reliability of count-based indices to estimate and compare specific population abundance. Our results suggest that the accuracy of count-based methods depends heavily on the ecology and behavior of the target species, as well as on the type of habitat in which surveys take place. Monitoring programs designed to assess the abundance and trends in butterfly populations should incorporate a measure of detectability. We discuss the relative advantages and inconveniences of current monitoring methods and analytical approaches with respect to the characteristics of the species under scrutiny and resources availability. PMID:22859980

  5. Oxygen abundance maps of CALIFA galaxies

    NASA Astrophysics Data System (ADS)

    Zinchenko, I. A.; Pilyugin, L. S.; Grebel, E. K.; Sánchez, S. F.; Vílchez, J. M.

    2016-11-01

    We construct maps of the oxygen abundance distribution across the discs of 88 galaxies using Calar Alto Legacy Integral Field Area survey (CALIFA) Data Release 2 (DR2) spectra. The position of the centre of a galaxy (coordinates on the plate) was also taken from the CALIFA DR2. The galaxy inclination, the position angle of the major axis, and the optical radius were determined from the analysis of the surface brightnesses in the Sloan Digital Sky Survey (SDSS) g and r bands of the photometric maps of SDSS Data Release 9. We explore the global azimuthal abundance asymmetry in the discs of the CALIFA galaxies and the presence of a break in the radial oxygen abundance distribution. We found that there is no significant global azimuthal asymmetry for our sample of galaxies, i.e. the asymmetry is small, usually lower than 0.05 dex. The scatter in oxygen abundances around the abundance gradient has a comparable value, ≲0.05 dex. A significant (possibly dominant) fraction of the asymmetry can be attributed to the uncertainties in the geometrical parameters of these galaxies. There is evidence for a flattening of the radial abundance gradient in the central part of 18 galaxies. We also estimated the geometric parameters (coordinates of the centre, the galaxy inclination and the position angle of the major axis) of our galaxies from the analysis of the abundance map. The photometry-map-based and the abundance-map-based geometrical parameters are relatively close to each other for the majority of the galaxies but the discrepancy is large for a few galaxies with a flat radial abundance gradient.

  6. Predicting the Dynamics of Protein Abundance

    PubMed Central

    Mehdi, Ahmed M.; Patrick, Ralph; Bailey, Timothy L.; Bodén, Mikael

    2014-01-01

    Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA–protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation

  7. Numerical resolution limits on subhalo abundance matching

    NASA Astrophysics Data System (ADS)

    Guo, Qi; White, Simon

    2014-02-01

    Subhalo abundance matching (SHAM) inserts galaxies into dark matter only simulations of the growth of cosmic structure in a way that requires minimal assumptions about galaxy formation. A galaxy is placed at the potential minimum of each distinct self-bound subhalo with a luminosity which is a monotonically increasing function of the maximum mass (or circular velocity) attained over the subhalo's earlier history. Galaxy and subhalo properties are linked by matching model and observed luminosity functions. Simulated structures can then be compared in detail with observation, for example, through galaxy correlation statistics, group catalogues or galaxy-galaxy lensing. Robust astrophysical conclusions can be drawn from such a comparison only on scales which are unaffected by the numerical limitations of the simulation. Here, we compare results for the Millennium Simulation (MS) with subhaloes defined using the SUBFIND to those obtained applying identical analysis to the much higher resolution Millennium-II. Correlation statistics on scales between 200 and 2 Mpc converge to within 20 per cent only for subhaloes with masses at infall corresponding to at least 1000 simulation particles in the MS. Numerically converged results can be obtained to much lower infall particle number, if galaxies are followed even after their associated subhaloes have been tidally disrupted, as in most recent semi-analytic galaxy formation simulations. This allows robust comparison between simulation and observation over a wider dynamic range in mass than for a SHAM analysis which ignores such `orphan' galaxies.

  8. Red Supergiants as Cosmic Abundance Probes

    NASA Astrophysics Data System (ADS)

    Davies, B.; Kudritzki, R.-P.; Bergemann, M.; Evans, C.; Gazak, Z.; Lardo, C.; Patrick, L.; Plez, B.; Bastian, N.

    2015-09-01

    By studying a galaxy's present-day chemical abundances, we are effectively looking at its star-forming history. Cosmological simulations of galaxy evolution make predictions about the relative metal contents of galaxies as a function of their stellar mass, a trend known as the mass-metallicity relation. These predictions can be tested with observations of nearby galaxies. However, providing reliable, accurate abundance measurements at extragalactic distances is extremely challenging. In this project, we have developed a technique to extract abundance information from individual red supergiant stars at megaparsec distances. We are currently exploiting this technique using the unique capabilities of KMOS on the VLT.

  9. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2012-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of O, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  10. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2014-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of 0, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  11. Assessing introduction risk using species' rank-abundance distributions.

    PubMed

    Chan, Farrah T; Bradie, Johanna; Briski, Elizabeta; Bailey, Sarah A; Simard, Nathalie; MacIsaac, Hugh J

    2015-01-22

    Mixed-species assemblages are often unintentionally introduced into new ecosystems. Analysing how assemblage structure varies during transport may provide insights into how introduction risk changes before propagules are released. Characterization of introduction risk is typically based on assessments of colonization pressure (CP, the number of species transported) and total propagule pressure (total PP, the total abundance of propagules released) associated with an invasion vector. Generally, invasion potential following introduction increases with greater CP or total PP. Here, we extend these assessments using rank-abundance distributions to examine how CP : total PP relationships change temporally in ballast water of ocean-going ships. Rank-abundance distributions and CP : total PP patterns varied widely between trans-Atlantic and trans-Pacific voyages, with the latter appearing to pose a much lower risk than the former. Responses also differed by taxonomic group, with invertebrates experiencing losses mainly in total PP, while diatoms and dinoflagellates sustained losses mainly in CP. In certain cases, open-ocean ballast water exchange appeared to increase introduction risk by uptake of new species or supplementation of existing ones. Our study demonstrates that rank-abundance distributions provide new insights into the utility of CP and PP in characterizing introduction risk. PMID:25473007

  12. Assessing introduction risk using species’ rank-abundance distributions

    PubMed Central

    Chan, Farrah T.; Bradie, Johanna; Briski, Elizabeta; Bailey, Sarah A.; Simard, Nathalie; MacIsaac, Hugh J.

    2015-01-01

    Mixed-species assemblages are often unintentionally introduced into new ecosystems. Analysing how assemblage structure varies during transport may provide insights into how introduction risk changes before propagules are released. Characterization of introduction risk is typically based on assessments of colonization pressure (CP, the number of species transported) and total propagule pressure (total PP, the total abundance of propagules released) associated with an invasion vector. Generally, invasion potential following introduction increases with greater CP or total PP. Here, we extend these assessments using rank-abundance distributions to examine how CP : total PP relationships change temporally in ballast water of ocean-going ships. Rank-abundance distributions and CP : total PP patterns varied widely between trans-Atlantic and trans-Pacific voyages, with the latter appearing to pose a much lower risk than the former. Responses also differed by taxonomic group, with invertebrates experiencing losses mainly in total PP, while diatoms and dinoflagellates sustained losses mainly in CP. In certain cases, open-ocean ballast water exchange appeared to increase introduction risk by uptake of new species or supplementation of existing ones. Our study demonstrates that rank-abundance distributions provide new insights into the utility of CP and PP in characterizing introduction risk. PMID:25473007

  13. Terrestrial salamander abundance on reclaimed mountaintop removal mines

    USGS Publications Warehouse

    Wood, Petra Bohall; Williams, Jennifer M.

    2013-01-01

    Mountaintop removal mining, a large-scale disturbance affecting vegetation, soil structure, and topography, converts landscapes from mature forests to extensive grassland and shrubland habitats. We sampled salamanders using drift-fence arrays and coverboard transects on and near mountaintop removal mines in southern West Virginia, USA, during 2000–2002. We compared terrestrial salamander relative abundance and species richness of un-mined, intact forest with habitats on reclaimed mountaintop removal mines (reclaimed grassland, reclaimed shrubland, and fragmented forest). Salamanders within forests increased in relative abundance with increasing distance from reclaimed mine edge. Reclaimed grassland and shrubland habitats had lower relative abundance and species richness than forests. Characteristics of reclaimed habitats that likely contributed to lower salamander abundance included poor soils (dry, compacted, little organic matter, high rock content), reduced vertical structure of vegetation and little tree cover, and low litter and woody debris cover. Past research has shown that salamander populations reduced by clearcutting may rebound in 15–24 years. Time since disturbance was 7–28 years in reclaimed habitats on our study areas and salamander populations had not reached levels found in adjacent mature forests.

  14. Manganese abundances in Galactic bulge red giants

    NASA Astrophysics Data System (ADS)

    Barbuy, B.; Hill, V.; Zoccali, M.; Minniti, D.; Renzini, A.; Ortolani, S.; Gómez, A.; Trevisan, M.; Dutra, N.

    2013-11-01

    Context. Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut between the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. Aims: The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. Methods: High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. Results: We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Galactic bulge. We find [Mn/Fe] ~ -0.7 at [Fe/H] ~ -1.3, increasing to a solar value at metallicities close to solar, and showing a spread around - 0.7 ≲ [Fe/H] ≲ -0.2, in good agreement with other work on Mn in bulge stars. There is also good agreement with chemical evolution models. We find no clear difference in the behaviour of the four bulge fields. Whereas [Mn/Fe] vs. [Fe/H] could be identified with the behaviour of the thick disc stars, [Mn/O] vs. [O/H] has a behaviour running parallel, at higher metallicities, compared to thick disc stars, indicating that the bulge enrichment might have proceeded differently from that of the thick disc. Observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196).Tables 1-6 and Figs. 1-6 are available in electronic form at http://www.aanda.org

  15. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

    PubMed

    Geib, Jennifer C; Strange, James P; Galenj, Candace

    2015-04-01

    here (nest abundance, forager abundance, and foraging distance) could increase the usefulness of foraging worker inventories in nionitoring, managing, and conserving pollinator populations.

  16. Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale.

    PubMed

    Serafy, Joseph E; Shideler, Geoffrey S; Araújo, Rafael J; Nagelkerken, Ivan

    2015-01-01

    Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several ontogenetically-migrating species. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. In the present study, using two different regression approaches, we pursued two questions related to mangrove-reef connectivity at the Caribbean regional scale: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? Specifically, we tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as "mangrove-dependent". Analyzed were data from an ongoing, long-term (20-year) citizen-scientist fish monitoring program; coastal human population censuses; and several wetland forest information sources. Quantile regression results supported the notion that mangrove forest area limits the abundance of eight of the 12 fishes examined. Linear mixed-effects regression results, which considered potential human (fishing and habitat degradation) and latitudinal influences, suggested that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. Recent work questioning the mangrove-reef fish subsidy effect likely reflects a failure to: (1) focus analyses on species that use mangroves as nurseries, (2) consider more than the mean fish abundance response to mangrove forest extent; and/or (3) quantitatively account for potentially confounding human impacts, such as fishing pressure and habitat degradation. Our study is the first to demonstrate at a large regional scale (i.e., the Wider

  17. Correlation between lithium abundances and ages of solar twin stars

    NASA Astrophysics Data System (ADS)

    Carlos, Marília; Nissen, Poul E.; Meléndez, Jorge

    2016-03-01

    Aims: We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence of planets. Methods: For a sample of 21 solar twins observed with the HARPS spectrograph at high spectral resolution (R ≃ 115.000) and very high signal-to-noise ratio (600 ≤ S/N ≤ 2400), precise lithium abundances were obtained by spectral synthesis of the Li i 6707.8 Å line and compared to stellar ages, masses, and metallicities determined from a spectroscopic analysis of the same set of HARPS spectra. Results: We show that for the large majority of the solar twins there is a strong correlation between lithium abundance and stellar age. As the age increases from 1 to 9 Gyr, the Li abundance decreases by a factor of ~50. The relation agrees fairly well with predictions from non-standard stellar evolution models of Li destruction at the bottom of the upper convection zone. Two stars deviate from the relation by having Li abundances enhanced by a factor of ~10, which may be due to planet engulfment. On the other hand, we find no indication of a link between planet hosting stars and enhanced lithium depletion. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory, (observing programs 072.C-0488, 183.C-0972, 188.C-0265, and 0.88.C-0323).

  18. Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale

    PubMed Central

    Serafy, Joseph E.; Shideler, Geoffrey S.; Araújo, Rafael J.; Nagelkerken, Ivan

    2015-01-01

    Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several ontogenetically-migrating species. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. In the present study, using two different regression approaches, we pursued two questions related to mangrove-reef connectivity at the Caribbean regional scale: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? Specifically, we tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as “mangrove-dependent”. Analyzed were data from an ongoing, long-term (20-year) citizen-scientist fish monitoring program; coastal human population censuses; and several wetland forest information sources. Quantile regression results supported the notion that mangrove forest area limits the abundance of eight of the 12 fishes examined. Linear mixed-effects regression results, which considered potential human (fishing and habitat degradation) and latitudinal influences, suggested that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. Recent work questioning the mangrove-reef fish subsidy effect likely reflects a failure to: (1) focus analyses on species that use mangroves as nurseries, (2) consider more than the mean fish abundance response to mangrove forest extent; and/or (3) quantitatively account for potentially confounding human impacts, such as fishing pressure and habitat degradation. Our study is the first to demonstrate at a large regional scale (i.e., the Wider

  19. Dramatic response of follicular thyroid carcinoma with superior vena cava syndrome and tracheal obstruction to external-beam radiotherapy

    SciTech Connect

    Wilford, M.R.; Chertow, B.S.; Lepanto, P.B.; Leidy, J.W. Jr. )

    1991-06-01

    We report a patient with follicular thyroid carcinoma progressing to superior vena cava (SVC) syndrome and tracheal obstruction despite multiple doses of radioactive iodine therapy but subsequently responding dramatically to external-beam radiotherapy (RT). Although RT is not considered to be the treatment of choice for follicular carcinoma, RT in our patient produced unequivocal improvement of SVC syndrome and tracheal obstruction.

  20. The Development of Evaluation Model for Internal Quality Assurance System of Dramatic Arts College of Bunditpattanasilpa Institute

    ERIC Educational Resources Information Center

    Sinthukhot, Kittisak; Srihamongkol, Yannapat; Luanganggoon, Nuchwana; Suwannoi, Paisan

    2013-01-01

    The research purpose was to develop an evaluation model for the internal quality assurance system of the dramatic arts College of Bunditpattanasilpa Institute. The Research and Development method was used as research methodology which was divided into three phases; "developing the model and its guideline", "trying out the actual…

  1. A Rural School/Community: A Case Study of a Dramatic Turnaround & Its Implications for School Improvement.

    ERIC Educational Resources Information Center

    Carlson, Robert V.

    This paper presents a case study of a rural community exhibiting a dramatic turnaround in community support for a new school bond issue. Demographic change was partly responsible for the change in community attitudes, with two waves of immigration altering the long-term conservative orientation of this community. After a series of failed…

  2. Debranching of soluble wheat arabinoxylan dramatically enhances recalcitrant binding to cellulose.

    PubMed

    Selig, Michael J; Thygesen, Lisbeth G; Felby, Claus; Master, Emma R

    2015-03-01

    The presence of xylan is a detriment to the enzymatic saccharification of cellulose in lignocelluloses. The inhibition of the processive cellobiohydrolase Cel7A by soluble wheat arabinoxylan is shown here to increase by 50% following enzymatic treatment with a commercially-purified α-L-arabinofuranosidase. The enhanced inhibitory effect was shown by T2 relaxation time measurements via low field NMR to coincide with an increasing degree of constraint put on the water in xylan solutions. Furthermore, quartz crystal micro-balance with dissipation experiments showed that α-L-arabinofuranosidase treatment considerably increased the rate and rigidity of arabinoxylan mass association with cellulose. These data also suggest significant xylan-xylan adlayer formation occurs following initial binding of debranched arabinoxylan. From this, we speculate the inhibitory effects of xylan to cellulases may result from reduced enzymatic access via the dense association of xylan with cellulose. PMID:25335745

  3. Coronal abundances determined from energetic particles

    NASA Technical Reports Server (NTRS)

    Reames, D. V.

    1995-01-01

    Solar energetic particles (SEPs) provide a measurement of coronal element abundances that is highly independent of the ionization states and temperature of the ions in the source plasma. The most complete measurements come from large 'gradual' events where ambient coronal plasma is swept up by the expanding shock wave from a coronal mass ejection. Particles from 'impulsive' flares have a pattern of acceleration-induced enhancements superimposed on the coronal abundances. Particles accelerated from high-speed solar wind streams at corotating shocks show a different abundance pattern corresponding to material from coronal holes. Large variations in He/O in coronal material are seen for both gradual and impulsive-flare events but other abundance ratios, such as Mg/Ne, are remarkably constant. SEP measurements now include hundreds of events spanning 15 years of high-quality measurement.

  4. Chemical abundances in Hg-Mn stars

    NASA Technical Reports Server (NTRS)

    Heacox, W. D.

    1979-01-01

    An abundance analysis has been conducted of 21 elements in 21 Hg-Mn, two Si-Cr, and six normal stars using model atmospheres and high-dispersion spectroscopy in the visible and UV. Manganese line strengths imply abundances that correlate well with stellar effective temperature. Within the studied sample of Hg-Mn stars there appears to be no correlation of abundances of any element with projected rotational velocity. Abundances in several Hg-Mn stars show patterns that are probably consistent with diffusion but difficult to reconcile with equilibrium nucleosynthesis. In general, no combination of gross stellar physical parameters is sufficient to characterize the patterns of line strengths observed in Hg-Mb Hg-Mn stars.

  5. The abundant elements in interstellar dust

    NASA Technical Reports Server (NTRS)

    Sofia, Ulysses J.; Cardelli, Jason A.; Savage, Blair D.

    1994-01-01

    We explore the incorporation of the cosmically abundant species O, C, N, Mg, Si, Fe, and S into interstellar dust. Column densities based on Goddard High Resolution Spectrograph 3.5 km/s resolution measurements from the literature for eight individual absorbing regions toward five lines of sight are used. Corrections are applied as needed in order to account for recent improvements in oscillator strengths. In order to acquire the most accurate column densities, and check on the accuracy of the oscillator strengths, we compare column densities based on the very strong Lorentzian damped lines of C II, O I, N I, and Mg II with results for the weak lines of these species, and confirm the previously determined f-values for O I lambda 1335, C II lambda 2325, and N I lambda lambda 1159, 1160. New empirical f-values of 1.25 x 10(exp -3) and 6.25 x 10(exp -4), respectively, are derived for the Mg II weak doublet at 1239 and 1240 A. Assuming a cosmic reference abundance based on solar and B star values, we derive depletions and dust-phase abundances which suggest that more than 70% of the available Mg and Fe is incorporated into dust-grain cores, whereas only 35% of the silicon is. This implies that oxides are important constituents of the grain core population. Mg and Fe atoms are mantled onto grain cores in a ratio of 1.8 to 1, whereas approximately 4.0 Si atoms are in the mantle per Fe atom. Since Si is not expected to accrete onto silicate or graphite grains, other grain cores, perhaps oxides and/or metallic Fe, may provide mantling sites for this species. The abundances of Fe and Mg in mantles would imply that graphite grains must have a substantial coating unless oxides provide significant mantling sites for these species. The abundance of O and N in the dust phase as implied by the solar reference abundance values are difficult to reconcile with the fact that these elements are not expected to participate in mantle formation, and the 3.1 micrometer H2O ice feature is

  6. Species Abundance Patterns in Complex Evolutionary Dynamics

    NASA Astrophysics Data System (ADS)

    Tokita, Kei

    2004-10-01

    An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g., gene expression.

  7. Elemental abundance determinations for meteors by spectroscopy.

    NASA Technical Reports Server (NTRS)

    Harvey, G. A.

    1973-01-01

    Relative elemental abundance determinations for meteors by spectroscopy are discussed. Relative abundances of spectroscopically accessible elements of four major shower meteors and one sporadic meteor are presented. A sporadic meteor with dominant sodium radiation and an iron-deficient sporadic meteor are analyzed. Empirical and theoretical tests for self-absorption in optical meteor plasmas have been conducted. Both ionization and incomplete dissociation are found to severely deplete certain neutral atoms from meteor plasmas.

  8. Coronae of Stars with Supersolar Elemental Abundances

    NASA Technical Reports Server (NTRS)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  9. A Dramatic Classroom Demonstration of Limiting Reagent Using the Vinegar and Sodium Hydrogen Carbonate Reaction

    ERIC Educational Resources Information Center

    Artdej, Romklao; Thongpanchang, Tienthong

    2008-01-01

    This demonstration is designed to illustrate the concept of limiting reagent in a spectacular way. Via a series of experiments where the amount of vinegar is fixed and the amount of NaHCO[subscript 3] is gradually increased, the volume of CO[subscript 2] generated from the reaction varies corresponding to the amount of NaHCO[subscript 3] until it…

  10. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  11. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  12. What We Know about the Dramatic Increase in PhD Degrees and the Reform of Doctoral Education Worldwide: Implications for South Africa

    ERIC Educational Resources Information Center

    Nerad, Maresi

    2011-01-01

    Theories of the "knowledge economy" view knowledge, and particularly new knowledge, as a critical resource to enhance a nation's economic growth. Governments around the world have invested in doctoral education expansion. Reforms in doctoral education are being shaped by the changing needs of society, of research modes, and of a changed labor…

  13. Abundance-occupancy relationships in metapopulations: examples of rock pool Daphnia.

    PubMed

    Östman, Örjan

    2011-03-01

    Intraspecific positive relationships between abundance and occupancy are observed for many species, suggesting that the same processes drive local and regional species dynamics. Two main groups of mechanisms explain this relationship: spatiotemporal variation in local population growth rates due to variation in habitat quality, or dispersal effects that increase occupancy of a species when locally abundant. Several studies show that spatiotemporal variation in population growth rates causes positive abundance-occupancy relationships, but few have shown dispersal effects. It is believed that such effects should be more evident for species whose dispersal is limited, e.g. metapopulations, but those studies are limited. This study investigates abundance-occupancy relationships in three Daphnia metapopulations in rock pools and the degree to which dispersal or habitat quality affect their local abundances and occurrence. Daphnia longispina and Daphnia magna showed positive abundance-occupancy relationships, but not Daphnia pulex. No single ecological factor could explain the abundance-occupancy relationships of any given species. Instead, dispersal processes and rock pool quality (mainly salinity and depth) seem to act together to shape the abundance-occupancy relationships. Such a conclusion is also supported by an immigration experiment in natural rock pools. This study suggests that although positive abundance-occupancy relationships may be commonly found for metapopulations, both dispersal processes and variation in habitat quality can be factors determining the abundance-occupancy relationship of metapopulations experiencing habitat heterogeneity. PMID:20740290

  14. Phylogenetic structure and host abundance drive disease pressure in communities.

    PubMed

    Parker, Ingrid M; Saunders, Megan; Bontrager, Megan; Weitz, Andrew P; Hendricks, Rebecca; Magarey, Roger; Suiter, Karl; Gilbert, Gregory S

    2015-04-23

    Pathogens play an important part in shaping the structure and dynamics of natural communities, because species are not affected by them equally. A shared goal of ecology and epidemiology is to predict when a species is most vulnerable to disease. A leading hypothesis asserts that the impact of disease should increase with host abundance, producing a 'rare-species advantage'. However, the impact of a pathogen may be decoupled from host abundance, because most pathogens infect more than one species, leading to pathogen spillover onto closely related species. Here we show that the phylogenetic and ecological structure of the surrounding community can be important predictors of disease pressure. We found that the amount of tissue lost to disease increased with the relative abundance of a species across a grassland plant community, and that this rare-species advantage had an additional phylogenetic component: disease pressure was stronger on species with many close relatives. We used a global model of pathogen sharing as a function of relatedness between hosts, which provided a robust predictor of relative disease pressure at the local scale. In our grassland, the total amount of disease was most accurately explained not by the abundance of the focal host alone, but by the abundance of all species in the community weighted by their phylogenetic distance to the host. Furthermore, the model strongly predicted observed disease pressure for 44 novel host species we introduced experimentally to our study site, providing evidence for a mechanism to explain why phylogenetically rare species are more likely to become invasive when introduced. Our results demonstrate how the phylogenetic and ecological structure of communities can have a key role in disease dynamics, with implications for the maintenance of biodiversity, biotic resistance against introduced weeds, and the success of managed plants in agriculture and forestry.

  15. Dramatic activity of mixed-phase TiO2 photocatalyst synthesized by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Li, Huiquan; Xu, Bolian; Fan, Yining

    2013-02-01

    The mixed-phase TiO2 photocatalysts with different anatase/rutile/brookite ratios and high specific surface area (157-218 m2/g) were prepared by hydrothermal method at 100 °C and the effect of rutile content in TiO2 on the BET surface area, light absorption and separation efficiency of photogenerated charge carriers was studied and correlated to the photocatalytic activity of TiO2. Rutile content increased from 0% to 100% by increasing the amount of TiCl4 in aqueous phase and the initial pH value of reaction solution played an important role in the phase composition of TiO2. The photocatalytic mechanism of mixed-phase TiO2 was discussed.

  16. Dramatic effect of elasticity on thermal softening and strain localization during lithospheric shortening

    NASA Astrophysics Data System (ADS)

    Jaquet, Yoann; Duretz, Thibault; Schmalholz, Stefan M.

    2016-02-01

    We present two-dimensional numerical simulations for shortening a viscoelastoplastic lithosphere to quantify the impact of elasticity on strain localization due to thermal softening. The model conserves energy and mechanical work is converted into heat or stored as elastic strain energy. For a shear modulus G = 1010 Pa, a prominent lithospheric shear zone forms and elastic energy release increases the localization intensity (strain rate amplification). For G = 5 × 1010 Pa shear zones still form but deformation is less localized. For G = 1012 Pa, the lithosphere behaves effectively viscoplastic and no shear zones form during homogeneous thickening. Maximal shearing-related increase of surface heat flux is 15-25 mW m-2 and of temperature at lower crustal depth is ˜150 °C, whereby these peak values are transient (0.1-1 My). Elasticity and related energy release can significantly contribute to strain localization and plate-like behaviour of the lithosphere required for plate tectonics.

  17. Dramatic Improvement of Crystal Quality for Low-temperature-grown Rabbit Muscle Aldolase

    SciTech Connect

    Park, H.; Rangarajan, E; Sygusch, J; Izard, T

    2010-01-01

    Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA-LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 {angstrom} Bragg spacing and structure determination. It was concluded that the improvement of crystal quality as indicated by the higher resolution of the new RMA-LC4 complex crystals was a consequence of the introduction of new lattice contacts at lower temperature. The lattice contacts corresponded to an increased number of interactions between high-entropy side chains that mitigate the lattice strain incurred upon cryocooling and accompanying mosaic spread increases. The thermodynamically unfavorable immobilization of high-entropy side chains used in lattice formation was compensated by an entropic increase in the bulk-solvent content owing to the greater solvent content of the crystal lattice.

  18. Peudomonas fluorescens diversity and abundance in the rhizosphere

    NASA Astrophysics Data System (ADS)

    Amina, Melinai; Ahmed, Bensoltane; Khaladi, Mederbel

    2010-05-01

    It is now over 30 years since that a several plant associated strains of fluorescent Pseudomonas spp. are known to produce antimicrobial metabolites, playing a significant role in the biological control of a lot of plant diseases. For that, the interest in the use of these bacteria for biocontrol of plant pathogenic agents has increased. However, few comprehensive studies have described the abundance of this soil borne bacteria in the region of Mascara (Northern-Algerian West). In the connection of this problem, this work was done by monitoring the number of indigenous Pseudomonas fluorescens organisms in three stations characterizing different ecosystems, to document their abundance, diversity and investigate the relationship between P. fluorescens abundance and soil properties. Our quantitative plate counting results hence the conception of their ecology in the rhizosphere. Thus, quantitative results has confirmed that P. fluorescens are successful root colonizers with strong predominance and competed for many ecological niche, where their distribution were correlated significantly (P<0.05) with the majority of soil properties. Keywords: P. Fluorescens, Ecosystems, Abundance, Diversity, Correlated, Soil Properties.

  19. Potential retention effect at fish farms boosts zooplankton abundance

    NASA Astrophysics Data System (ADS)

    Fernandez-Jover, D.; Toledo-Guedes, K.; Valero-Rodríguez, J. M.; Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  20. Intravenous application of an anticalin dramatically lowers plasma digoxin levels and reduces its toxic effects in rats

    SciTech Connect

    Eyer, Florian; Steimer, Werner; Nitzsche, Thomas; Jung, Nicole; Neuberger, Heidi; Müller, Christine; Schlapschy, Martin; Zilker, Thomas; Skerra, Arne

    2012-09-15

    Lipocalins tailored with high affinity for prescribed ligands, so-called anticalins, constitute promising candidates as antidotes. Here, we present an animal study to investigate both pharmacokinetic and clinical effects of an anticalin specific for the digitalis compound digoxin. Intravenous digoxin (2.5–50 μg/kg/min) was administered to rats until first changes in the ECG occurred (dose finding study) or a priori for 30 min (kinetic study). The anticalin DigA16(H86N), dubbed DigiCal, was administered intravenously at absolute doses of 1, 5, 10 and 20 mg, while the control group received isotonic saline. Hemodynamic changes, several ECG parameters and digoxin concentration in plasma were monitored at given time intervals. After DigiCal administration free digoxin concentration in plasma ultrafiltrate declined dramatically within 1 min to the presumably non-toxic range. There was also a significant and DigiCal dose-dependent effect on longer survival, less ECG alterations, arrhythmia, and improved hemodynamics. Infusion of a lower digoxin dose (2.5 μg/kg/min) resulted in a more sustained reduction of free digoxin in plasma after DigiCal administration compared to a higher digoxin dose (25 μg/kg/min), whereas ECG and hemodynamic parameters did not markedly differ, reflecting the known relative insensitivity of rats towards digoxin toxicity. Notably, we observed a re-increase of free digoxin in plasma some time after bolus administration of DigiCal, which was presumably due to toxin redistribution from tissue in combination with the relatively fast renal clearance of the rather small protein antidote. We conclude that anticalins with appropriately engineered drug-binding activities and, possibly, prolonged plasma half-life offer prospects for next-generation antidotal therapy. -- Highlights: ► We provide an advanced model of digoxin toxicity in rats. ► We report on binding of digoxin to a novel designed anticalin. ► We report on pharmacokinetics of digoxin